Abstract:

Xuefeng sweet oranges and Se-rich rice bran were used as the raw materials to develop an orange-flavored vinegar by liquid-sate fermentation. Orthogonal array design was employed to obtain optimal alcohol and acetic acid fermentations. Additionally, fermented vinegar product was evaluated for sensory quality and physicochemical hygiene indicators. Results showed that the optimal alcohol fermentation parameters were determined as follows: ratio of rice bran hydrolysate to orange juice 7:3, yeast inoculation amount 8%, and temperature 30 ℃ for a fermentation period of 96 h, and the optimal acetic acid fermentation was achieved by fermentation at 35 ℃ for 84 h with an acetic acid bacteria inoculation amount of 5%. Vinegar obtained under the optimized conditions contained contents of acetic acid Se of 4.98 g/100 mL and more than 12 μg/100 mL, respectively.

Key words: selenium-rice rice bran, Xuefeng sweet orange, alcohol fermentation, acetic acid fermentation, processing parameter, fruit vinegar