Gıda Mühendisliği Anabilim Dalı

Su kefirinin şalgam suyu benzeri içecek üretiminde kullanımı

Bu çalışmada farklı tipteki (ticari toz, ticari dane, ve ev yapımı dane) su kefirleri kullanılarak geleneksel yöntem ile şalgam suyu üretimi amaçlanmıştır. Böylece şalgam suyunun fonksiyonel özelliklerini arttırmak ve üretimde fermantasyon süresini kısaltmak hedeflenmiştir. Elde edilen verilere göre üretilen içeceklerde toplam asitlik, laktik asit cinsinden, 6,47-12,26 g/L arasında değişmiş ve en düşük değer kontrol grubuna aitken en yüksek değer ise ticari toz su kefiri ilavesi olan denemede tespit edilmiştir. pH değerleri en düşük kontrol grubu ve en yüksek ticari dane su kefiri ilave edilen denemede olmak üzere 3,79 ile 4,30 arasında değişmiştir. Toplam monomerik antosiyanin içeriği, siyanidin-3-glikozit cinsinden, 170,50-295,85 mg/L arasında değişirken, toplam fenolik madde içeriği ise gallik asit cinsinden 836,45-2613,00 mg/L arasında değişmiştir. Toplam monomerik antosiyanin değeri en yüksek ticari dane su kefiri ilavesi olan içecekte bulunurken, en yüksek toplam fenolik madde içeriği ise ticari toz su kefiri ilavesi olan içecekte belirlenmiştir. Şalgam benzeri içeceklerin antioksidan aktiviteleri iki farklı yöntemle (DPPH ve ABTS) tespit edilmiş ve her iki yöntemde en düşük ve en yüksek antioksidan aktivite değerleri sırasıyla kontrol ve ev yapımı dane su kefiri denemelerinde tespit edilmiştir. DPPH değerleri 30,45-75,68 µmol TE/mL arasında değişirken, ABTS değerleri ise 52,46-90,51 µmol TE/mL aralığında belirlenmiştir. Fermantasyon sırasında laktik asit bakteri sayısı 3,95-7,95 log kob\mL aralığında değişirken, toplam mezofilik aerobik bakteri sayısı 5,09-8,19 log kob\mL aralığında, toplam maya sayısı 4,86-8,29 log kob\mL aralığında ve Saccharomyces spp. olmayan maya sayıları 4,05-6,11 log kob\mL aralığında değişmiştir. Duyusal analiz ve satın alınabilirlik analiz sonuçlarına bakıldığında kontrol grubu şalgamın en fazla beğenildiği ancak su kefiri ilaveli şalgam benzeri içeceklerin ise kontrol grubuna yakın puanlar aldığı görülmüştür. Su kefirinin ilavesi ile fermente edilen şalgam suyunun fonksiyonel özelliklerinin arttığı tespit edilmiştir.

Süzme yoğurtlarının fonksiyonel özelliklerinin arttırılmasında bazı diyet liflerin kullanılması üzerine araştırmalar

Günümüzün değişen dünya koşullarına ve gelişen teknolojilere bağlı olarak tüketiciler değişik beklentiler içine girmişlerdir. İnsanlar çevre kirliliği ve günlük hayattaki stresin artması ile birlikte beslenme ve sağlık koşullarına daha çok dikkat etmek zorunda kalmışlardır. Bu nedenle son yıllarda düşük kalorili, az yağlı, düşük kolesterollü gıdalarla birlikte fonksiyonel gıdalara olan taleplerde artış gözlenmiştir. Fonksiyonel gıdalar sağlık üzerine pozitif etkiler oluşturmayı hedefleyen gıdalar olarak tanımlanmaktadır. Bu konudaki önemli bir gelişme diyet lif katkılı ürünlerde olmuştur. Diyet lifleri ince bağırsakta sindirilemeyen heterojen bir karışımdır. Diyet liflerinin beraber gıda maddesinde kullanımı ile fonksiyonel özellikleri arttırılmış ürünler elde edilmektedir. Günümüze kadar diyet liflerinin gıdalarda kullanımı ile ilgili çalışmalar daha çok yoğurt benzeri fermente süt ürünlerinin geliştirilmesine odaklanmıştır. Geleneksel Türk kültürümüzün vazgeçilmez lezzetlerinden biri olan süzme yoğurt, günlük beslenmemizde sıklıkla kullanılmaktadır. Uzun süre dayanabilen ve saklama kolaylığı olan bu yoğurt, toplumumuzun beslenmesinde önemli bir yere sahiptir. Kendisine has tat, koku ve yapıya sahip olan bu ürün, protein yönünden oldukça zengindir. İsteğe göre yağ oranı farklı yoğurtlardan üretilen süzme yoğurdun randımanı %20-30 arasında değişmektedir. ABD ve Avrupa ülkelerinde lifli gıdalara olan ilgi gittikçe artmaktadır. Bu nedenle değişik bitkisel kaynaklı lifler ekstrakte edilerek günlük tüketilen gıdalara ilave edilmektedir. ABD ve Avrupa ülkelerine paralel olarak ülkemizde de diyet liflerin kullanılması konusu önem kazanmaktadır.Çalışmada, temin edilen inek sütlerinden önce diyet lifli yoğurt, elde edilen diyet lifli yoğurtların süzülmesi ile de diyet lifli süzme yoğurt üretimi yapılmıştır. Çalışmada %1, %2 ve %3 elma lifi (AF1, AF2, AF3); %1, %2 ve %3 buğday lifi (WF1, WF2, WF3) ve %1, %2 ve %3 bambu lifi (BAF1, BAF2, BAF3) katkılı olmak üzere 9 farklı yoğurt üretilmiştir. 21 günlük depolama süresince depolamanın 1.,7., 14. ve 21. günlerinde diyet lifli süzme yoğurt örneklerinin kimyasal, fiziksel ve duyusal özellikleri belirlenmiştir. Kurumadde, yağ, kül, kolesterol ve randıman analizleri depolamanın sadece 1. günlerinde gerçekleştirilmiştir. Elde edilen sonuçlara göre süzme yoğurt üretiminde randıman %29.07-41.90 arasında değişmiştir. Kullanılan diyet liflerin farklı olması örneklerin renk, tekstür, yağ asitleri, kolesterol ve duyusal analiz değerleri üzerine etkili olduğu belirlenmiştir. Bambu ve buğday lifinin tüketim için uygun olduğu, süzme yoğurt üretiminde kullanılanılabileceği duyusal analizler sonucunda belirlenmiştir.Ülkemizin beslenmesinde önemli yer tutan süt ürünlerinden yoğurdun üretiminde diyet liflerinin kullanılması konusunda çalışmalar yapılmaya başlanmıştır. Bu çalışma ışığı altında inek sütünden yoğurt üretiminde diyet liflerinin kullanımı ile süzme yoğurdunun fonksiyonel özelliklerinin arttırılabileceği düşünülmüştür. Yapılan bu çalışmayla fonksiyonel yeni bir ürünün üretilebilme olanakları belirlenmeye çalışılmıştır. Bununla birlikte böyle bir çalışma halkımızın beslenmesinde ve yoğurt teknolojisinin ürün yelpazesinin genişletilmesinde önemli bir rolünün olacağı düşünülmektedir. Bunun yanında böyle bir girişim ile sadece sağlık ve beslenme açısından değil değeri arttırılmış bir yoğurt türü üretimi ve satışının üreticilerin piyasadaki pazar payını da arttıracağı ve ülkemiz süt endüstrisine ekonomik canlılık kazandıracağı düşünülmektedir.

Gluten-free fresh pasta: Influence of pregelatinized starch, inulin, and probiotic usage on extrusion and cooking properties

This study aims to define the best fresh gluten-free pasta (GFP) formulation, based on corn starch partially replaced (10, 20, and 30%) with pregelatinized starch (PGS), by hybrid multi-criteria decision making including AHP and TOPSIS, respectively, to enrich with inulin with two different degrees of polymerization (DP≥10 and DP≥23) and concentrations (4 and 8%), and then Bacillus coagulans GBI-30, 6086 as a probiotic source, respectively, and evaluate the extrusion attributes, cooking properties with different time intervals (0, 1, 5, 10, and 15 min), sensory characterization, and the cell viability of probiotics with/without inulin as a prebiotic source. The criteria weights of extrusion yield, cooking loss, yellowness index, hardness, and taste were 0.34, 0.22, 0.05, 0.11, and 0.29, respectively, as defined by the AHP method. According to TOPSIS results, the control sample based on durum wheat semolina was the first-ranked pasta, followed by 20% PGS-incorporated GFP, which was the best alternative to the control group. In general, the moisture, water absorption capacity, swelling index, cooking loss, volume increase, turbidity, and amylose leaching were increased, whereas color (L*, a*, b*, yellowness index, and color score) and texture profile attributes were decreased as the cooking time prolonged in all fresh GFP with/without inulin or probiotic source. The probiotic inclusion into fresh GFP with/without inulin generally negatively influenced the end-product quality. However, the viability of probiotics was above approximately 85% and 67% in inulin-fortified GFP with different DP and concentrations at 5 min and 10 min of cooking, respectively. Therefore, except for probiotic-enriched fresh GFP without inulin cooked for 10 min, the results were still above the acceptable threshold to show a potential positive impact on host health, which corresponds to at least 106 CFU/g of live strains.

Encapsulation of oils from sour cherry kernel and berry seeds by protein-protein complexes

In this study, the encapsulation of raspberry seed oil (RSO) and sour cherry seed oil (CHSO) which have high amount of Omega 3 and 6 fatty acids by heteroprotein complexes and coacervates was investigated. In the first part of thesis, formation of complexes and coacervates was examined between two oppositely charged globular proteins, lactoferrin (LF) and pea protein isolate (PPI) with a specific PPI/ LF molar ratio at room temperature. Structural aspects of the electrostatic complexes probed at different length scales were investigated as a function of pH by means of dynamic light scattering, small angle X-ray scattering (SAXS), turbidity measurements, transmission electron microscopy (TEM) and atomic force microscopy (AFM). In an optimum narrow range of pH 5.0-5.8, a viscous liquid phase of complex coacervate was obtained whereas soluble complexes were formed between pH 6.2-7.5. In the second part, emulsions were prepared with different methods at optimum complex (pH 7) and coacervate (pH 5.4) conditions. The most appropriate method was determined as formation of complexes and coacervates at the last stages of encapsulation based on droplet size, droplet charge, emulsion stability and microstructure analysis. The effect of oil concentrations on (2-10 wt%) droplet size and rheology of emulsions was evaluated in the third part of thesis. Emulsions were later freeze dried to evaluate loading capacity, encapsulation efficiency, loading efficiency, moisture content and encapsules morphology. The results revealed that increasing oil concentration cause significantly effect on encapsulation efficiency and particle morphology (p<0.05). Encapsules produced at optimized conditions (6 wt% oil, 2 wt% protein) with RSO and CHSO were evaluated for their physicochemical properties and oxidative stability. They were stable at 45°C during storage. Pure oil showed higher lipid oxidation which indicates protective effect of encapsulation on oxidative stability. Based on the results, it was found that heteroprotein complexes and coacervates can be used to encapsulate omega rich oil.

Soya esaslı süt alternatifi kullanımının glutensiz kek nitelikleri üzerindeki etkileri

Çalışmada çölyak, laktoz intoleransı, süt alerjisi vb. sağlık problemleri nedeniyle bazı proteinleri ve süt ürünlerini tüketemeyen veya sürdürülebilirlik, vegan vejetaryan beslenme gibi sebeplerden hayvansal gıda tüketmeyen bireyler için soya esaslı süt alternatifi kullanılarak glutensiz kek üretimi gerçekleştirilmiştir. Bu amaçla %100, %150 olmak üzere 2 farklı soya esaslı süt alternatifi konsantrasyonu ile ksantan gam, guar gam ve bu iki hidrokolloidin kombinasyonu değişken oranlarda (%0.5, %1, %2) kullanılarak glutensiz hamur ve kekin nitelikleri üzerindeki etkileri incelenmiştir. Araştırma sonuçlara göre, soya esaslı süt alternatifi (SESA) içeren örneklerin hamur ve kek yapısına olumsuz yönde etki eden herhangi bir sonuca rastlanmamış olup, SESA'nın glutensiz ve yumurtasız kekte süt ikamesi olarak kullanımının uygun olduğu sonucuna varılmıştır. SESA konsantrasyonundaki artışın hamur ve kekte istenilen fiziksel ve tekstürel özelliklerin gelişmesine katkı sağladığı saptanmıştır. Depolama analiz sonuçları %0.5 konsantrasyonda kullanılan guar ve ksantan gam, kek kalitesini artırıcı etkileri bulunurken, %2'lik konsantrasyonun yapıyı yoğunlaştırmakta, gaz tutulumunu zorlaştırmakta ve nihai ürün kalitesini düşürmektedir. Tekstür profil analizlerinde (TPA) ise, ksantan ve guar gamların keklerin sertlik, yapışkanlık, çiğnenebilirlik ve elastikiyet gibi mekanik özelliklerini iyileştirerek ürün yapısında bütünlük ve dayanıklılık oluşturduğunu göstermiştir. Duyusal değerlendirmelerde ise, gamların kontrollü oranlarda kullanılması durumunda ürünlerin lezzet profilinde olumsuz bir değişiklik yaratmadığı; hatta bazı kombinasyonların dokuya pozitif katkı sağlayarak tüketici kabulünü artırdığı belirlenmiştir.

