Changes in the Phytochemical and Bioactive Compounds and the Antioxidant Properties of Wolfberry during Vinegar Fermentation Processes.

Wolfberry (Lycium barbarum L.), as a kind of functional fruit, has various nutritional and bioactive components, which exhibit healthy benefits. However, wolfberry is not easy to preserve, and the intensive processing of wolfberry needs to be developed. In the present study, the changes in the phytochemical and bioactive compounds, as well as the antioxidant properties of wolfberry, were evaluated in the brewed processes. We found that the sugar contents were significantly decreased, and the total acids values were significantly increased during the fermentation processes. The sugar and fat contents were low in the wolfberry fruit vinegar after fermentation, which is of benefit to human health. In addition, amino acids were examined during the fermentation processes, and histidine, proline, and alanine were found to be the main amino acids in vinegar. The total phenolics and flavonoids contents were significantly increased by 29.4% and 65.7% after fermentation. 4-Hydroxy benzoic acid, 3-hydroxy cinnamic acid, and chlorogenic acid were the primary polyphenols in the wolfberry fruit vinegar. Moreover, the antioxidant activity of wolfberry fruit vinegar was significantly increased compared with that of wolfberry fruit after the fermentation processes. Polysaccharides and polyphenolics were strongly correlated with the antioxidant activity during the fermentation processes. The findings suggest that wolfberry fruit vinegar has a high antioxidant capability, and could be a beneficial food in the human diet.