本文研究了A、B、F三株酿酒酵母在模拟葡萄汁发酵过程中褪黑素及同分异构体产生及变化的规律，并初步探讨了与酵母酒精发酵进程的关系，最后用草莓、蓝莓、桑葚、树莓四种浆果发酵进行了验证。结果发现褪黑素含量在发酵的第1 d达到最大值，A、B、F菌含量分别为0.773、0.647、0.825 ng/mL，随后迅速下降。褪黑素同分异构体含量在发酵的第3 d达到最大值，A、B、F菌含量分别为34.89、19.24、26.79 ng/mL，后期逐渐下降，且同分异构体含量远高于褪黑素(p<0.01)。草莓、蓝莓、桑葚、树莓发酵前后褪黑素含量无显著性差异，同分异构体含量分别达到64.4、7.37、81.9、55.5 ng/mL，均显著高于褪黑素的含量。总之，褪黑素及其同分异构体在酒精发酵初期产生，中后期逐渐下降，推测与酵母发酵初期逆境代谢密切相关。

The variations in melatonin and its isomer content were studied during ethanol fermentation by three different Saccharomyces cerevisiae strains, that is, A, B, and F. Additionally, the relationship between melatonin/melatonin isomer and the fermentation process was preliminarily explored and verified by wine fermentation of four types of berries (strawberry, blueberry, mulberry, and raspberry). The results showed that the melatonin content reached the maximum on day 1 and then decreased rapidly. Maximum values obtained for S. cerevisiae strains A, B, and F were 0.773, 0.647, and 0.825 ng/mL, respectively. The content of melatonin isomer reached the maximum on day 3 and then gradually decreased toward later stages. The maximum values obtained for S. cerevisiae strains A, B, and F were 34.89, 19.24, and 26.79 ng/mL, respectively. Thus, the content of the melatonin isomer was significantly higher than that of melatonin (p < 0.01). However, there were no significant differences in melatonin content before and after wine fermentation of the berries (strawberry, blueberry, mulberry, and raspberry), whereas the melatonin isomer content after fermentation was 64.4, 7.37, 81.9, and 55.5 ng/mL, respectively, which was significantly higher than the melatonin content. In summary, melatonin and its isomer were produced in the early fermentation stage and their individual content gradually decreased during the mid-to-late stage, which was speculated to be closely related to the stress response by S. cerevisiae during early stages of fermentation.

科技部十二五科技支撑计划项目（2012BAD31B07）；农业部公益性行业专项（201303073-2）