Determination of total phenolic content, phenolic composition, antioxidant capacities and some physicochemical features of rosehip (Rosa canina) and hawthorn (Crataegus orientalis) wild fruits growing in the region of tunceli

Free radicals occur in our environment and daily life conditions because of various reasons; therefore, so as to prevent their negative effects on live organisms, natural antioxidants are becoming more and more important. In this work, some physicochemical characteristics, antioxidant activities, total phenolic content (TPC) and phenolic compositions of rosehip (Rosa canina) and hawthorn (Crataegus orientalis) wild fruits, which are indigenous to the region of Tunceli and were picked in 3 different counties (Pertek-Mazgirt-Hozat) have been determined. By using UV-VIS spectrophotometer; TPC has been determined by Folin-Ciocalteu method, their antioxidant activities have been determined according to the way to terminate DPPH˙ (2,2-difenil-1-pikril hidrazil) radical. Phenolic content compositions have been determined by using high performance liquid chromatography. Physicochemical analysis result according to the places fruits have been picked and activities to terminate DPPH˙ radical have been compared by using one-way manova statistical test. TPC of rosehip and hawthorn samples have been compared with Mann-Whitney U test, their antioxidant activities have been compared with two independent samples of T-test. At the end of the physicochemical analyses and according to the counties rosehips were picked; water activity has been determined between 0.692-0.716, pH 3.56-3.61, colour measurement L* value 28.97-30.37, a* value 16.42-18.38, b* value 11.90-12.83, total amount of dry matter 44.74-51.67% and ash content 2.61-3.13%. Of parameters determined among the samples of rosehip, only the change of colour measurement values (L*,a*,b*) in the city center and its counties has been considered statistically significant. In the samples of hawthorn, water activity has been determined between 0.715-0.824, pH 3.54-3.58, colour measurement L* value 33.68-38.41, a* value 5.26-8.34, b* value 13.72-16.37, total amount of dry matter 28.07-31.62% and ash content 0.75-1.23%. The change of water activity and colour measurement values (L*,a*,b*) of hawthorn according to places it was picked has been considered statistically significant. In the fruits of rosehip and hawthorn, respectively, TPC has been determined 1265.02-1344.68 and 318.18-370.85 mg GAE kg-1 fresh weight; the activity to terminate DPPH˙ radical has been determined 4.83-5.26 and 1.85-2.36 μmol ascorbic acid equivalence g-1 fresh weight. Among wild fruits in respect for TPC and the activity to terminate DPPH˙ radical, it has been found out that there's a statistical difference and rosehip has higher values than hawthorn with regard to both parameters. In the analyses to determine phenolic content profiles, procyanidin B2 and catechin phenolics have been defined as basic phenolics for rosehip, catechin and epigallocatechin phenolics for hawthorn. It has been noticed among the fruits that there's at the amounts of epigallocatechin, protocatechuic acid and quercetin-3-O-glucoside phenolic compounds and the fruit of hawthorn contains these phenolics at a higher rate than rosehip. Key Words: Rosehip, Hawthorn, Free radical, Antioxidant, Total phenolic content, Antioxidant activity, Phenolic profile, HPLC, Tunceli.