Future projection for Syrian food industry

Syria is a middle-income developing country with an economy that heavily depends on the food and agricultural sectors. However, with the crisis, which started in March 2011, Syria's food and agricultural industries have been badly affected. While the most of the processing factories and agricultural facilities such as greenhouses, irrigation canals and pumps have been damaged in the conflict areas, this resulted in a huge recession in the agricultural productivity of Syria. It is estimated that this will impact the country to meet the future food requirements as well. In this study the food and energy (nutritional) requirements in Syria for the years 2020, 2030, 2040 and 2050 were calculated by assessing the demand and capacity of the country before the Syrian crisis. The food requirements (ton/year) based on the various sectors and food groups were calculated, which were used to determine the amount of food to feed Syria and investment projections on the food sector. For the enhancement of the agricultural productivity, shortcomings in the sector were identified. It is aimed to provide a guidance on which basic steps should be taken during the rehabilitation period by assessing the agricultural self-sufficiency of Syria. Key Words: Syria; Food; Agriculture; Food Industry; Economy

A research on the usage of rice produced in Turkey to produce sake

Sake has been processed from rice in Japan since the ancient times as a national beverage. It is consumed at the religional and traditional ceremonies. Polishing, washing, soaking, steaming, koji preparation, the preparation of moto as yeast starter and moromi fermentation are the main steps for sake brewing. In the present study, it was aimed to designate features and the techniques of sake using short rice produced in Turkey. In this study, short type rice (Karacadağ and Krasnodarsky-424), which were taken from local rice producers, were soaked in water after the polishing operation about 70 % remain. Then, Aspergillus oryzae was inoculated and solid-fermented starter koji was added. Then, Saccharomyces cerevisiae was inoculated and waited for fermentation for a certain time. Solid-liquid mix, which was obtained from fermentation, was filtered; sake, which was liquid part, was obtained. As a result, 12.65 and 13.8 % alcohol contents were obtained by using Karacadağ and Krasnodarsky-424 type short rice, respectively. When the results of sensory analysis were evaluated, it was observed that sake produced from Karacadağ type rice was acceptable.

The use of carob flour and stevia as sugar substitutes for cake production and enrichment with wheat germ

In this study, carob flour and stevia were used instead of sugar which is one of the main ingredients in the production of cakes. Also, wheat germ was used to enrich nutritional value of cake. Process variables were sugar (0-25 %), stevia concentration (0-2 %) and carob flour concentrations (0-30 %) in constant amount of wheat flour. From these variables, 20 different cakes were produced. The best cake formulation was decided from optimization and it was PC12 among these cakes. In optimization process, UI was set as zero. SSV, TSV, hardness, cohesiveness, gumminess, chewiness and resilience were minimum; springiness and volume were set as maximum. Also, maximum taste and general evaluation values were set parameters of sensory analysis. In order to increase nutritional values of the best cake decided, the wheat germ was replaced with wheat flour in different amounts (0-10 %) and 8 different cakes were produced. Among these cakes, the best cake formulation was decided from optimization of the parameters mentioned above. Enrichment with wheat germ led to increase some properties of cakes such as UI value got zero. TSV, cohesiveness and resilience were decreased. It led to increase springiness of cakes. Moreover, it affected the sensorial properties that both taste and general evaluation were increased. On the other hand, addition of wheat germ had negative effect on cakes such as increasing hardness, gumminess and chewiness. It decreased the volume of cakes. Besides all of them, the addition of wheat germ had no effect on SSV.

Investigation of consumption of honey and pollen together with green tea

Green tea (Camellia sinensis) is a tea species originated in China and has common production in many countries in Asia. This plant species has polyphenols with natural antioxidant properties which are very beneficial for human health in its structure. In addition, it has been reported that antioxidant substances, which are available, are good for the health problems caused by smoking. The aim of the study was to develop a likable product made with green tea, honey, and pollen which are also rich in natural antioxidants. The ratio of honey to pollen and percentage of non-tea substances constitute 2 factors of design. The results were compared with untreated green tea after the sensory analysis, total phenolic content, antioxidant capacity determination, ascorbic acid determination, and sugar analysis were carried out. The optimization of the final product was carried out by considering the highest total phenolic content, total antioxidant, and overall sensory evaluation. The optimized conditions were 4:1 honey to pollen ratio and 6% total concentration of non-tea substances with TPC of 578.674 mg GAE/L sample and TAC of 94.463 DPPH•IC50. Optimum score determined for sensorial evaluation was 3.8.

Effects of dried bergamot peel powder on the structural properties of dark chocolate

ABSTRACT EFFECTS OF DRIED BERGAMOT PEEL POWDER ON THE STRUCTURAL PROPERTIES OF DARK CHOCOLATE SARIGÜL, Hazal M.Sc. in Food Engineering Supervisor: Prof. Dr. Ali Rıza TEKİN May 2019 62 pages Functional chocolate is a new trend that the food-grade ingredients are used in and is preferred by consumers due to flavour or other beneficial nutritive constituents. The aim of this study is to examine the effect of dried bergamot peel powder on the structural properties of dark chocolate such as the solid fat content, melting point and textural and sensory properties of chocolate. Bergamot peel powder has been added to dark chocolate with the percentages of 0.75%, 1.00%, and 1.25%. The melting points of the three samples did not change significantly on DSC plots and were around 32°C which was the same melting temperature of the standard dark chocolate. At the 0th, 15th, 30th and 365th days, melting points were in the range of 31.3°C – 32.5°C. SFC analysis results of bergamot dark chocolate samples showed that % solid fat content were not significantly different at different temperatures. Hardness of the chocolate samples were analyzed by Texture Analyzer and the analysis showed that the bergamot dark chocolate samples were harder than the standard dark chocolate. The reason for this is thought to be the reduction in the percentage of cocoa mass added to chocolate recipe and the fibrous nature of bergamot peel. The samples were evaluated by trained panellists. In this sensory analysis, a difference in flavour was clearly perceptive between the standard sample and bergamot chocolate samples. All the panellists noted that the bergamot flavour was felt dominantly on all three samples. Consequently, use of bergamot peel powder at minimal ratios didn't affect the melting point and solid fat content of chocolate, but it increased the hardness and strengthened the flavour on a severe level. Key Words: Bergamot, Chocolate, Dark Chocolate, Cocoa, Sensory Analysis

Arı ürünleri karışımında yüzey yanıt yöntemi ile bileşen optimizasyonu: Fonksiyonel özellikleri ve raf ömrü niteliklerinin belirlenmesi

Bal dışı arı ürünlerinin bilinirliği ve tüketimi, fonksiyonel nitelikleri ve besinsel içerikleri itibariyle son yıllarda artmıştır. Bal dışı arı ürünleri polen, propolis, arı sütü, arı ekmeği, arı zehri, apilarnil, balmumu olarak sıralanabilir. Bal, birçok açıdan insan beslenmesinde önemli yeri olan hayvansal kökenli doğal bir üründür. Propolis, bal arılarının (Apis mellifera) bitkinin yapraklar, çiçek tomurcukları ve ağaç kabukları gibi bitkinin çeşitli yerlerinden topladıkları özsu, reçine ve müsilajlardan ürettikleri, daha sonra karıştırdıkları, arı tutkalı olarak da bilinen doğal ve yapışkan bir malzemedir. Karbonhidrat içeriği nedeniyle, yüksek emilim oranına sahip önemli enerji kaynağıdır. Balın botanik orijini ve toplandığı coğrafi bölge, balın kimyasal bileşimi üzerinde önemli rol oynar. Polen, arılar tarafından toplanan, bitkilerin erkek üreme hücresi olan çiçek tozlarıdır. Arıların temel gıda kaynağı olan polenler, yavru beslenmesinde kullanılmak üzere koloninin arı sütü üretiminde ve protein ihtiyaçlarını karşılamak maksadıyla işçi arılar tarafından toplanır. Bu tez çalışmasında, kestane ve çiçek olmak üzere iki farklı bal kullanılarak hazırlanan arı ürünleri karışımında polen ve propolis miktarları, Yüzey Yanıt Yöntemi, Merkezi Deneme Deseni kullanılarak optimize edilmiştir. Optimizasyonda antioksidan aktivite, toplam fenolik madde miktarı, toplam mineral madde ve duyusal değerlendirme skorları yanıt (response) olarak, polen ve propolis miktarları ise bağımsız değişkenler olarak alınmıştır. Optimizasyonda, bağımsız değişkenlerin optimizasyonu ve yanıtların ise maximizasyonu istenmiştir. Optimizasyon sonucu kestane ballı ve çiçek ballı karışım için beklenen sonuçların validasyonu ile doğrulamaları yapılarak sonuçlar istatistiksel olarak yorumlanmıştır. Formül optimizasyonu sonucu üretilen kestane ve çiçek ballı karışımları, tezin ikinci aşamasında besinsel, fizikokimyasal ve bazı depolama parametreleri açısından karşılaştırılmıştır. Optimizasyon sonucu kestane ballı karışım için optimize polen miktarı 10,24 g ve propolis miktarı 4,07 g olması durumunda antioksidan aktivite miktarı %86,30; toplam fenolik madde miktarı 1215,33µg/g; toplam mineral madde miktarı %0,870 ve duyusal değerlendirme skoru 3,62 olarak belirlenmişir. Çiçek ballı karışım için optimize polen miktarı 10,24 g ve propolis miktarı 1,73 olması durumunda antioksidan aktivite miktarı %66,34; toplam fenolik madde miktarı 780,33µg/g; toplam mineral madde miktarı %0,443 ve duyusal değerlendirme skoru ise 3,84 olarak belirlenmişir. Optimum sonuçlara göre hazırlanan çiçek ve kestane ballı karışımlar karşılaştırıldığında, kestane ballı karışımın antioksidan aktivite miktarı, toplam fenolik madde ve toplam mineral madde içeriğinin daha yüksek olduğu ancak duyusal skorun çiçek balına göre daha düşük olduğu tespit edilmiştir. Her iki karışım için de elde edilen ürünlerde fenolik madde içeriği, madde kompozisyonu, aminoasit kompozisyonu açısından karakterizasyonu yapılarak yapı aydınlatma çalışması gerçekleştirilmiştir. Kestane ballı karışımın fenolik madde içeriği değerlendirildiğinde Trans ferulik asit, çiçek ballı karışım da en yüksek kafeik asit tespit edilmiştir. Fenolik madde kompozisyonunu polen ve propolis önemli derecede etkilemiştir. Kullanılan hammaddeler ve elde edilen karışımların mineral madde içerikleri bir arada değerlendirildiğinde, polenin önemli bir mineral madde kaynağı olduğu ve karışımın son mineral madde kompozisyonunu önemli düzeyde etkilediği tespit edilmiştir. Kestane ve çiçek ballı karışımda en yüksek K elementi olduğu belirlenirken, bunu Ca, Na ve P elementleri takip etmiştir. Kestane ballı karışımın Na, Mn, Fe, K ve Ca elementlerinin çiçek ballı karışımdan daha yüksek olduğu belirlenmiştir. Hammadde olarak kullanılan polenin incelenen 17 aminoasitin tamamını içerdiği, ayrıca çiçek balının kestane balından daha yüksek düzeye sahip olduğu tespit edilmiştir. Buna bağlı olarak çiçek ballı karışımının aminoasit düzeyleri de daha yüksek bulunmuştur.

