engleski

PHENOLIC COMPOSITION AND ANTIOXIDANT ACTIVITY OF cv. Malvasia istriana MUST AND WINE

The aim of the present work was to study the phenolic composition of must and wine produced from cv. Malvasia istriana grafted onto Kober 5BB rootstock, harvested in different stages of maturity (early, intermediate and late stages). The phenolic composition of must and wine has been determined by the high performance liquid chromatography (HPLC) with photodiode array detection. In all samples determined total phenol content and antioxidant activity. For a more reliable assessment, antioxidant activity had been measured with two different methods: 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging method and β -carotene bleaching (BCB) method. The results showed that in comparison to the must samples, in wine samples higher content of vanillic, caffeic, p-coumaric and ferulic acids was observed. Unlike these results, the content of gallic acid, protocatechuic acid, (+)-catechin and (-)-epicatechin and (-)-epicatechin gallate in wine was decreased. During the maturity of grapes the content of phenolic compounds was constantly decreasing and was found to be the highest in the early stage of harvest.

antioxidant activity; BCB; DPPH. cv. Malvasia istriana; polyphenols

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