Quality Characteristics and Antioxidant Activity of Vinegar by the Addition of Aronia Juice (Aronia melanocarpa)

摘要

This study investigated the physicochemical properties, antioxidant content, and antioxidant activity of vinegar prepared by mixing aronia juice with distilled water in the ratios 10, 25, and 50% (w/w). A steady increase of alcohol content was observed during the fermentation period, increasing from 8.8 to 9.9%, on the 7th day of alcohol fermentation. pH levels significantly decreased compared to the initial stage of fermentation, and were determined to be 3.72 to 4.03 at the end of alcohol fermentation. After acetic acid fermentation, vinegar supplemented with 10% aronia juice had the minimum pH (2.35), whereas supplementation with 50% aronia juice imparted pH 4.36. On completion of the 21st day of acetic acid fermentation, the acidity of vinegar increased to 4.94, 4.12, and 2.31 with 10, 25, and 50% aronia juice, respectively. The rate of acidity increase was faster in vinegar with 10% aronia juice. The major free sugar of aronia vinegar was sorbitol, the main organic acid was acetic acid, and the major amino acids were alanine, valine, phenylalanine, arginine, and tyrosine. Chromaticity evaluation revealed decreasing L and b values and increasing a value, with increasing levels of aronia juice. Total polyphenols, flavonoids and total anthocya-nin contents were higher with increasing ratio of aronia juice. In addition, antioxidant activity assessed by 1,1-di-phenyl-2-picrylhydrazyl and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt assays revealed higher radical scavenging activity with increasing aronia juice content. In conclusion, we propose the possibility of commercialization of vinegar prepared by adding aronia juice would be lucrative.