Ulusal pazardaki propolislerin bazı kalite niteliklerinin incelenmesi ve mevcut mevzuatlara göre değerlendirilmesi

Propolis (arı tutkalı) bal arılarının çesitli bitkilerin tomurcuk ve sürgünlerinde bulunan reçineye balmumu katarak oluşturdukları, kovanda çesitli amaçlarla kullandıkları yapışkan, koyu renkli bir maddedir. Propolis çeşitli biyoaktivitelere sahip 300'den fazla kimyasal bileşik içermektedir. Propolis antibakteriyel, antifungal, antitumoral, antioksidatif, imunomodulator ve diğer faydalı aktiviteleri ile dogal ilaç olarak kullanılan önemli bir arı ürünü olup bu çalısmada ticari olarak satışa sunulan 7 su bazlı, 7 alkol bazlı olmak üzere 14 adet sıvı propolis örneğinin çesitli fiziksel, kimyasal ve biyoaktif özelliklerinin belirlenmesi amaçlanmıstır. Elde edilen veriler doğrultusunda propolis örnekleri kendi aralarında karşılaştırılmış, aynı zamanda literatüre göre değerlendirilmiştir. Ayrıca propolis ekstraktlarına dair elde edilen veriler mevcut mevzuatlarda belirtilen limit değerlere göre de değerlendirilmiş, ulusal pazarda tüketime sunulan nihai propolis ürünlerinin değerlendirmesi yapılmıştır. Elde edilen sonuçların henüz taslak çalışmaları yapılan arı ürünleri tebliğine ve ilgili mevzuatlara kaynak oluşturması ve bir gıda takviyesi olan propolise dair ulusal standardizayona katkı sağlaması hedeflenmiştir. Ulusal pazarda tüketime sunulan örneklerin propolis içeriklerinin %7.5-40 aralığında olduğu ve 4 örneğin Takviye Edici Gıda Belge numarasının beyan edilmediği belirlenmiştir. Etil alkolle çözünen propolislerin fenolik asit ve antioksidan kapasitesi su ile çözünenlere göre önemli düzeyde yüksek (p<0.05) bulunmuştur. Benzer şekilde alkolle çözünen örnekler daha yüksekBrixdeğerleri vermiştir. Örneklerin tümünde ağır metal içerikleri mevzuata uygun sınırlar içerisinde bulunmuştur. Arsenik için mevzuatta limit olmamasına karşın 5 numunede 1000 ppbden yüksek düzeyde rastlanılmıştır. Ürünlerin Fenolik asit kompozisyonları değişkenlik göstermiş, bundaekstraksiyon metodu, işlem parametreleri ve propolisin botanik orijini gibi unsurların etkili olduğu düşünülmüştür. Yapılan bu çalışma ile belli bir bölgeye ait propolisler için kalite kriterlerini belirleyici bir standart oluşturmanın mümkün olduğu sonucuna varılmıştır.

Kastamonu pastırmasının fiziksel kimyasal ve mikrobiyolojik özellikleri

Araştırmada Kastamonu piyasasında pastırma üretimi ve satışı yapan 8 farklı işletmeden 3 farklı zamanda pastırma örnekleri temin edilmiştir. Pastırma örneklerinde mikrobiyojik özellikler, kalıntı nitrit, tuz, serbest yağ asidi miktarı belirlenmiştir. Ayrıca örnekler nem ve pH yönünden de test edilmiştir. Analizler sonucunda pastırma florasına laktik asit bakterileri ve Micrococcus ve Staphylococcus cinsi bakterilerin hakim olduğu tespit edilmiştir. Micrococcus/Staphylococcus sayısı 5,60-7,69 log kob/g, laktik asit bakterileri sayısı 4,85-8,39 log kob/g olarak belirlenmiştir. Toplam aerobik ve mezofilik bakteri (TAMB) sayısı ve maya küf sayısı ise sırasıyla 6,20-8,40 log kob/g ve 3,46-7,21 olarak tespit edilmiştir. Enterobacteriaceae sayısı ise genellikle saptanabilir sınırın altında iken C, D, F, G, K firmalarında belirli dönemlerde 102-104 kob/g arasında değişen sayılar belirlenmiştir. Pastırmada pH değeri 5,25-6,42; nem değeri %43,17-56,03 arasında, tuz ise %2,98-8,78 olarak belirlenmiştir. Serbest yağ asidi miktarı ise %0,021-%0,242 arasında belirlenirken, kalıntı nitrit miktarı en çok 16,59 ppm olarak tespit edilmiştir.

Türkiye ve Suriye'den toplanan aromatik birkilerin antimikrobiyal özellikleri

This study was carried out to determine the antimicrobial properties of aromatic plant essential oils; thyme, anise, mint, chamomile, and basil were collected from Gaziantep in Turkey and from Aleppo and Idleb in Syria. The essential oils were assayed against following microorganisms: Escherichia coli, Salmonella enterica subsp. enterica ser. Typhimurium, Yersinia enterocolitica, Pseudomonas aeroginosa, Listeria monocytogenes, Shigella dysanteria, Staphylococcus aureus, Bacillus cereus, Bacillus subtilis, Klebsiella pneumoniae, Enterococcus faecalis, Streptococcus thermophilus, Saccharomyces cerevisiae, Candida rugosa, Aspergillus flavus, Aspergillus ochraceus, Aspergillus niger, Penicillium expansum, Rhizopus oryzae and Fusarium graminearum.. The MIC (minimal inhibitory concentration), MBC (minimal bactericidal concentration), and MTC (maximum tolerance concentration) were determined for these five types essential oils against the microorganisms. The MIC values for thyme essential oils ranged from 0.1 to 1.25 µg/ml while the MBC from 0.5 to 1.75 µg/ml. For anise essential oil MIC values varied from 5 to 70 µg/mL while the MBC from 10 to 80 µg/ml. For mint essential oils the MIC ranged from 10 to 90 µg/mL while the MBC from 20 to 100 µg/mL. For chamomile essential oils the MIC ranged from 2.5 to 125 µg/mL while the MBC from 2.5 to 130 µg/ml. For basil essential oils the MICranged from 7.5 to 60 µg/mL while the MBC from 10 to 75 µg/ml. The MIC/MBC ratio for essential oils obtained from Turkey and Syria plants is closed to 1. On the other hands, the Turkish and Syrian essential oils have a more antimicrobial effect on selected microorganisms than other species essential and the Syrian basil has higher MIC means than essential oils of species that extracted from the neighbor cities (Gaziantep in Turkey and Aleppo and Idleb in Syria) have similar compounds so, they have similar antimicrobial effect.

Production of a healthy snack bar

In this study, a new healthy and nutritious snack bar was produced. Firstly, the candidate ingredients (Pistachio, chia seed, flax seed, quinoa and mulberry molasses / apple concentrate) were selected. During the selection of these components, being nutritional, preservative-free and having minimum amount of sugar were the main criteria. Mucilage (gel-like substance) extracted from the water suspension of chia and flaxseed was used to minimize the level of sugar, which is commonly in use as binding agent and sugar sweetener in the snack bar industry. Molasses and apple juice concentrate were used to obtain a sweet taste and oil seeds were preferred because of their high PUFA, protein and pulp content. Thus, three different possible product formulations were developed. The product, which contains pistachio, chia, flax seed, apple juice concentrate and quinoa formulation, received a higher score (6.93 compared to 7-point hedonic scale) at the sensory analysis. Following the selection of the components, drying methods (atmospheric oven, vacuum oven and vacuum oven combined with microwave oven) and time were studied. Texture profile analysis (hardness, fracturability), color analysis and 7-point hedonic sensory analysis (in terms of fracturability, hardness, chewiness and overall acceptability) performed to determine the appropriate drying method and time to be used in the highest scored product. Finally, energy (594.8 kcal), sugar (15.05g), protein (16.89g), fat (33.17g), ash (2.38g) and total phenolic (2436mg GA) contents were determined for 100g of the final product.

Köfte üretiminde portakal lifi kullanımının ürünün tekstürel ve diğer bazı kalitatif özellikleri üzerine etkisi

Araştırmada sığır etinden üretilen köftelerde portakal lifi kullanımı ve pişirme sıcaklıkların tekstürel ve kalitatif özellikleri üzerine etkilerinin belirlenmesi amaçlanmıştır. Bu amaçla portakal lifi kullanımı (%0, %1, %3 ve %5) ve pişirme sıcaklıkları (175℃, 200℃ ve 225℃) faktör olarak ele alınmıştır. Hazırlanan köfte örnekleri pişirme işleminden sonra pH, nem, kül, yağ, TBARS, mineral madde, tekstür profil ve duyusal analizlere tabii tutulmuştur. Köftelere yapılan analizler neticesinde lif oranının pH, nem, yağ, kül, Na, Mg, Ca, K, Fe, Zn, Al, Mn, pişirme verimi, çap azalımı, pişirme kaybı ile duyusal parametrelerden tat, pişirme derecesi ve genel kabul edilebilirlik ve tekstür parametrelerinin tamamı üzerine çok önemli (P<0,01) tespit edilmiştir. Bunun yanısıra lif oranının TBARS, Cu, Se ve duyusal parametrelerden renk ve tekstür üzerine ise önemli (P<0,05) düzeyinde etkisi belirlenmiştir. Duyusal görünüş ve koku değerleri ise portakal lifi faktöründen istatistiki olarak etkilenmemiştir (P>0,05). Pişirme sıcaklığı değişkeni ise nem, TBARS, kül, Na, Mg, Ca, Mn, Cu, Se, pişirme verimi, çap azalımı, pişirme kaybı ile duyusal parametrelerden renk ve genel kabuledilebilirlik, kohesivlik ve elastikiyet çok önemli; duyusal parametrelerden görünüş ile sertlikte ise önemli değişime neden olmuştur. Bu iki faktörün interaksiyonu ise pH, TBARS, Na, Ca, K, Al, çap azalımı, sertlik, elastikiyet, kohesivlik, çiğnenebilirlik, sakızımsılık ve esneklik üzerine önemli veya çok önemli seviyede etki göstermiştir. Özellikle duyusal parametreler açısından panelistler %5 oranında lif kullanılan grupları beğenmezken diğer grupları beğenmiştir. Diğer taraftan genel olarak 200 ve 225°C'de pişirilen köfteler de panelistlerin beğenisini kazanmıştır. Portakal lifi kullanım oranının artışı ile pH, nem, yağ, kül, Na, K, Zn, çap azalımı ve pişirme kaybı parametrelerinde azalma gözlemlenmiştir. Tekstür değerleri ise lif kullanımı ile genellikle azalmıştır. Pişirme sıcaklığının 225°C olması ile sertlik değeri artmıştır. Diğer taraftan pişirme sıcaklığının 200 ve 225°C olması kohesivlik değerini düşürmüştür.

Application of Sous vide technology on a several meat product; tripe

Sous-vide technology is the process of pasteurization of product with hot water bath at the desired temperature and time by using vacuum bags. Sous-vide technology is basically a method of cooking under vacuum, so it is aimed to minimize the aroma and taste loss in the food product. Many foods can be cooked using this technology. By using Sous vide technology; it is aimed to make the chemical, microbiological and sensorial analysis of the tripe by cooking at a certain temperature and cooking at the specified temperature and time. The most suitable cooking temperature and duration were determined as 86 ° C and 90 minutes. Samples of tripe taken from the slaughterhouse brought to the laboratory immediately on the day of the experiment; weighing, cleaning, vacuum packaging processes were done. It was placed in salt and hot water solution, and cleaned from dirt and cut in appropriate sizes, weighed and then packed in vacuum bags and ready for cookery. Food samples were cooked in a hot water bath at 86°C for 90 minutes, after the cooking process they were immersed into a cold water bath. In the cooking and cooling processes, instantaneous temperature changes were recorded with food thermometers using the Scan link program. After the initial day analysis, it was kept at + 4 ° C for weekly analysis. The aim of this study was to investigate acidity, color measurement, TBARs and texture profile analysis (TPA), and total aerobic mesophilic bacteria count, Salmonella, and Enterobacteriaceae as microbiological analyzes. The panelists selected for the sensorial analysis carried out weekly scoring. At the end of the eight-week storage period, it is observed that the tripe sample preserved as a fresh on the side of chemical, microbiological and physical aspects.

