Total Phenolic and Flavonoid Contents, Phenolic Compositions and Color Properties of Fresh Grape Leaves

Abstract

Grape leaves have been consumed as fresh and canned for years. Stuffed grape leaves (dolma) is a traditional delicacy for Turkish, Balkan and Middle East nations. In this study; grape leaves from Sultani Çekirdeksiz (SÇ), Sultan1 (S1), Sultan7 (S7) Saruhanbey (SB) and Narince (N) grape cultivars were assayed for their total phenolics, total flavonoids, some phenolic compounds and color properties. Total phenolic and total flavonoid contents of the samples were determined by Folin Ciocalteu and colorimetric aluminum chloride methods respectively. Results were expressed as Gallic acid and (+)-catechin equivalent mgg-1. The phenolic compositions of the samples were separated by HPLC. L*, a*, b* values of the samples were measured by Minolta Colorimeter and a/b values were calculated. Total phenolic contents varied from 9.72 to 14.22 mg g-1 fresh leaves and total flavonoid contents from 5.08 to 7.22 mg g-1 fresh leaves. L* values of samples were measured between 37.9─45.0 and a* values -8.3─ -3.9 and b* values 8.6 ─ 15.0. a/b values were calculated between -0.57─ -0.45. (+)-catechin. (-) epicatechin, gallic acid, caffeic acid and vanillic acid were detected in all grape leaf samples