Phytic acid content of durum wheat varieties, changes during pasta processing and reduction of phytic acid

In the first part in this study, samples of eight durum wheat (Tritucum durum L.) cultivars (Çeşit-1252, Eminbey, Güney Yıldızı, Kızıltan 91, Maestrale, Mirzabey, Svevo and Zenith) commonly grown in Turkey were used to determine the effects of bran addition on some nutritional and quality properties of spaghetti. Spaghetti was produced by adding bran at different ratios (0%, 7.5%, 15.0%, 22.5%). The main purposes were to determine phytic acid and dietary fiber contents of commonly grown durum wheat varieties, to detect changes in the amounts of phytic acid during various pasta processing stages and to examine possibilities of decreasing phytic acid content of pasta. Total dietary fiber and phytic acid contents of durum wheat and their pasta samples were determined. Furthermore physical, chemical, rheological and textural analyses were carried out to determine the quality characteristics of wheat, flour, semolina and pasta samples. In the second part of this study, samples of five durum wheat cultivars (Kızıltan 91, Eminbey, Çeşit-1252, Altın 40/98, Mirzabey 2000) grown in four different locations (Altınova, İkizce, Malya, Ulaş) were used to evaluate the effects of variety and location on phytic acid, dietary fiber, mineral matter (Ca, P, Mg, K, Na, Cu, Fe, Zn, Mn, Ni, B), certain physical, chemical and physicochemical properties. The results of the study in the first part showed that addition of bran increased the "a" value, protein, ash, dietary fiber and phytic acid contents, TOM, cooking loss and stickiness value determined by texture analyses but decreased the "L" and "b" values, sensory properties (firmness, stickiness, bulkiness) and some of the textural properties (breaking strength and flexibility, distance, hardness, springiness). During the production of semolina from wheats, 63.6% reduction was observed in the pyhtic acid content. It was found that the decrease in pyhtic acid content of pasta was approximately 24.1% as compared to the semolina used for pasta production. Compared to control pasta samples, addition of bran at different ratios (7.5%, 15.0%, 22.5%) caused increases (average) 72.2%, 108.9%, 150.7% in the pyhtic acid content, respectively. The changes in the pyhtic acid content were investigated by adding different amounts of enzyme in pasta (supplemented with 22.5% bran) processed from Güney Yıldızı cultivar. Bran and enzyme mixtures were kept in controlled temperature cabinet for 2 hours at 45°C. The maximum reduction (56.10%) of pyhtic acid content was found in the enzyme added (2.7 g) pasta sample which was kept 2 hours in controlled temperature cabinet. The results of the second part, the study illustrated that both the cultivars and locations influenced the quality parameters investigated. The wheat samples grown in İkizce, Malya and Altınova locations had better results as compared to the wheats grown in Ulaş in terms of their quality characteristics. Lower phytic acid contents were found in the wheats grown in Ulaş location. Wheats grown in İkizce location had higher mineral contents (P, K, Mg, B, Cu, Fe, Mn and Zn) compared to the wheats grown in other locations. Keywords: Durum wheat, bran supplemented pasta, phytic acid, dietary fiber, pasta quality, mineral content.