Çiğ sütlerde polisiklik aromatik hidrokarbonların düzeylerinin ve dağılımlarının belirlenmesi

Polisiklik aromatik hidrokarbonlar (PAH'lar), organik bileşiklerin tam yanmaması sonucu ortaya çıkan karsinojen ve diğer toksik etkilere sahip organik bileşiklerdir. PAH'lar toprakta, havada, suda ve gıdalarda görülmektedir. Her yerde bulunabilen lipofilik organik bir kirletici olarak PAH'lar sütte de yaygın olarak bulunabilmektedir. Bu tez çalışmasında USEPA tarafından listelenen önemli kirleticiler arasında yer alan 16 PAH [Naftalin (Np), Asenaften (Anp), Floren (Flr), Fenantren (Phe), Floranten (Flu), Antrasen (An), Piren (Py), Krisen (Chr), Benzo(a)antrasen (BaA), Benzo(b)floranten (BbF), Benzo(k)floranten (Bkf), Banzo(a)piren (BaP), Indeno(1,2,3-cd)piren (IcdP), Dibenzo(a,h)antrasen (DahA), Benzo(g,h,I)perilen (BghiP)] bileşiği çiğ inek sütlerinde GC-MS cihazı ile analiz edilerek bunların miktarları, hangilerinin baskın PAH bileşikleri olduğu, Kastamonu ve benzer ekolojik ve iklimsel özelliklere sahip çevre illerden (Karabük, Bolu, Bartın, Çankırı, Zonguldak) alınan süt numunelerinin PAH düzeylerinin istatistiki olarak anlamlı derecede birbirinden farklı olup olmadığı araştırılarak sağlık açısından oluşabilecek risklerin değerlendirilmesi yapılmıştır. Numuneler hava kirliliğinin bölgede yoğun olduğu Ocak ayı içerisinde ve hava kirliliğinin düşük olduğu Haziran ayı içerisinde 2 kez aynı süt toplama merkezleri ve üreticilerden doğrudan temin edilmiştir. İncelen 72 süt numunesinde, en az bulunan PAH bileşiği ikişer numune ile Flu ve BaP iken en fazla bulunan 72 numune ile Np'dir. Ayrıca, Np tüm numunelerde bulunan tek bileşiktir. Tüm numunelerin Toplam PAH miktarlarının ortalaması 121,9±37,6 μg/kg olarak tespit edilmiştir. En yüksek Toplam PAH içeriğine 231,5 μg/kg ile Karabük ilinden Ocak ayında alınan bir numunede (KRO2) rastlanmıştır. En düşük Toplam PAH içeriğine 45,9 μg/kg ile Kastamonu ilinden Haziran ayında alınan bir numunede (KSH1) rastlanmıştır. Çalışmamızda Uluslararası Kanser Araştırmaları Ajansı (IARC) sınıflandırmasında Grup 1 Karsinojen olarak belirtilen BaP iki numunede tespit edilmiştir. Bu numuneler; Karabük ilinden Ocak ayında alınan KRO6 ve Çankırı ilinden Ocak ayında alınan ÇO1 kodlu numeneledir. Tespit edilen bu BaP konsantrasyonları, maksimum limit (bebek ve çocuk ek gıdaları maksimum limiti; 1 μg/kg) seviyesini aşmamıştır. İncelenen 72 numunenin, 23 tanesi Ocak ayında ve 18 tanesi de Haziran ayında olmak üzere toplam 41 tanesinde PAH4 miktarlarının bebek ve çocuk ek gıdaları maksimum PAH4 limitinin (1 μg/kg) üzerinde olduğu tespit edilmiştir. Ayrıca çalışmamızda süt numunelerinin yağ miktarları ile PAH4 miktarları arasında pozitif yönlü anlamlı ilişki olduğu belirlenmiştir (p<0,05). Bolu 2 numune ile PAH4 limitinin en az aşıldığı il iken, Karabük 10 numune ile bu limitin en fazla aşıldığı il olmuştur. Ayrıca, PAH4 konsantrasyonunun en yüksek olduğu numune (KRO6) 92 μg/kg PAH4 içeriği ile Karabük ilinden Ocak ayında alınan bir numuneye aittir. Karabük ilinin PAH4, BaP ve Toplam PAH rastlanılma sıklığı ve tespit edilen miktarların yüksekliğiyle öne çıkmasının sebebi olarak numunelerin toplandığı Karabük Merkezde kok fırını içeren bir fabrikanın bulunması nedeniyle çevre kirliliğinin yüksek olması düşünülmüştür. Çalışmamızın sonuçlarından bebek ve çocuk ek gıdası olarak düşünülebilen ve toplumun önemli kesiminin de severek tükettiği sütlerde PAH bileşikleri açısından bir sağlık riski söz konusu olduğu ortaya çıkmıştır. İnsan sağlığını uzun vadede olumsuz etkileyebilen PAH'lar, kanser, bağışıklık sistemi ve hormonların bozulmasına neden olabilmektedir. İncelenen numunelerde PAH4 için bebek ve çocuk ek gıdaları ile ilgili tespit edilen limiti aşanların olduğu görülmektedir. Limitin aşılması sağlık risklerinin oluşmasına neden olabileceğinden yetkililerin bu konuda önlem alması ve bu önlemleri ülke geneline yayması gerektiği düşünülmektedir. Özellikle çevre kirliliğinin yüksek olduğu illerde yeni çalışmalar yapılmalı, kirliliğin azaltılması için mevzuatlar oluşturulmalı ve toplumun bilinçlendirilmesi gerekmektedir.

Drying of zucchini by using tray drying and microwave pretreatment

In this thesis, zucchini (Cucurbita pepo L. var cylindrica) slices were dried with and without microwave pretreatment in the tray dryer. Microwave pretreatment was applied for 7 minutes at three different microwave power levels (350, 490 and 700 W). Hot air drying was carried out at three different temperatures (40, 50 and 60°C) and two different air flow rates (1.0 and 1.2 m/s). Drying behaviors, bulk density and color changes of the dried zucchinis were examined. Increasing the temperature, microwave power and air flow rate reduced the drying time. The microwave pretreatment was led to a significant reduction in the drying time compared to the non-pretreated samples. The shortest drying time was observed in the zucchini at 60°C with an air flow rate of 1.2 m/s and 700 W. Effective moisture diffusivity values (Deff) were found as between 1.54*10-10 and 2.75*10-9 m2/s. The minimum activation energy was found as 20.51 kJ/mol for hot air drying at 1.2 m/s air flow rate, and maximum activation energy was found as 65.50 kJ/mol for microwave pretreatment at 700 W air flow rate of 1.2 m/s. For color values of L*, a*, b* and ΔE, there were significant change (p<0.05) between air flow rates and hot air temperatures. Minimum total color difference (ΔE) was found 10.60±2.30 during hot air temperature at 60°C and 1.0 m/s air flow rate and 700 W microwave pretreatment. Shrinkage values varied in between 0.75 and 0.80. Bulk density values were found between 0.21±0.02 and 0.41±0.01 g/mL. Keywords: Zucchini, Microwave, Drying, Diffusion, Color

Formulation and physical characterization of high methoxyl pectin and sunflower oil wax emulsions

ABSTRACT FORMULATION AND PHYSICAL CHARACTERIZATION OF HIGH METHOXYL PECTIN AND SUNFLOWER OIL WAX EMULSIONS AKKAYA, Sinem M.Sc. in Food Engineering Supervisor: Prof. Dr. Fahrettin GÖĞÜŞ Co-Supervisor: Assoc. Prof. Dr. Mecit Halil ÖZTOP July 2019 69 pages Pectin is a polysaccharide found on the cell walls of many plants. It is used often in food industry due to its gelling properties. Waxes are commonly used as edible coatings to enhance the water barrier properties of food products. There are many studies about emulsions, which are prepared with oil, wax and polysaccharides. This study focused on preparing emulsions with sunflower oil wax and pectin at different concentrations and characterization of the emulsions by using particle size, rheology, light microscope and low-resolution Time Domain NMR relaxometry experiments. Pectin and wax emulsions were prepared at concentrations of 5% wax and 5%, 7%, 10% pectin by using high shear homogenization. The mean particle size results of the emulsions were recorded between 1-3 µm. The optical microscope results confirmed the particle size measurements. Considering the rheology results, it was concluded that the flow behavior did not change depending on the pectin concentration. NMR spin-spin T2 relaxation times were also measured to understand the differences between emulsions. T2 (relaxation times) decreased, as pectin concentration increased and the change in relaxation times provided insight on the formation and stability of the emulsions. It was measured as 312.48±4.70 ms for 5% pectin containing sample and 197.62±1.26 ms, 115.24±1.87 ms for 7% and 10%. Key Words: Pectin, Sunflower Wax, Particle Size, Rheology, NMR Relaxometry

Wangashi peynirinin standardizasyonu ve üretiminin karakterizasyonu

Wangashi cheese processing based on the use of Calotropis procera plant stems as a coagulant was characterized and standardized. Crude extract obtained from Calotropis plant stems was used to set solution of milk powder at various pH (4-8) and temperature (35-80oC) in order to examine effect of pH and temperature on milk clotting and proteolytic activities. The pH 5.5 and temperature of 70oC were recorded as optimum pH and temperature. After that concentration of the crude extract enzyme was assayed to purify using ammonium sulfate precipitation at various percentage of saturation (20%-80%) at determined optimum pH and temperature, whereby the saturation of 70% was detected to be the best because of its high specific activity, yield and purification fold. Two different of Wangashi cheese were produced in laboratory, one using directly the crude extract and the other the purified crude extract from Calotropis procera at optimum condition. Their chemical, textural and thermal properties were determined using standard methods. A significant difference between parameters tested was observed (p < 0.05). A decreasing in moisture content, increasing in protein content and also an improvement of color and textural parameters were recorded in cheese obtained using purified crude extract Calotropis procera stems. Key Words: Wangashi cheese, Calotropis procera, milk clotting activity, proteolytic activity, Standardization.

Extraction of triterpenic acids from wet olive pomace by using closed microwave extraction system

In this study, triterpenic acids (maslinic and oleanolic acid) were extracted from wet olive pomace (51.5 moisture content/100 g wet pomace) under pressure by using closed vessel microwave extraction system with a nonpolar solvent, hexane. Effects of microwave power (150-300 Watt), extraction time (4-20 min) and solvent to solid ratio (5:1-10:1) on extraction efficiency were examined. Optimum conditions which provide the highest efficiency were found as 250 Watt, 12 min and 10:1 for microwave power, time and solvent to solid ratio, respectively. Total amount of triterpenic acid extract which obtained under optimum conditions was 26 mg/g dry pomace. The identification and quantification of obtained triterpenic acids were performed by using HPLC, TLC and ESI-MS. The percentages of the acids present in the extract were 80% maslinic acid and 20% oleanolic acid. The acids present in the extract was separated from each other by using column chromatography with hexane:ethyl ether:acetic acid (65:34:1) mixture. The antioxidant and antimicrobial activity for extract and acid fractions were determined. According to the DPPH (% inhibition 22.87) and FRAP (263.087 μM TE) results the maslinic acid fraction had shown the highest antioxidant activity. In addition, it was observed that the maslinic acid fraction had almost as much antimicrobial effect on the studied microorganisms as amoxicillin. Key words: microwave assisted extraction, maslinic acid, oleanolic acid, olive pomace

Aktif ambalaj polimer filmlerinin difüzyon özelliklerinin incelenmesi ve kaşar peynir uygulamaları

The thesis was started up to present the diffusion kinetic of antimicrobials from active polymer films. The barrier, thermal and mechanical and, the antimicrobial properties, and application of the antimicrobial active films were also analyzed. Nisin, potassium sorbate, silver substituted zeolite and chitosan were the antimicrobials used in the active films to form N-, PS-, AgZeo- and CTS-films, respectively. It was seen that diffusivity constants of nisin and potassium sorbate (Dn and Dps) were affected by the pH, aw and temperature. Diffusivity of silver substituted zeolite (DAg) was the lowest of all and depended on pH and temperature; however diffusion of chitosan from antimicrobial films was not detected. Temperature dependence of diffusivity of antimicrobials was evaluated using the Arrhenius type model showed the activation energy of DAg was the highest with a value of 34.16 kJ/mol, indicating the highest temperature sensitivity. Diffusion of antimicrobials to the surface of the Kaşar cheese was checked, and the lowest detection belonged to AgZeo-film. Incorporation of antimicrobials into polymer film was not ended with adverse effects on the properties of the films. The study was completed by applying antimicrobial films to pack Kaşar cheese, and they were stored at 5, 15 and 25°C. Usage of antimicrobial films improved the shelf life of Kaşar cheese twice. Hence, it was possible to state that all active films studied could be used as a food packaging material.

