Abstract
In this study, we aimed to develop functional vinegar with different levels of black garlic through two stages of fermentation. Black garlic vinegars were prepared from black garlic and water (w/w) mixed with 1:2 (BG3), 1:5 (BG6), 1:9 (BG9) and 1:11 (BG12), and adding the sugar by adjusting the soluble solids content to 14 °Brix. The alcohol content of black garlic vinegar was 5.2-5.5% after 7 days of alcohol fermentation at 25°C. Acetic acid fermented was at 30°C for 25 days and samples were taken at 3, 6, 9, 12, 15, 20 and 25 days. The pH of black garlic vinegar was not significantly different among the samples, but acidity was increased during fermentation. Total polyphenol contents showed irregular changes with the fermentation periods and were higher by black garlic content. At 25 days fermentation, total polyphenol contents were 18.96-56.56 mg/100 mL. Acetic acid content of black garlic vinegars was higher than other organic acids. S-allyl cysteine (SAC) contents of BG3 and BG6 were 13.03-14.54 and 1.69-2.20 mg/L, respectively. However SAC was not detected in BG9 and BG12. In 25 days fermented black garlic vinegar, the major mineral was K with a content ratio of 61-68% of total minerals. The DPPH and ABTS radical scavenging activity of 25 days fermented black garlic vinegar were stronger at higher black garlic content.

Key words: vinegar, black garlic, fermentation, acetobacter, S-allyl cysteine