添加不同微生物数控发酵对普洱熟茶风味物质的影响

Effects of numerical controlled fermentation with different microorganisms on the flavor compounds of Pu-erh ripe tea

目的研究数控发酵中微生物对普洱熟茶风味物质的影响。方法以云南大叶晒青毛茶为原料,采用固态混合菌接种微小根毛霉、烟曲霉、米曲霉、溜曲霉、总状毛霉、泡盛曲霉、异常毕赤酵母、黑曲霉、热带假丝酵母等不同微生物,追踪检测发酵过程理化指标动态变化;气相色谱-质谱法分析香气物质。通过其发酵过程中的理化指标变化、感官审评结果及发酵成品香气物质对比,分析接菌数控发酵对普洱熟茶风味物质的影响。结果在发酵过程中,各实验组之间理化成分存在差异性(P<0.05),总体大框发酵效果好于小框发酵;茶叶中香气成分接菌发酵后烷烃、杂氧化合物、酚类及其衍生物、含氮化合物、酸类化合物等化合物的相对含量呈增长趋势,酮类、醇类化合物减少,其余物质变化趋势不大,波动略小。结论添加不同微生物数控发酵能够有效缩短发酵时长,减少杂菌污染,提升普洱熟茶品质。

Objective To study the effects of microorganisms on the flavor compounds of Pu-erh ripe tea in computer numerical control fermentation.Methods Using gradeⅢsun-baked tea as raw material,different microorganisms such as Trichoderma reesei,Aspergillus fumigatus,Aspergillus oryzae,Trichoderma reesei,Aspergillus fermentum,Pseudomonas abnormalis,Aspergillus niger and Pseudomonas tropicalis were inoculated with solid-state monocultures and mixed bacteria,and the dynamic changes of physicochemical indexes during fermentation were tracked and detected;aroma compounds were analyzed by gas chromatography-mass spectrometry.Through the change of physical and chemical indexes,the sensory review results and the comparison of aroma compounds in the fermentation of finished products,the influences of computer numerical control fermentation on the flavor compounds of Pu'er ripe tea were analyzed.Results In the process of fermentation,there were differences in physical and chemical components among the experimental groups(P0.05),and the overall effect of large-frame fermentation was better than that of small-frame fermentation.After inoculation and fermentation,the relative content of aroma components in tea,such as alkanes,heterooxides,phenols and their derivatives,nitrogen-containing compounds,acids and other compounds,showed an increasing trend,while ketones and alcohols decreased,while the other compounds showed little change trend and slight fluctuation.Conclusion The addition of different microbial computer numerical control fermentation can effectively shorten the fermentation time,reduce the contamination of miscellaneous bacteria and improve the quality of Pu-erh ripe tea.