铁观音中降解β-胡萝卜素菌株的筛选及其陈香提升应用

Screening ofβ-carotene-degrading strains in Tieguanyin and its application in aged aroma enhancement

陈香型铁观音具有独特陈香风味,但其自然陈化周期漫长,提高铁观音的陈香品质并缩短陈化周期具有重要的经济和文化价值。从铁观音中筛选获得3株具有β-胡萝卜素降解能力的菌株并鉴定为Aspergillus niger(HA)、Bacillus velezensis(Hb)、Saccharopolyspora gregorii(Hc),它们的降解率分别为94.54%、72.97%、61.26%。将菌株投入茶叶进行强化发酵,并测定发酵结束后茶叶的挥发性物质含量和感官品评得分。结果表明,HA和Hb发酵茶样含量提升幅度最大的是酮类化合物,分别提升了128.12%和109.38%;Hc发酵茶样醛类化合物提升幅度最大为61.11%,发酵茶样中的类胡萝卜素降解产物总量也分别提升了1.6、1.4、1.3倍。发酵茶样总体评价均高于对照,同时HA发酵茶样的甜香得分提高,Hb发酵茶样的果香得分提高,Hc发酵茶样的甜香和陈香得分提高。该研究筛选出一株降解β-胡萝卜素的Saccharopolyspora gregorii,成功在短期内实现了铁观音陈香品质的提升。

Aged Tieguanyin has a unique aged aroma,but its natural aging period is long.It is of great economic and cultural value to improve the aged aroma quality and shorten the aging period of Tieguanyin.Three strains withβ-carotene-degrading ability were selected from Tieguanyin and identified as Aspergillus niger(HA),Bacillus velezensis(Hb),and Saccharopolyspora gregorii(Hc),and their degradation rates were 94.54%,72.97%and 61.26%respectively.The strains were put into tea for enhanced fermentation,and the volatile compounds content and sensory evaluation scores were determined after fermentation.Results showed that the content of ketones in HA and Hb fermented tea samples increased the most,by 128.12%and 109.38%,respectively,and the content of aldehydes in Hc fermented tea sample increased the most by 61.11%.The total content of carotenoid degradation products in HA,Hb,and Hc fermented tea samples also increased by 1.6,1.4,and 1.3 times respectively.The overall evaluation scores of fermented tea samples were higher than that of the control.Meanwhile,the score of sweetness aroma of HA fermented tea sample,fruit aroma of Hb fermented tea sample,and sweetness and aged aroma of Hc fermented tea sample increased.This study screened out a strain of Saccharopolyspora gregorii,which degradedβ-carotene,and successfully improved the aged aroma quality of Tieguanyin in a short time.