Characteristics of fermented vinegar using mulberry and its antioxidant activity

Abstract

This study was carried out to investigate the physicochemical characteristics and antioxidant properties of mulberry juice (MJ) and mulberry vinegar (MV). MV, with acidity of 6.05% and a pH 3.06, was obtained from MJ after 8 days with alcohol fermentation and 20 days with acetic acid fermentation at 30℃. After fermentation, the major sugars in MV were lactose, glucose, and fructose, showing 1,310.06, 293.20, and 41.25 mg%, respectively. The major organic acids in MV were acetic acid (2,725.59 mg%), citric acid (524.66 mg%), and succinic acid (480.63 mg%). The total free amino acid content of MV, such as lysine, arginine, phenylalanine, and tyrosine, was 34.52 mg%. MJ and MV showed radical scavenging activities with respect to 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl (OH), superoxide anion (O2-), and nitric oxide (NO) radicals in dose-dependent manner, which were closely related to the total polyphenol and flavonoid contents in MJ and MV. In addition, a strong scavenging effect with regards to the OH radical was observed in MJ and MV, an IC50 value of 0.04 μg/mL. In particular, MV showed a higher O2- radical scavenging activity than that of MJ. These results suggest that MV can be used as a functional vinegar with antioxidant activity against free radicals. Copyright ? The Korean Society of Food Preservation.