强化发酵藏茶的工艺优化及品质评价

Process Optimization and Quality Evaluation of Enhanced Fermented Tibetan Tea

本研究旨在优化地衣芽孢杆菌强化发酵藏茶的工艺参数,并探究其体外抗氧化活性及香气成分特性。在单因素试验基础上,以发酵温度、发酵时间、接种量为影响因素,总抗氧化值为评价指标,采用正交试验优化发酵工艺,并对比强化发酵藏茶与自然发酵藏茶的总抗氧化能力、ABTS自由基的清除能力、总酚含量、类黄酮含量及香气成分差异。结果表明,藏茶强化发酵温度为37℃、发酵时间为3d、接种量为1.0%时,强化发酵藏茶的总抗氧化能力、ABTS自由基清除能力分别为自然发酵藏茶的8.09、2.48倍;同时强化发酵藏茶多酚含量提升,为自然发酵藏茶的1.35倍;而强化发酵藏茶类黄酮含量下降,为自然发酵藏茶的54%;固相微萃取技术和气相色谱质谱(GC-MS)联用技术检测到强化发酵藏茶的香味物质种数高于自然发酵,香气物质增加了15种,且酮、醇、醛、酸含量均高于自然发酵藏茶。这表明地衣芽孢杆菌强化发酵对藏茶的抗氧化能力及香气成分均有提升作用,能有效提升藏茶品质。

The objective of this study is to optimize the technological parameters of Bacillus licheniformis enhanced fermentation of Tibetan tea,and to investigate its antioxidant activity in vitro and aroma components.On the basis of single factor experiment,with fermentation temperature,fermentation time and inoculation amount as the influencing factors and total antioxidant value as the evaluation index,orthogonal experiment has been used to optimize the fermentation process,and the differences of total antioxidant capacity,ABTS free radical scavenging ability,total phenolic content,flavonoids content and aroma composition between intensive fermented Tibetan tea and natural fermented Tibetan tea are compared.The results show that the total antioxidant capacity and ABTS free radical scavenging capacity of enhanced fermented Tibetan tea are 8.09 and 2.48 times as much as those of natural fermented Tibetan tea,respectively,when the fermentation temperature is 37℃,fermentation time is 3 d and inoculation amount is 1.0%.Meanwhile,the polyphenol content of intensive fermented Tibetan tea is increased,which is 1.35 times as much as that of natural fermented Tibetan tea,while the flavonoid content of intensive fermented Tibetan tea is decreased,which is only 54%of that of natural fermented Tibetan tea.Solid phase microextraction technology and gas chromatography-mass spectrometry(GC-MS)hyphenated technology detect that the number of aroma substances in enhanced fermentation Tibetan tea is more than that in natural fermentation,and the aroma substances increase by 15 kinds,and the contents of ketone,alcohol,aldehyde and acid are higher than those in natural fermentation Tibetan tea.The results show that the enhanced fermentation of bacillus licheniformis could improve the antioxidant capacity and aroma components of Tibetan tea,even effectively improve the quality of Tibetan tea.