Susam protein izolatının asitle jelleşmesi üzerine yüksek basınçlı homojenizasyonun etkisi

Protein jelasyonu, canlı organizmalardan gıda hazırlamaya kadar hayati bir rol oynamakta ve birçok endüstriyel uygulamada kullanılmaktadır. Bu çalışmada, susam kekinden ekstrakte edilen susam protein izolatının glukono-δ-lakton (GDL) ile asitlendirilerek jelleşme özelliği üzerine yüksek basınçlı homojenizasyonun (YBH) etkileri araştırılmıştır. Bu amaçla %8 konsantrasyonunda hazırlanan susam protein solüsyonuna 0 (kontrol), 25, 50, 100 ve 150 MPa basınçlarda homojenizasyon uygulanmış ve ardından örneklere %2 oranında GDL ilave edilerek jelleşme özellikleri belirlenmiştir. Çalışmada asitlenme ve jelleşme kinetiği ile jellerin fizikokimyasal, yapısal, reolojik özellikleri ve moleküller arası kuvvet incelenmiştir. V max , T 5 ve T 4.5 gibi asitlenme kinetik parametreleri, uygulanan homojenizasyon işleminden etkilenmiştir. Maksimum V max (0,062 pH birimi/dk) değeri 100 MPa basınç uygulanmış örnekte tespit edilmiştir. Bununla birlikte uygulanan yüksek basınç proteinin jelleşme süresinin (T 4.5 ) azalmasına neden olmuştur. Uygulanan homojenizasyon basıncı arttıkça, özellikle jelleşmeden önce partikül boyutu azaldığı ve bunun da jelleşme sonrasında daha düşük partikül boyutlu agregatların oluşumunda rol oynadığı gözlenmiştir. Jellerin su bağlama kapasitesi uygulanan YBH ile önemli düzeyde iyileşmiş ve en yüksek değer (%69,02) 100 MPa basınç uygulanan örnekte tespit edilmiştir. Homojenizasyon basıncının 100 MPa'ya kadar arttırılmasıyla jellerin beyazlık indeksinde önemli düzeyde artma eğilimi gözlenmiş olması ile birlikte en yüksek toplam renk farkı (ΔE) 50 MPa basınç uygulanan örnekte saptanmıştır. Örneklerin G' değeri zamana bağlı olarak ve uygulanan yüksek basınç ile birlikte artma eğilimi göstermiş ve bunun da susam protein jelinin elastikiyetinde önemli düzeyde iyileşme sağlayarak jel mukavemetini artırdığı saptanmıştır. Bütün jel örnekleri artan kayma hızıyla birlikte azalan viskoziteye bağlı olarak kayma incelmesi davranışı sergilemiştir. Jel örneklerinde hidrofobik etkileşimlerin hakim olduğu belirlenmiş ve en yüksek değer (8,28 mg/mL) 100 MPa basınç uygulanan örnekte tespit edilmiştir. Bu çalışma ile GDL kullanılarak elde edilen susam protein jelinin özelliklerinin YBH uygulaması ile birlikte geliştirilebileceği ve özellikle 100 MPa basınç uygulamasının ideal olduğu ortaya konmuştur.

Investigation of the use of resistant starch in the production of gluten-free biscuits

In this study, resistant starch (RS) were used as a functional component and a source of dietary fiber in the production of gluten-free biscuits. The amount of gluten-free flour in the biscuit formulation was reduced by 10, 20 and 30% and RS was used instead of gluten-free flour; and the baking time of the biscuits was kept constant, and they were baked at 175, 200 and 225oC. Biscuits were compared by measuring the quality parameters in terms of moisture, water activity, pH, color, diameter, height, texture and dietary fiber. When samples are baked at different baking temperatures observed that as temperature increased, moisture, water activity, pH, biscuit diameter, L*, hardness and fracturability decrease; biscuit height and a* and b* values increased. Generally, as the proportion of RS increases at each baking temperature, moisture, water activity and L* value increased; pH, a*, b*, biscuit diameter and height decreased. As the proportion of RS addition increases, hardness value increased, fracturability value decreased compared to the control value. But with the exception of control biscuits, as the amount of RS increases, the hardness value decreases. Despite this decrease, the results are above the control biscuit values. Dietary fiber amounts of biscuits baked at 200oC were measured. Control, 10, 20 and 30% RS added biscuits dietary fiber amounts were measured as 1.51, 2.79, 5.35 and 5.84%, respectively. The amount of dietary fiber increased with increasing the amount of RS. As a result, according to the study, it was observed that the use of RS instead of gluten-free flour had positive effects and enabled the production of healthy biscuits.

Köfte üretiminde safran kullanımının ürünün kalite karakteristikleri üzerine etkisi

Araştırmada dana kıymadan üretilen köftede farklı miktarlarda safran kullanımının (%0, %0,25; %0,50 ve %1) fenolik bileşikler, mikrobiyolojik özellikler ve diğer kalite kriterleri (pH, nem, renk, mineral madde ve TBARS (tiyobarbitürik asit reaktif maddeler)) üzerine etkilerinin belirlenmesi amaçlanmıştır. Hazırlanan köfte örnekleri vakum ambalaj yapılarak +4 o C'de 4 hafta boyunca muhafaza edilmiş ve bu süre içerisinde pH, nem, renk, TBARS ve mikrobiyolojik analizlere tabi tutulmuştur. Köftelere yapılan analizler sonucunda, safran oranının pH, nem, renk, TBARS, Mn, Se, Zn, Cu, Fe, Na, Mg, Ca, K, P, Enterobacteriaceae ve maya-küf değerleri üzerine etkisi önemli bulunmuştur (P<0,01). TAMB (toplam aerobik mezofilik bakteri) sayısı ise safran oranından istatistiki olarak etkilenmemiştir (P>0,05). En yüksek TBARS ve maya-küf değeri ile en düşük Enterobacteriaceae sayısı %1 safran içeren örnekte belirlenmiştir. Diğer taraftan safran kullanımı ile L* değeri düşerken a* ve b* değeri artmıştır. Köfte örneklerinde analizi yapılan fenolik bileşiklerden sadece kateşin ve gallik asit tespit edilmiş, diğer analizi yapılan fenolik bileşikler belirlenmemiştir. Tespit edilen kateşin ve gallik asit üzerine ise safran kullanımının istatistiki bir etkisi belirlenmemiştir (P>0,05). Mineral maddeler ise safran ilavesi ile genel olarak artış eğilimi göstermiştir. Depolama süresi faktörünün ise nem, TBARS, renk, pH, maya-küf, TAMB ve Enterobacteriaceae üzerine P<0,01 düzeyinde etkisi belirlenmiştir. Depolama süresince pH, nem ve a* değeri bir azalma gözlemlenmiştir. Diğer taraftan L* değeri depolama süresince azalmıştır. Ayrıca b* değeri ile maya-küf, TAMB ve Enterobacteriaceae sayısı başlangıçta bir miktar artsa da daha sonradan azalmıştır. Bu iki ana varyasyon kaynağının interaksiyonu ise TBARS, pH, nem, a*, b*, maya-küf, TAMB ve Enterobacteriaceae sayısı üzerine istatistiki olarak etkili olmuştur (P<0,01).

Farklı tekniklerle modifiye edilen susam proteininin tahinde faz ayrımı üzerine etkisi

Tahin yağ içinde protein içeren hidrofilik partiküllerin oluşturduğu konsantre kolloidal bir süspansiyon olmasından dolayı depolama sırasında yoğunluk farkı nedeniyle yağ fazının ayrılması ve yapıyı oluşturan partiküllerin zamanla çökelmesi gibi fiziksel bozulmalara maruz kalmaktadır. Katı partiküllerin sedimentasyonu ve yağ fazının ayrılması doğal bir olay olmasına rağmen tüketiciler tarafından arzu edilmemekte, ürünün bozuk veya kalitesiz olarak algılanmasına neden olmaktadır. Bu çalışmada termal olmayan yeni işleme teknikleri ile modifiye edilmiş susam protein izolatının tahinde meydana gelen faz ayrımı ve oksidasyon problemlerinin giderilmesinde ve depolama stabilitesinin iyileştirilmesinde kullanım potansiyelinin belirlenmesi amaçlanmıştır. Bu kapsamda susam küspesinden ekstrakte edilen modifiye edilmeyen susam protein izolatı ile yüksek basınçlı homojenizasyon (YBH), ultrases (US) ve yüksek hidrostatik basınç (YHB) ile modifiye edilen susam protein izolatı tahine ilave edilmiş ve tahinin fizikokimyasal, reolojik ve duyusal özellikleri ile depolama stabilitesi belirlenmiştir. Modifiye edilmemiş ve modifiye edilmiş susam portein izolatlarının fiziksel ve teknolojik özelikleri de araştırılmıştır. Protein izolatının partikül boyutu 65,73 μm'den 1,48 μm'ye kadar azalmış, zeta potansiyeli ise yaklaşık 18 mv düzeyinde artış göstermiştir. Başlangıçta %58,03 olan proteinin suda çözünürlüğü modifikasyonla birlikte %88,18'e kadar ulaşmıştır. Örneklerde en yüksek yağ bağlama kapasitesi ile emülsiyon aktivite indeksi (EAI) ve emülsiyon stabilite indeksi (ESI) YBH ile modifiye edilen protein izolatlarında tespit edilmiştir. Tahine susam proteini ilavesi genel olarak kurumadde ve protein içeriğinde artışa neden olmuş, protein ilaveli örnekler arasında önemli bir fark gözlenmemiştir. Susam proteini ilavesi, protein ilavesi yapılmayan tahin örneğine (kontrol) kıyasla tahinde hızlandırılmış faz ayrılmasını %48'e kadar azaltmış ve ayrıca tahin örneklerinin zeta potansiyelini, sertliğini ve sürülebilirliğini önemli ölçüde iyileştirmiştir. Ancak peroksit ve serbest yağ asitliği değerlerinde kısmi bir artışa neden olmuştur. Susam proteininin tahine ilavesi ve modifikasyon işleminin renk farklılığına neden olmasına rağmen gözle görülür fark algılanamamaktadır. Modifiye protein ilavesi ile tahin örneklerinin mikroyapıları kontrol örneğine kıyasla daha yoğun ve kompakt bir görünüm kazanmış, daha az topaklanma meydana gelmiştir. Duyusal açıdan tahine protein ilavesi önemli bir değişikliğe neden olmamıştır. Tahin örneklerinin akış özellikleri Herschel-Bulkley modeline tam uyum (R2>0,9999) sağlamıştır. Protein ilavesi ve ilave edilen proteinin farklı yöntemlerle modifikasyonu da tahin örneklerinin akış özelliklerinin iyileştirilmesinde önemli rol oynamıştır. Susam proteini ilavesiyle viskoelastik karakterde önemli iyileşme tespit edilmiştir. Hızlandırılmış yağ ayrılması analizi sonucu ile uyumlu olarak 4°C, 25°C ve 40°C'de depolanan örneklerde en fazla yağ ayrılması kontrol örneğinde gözlenmiş, tahine protein ilavesi yağ ayrılmasını azaltmıştır. Genel olarak değerlendirildiğinde, modifiye susam proteinin tahinde faz ayrımını depolama süresince en az %20 oranında azaltmıştır. Buna karşılık YBH teknolojisiyle modifiye edilmiş susam proteininin tahinin kalitesini artırma ve faz ayrılmasını önleme konusunda önemli bir potansiyele sahiptir.

The effect of ultrasound on the physicochemical and emulsifying properties of soy proteins

In this study, the effect of ultrasound application on the physicochemical and emulsifying properties of soy protein emulsions was investigated. Ultrasound was treated to a soy protein isolate (SPI) solution at 5, 10 and 15 amplitude. Results showed that the ultrasound treatment reduced the droplets size of emulsions and caused an increase in the emulsifying activity and stability of emulsions at 15 amp. The effect of pre-heating and pH treatment on the ultrasound treated SPI emulsion was also analyzed. Increased heat treatment from 60 to 70 and 80°C showed better emulsification properties. The best functional properties were observed at pH 9 in comparison to pH 5 and pH 7. On the other hand, CaSO4-induced SPI gel-like emulsions were prepared by the cold-set and heat-set method. Ultrasound pre-treatment of SPI emulsions caused an increase in functional properties ofCaSO4-induced SPI gel-like emulsions. Gel-like emulsions were heated at 95°C for 20 min. Heat treatment, due to the structural changes in SPI molecules, led to smaller droplet size and uniform microstructure. And also, water holding capacity (WHC) and fat holding capacity (FHC) of gel-like emulsions increased.

