Abstract:

The paper aimed to explore the effect of dimethyl dicarbonate (DMDC) pretreatment as a non-thermal sterilization
technology on the fermentation characteristics and quality of Citrus reticulata cv. Chachiensis fruit wine. The effects of
DMDC sterilization and pasteurization on the changes in quality indicators such as total soluble solid, ethanol, higher
alcohol, total acid, organic acid and ascorbic acid contents, sugar composition, pH and antioxidant activity during the
fermentation process and the differences in the microbial community before and after fermentation were compared with
those of the non-sterilized control. Results showed that both DMDC addition and pasteurization could improve the effective
utilization of sugar and the yield of ethanol and restrain the synthesis of fusel by killing unwanted bacteria when compared
with the control. The ethanol contents of the control, DMDC treatment, and pasteurization treatment were 13.10%, 13.30%,
and 13.73%, respectively. Importantly, when compared with pasteurization, DMDC treatment gave higher ascorbic acid
concentration (211.40–221.70 mg/L) and antioxidant activity (20.83–23.26 μmol TE/mL) in fermented Citrus reticulata cv.
Chachiensis fruit juice. However, DMDC treatment showed higher residues of resistant bacteria such as Lactobacillus and an
increment of lactic acid. To sum up, DMDC sterilization is worthy of further investigation for application as a non-thermal
sterilization technology in sample pretreatment for the fermentation of Citrus reticulata cv. Chachiensis fruit wine.

Key words: dimethyl dicarbonate, pasteurization, Citrus reticulata cv. Chachiensis fruit wine, fermentation characteristics;non-thermal sterilization