摘要
为明确红茶汁液态发酵过程中生成的泡沫组成,对通气发酵过程的泡沫进行分离,采用分光光度计和高效液相色谱仪分析茶多酚、氨基酸和茶皂素、儿茶素、茶黄素等非挥发性化合物,并采用顶空固相微萃取结合气相色谱-质谱联用技术分析挥发性化合物的含量分布。结果表明:红茶汁匀浆和通气过程产生的泡沫中茶皂素、茶多酚、咖啡碱、部分儿茶素和茶黄素的质量浓度较隔离泡沫的茶汁中高,挥发物总量和癸醛、柠檬醛、芳樟醇、香叶醇和β-紫罗兰酮5种呈甜花香化合物,己醛、1-辛烯-3-醇、苯乙醛、水杨酸甲酯和(E)-2-己烯醛5种呈青气化合物也有提高,这表明产生的泡沫会带走较多的品质成分。为保留品质成分,向红茶汁发酵液中添加消泡剂防止泡沫形成,发现体积分数0.2%的消泡剂可有效控制泡沫形成,对茶多酚、氨基酸的质量浓度无显著影响,对发酵进程无不利影响,而且可促进茶汁中挥发物的释放。
In order to clarify the biochemical and volatile constituents of foam formed during the aerobic fermentation of black tea juice,foam was collected at different stages of aeration and analyzed for non-volatile compounds such as tea polyphenols,amino acids,tea saponins,catchins and theaflavins by spectrophotometry and high performance liquid chromatography(HPLC),and for volatile compounds by head space solid-phase microextraction(HS-SPME)combined with gas chromatography-mass spectrometry(GC-MS).The results showed that the concentrations of tea saponins,tea polyphenols,caffeine,catechins and theaflavins in the foam formed during tea leaf homogenization and aeration were higher than those in the residual tea juice.The total amount of volatile compounds;the contents of decanoic aldehyde,citral,linalool,geraniol andβ-ionone,responsible for the sweet and flowery aroma;and the contents of hexanolaldehyde,1-octyl-3-alcohol,phenylacetaldehyde,methy salicylate and(E)-2-hexenal,responsible for the green aroma,were also higher than those in the residual tea juice,indicating that the foam took away many quality components.In order to retain the quality components,an antifoaming agent was added in black tea juice to prevent foam formation.It was found that 0.2%of the defoamer effectively controlled foam formation while having no significant effect on tea polyphenols or amino acids,and no adverse effect on the fermentation process,and promoted the release of volatile compounds in black tea juice.
作者
梁爽
傅燕青
尹军峰
许勇泉
LIANG Shuang;FU Yanqing;YIN Junfeng;XU Yongquan(Tea Research Institute,Chinese Academy of Agricultural Sciences,Hangzhou 310008,China;Graduate School of Chinese Academy of Agricultural Sciences,Beijing 100081,China)
出处
《食品科学》
EI
CAS
CSCD
北大核心
2022年第8期238-246,共9页
Food Science
基金
浙江省重点研发计划项目(2019C02072)。
关键词
茶
鲜叶
液态发酵
泡沫
茶皂素
红茶汁
tea
fresh tea leaves
liquid-state fermentation
foam
tea saponins
black tea juice