Peynir ve tereyağında pestisit ve polisiklik aromatik hidrokarbon kalıntılarının incelenmesi

Verim artırıcılar ve pestisitlerin kullanımı, dünya nüfusunun artmasıyla birlikte insanlığın beslenme problemi yaşamaması için gerekli görülmüştür. Yaşamın başlangıcından bu yana süt ve süt ürünleri, insanların yaşamlarını sürdürebilmeleri için gereken temel besinlerin başında gelmektedir. Ancak, pestisitler ve polisiklik aromatik hidrokarbonlar (PAH) süt ürünlerinde ve sütte bulunması istenmeyen, sağlık sorunlarına neden olabilen maddelerdir. Tüm dünyada yaygın olarak tüketilen süt ürünlerinde tespit edilen kimyasal kalıntılar, hem yetişkinler hem de çocuklar için ciddi sağlık tehditleri oluşturabilir. Bu sebeple, süt ürünlerinde ve sütte bulunabilecek kimyasal kalıntılar için yasal kısıtlamalar getirilmiştir. Bu çalışmada, Karabük, Kastamonu, Çankırı ve Çorum illerinden alınan 20 adet peynir ve 20 adet tereyağı numunesi, kalıcı organoklorlu pestisitler ve PAH kalıntıları açısından incelenmiştir. Hiçbir numunede pestisit kalıntısı ölçülebilir düzeyde bulunmamıştır. Ayrıca, 16 PAH bileşiği arasında öncelikli kirleticiler olarak kabul edilen ve toksik, kanserojen etkileri nedeniyle IARC (Uluslararası Kanser Araştırmaları Ajansı) tarafından Grup 1 Karsinojen olarak sınıflandırılan BaP (Benzo(a)pyrene), peynir ve tereyağı numunelerinin hiçbirinde tespit edilmemiştir. Peynir numunelerindeki ortalama PAH kalıntı düzeyleri Np için 206,45 µg/kg, Flr için 7,88 µg/kg, Phe için 4,24 µg/kg, An için 0,22 µg/kg, BaA için 1,16 µg/kg, Chr için 2,46 µg/kg olup, ortalama PAH4 kalıntı düzeyi 2,14 µg/kg olarak bulunmuştur. Peynir numunelerinin toplam PAH ortalaması, minimum ve maksimum seviyeleri sırasıyla 210,83; 170,84 ve 286 µg/kg olarak tespit edilmiştir. Tereyağı numunelerinde ise ortalama PAH kalıntı düzeyleri Np için 209,88 µg/kg, Anp için 1,18 µg/kg, Flr için 3,05 µg/kg, An için 1,36 µg/kg, BaA için 6,16 µg/kg, Chr için 8,06 µg/kg, Py için 3,52 µg/kg olup, ortalama PAH4 kalıntı düzeyi 10,85 µg/kg olarak bulunmuştur. Tereyağı numunelerinin toplam PAH ortalaması, minimum ve maksimum seviyeleri ise sırasıyla 218,61; 150,52 ve 260,6 µg/kg olarak belirlenmiştir. Tereyağı numunelerindeki toplam PAH ortalamasının, peynir numunelerindekinden daha yüksek olduğu görülmüştür. Peynir numunelerinin PAH4 (BaP, BaA, BbF, Chr toplamı) ortalama konsantrasyonları, Türk Gıda Kodeksi Bulaşanlar Yönetmeliği'ne göre bebek ve çocuk ek gıdası için belirlenen limit (1 µg/kg) açısından değerlendirildiğinde, ÇRP1 (3,84 µg/kg), ÇRP4 (1,72 µg/kg), KRP1 (1,48 µg/kg), KRP4 (3,88 µg/kg), KRP5 (1,64 µg/kg), KSP1 (3,52 µg/kg), KSP5 (1,76 µg/kg) peynir numuneleri bu limiti aşmış olarak değerlendirilmiştir. Ancak, diğer gıda ürünleri açısından (12-35 µg/kg; tütsülenmiş et ve et ürünleri, tütsülenmiş balıkçılık ürünleri, hindistan cevizi yağı, tütsülenmiş çift kabuklu yumuşakçalar) bu limitlerin aşılmadığı görülmüştür. Tereyağı numunelerinin PAH4 ortalama konsantrasyonları, aynı yönetmeliğe göre bebek ve çocuk ek gıdası için belirlenen limit (1 µg/kg) açısından değerlendirildiğinde, ÇNT1 (11,24 µg/kg), ÇNT3 (4,64 µg/kg), ÇNT4 (2,52 µg/kg), ÇRT1 (6,40 µg/kg), ÇRT5 (11,36 µg/kg), KRT1 (2,76 µg/kg), KRT2 (5,36 µg/kg), KRT3 (10 µg/kg), KRT4 (7,92 µg/kg) ve KST3 (3,56 µg/kg) kodlu tereyağı numuneleri bu limiti aşmış olarak değerlendirilmiştir. Tütsülenmiş et ve et ürünleri ile tütsülenmiş balıkçılık ürünleri için belirlenen limit (12 µg/kg) açısından değerlendirildiğinde ise ÇNT2 (15,36 µg/kg), ÇNT5 (27,8 µg/kg), KST1 (18,48 µg/kg), KST2 (24,52 µg/kg) kodlu tereyağı numunelerinin bu limiti aştığı belirlenmiş, diğer gıda ürünleri açısından (20-35 µg/kg; hindistan cevizi yağı, tütsülenmiş çift kabuklu yumuşakçalar) ise limitlerin aşılmadığı tespit edilmiştir.

Zeytinyağı üretimi atıklarının ekstraksiyonu sonucu elde edilen ürünlerin antioksidan etkinliğinin belirlenmesi

Zeytinyağının ülkemiz için üretim kapasitesi ve ekonomik önemi büyüktür. Zeytinyağı üretimi sırasında çevreye zarar verici nitelikte pirina, karasu ve deodorize distilatı açığa çıkmaktadır. Bu atıklar, zeytin ve zeytinyağından kaynaklanan yağ asitleri, hidrokarbonlar, tokoferoller, steroller ve fenolik bileşikler gibi zengin bir içeriğe sahiptirler. Bu tez çalışmasında zeytinyağı üretimi atıklarının ekstraksiyonu sonucu elde edilen ürünlerin antioksidan etkinliğinin belirlenmesi amaçlanmıştır. Çalışmanın sonucunda, bütün numunelerin uçucu yağ bileşenleri ve yağ asidi bileşimleri GC-MS ile %100 oranında tanımlanmıştır. Toplam fenolik madde miktarları ise gallik asit cinsinden hesaplanmış ve fenolik madde miktarlarıdeodorize distilatında 989,47 ppm, karasuda 495,13 ppm ve pirinada 228,8 ppm olarak tespit edilmiştir. DPPH antioksidan kapasite tayin yöntemi ile IC50 değerleri; pirina 36,35 mg/L, karasu 51,51 mg/L ve deodorize distilatı 61,96 mg/L olarak belirlenmiştir. Tüm numunelerin toplam fenolik madde miktarları ve antioksidan aktiviteleri karşılaştırılmış ve aralarındaki farklılıkların istatistiksel olarak önemli olduğu (p<0,05) tespit edilmiştir. Elde edilen sonuçlara göre; zeytinyağı atıklarının, yeni ve fonksiyonel gıda üretmek için fenolik bileşik, aroma ve antioksidan kaynağı olarak değerlendirilme potansiyeline sahip olduğu belirlenmiştir.

Effect of calcium chloride application on some physical and sensorial properties of pumpkin dessert

Pumpkin dessert is one of the most popular desserts in our country. In this study, effects of calcium chloride on sensorial and physical properties of pumpkin dessert was investigated. Cucurbita maxima was used to obtain traditional pumpkin dessert. Response surface methodology was applied to optimize pumpkin dessert conditions. Temperature (20-40 °C), calcium chloride concentration (0.50-2.50 %), and holding time (10-60 minute) were the independent process variables. The optimum conditions of pumpkin dessert were based on the maximum and minumum levels of responses. It was found that calcium chloride concentration had higher effect on hardness of the pumpkin dessert than temperature and holding time. On the other hand, temperature and holding time increased L* values of pumpkin dessert increased. For total carotenoid content analysis, the increase in temperature and holding time lead to lower total carotenoid content. The optimum temperature, calcium chloride concentration and holding time were estimated as 29.89⁰C, 2.14 % and 56.22 minute for pumpkin dessert. The maximum and minmum levels of responses under optimum conditions were hardness 28.31 N, L* 45.75, a* 9.2, b* 28.44, 112.77 μg/ml. It was found that temperature, holding time and calcium chloride concentration were important parameters in production of pumpkin dessert. Key Words: Pumpkin Dessert, Calcium Chloride, Hardness, Color, Optimization

Üzüm posasiyla zenginleştirilmiş üzüm pekmezi

Grapes are multiple fruits consumed in a wide range of popular foods all around the world. Grape utilizing industries, such as wine and fruit juice producing sectors, bring out a various waste and byproducts, including peel, pulp, and seeds. These valuable byproducts are rich in phenolic compounds. Because it is well known that grape pomace (GP) is an interesting source of fiber and antioxidants with significant nutritional activities, some research has been performed toward using GP for food applications. Therefore, it was aimed to use grape pomace in pekmez (grape molasses) as an additive and to investigate the physico-chemical properties of the pomace-added pekmez. Pekmez (grape molasses) is a popular processed product from grape fruits with dark-colored, sweet and viscous liquid characteristics. In this study, the grape pomace was dried by using tray drier, vacuum oven and freeze drier before addition of it into grape pekmez. The freeze-dried pomace showed the best phenolic content and color properties; therefore, it was decided to add freeze-dried pomace into pekmez. The phenolic content, antioxidant activity, and sugar content of the pekmez were increased by addition of grape pomace into the pekmez. The sensory analysis done at the end of the production of pekmez revealed that the pekmez containing grape pomace dried in the freeze drying were mostly liked by panelist. This study may be considered as an alternative recovery way of treatment of waste grape pomace. Key words: Grape Pekmez, Grape pomace, Freeze Drying, Antioxidant Activity, Total Phenolic Compounds

Raspberry seed oil encapsulation by complex coacervation of heteroprotein

In this study, the encapsulation of raspberry seed oil (RSO) which has a high amount of Omega 3 and 6 fatty acids by heteroprotein complexes between the pea protein isolate (PPI) and Lactoferrin (LF) was investigated. In the first part of the thesis, main goal was increasing the solubility of the pea protein isolate (PPI). The solubility of the pea protein isolate was increased by enzyme hydrolysis. For this purpose, different amounts of enzymes and different hydrolysis times were used for the hydrolysis. Hydrolysis times were chosen for 5,10,15,30 and 60 minutes. The enzyme/substrate ratios were chosen as 1:250 (HPPI250), 1:1000 (HPPI1000), 1:2000 (HPPI2000), 1:3000 (HPPI3000) and 1:4000 (HPPI4000). In the second part of the thesis, the formation of complex coacervate was examined between two oppositely charged globular proteins, lactoferrin and hydrolyzed pea protein isolate. The effect of biopolymer ratio, pH, ionic strength and temperature on complex formation was investigated. Optimum emulsion model was prepared with 10% oil (wt%) and 1% protein (wt%). In the third part of this thesis, emulsions were freeze dried to evaluate encapsulation efficiency, moisture content and color properties. The results revealed that the hydrolyzed of pea protein isolate with enzyme cause a significant increase effect on solubility. It was decided that the different amounts of enzymes and different hydrolysis times were used for the hydrolysis significantly affect the degree of hydrolysis. Capsules produced at optimized conditions with RSO were evaluated for their properties and it was found that heteroprotein coacervates can be used to encapsulate omega-rich oil. Key Words: Lactoferrin, Pea Protein Isolate, Raspberry Seed Oil, Complex Coacervation, Encapsulation

Effect of combined radio-frequency and solar assisted air drying on properties of dried apricot

Dried apricot, one of the most important agricultural export commodities of Turkey, is still produced by using traditional drying (sun drying) method with the expense of high product losses and low grade products with lower economical value. In this study, the experimental design was generated using response surface methodology for radio-frequency drying experiments following solar assisted air pre-drying. For this purpose, the effect of independent variables on the response values was investigated with Box Behnken experimental design for drying of unsulfured apricots. Independent variables were pre-drying temperature (50-70°C), pre-drying time (300-1140 min), radio-frequency electrode gap (77-85 mm) and radio-frequency drying time (270-690 min). Moisture content (%), quantity of browning products (A420/gdryweight), total color change (ΔE) and hardness value (N) were selected as the responses. The drying conditions were optimized for minimum process time, browning, color change and optimum hardness and moisture content. Under optimum conditions of 63.5 °C pre-drying temperature, 895 min pre-drying time, 77 mm distance between radio-frequency electrodes and 385 min radio-frequency drying time; the moisture content (%), quantity of browning products (A420/gdryweight), total color change (ΔE) and hardness (N) were 22.31±2.82, 0.69±0.03, 37.65±2.23 and 1293.46±61.96, respectively. Radio-frequency drying following solar assisted air drying system provided high quality whole apricots while reducing the processing time.

Hydrolysis of bioactive peptides from bulgur waste

Bulgur is one of the ready or semi-ready to eat cereals produced from wheat specifically Triticum durum variety. Residue of bulgur from manufactures are useless while, these wastes rich in some food components. Protein is one of the main components of bulgur that may remain in the wastes. This study was carried out to extract bioactive peptides from the bulgur waste samples and indicate the activity against oxidation stress, microbial inhibition and hypertension control. The analysis made in this study were determination of protein, fat, ash and moisture content, extracting protein from the bulgur wastes, the samples hydrolyses by four diverse enzymes including pepsin, trypsin, chymotrypsin and protease in a suitable incubation conditions for entire 360 minutes. Effect of concentration, time and different types of enzyme has been investigated on each activity. The extracted protein content by alkaline processes was determined as 2.84% (w.b) by kjeldahl method. The hydrolysis rate, antioxidant activity, antimicrobial activity and antihypertensive activity show either an increases or decreases according to the incubation conditions. This study illustrate the extracting of protein content by alkaline processes and hydrolysis by four diverse enzymes and proofing the anti-oxidant, antimicrobial and antihypertensive activity of the accessible bioactive peptides in the bulgur waste samples.

