Akademik Veri Yönetim Sistemi
INTERNATIONAL JOURNAL OF FOOD SCIENCE AND TECHNOLOGY, cilt.43, sa.1, ss.154-159, 2008 (SCI-Expanded)
In this study, total phenolic contents and antioxidant activities of grape seed extracts obtained from twelve different grape seeds from common varieties grown in Turkey were determined. Grape seeds were extracted with 70% acetone and extraction yield of grape seed were calculated. The total phenolic content of grape seed extracts were determined by the Folin-Ciocalteu procedure and ranged from 33 945 to 58 730 mg per 100 g extract as gallic acid equivalent. Antioxidant activities of grape seed extracts with two different free radical scavenging methods, ABTS [2,2/-azinobis (3-ethylbenzothiazoneline-6-sulfonic acid)] and DPPH (2,2-diphenyl-picrylhydrazyl) assays, using Trolox equivalent as standards, were investigated. Grape seed extracts exhibited antioxidant activities 2.46-4.14 and 3.55-5.76 [Trolox equivalent antioxidant capacities (TEAC) mg(-1) extracts] in ABTS and DPPH assays, respectively. Compared with varieties, Muskule extracts exhibited the lowest total phenolic content, TEAC(ABTs) and TEAC(DPPH) value while Narince extracts had the highest total phenolic content and TEACDPPH value, and Alphonse Lavallee had the highest TEAC(ABTS) value. Total phenolic content showed that there is a significant correlation with TEACDPPH (r = 0.7974, P <= 0.001) and TEAC(ABTS) values (r = 0.4860, P <= 0.05).