Physicochemical properties and antioxidant activities of vinegar using black raspberry pomace

In this study, vinegar was prepared using black raspberry pomace to increase its utilization capacity. As a result of alcohol fermentation, the final alcohol content was 8.90% and the sugar content was 7.03oBrix. The total acid content after acetic acid fermentation was 4.44%, which was 0.38% higher than that of the juice. Among the organic acid content, the acetic acid content was higher in the pomace than in the juice. The total polyphenol (51.58 TAE mg/mL), total flavonoid (9.55 RUE mg/mL), and total anthocyanin (6.05 CYE mg/mL) contents of vinegar produced using black raspberry residue were higher than those of the juice. In addition, 2,2'-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical scavenging activity, reducing power, and ferric reducing antioxidant power (FRAP) activity were higher than those of the juice, indicating strong antioxidant properties. Thus, black raspberry pomace has excellent acetic acid fermentation ability and high antioxidant activity, indicating that it can be used as a functional fermented vinegar.