Currant successfully grown in a wide area in Turkey due to its environmental plasticity. The aim of this study is to determine variations in phytochemical contents and antioxidant capacity from certain currant cultivars and genotypes commercially grown in Turkey. Fruit samples taken from two red currant cultivars (‘Red Lake’, ‘Rovada’) and four black (‘S. Nigrum’, ‘Tokat 2’, ‘Tokat 3’ and ‘Tokat 4’) and the genotype 1310 (red currant) were subjected to analysis for phenolic compounds (protocatechuic, vanillic acid, ellagic acid, rutin, quercetin, gallic acid, catechin, chlorogenic acid, caffeic acid, syringic acid, p-coumaric acid, o-coumaric acid, phloridzin and ferulic acid), organic acids (citric acid, tartaric acid, malic acid, succinic acid, and fumaric acid), vitamin C, antioxidant capacity (Trolox equivalent antioxidant capacity [TEAC] assay) and sugars (glucose, fructose and sucrose). Results showed that phytochemical contents and antioxidant capacities statistically varied among currant cultivars and genotype (p<0.05). Caffeic acid was determined only in the genotype 1301. Ellagic acid (1.680 mg/100 g), gallic acid (2.022 mg/100 g), rutin (4.649 mg/100 g), catechin (8.005 mg/100 g) and chlorogenic acid (2.721 mg/100 g) were found the highest values in ‘Tokat 3’, ‘Red Lake’, ‘Tokat 3’, 1310 and ‘S. Nigrum’, respectively. Citric acid, fumaric acid, and malic acid were dominant among organic acids for all cultivars and the genotype 1310. Contents of glucose and fructose among sugars were measured to be higher than content of sucrose for all cultivars and the genotype. The highest antioxidant capacity was detected in cultivar of ‘Rovada’ and the genotype 1310.

The Erzincan plain is one of the richest regions in Turkey in terms of plant biodiversity. In this region, the famous grape cultivar ‘Karaerik’ has always dominated grape production due to its berry characteristics. The cultivar shows great morphological variation at clonal level. In this study, the total phenolic content and antioxidant activity of peel, pulp and seed extracts of nine ‘Karaerik’ clones sampled from same location were investigated. The Folin–Ciocalteu method was used to determine the total phenolic content of peel, pulp and seed extracts of nine clones. To determine antioxidant activity, three well known assays such as DPPH (2,2-diphenyl-1-picryl-hydrazyl-hydrate), FRAP (Ferric Reducing Antioxidant Power) and TEAC (Trolox Equivalent Antioxidant Capacity) were used. In addition, the correlation between total phenol content and DPPH, FRAP and TEAC was determined. Results showed that among the tissues, seed samples in berries of all clones had the highest total phenol content and antioxidant activity determined by three assays. Seed samples were followed by peel and pulp for total phenolic content and antioxidant activity. Among the nine ‘Karaerik’ clones, Clone 8 had the highest total phenolic content (149 mg GAE/100 g FW) while Clone 3 had the lowest (111 mg GAE/100 g FW). Peel, pulp and seed samples of nine ‘Karaerik’ clones showed strong antioxidant activity in DPPH, FRAP and TEAC assays. In particular, grape seeds were found rich for better in phenolic compounds including gallic acid, quercetin, catechin, chlorogenic acid, caffeic acid and p-coumaric acid. Clones such as 7, 8 and 9 higher antioxidant activity may present great potential for grape breeders and the food industry as well as health-conscious consumers.

Wild edible fruits have been gaining much interest more recently because of their better biochemical content and widely use in ethno medicine treating common disease such as cold, fever and other medicinal claims are now supported with sound scientific evidences. In this study, diversity of some important physicochemical characteristics (plant growth habit, fruit shape, fruit color, fruit weight, pulp ratio, soluble solid content, total phenolics, total anthocyanin, antioxidant activity, sugars, organic acids) of fruits from fourteen promising barberry (Berberis vulgaris L.) selections grown in Erzurum province in Turkey were investigated. Significant differences were observed between the studied genotypes for most of the physicochemical parameters. Fruit weight and pulp ratio were found between 0.102 (25ERZ5) and 0.342 g (25ERZ7) and 60.81% (25ERZ2) and 75.41% (25ERZ11). Total phenolic and anthocyanin content ranged from 2281 (25ERZ5) to 3462 (25ERZ7) as mg GAE per liter fruit juice and 360 to 874 mg as cyanidin-3-glucoside per liter fruit juice. Glucose and fructose were found to be dominant sugars in all barberry accessions analyzed.