Abstract

Biorefinery of onion vinegar (OV) is attractive as a method for producing functional foods from onions or onion by-products. In this study, a two-stage fermentation of OV using Saccharomyces cerevisiae ATCC9763 and Acetobacter pasteurianus CICC20001 was carried out at 28 °C, the titratable acidity reached 4.01%, and the Y_A/E was 69.64% at 72 h. Based on this, semi-continuous fermentation was performed, proceeded to charge-discharge consisting of three cycles, and the yield, productivity, and specific production rate were 76.71%, 17.73 g/(L·d), and 20.51 h⁻¹, respectively, which was higher than fed-batch fermentation. The in vivo antioxidant experiments showed that OV significantly increased GSH-Px, SOD, and CAT enzyme activities of Caenorhabditis elegans at 271.57, 129.26, and 314.68%, respectively. Nutritional analysis revealed that the total flavonoids and polyphenols were 3.01 mg/mL and 976.76 µg/mL, respectively. It was also shown that the acetic acid to total organic acid (A/T) ratio of OV was 79.02%, and the total free amino acid content was 262.30 mg/100 mL, 1.78–7.44 times higher than other fruit vinegar. The OV prepared in this study showed higher quality than the commercial vinegar.

摘要

洋葱醋 (OV) 的生物精炼作为一种从洋葱或洋葱副产品中生产功能性食品的方法很有吸引力。本研究采用酿酒酵母ATCC9763 和巴氏醋杆菌CICC20001 在 28 °C 下对 OV 进行两步发酵，可滴定酸度达到 4.01%，72 h 的Y _A/E为 69.64%。在此基础上进行半连续发酵，进行三循环充放电，得率、产率和产率分别为76.71%、17.73 g/(L·d)、20.51 h ^-1，分别高于补料分批发酵。在体内抗氧化实验表明，OV 显着增加了秀丽隐杆线虫的 GSH-Px、SOD 和 CAT 酶活性，分别为 271.57、129.26 和 314.68%。营养分析显示，总黄酮和多酚含量分别为 3.01 mg/mL 和 976.76 µg/mL。还显示OV的乙酸与总有机酸(A/T)比为79.02%，总游离氨基酸含量为262.30 mg/100 mL，是其他果醋的1.78-7.44倍。本研究中制备的 OV 显示出比商业醋更高的质量。