Encapsulation of flaxseed oil enriched in carotenoid by microwave technique using innovative wall materials

In this study, flaxseed oil enriched in carotenoid by microwave technique was encapsulated using innovative wall materials. In the first part of the study, the effect of microwave technology and the use of flaxseed oil as the solvent on the yield of carotenoid extraction from carrot juice processing waste were investigated. Response surface methodology was employed to optimize the effect of microwave power (50-200 W), extraction time (1-12 min) and oil to solid ratio (5:1-20:1 g/g) on percentage recovery of carotenoid. Optimum conditions obtained for microwave-assisted carotenoid extraction were 165 W, 9.39 min and 8.06:1 g/g of oil to solid ratio which gave carotenoid recovery of 77.48%. Selected physical and chemical properties of flaxseed oil and carotenoid enriched flaxseed oil were investigated in terms of fatty acid composition, acid value, peroxide value, p-anisidine value, colour parameters (Hunterlab L*, a* and b* values), β-carotene content, total phenolic content and antioxidant activity (DPPH). Encapsulation of the enriched flaxseed oil was performed by spray freeze drying by using different emulsion formulations. Emulsions which contain various concentrations of carotenoid enriched flaxseed oil (6, 9, 12 and 15% w/w) and ratios of maltodextrin/(pectin+wax) proportions (3:1, 6:1, 9:1 and 12:1 g/g) were encapsulated by spray freeze drying to determine the emulsion formulation with the highest encapsulation efficiency. Spray freeze drying and spray drying techniques were compared in terms of the encapsulation efficiency, moisture content, particle size, flowing properties, morphological properties and oxidative stability.

Effect of carvacrol on oxidative stability of sunflower seed oil during storage

Natural antioxidants recently have gained popularity since synthetic ones have toxic and carcinogenic effects. In the present study, carvacrol was used as a natural antioxidant and compared with a synthetic antioxidant BHT. In this study, the shelf- life of oils was determined both under normal conditions and using accelerated tests. Rancimat and PetroOXY devices are used to investigate the oxidative stability and shelf-life of edible oils. Therefore, the purpose of this study was to predict shelf-life of mid-oleic sunflower seed oil by Rancimat and PetroOXY test devices. The study was performed at 110, 120, 130oC with both Rancimat and PetroOXY devices as accelerated methods. In addition, sunflower seed oil was stored at normal storage temperatures of 20, 30 and 40oC. It was determined that carvacrol was not as protective as BHT in both normal storage conditions and accelerated methods. The induction periods (IP) with Rancimat and PetroOXY devices were measured as 5.45, 2.86 and 1,45 and 2.23, 1.12 and 0.62 hours at temperatures of 110, 120 and 130oC, respectively. At normal storage temperatures, the IP values were measured by tangent method in terms of days. The peroxide values (PV) at the determined IP values were 12.08, 29.24 and 33.09 at 20, 30 and 40 oC, respectively. The induction periods predicted from Rancimat and PetroOXY devices for normal storage temperatures of 20, 30 and 40°C were 88.71, 48.85 and 23.22 and 30.17, 15.91 and 8.38 days, respectively. The shelf-life prediction for normal storage temperatures from Rancimat method was seems more reliable than those of PetroOXY device. Also, there was a good correlation between two accelerated methods and it was observed that PetroOXY was a faster method than Rancimat. Key Words: Rancimat, PetroOXY, Oxidation Stability, Induction Period, Storage

Effect of various drying techniques on quality properties of organic blueberry fruit

ABSTRACT EFFECT OF VARIOUS DRYING TECHNIQUES ON QUALITY PROPERTIES OF ORGANIC BLUEBERRY FRUIT GÖK, Gülşah M.Sc. in Food Engineering Supervisor: Prof. Dr. Medeni MASKAN Co-Supervisor: Assoc. Prof. Dr. K. Bülent BELİBAĞLI December 2019 81 pages The effects of convectional air and microwave-convectional (hybrid) drying methods, and ultrasound and osmotic dehydration pretreatment on drying characteristics and some quality parameters of organic blueberry were investigated. Convectional drying was performed at 60, 70, and 80 °C temperatures. Hybrid drying was performed at 150, 180 and 210 W power levels at 60 °C constant air temperature. Blueberries were exposed to a simultaneous ultrasound and osmotic dehydration pretreatment. An organic apple juice concentrate (70 °Brix) was used as the osmotic medium. The ultrasound pretreatment extended the drying process. Hybrid drying resulted in shorter drying times compared to air drying. Increasing temperature in air drying and microwave power in hybrid drying increased the drying rates. The best fitting model for all drying conditions was determined as Midilli et al. model. Higher total phenolics content (TPC) and antioxidant activity (AA) levels were obtained by the hybrid drying compared to hot air method. The highest TPC and AA values were obtained at 180 W hybrid drying, while the lowest values were obtained at 70 oC air drying. Application of ultrasound and osmotic dehydration treatment led to a significant decrease in TPC and AA. Color values were generally similar to each other. As a conclusion, hybrid drying can be considered as an alternative dehydration method for the drying of blueberries. Key Words: Organic Blueberry, Drying, Ultrasound, Phenolics Content, Microwave

Search on the production techniques of wheat and red lentil brans low calorie dietary fiber

Awareness of the importance of healthy and low calorie diets is increasing overall the world due to its nutritional and functional effects on the healthy body. Enrichment dietary products with dietary fibers become common a lot nowadays. In this study, physical and chemical changes of wheat and red lentil dietary fiber were determined for soaking, cooking, microwave and ultrasound treatments. The moisture (%, w.b.), protein (%, d.b.), ash (%, d.b.), fat (%, d.b.), starch (%, d.b.), sugar (%, d.b.), carbohydrates (%, d.b.), total dietary fiber (%, d.b.), calorie and color values (L*, a*, b* and YI) were determined. It was found that the chemical properties of wheat and red lentil brans significantly (p≤0.05) changed based on production methods, soaking, cooking, microwave and ultrasound. According to the results of analyses, the fat content of wheat and red lentil dietary fibers did not change (p< 0.05) in all treatments. The dietary fibers calorie content decreased (p≤0.05) in all different treatments and the dietary fiber content increased (p≤0.05) in all different treatments except soaked wheat bran. Key Words: Wheat Bran, Red Lentil bran, Soaking, Cooking, Microwave, Ultrasound, Physical and Chemical Properties, Dietary Fibers.

Ayran-shalgam mixture: A study on rheological properties, shelf life, and sensory evaluation

The objectives of this study were to evaluate the rheological properties, shelf life and sensory properties of different ayran-shalgam mixtures. Mixtures of ayran and shalgam in different ratios [25% ayran + 75% shalgam (v/v), 50% ayran + 50% shalgam (v/v) and 75% ayran + 25% shalgam (v/v)] were subjected to rheological measurements at different temperature levels (4, 8 and 12 °C). Power law model was used to define the rheological data. It was apparent that temperature had no effect on the flow behavior index of the mixtures. On the other hand, as the temperature increased consistency index of the mixtures decreased. Ayran-shalgam mixtures had similar flow behavior index with that of shalgam no matter whatever the amount of ayran or shalgam in the mixtures was. However, consistency index increased as the amount of ayran increased in the mixtures at a constant temperature. Shelf life analyses up to 4 weeks at 4 °C indicated that serum separation increased up to second week and then stabilized for all the mixtures. Slight increase (0.05 to 0.1 unit) in the pH values was observed during the first week, then, pH values were stabilized just like the serum separation. Microbiological analyses revealed that mixtures had a similar shelf life with that of ayran. Mixture with the highest ayran content [75% ayran + 25% shalgam (v/v)] had the highest scores in sensory evaluation. It was concluded that ayran-shalgam mixture had a huge potential for commercial production. Key Words: Ayran, Shalgam, Fermented Beverages, Rheology, Shelf life, Microbiology

Extraction and food application of mucilage from okra

The main objective of this study is to investigate the extraction of mucilage from okra (Abelmoschus esculentus) thereby evaluate and compare the functional properties of okra. Experimental design was performed by using Response Surface Methedology (RSM). The independent variables used in this study were extraction temperature (25–80ºC), extraction time (1-7 hr) and water to raw material ratio (4:1–10:1). The dependent variables were extraction yield, swelling index, emulsion capacity, emulsion stability, antioxidant activity and phenolics content. By numerical optimization of independent process variables, it was found that the optimum variables for extraction time, water to okra ratio and extraction temperature were 1.52 hr, 7.2 and 50.51ºC, respectively. At these optimum conditions; extraction yield, swelling capacity, emulsion capacity, emulsion stability, antioxidant capacity and total phenolics content were predicted to be 23.24 %, 44.2 (mL/g), 47.05 %, 50.18 %, 38.95% and 36.75, respectively. Oiling off was decreased with addition of mucilage and stability of the emulsion was enhanced. Organoleptic evaluation of okra mucilage found to be acceptable and satisfactory. The okra mucilage was used in pistachionuts paste as a stabilizer. It was found that as the percentages of okra mucilage in pistachionuts paste increased, ability of holding oil increased and amount of oil accumulated at the top decreased. Results showed that okra mucilage can be used as a promising additive in food formulations.

Bio-refinery of pistachio production by-products

The objective of this thesis was to perform bio-refinery of pistachio production by-products, pistachio hull (PH) and shell (PS). For this purpose, microwave-assisted solvent extraction (MASE) of polar and non-polar compounds from PH was performed. The results showed that the pistachio hull extracts were rich in bioactive compounds such as phenolics, antioxidants and tocopherols. Also, MASE has been shown to be advantageous in extracting bioactive compounds with higher yield, antioxidant activity, and reduced extraction time and solvent consumption. Alkali pre-treatment of PS was carried out by using microwave and/or ultrasound-assisted methods to fractionate PS into hemicellulose solid precipitate and cellulose rich solid phase. The pre-treatment conditions were optimized to obtain maximum hemicellulose and cellulose recoveries and the optimum pre-treatment conditions were determined as ultrasound power of 640 W, microwave power of 248 W and NaOH concentration of 1.58 N for sequential ultrasound-microwave-assisted alkaline pre-treatment (SUMAAP). Under these conditions, the hemicellulose and cellulose recoveries were 66.14% and 90.78%, respectively. SUMAAP increased the hemicellulose recovery with a significant reduction in processing time and amounts of chemical used for the fractionation of PS into hemicellulose and cellulose. Finally, enzymatic hydrolysis of the pre-treated cellulose-rich fractions was performed to produce fermentable sugars and the highest glucose yield of 95.78 mol% obtained after SUMAAP.

Extraction of pectin from pistachio hull and its use in emulsion system

The aim of this study is to obtain pectin from pistachio hull and to investigate the emulsifying properties of pectin obtained in the oil-in-water emulsion system. Extraction was carried out by using two different methods, conventional extraction (CE) and ultrasound-assisted extraction (UAE). Two different extraction solvents, water and citric acid solutions were used separately as extraction solvents. While the highest yield (32.3±1.44%) was obtained using citric acid solution in CE method, the lowest yield (5.56±0.25%) was obtained using water in UAE method. The physical and chemical properties of the pectin obtained were determined. The results showed that pectin obtained under optimum conditions was low methoxyl (about 19.29% DE) with moisture content of 4.9±0.062%, ash content of 1.49±0,026%, protein content of 1.85±0.14%, total phenolic content of 6.03±0.08 mg GAE/g, total sugar content of 56.84±2.36 mg sugar/g, and acidity of 38.94±0.17%. The galacturonic acid content had been found as 65.81%. Additionally, the emulsifying property of pectin extracted was investigated in an o/w emulsion system. O/W emulsions were prepared at six different pectin concentration (2, 4, 5, 6, 8 and 10% (w/w)) and at fixed oil ratio (20% (w/w)). Emulsion performance was investigated in terms of emulsion stability, morphological characteristics, droplet size and rheological properties were examined. The best emulsion characteristics were obtained at 6% pectin concentration.

