不同杀青方式对富硒抹茶品质的影响

杀青是抹茶加工过程中的重要步骤。采用蒸青和炒青两种方式进行杀青,结合感官评定、理化成分、色泽、香气指纹和滋味等分析,探究不同杀青方式对富硒抹茶品质的影响。结果:蒸青富硒抹茶的水浸出物、茶多酚以及Se、K、Mg、P等矿质元素均明显高于炒青富硒抹茶,而炒青富硒抹茶的游离氨基酸、咖啡碱、可溶性蛋白等营养成分含量略高于蒸青富硒抹茶;色泽评价表明蒸青富硒抹茶比炒青富硒抹茶色泽更绿黄;香气特征指纹主成分分析和判别函数分析能很好区分两种杀青富硒抹茶;电子鼻结果表明:蒸青富硒抹茶可能含一定量的硫化物成分;电子舌能有效区分不同杀青抹茶的品质特性。感官评定表明,蒸青富硒抹茶得分显著(p=0.001)高于炒青富硒抹茶。因此,不同杀青处理的富硒抹茶在理化成分含量、色泽、香气及滋味特征等方面均有所差异;采用蒸青杀青所制抹茶具有较好的感官品质特征,能够更好地固定富硒抹茶的硒元素、茶多酚、总糖等主要营养物质和香气物质,可以作为提高富硒抹茶品质的加工措施。 

Effect of different fixing methods on the quality of selenium-enriched matcha

Fixation is an important step in the process of tea processing. This research discussed effects of two fixation methods(Steaming and stir fixation) for selenium-enriched Matcha through sensory evaluation,chemical composition,color,aroma and taste of the fingerprint. The results showed that the content of Steaming fixation for selenium-enriched Matcha such as water extract,tea polyphenol,Se,K,Mg,P and other mineral elements were significantly higher than that of Stir fixation. While nutrient composition content of Stir fixation,including amino acid,caffeine contents,soluble protein,was slightly higher than that of Steaming fixation;Steaming fixation of color evaluation showed that it be more chartreuse. Analysis of aroma characteristic fingerprint of principal component analysis(PCA) and discriminant function analysis could well distinguish the two fixation methods.Electronic nose results showed that Steaming fixation might be conducive to formation sulfide component.Electronic tongue could be effectively distinguished quality characteristics of different fixation ways. Sensory evaluation showed that the scores of steaming fixation significantly higher( p = 0. 001) than the other one.Therefore,fixation method for selenium-enriched Matcha leaded to different results,such as physical and chemical component content of selenium enriched green tea color,aroma,taste and character. The steaming fixation had good characteristics sensory quality,which could be better fixed selenium,tea polyphenols,total sugar and other major nutrients and aroma,so it could be used as measures of selenium-enriched tea to improve machining quality.