DMDC发酵前处理对荔枝酒发酵特性的影响

Effect of Pre-Fermentation Treatment with Dimethyl Dicarbonate on the Fermentation Characteristics of Litchi Wine

摘要:

本文以发酵荔枝酒为研究对象，比较了二甲基二碳酸盐（DMDC）、亚硫酸盐以及巴氏杀菌发酵前处理对荔枝汁中微生物菌群、荔枝酒主发酵6 d期间可滴定酸、乙醇、高级醇、色泽、多酚以及主发酵结束后各挥发性风味物质的影响。结果表明：与对照组相比，添加DMDC和亚硫酸盐以及巴氏杀菌处理均能很好的抑制荔枝汁中天然污染菌的生长，减缓荔枝果酒pH的下降和可滴定酸的升高，提高荔枝发酵酒的乙醇得率。其中，DMDC对荔枝汁中酵母菌、乳酸菌和霉菌的杀菌能力显著强于亚硫酸盐(p<0.05)。添加亚硫酸盐的实验组多酚保留率显著高于其它三个发酵前处理组(p<0.05)，△E*变化最小，能起到明显护色效果；巴氏杀菌使得荔枝酒典型风味成分损失较大。综合而言，DMDC是可以代替或部分代替亚硫酸盐和巴氏杀菌在荔枝酒中推广应用。

Abstract:

This study examined the effects of pre-fermentation treatment with dimethyl dicarbonate (DMDC), sulfite, and pasteurization on litchi juice microflora; color; and titratable acid, alcohol, fusel oil, and polyphenol contents in litchi wine during 6 days of primary fermentation and on volatile components in litchi wine at the end of the primary fermentation. DMDC, sulfite, or pasteurization pretreatment effectively inhibited the growth of naturally occurring bacteria, slowed the decline in pH, increased the content of titratable acids, and improved the yield of alcohol compared with control treatment. DMDC pretreatment inhibited the growth of yeast, lactobacilli, and molds in litchi juice compared with sulfite pretreatment (p < 0.05). Sulfite pretreatment significantly increased polyphenol retention rate, induced minimal change in △E*, and exerted an apparent color-protective effect compared with the other three pretreatments (p < 0.05). In contrast, pasteurization pretreatment resulted in the loss of a unique flavor ingredient in litchi wine. Thus, these results indicated that DMDC could completely or partially replace sulfite or pasteurization pretreatment in the production of litchi wine.