Effect of minimal refining on the minor constituents and oxidation stability of sunflower seed oil

Question of thesis was "if minimal refining process should be accomplished with the minimum losses of desirable substances for production of sunflower seed oil rich with micronutrient". The overall objectives of the study were to produce oxidatively stable minimal neutralized sunflower seed oil using three chemicals (Ca(OH)2, MgO and Na2SiO3) as alternatives to strong alkali (NaOH), which is used in conventional neutralization method; to optimize minimal neutralization operations by the response surface methodology; to determine optimal process conditions for sunflower seed oil. First part of this study suggested that the minimal operation is possible to obtain sunflower seed oil having high nutrition value by altering the neutralization process. Second part indicated that sunflower seed oils obtained by minimal neutralization having lower free fatty acids (FFAs) content and better oxidative stability than oil neutralized by traditional method. Third part focused on which weak alkaline has higher oxidation stability, minimum FFA content and maximum α-tocopherol content. The estimated optimal values for minimal neutralization of sunflower seed oil were an amount of Ca(OH)2 of 0.30 %, 53.0 ºC and 19.7 minutes; an amount of MgO of 0.38 %, 57.6 ºC and 17.8 minutes; an amount of Na2SiO3 of 0.81 %, 55.7 ºC and 19.1 minutes. It was concluded that the oil neutralized by NaOH had the shortest hydroperoxide and hexanal lag phases, thus, were the least stable oil and oils neutralized by Ca(OH)2, MgO and Na2SiO3 had lower FFA and higher oxidative stability than oil neutralized by NaOH. The oil neutralized by Ca(OH)2 had the lowest FFA, anisidine value and highest total phenolics and α-tocopherol contents and had better oxidative stability than oil neutralized by NaOH. It suggests that Ca(OH)2 could be more effective in producing a high quality oil. Key Words: Sunflower Seed Oil, Minimal Refining, Antioxidant Activity, Lipid Oxidation, Tocopherol

Evaluation of durum clear flour

Use of pestil as an edible film and coating

Pestil, a well known fruit leather in Turkey, was prepared from boiled grape juice and starch mixture by using traditional technique. Drying of pestil was carried out by hot air drying and sun drying. The factors investigated in hot air drying were air temperature (55, 65 and 75°C), sample thickness (Si=0.71, S2=1.53, S3=2.20 and S4=2.86 mm) and air velocity (Vi=0.86, V2=1.27 and V3=1.82 m/s). The effects of drying time temperature and slab thickness on moisture content of pestil during drying were significant (P<0.05) and of air velocity was not (P>0.05). Depending on sample thickness and air temperature, the drying time ranged between 50-140 min to achieve the commercial moisture content of pestil (11 % wet basis) in air drying. Whereas, sun drying took 180 to 1500 min. Almost all samples dried in the falling rate period, except S2, S3, S4 of sun drying and S4 at 55°C. The latter had a short (negligible) constant rate period. Effective moisture IIIdiffusivity values were estimated from Fick's diffusion model. These values were between 3.00-37.6x1 0"11 m2/s for hot air drying and 1.93-9.16x10"11 m2/s for sun drying. Activation energy value of water diffusion was calculated using an Arrhenius-type equation. The estimated values were 21.7, 16.5, 12.0 and 10.3 kJ/mol for Si, S2. S3 and S4, respectively. The Hunter colour parameters (L, a, b) of grape juice during boiling and of pestil samples during drying were investigated. It was found that most of the colour destructed during boiling. All Hunter parameters changed significantly. However, either during hot air or sun drying, only Hunter-a value changed. The colour destruction reaction followed a zero order reaction kinetics. The water vapour permeability (WVP) properties of pestil at three different temperatures (15, 25 and 37°C) and four relative humidity gradients (20, 50, 70 and 100% RH) were tested. It was found that water vapour permeability was strongly dependent on relative humidity. Pistachio nut meat was coated with pestil solution and kept at 15°C and three different relative humidities. Results showed that when the coated pistachio nut samples were kept at about 55% relative humidity, weight of the samples were almost constant. The coated samples absorbed moisture at high relative humidity (76.46%) and lost water at low relative humidity (33.33%) environments. Key words : Grape, pestil, drying, colour change, edible film, water vapour permeability, pistachio nut meat.

Rheological properties of reduced-fat Gaziantep cheese

ABSTRACT RHEOLÖGICAL PROPERTIES OF REDUCED-FAT GAZİANTEP CHEESE KAHYAO?LU, Talip M.Sc. in Food Engineering Supervisor: Assist. Prof. Dr. Sevim KAYA January 2002, 76 pages The effects of fat reduction, heat treatments and storage temperatures (13 and 25 °C) on the physical and chemical properties of Gaziantep cheese were investigated. Three different heat treatment temperatures (75, 85 and 95°C) were applied to three different fat (50.4, 33.4, 13.5%) containing cheese samples. With and without heat treatment, samples were analyzed with respect to viscoelastic parameters, color, meltability and texture. Decreasing fat content of the cheeses increased the hardness and elasticity. Heat treatments also imparted elasticity to the cheese. It was found that melting temperature of the cheese inversely related with fat content and temperature of the heat treatment. The gel strength constants of Gaziantep cheese were found in the range of 0.18-0.22. Differences in physical properties of the cheese in which fat content was reduced by 30 % with full-fat Gaziantep cheese were in an acceptable level. Heat treatment can be used for improving physical properties of fat-reduced Gaziantep cheese. Whiteness (L- value) significantly changed by the effect of fat reduction and heat treatment. It was observed that increase in storage temperature decreased whiteness and increased hardness of the samples. Key Words: Gaziantep cheese, reduced-fat cheese, cheese rheology, viscoelastic properties, creep test, meltability, color.

Effect of wheat germ addition on the selected properties of bread

ABSTRACT EFFECT OF WHEAT GERM ADDITION ON THE SELECTED PROPERTIES OF BREAD ÇİFTÇİ, Veliddin M.Sc. in Food Engineering Supervisor: Prof.Dr. Zerrin SÖYLEMEZ April 2002, 64 pages Enrichment of bread with 5, 7.5, 10, 12.5, 15, 17.5 and 20 % raw wheat germ was studied by using a laboratory scale bread machine. Bread value numbers, volumes, heights, weights and general structure of the enriched bread were examined. Bread value numbers were decreased by addition of wheat germ. To eliminate this, ascorbic acid was used and the effect of ascorbic acid on wheat germ bread was investigated. An addition of 150 mg ascorbic acid/kg was used for each formulation having 5 to 20 % wheat germ. Although negative effects of raw wheat germ was observed, bread enriched with 15 % wheat germ was found satisfactory after ascorbic acid treatment in terms of bread properties. Key words: Wheat germ, Bread, Enrichment of bread in

Effects of some storage contidions and additives on quality and stability of Sucuk (Turkish dry-fermented sausage)

ABSTRACT EFFECTS OF SOME STORAGE CONDITIONS AND ADDITIVES ON QUALITY AND STABILITY OF SUCUK (TURKISH DRY-FERMENTED SAUSAGE) Bozkurt, Hüseyin Ph. D. in Food Engineering Supervisor: Assoc. Prof. Dr. Osman ERKMEN December 2002, 219 pages In this work, aerobic plate counts (APC), mold and yeast counts and lactic acid bacteria (LAB) counts; pH values, 2-thiobarbituric acid (TBA) values, nitrosomyoglobin conversion rate, residual nitrite level and biogenic amine formations; and overall sensory quality were monitored for microbial, chemical and organoleptic changes in sucuk (Turkish dry-fermented sausage) during the ripening and storage periods (20, 30 and 40°C with 50, 65 and 80 % RH). These analyses were also determined in sucuks collected from local markets (firm-made) and butchers (traditional). APC and LAB increased (P<0.05) during the first 10 days of ripening and decreased (P<0.05) during the further ripening and storage periods. Starter culture had no effect (P>0.05) on the reduction of APC. Additives (nitrite, nitrate, a- tocopheroL ascorbic acid, potassium sorbate, potassium pyrophosphate, di-potassium hydrogen phosphate) had significant effect on the reduction of APC, LAB, and mold and yeasts counts. Increasing the storage temperature and % RH increased APC and LAB count significantly (P<0.05). pH values of sucuks were sharply decreased (P<0.05) during the ripening. Additives and starter culture decreased TBA values but increased pH values and nitrosomyoglobin conversion rate. Increasing % RH of storage room increased the TBA and nitrosomyoglobin conversions values but not pH values. The residual nitrite level sharply decreased (P<0.05) in sucuks made with nitrate/nitrite during thefirst five days of ripening periods. The amount of residual nitrite was low (P<0.05) in sucuks stored at 30°C. Histamine ranged from 0.00 to 292.66 mg/kg during the ripening and storage periods. Starter culture and additives limited (P<0.05) the histamine, tyramine and putrescine formation. Histamine formation was highest (P<0.05) at high RH (80 %) storage. The lowest (P<0.05) tyramine, Mstamine and putrescine concentrations were observed in sucuk type B9. Putrescine concentration changed inversely related with the pH values of sucuks. Its formation decreased (P<0.05) with addition of additives and starter culture into sucuks. It was found that additives had no effect (P>0.05) on the tryptamine and polyamines (spermidine and spermine) formation. It was observed that 1,7-diamino heptane, serotonin, spermidine and spermine concentrations were changed between 0.00-43.54, 0.00-57.26, 0.00-30.60 and 0.00- 3 1.29 mg/kg, respectively, in sucuks during the ripening and storage periods. Overall sensory quality increased during the first days of ripening. The lowest overall sensory quality was observed in sucuk type Al. Starter culture and additives increased (P<0.05) overall sensory quality. Nitrite/nitrate played important role in the formation of desired color (nitrosomyoglobin) and flavor; ascorbic acid, and o> tocopherol reduced the lipid oxidation; and phosphates improved textural properties of sucuks. Empirical equations were used to predict the chemical, microbial and overall sensory qualities of sucuks during the storage periods. It was found that empirical equations were well fitted to the experimental data. Traditional sucuks had higher APC, and mold and yeasts counts than that of firm-made sucuks. pH values and residual nitrite level of firm-made sucuks were higher (P<0.05) than that of traditional sucuks. Traditional sucuks were spicier and the dominant aroma was from spices. Generally, firm-made sucuks had no desired aroma. Key Words: Sucuks, stability, quality, safety, biogenic amine, TBA value, residual nitrite level u

Effect of different milling systems on selected quality parameters of bulgur

ABSTRACT EFFECT OF DIFFERENT MILLING SYSTEMS ON SELECTED QUALITY PARAMETERS OF BULGUR YILDIRIM, Ali M.Sc. in Food Engineering Supervisor: Prof. Dr. Mehmet Durdu ÖNER April 2004, 83 pages Effect of different milling systems on selected quality parameters of bulgur was searched in this study. Studies were made with disc and roller mills, horizontal helical polisher and color sorting systems for bulgur production. Conventional disc mill and newly improved roller mill (with four rolls and three passing) used in bulgur production were compared based on; energy, capacity, yield, loss, milling characteristics, ash content, hectoliter weight, color and protein contents. The gaps of first-second rolls, second-third rolls and third-fourth rolls were adjusted to 1.90, 1.60 and 1.30 mm; 1.20, 1.00 and 0.80 mm, and 0.40, 0.50 and 0.60 mm, respectively, and twenty seven variations of those gaps were studied for roller mills. On the other hand, nine different gaps 1.90, 1.60, 1.30, 1.20, 1.00, 0.80, 0.60, 0.50 and 0.40 mm were studied for disc mill. The produced samples from both types of milling systems were screen analyzed using 3.50, 2.00, 1.00 and 0.50 mm size sieves. Screened fractions of (+/3.50), (3.50/2.00), (2.00/1.00), (1.00/0.50) and (0.50/-) mm named as coarse, pilaf, middle, fine sized bulgur and loss of bulgur, respectively. Also effect of the horizontal helical polishing system used in bulgur production line on quality factors such as color, protein content, loss, yield, moisture content and hectoliter weight of bulgur samples were researched. Color sorting system is applied on peeled intact, mixed and fine bulgur samples and effects of the system on percent purity (yield), loss and color values of the products were investigated. Yield values of 11samples from disc mill were found as 13.13, 72.33 and 84.84 % for gaps adjustments of 0.40, 0.50 and 0.60 mm, respectively. On the other hand, yield values of samples from roller mill were obtained between 84.77 and 99.75% for the same gaps. Especially for the fine bulgur, the yield values of the disc mill were found to be too low. The amount of loss in disc mill, especially for the 0.40 mm break was increased up to 86.87 %, was higher than that for improved roller mill. Even in the finest break of the improved roller mill system, the loss value was at most 15.23 %. The hectoliter weight values for the disc mill system were found to be higher than those of roller mill. In the roller system, coarse, pilaf, middle and fine bulgur products could have been produced simultaneously. The moisture and ash content were decreased from 13.08 to 11.15 % and 1.53 to 1.41% respectively, but hectoliter weight value measured on 2 mm sieve was increased from 67.16 to 85.35 kg/hi in horizontal helical polishing system. The measurements of color values from inlet and outlet of polisher were indicated decrease in L and increase in b values. Also, increase in YI (yellowness index) value which was parallel with this change reveals the fact that using polisher produces bulgur with desired amber color. Analysis of percent purity of intact, mixed and fine bulgur samples from color sorting system was showed that the highest value, 99.10 %, was obtained for intact bulgur. Key words: bulgur, roller mill, disc mill, polisher, color sorting system. m