低温液氮粉碎对绿茶粉品质影响

为减少茶叶粉碎过程中热敏性物质损失,提出茶叶低温液氮粉碎的新方法。该论文以绿茶为原料,在粉碎过程中添加液氮,比较常规粉碎与低温液氮粉碎方法处理对绿茶粉品质的影响。结果表明,与常规粉碎法相比,液氮粉碎法的出粉率高,所得的茶粉泡制成的茶汤在色泽、滋味和品质评分上明显占优,其水浸出物中茶多酚、咖啡碱、游离氨基酸、可溶性蛋白、可溶性糖等功效成分的质量分数分别高出25.12%、10.12%、9.50%、6.75%、12.63%、9.05%;2种茶粉的香气成分组成基本相同,但液氮粉碎法所得茶的茶粉中法呢烯、橙花叔醇、1H-吲哚、己酸-3-己烯酯、五甲基庚烷、苦杏仁苷、3-甲基丁酸2-甲基丙酯质量分数分别高出10.88%、13.70%、14.06%、5.61%、2.08%、24.39%、5.68%。表明液氮粉碎能较好的保留茶粉的品质,为液氮粉碎在绿茶加工中的应用提供参考。

Effects of low temperature liquid nitrogen on quality of green tea grinding

In order to reduce the loss of thermal sensitive materials,a new method to grind green tea with low temperature liquid nitrogen was studied.Liquid nitrogen was added in the pulverizing green tea which as the research object in this study.The qualities of green tea pulverized by the liquid nitrogen pulverizing and conventional crushing method were compared.The results showed that,compared with the traditional crushing,the rate of powder pulverized with liquid nitrogen was higher and the qualities of color,taste and sense of the tea were higher.The hydrosoluble materials including the tea polyphenol,caffeine,the free amino acids,soluble protein,soluble sugar contents were respectively improved by 25.12%、10.12%、9.50%、6.75%、12.63%、9.05% after liquid nitrogen pulverizing.GC-MS analysis showed that the most aroma compositions of tea powder processed by the two kinds of crashing method were almost the same,but the contents of farnesene,nerolidol,1H-indole、hexanoicacid-3-hexene ester,2,2,4,4,6-Pentamethyl heptanes,amygdalin and 3-methyl butyric acid/2-methyl propyl ester were higher by 10.88%、13.70%、14.06%、5.61%、2.08%、24.39%、5.68% respectively for the liquid nitrogen pulverizing.This study results indicate that grinding with liquid nitrogen can maintain good quality of tea,and can provide a reference for green tea processing with liquid nitrogen pulverizing.