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.