Abstract:  In this study, the content of total phenols, the activities of polyphenol oxdise (PPO) and peroxidase (POD) and browning degree of persimmon vinegar during storage were spectrometically assayed. Meanwhile, the effects of selected inhibitors such as NaCl, citric acid and L-ascorbic acid on the browning of persimmon vinegar were also investigated. The results indicated that the browning of persimmon vinegar during storage was enzymatic browning due to the oxidation of total phenols by PPO and POD in the presence of oxygen. Browning inhibitors such as NaCl, citric acid and L-ascorbic acid could maintain the content of total phenols, significantly inhibit the activities of PPO and POD, and delay the browning of persimmon vinegar during storage. In addition, 0.24 g/100 mL NaCl, 1.2 g/100 mL citric acid and 0.48 g/100 mL L-ascorbic acid revealed better inhibitory effect. 

Key words:  persimmon vinegar, browning, browning inhibitors