Effects of Different Fixation Methods on the Quality of Polygonatum cyrtonema Tender Bud Tea

With Polygonatum cyrtonema tender buds as subjects, Polygonatum cyrtonema tender bud tea was prepared using the technology for processing flat green tea after fixation by microwave, pan frying and steaming, respectively. The effects of different fixation methods on the quality of Polygonatum cyrtonema tender bud tea was then explored through physicochemical composition, color and gloss of tea broth, volatile aroma component analysis and organoleptic evaluation. The results showed that the Polygonatum cyrtonema tender bud tea prepared by microwave fixation not only presented good organoleptic properties, but also had the highest contents of water extract, soluble sugar, tea polyphenols and total flavonoids, 48.04%, 14.49%, 1.32% and 1.66%, respectively. A total of 84 volatile olfactory compounds were detected in Polygonatum cyrtonema tender bud tea prepared by the three different fixation methods, mainly consisting of aldehydes (12 types), ketones (11 types), olefins (10 types), alcohols (8 types) and esters (8 types). There were 10, 12 and 7 key aroma components in Polygonatum cyrtonema tender bud tea with microwave, pan frying and steaming fixation, respectively. Among them, ethyl butyrate was a unique key aroma component to microwave fixation, while heptanal, pentanal, hexanal and 1-pentanol were the key aroma components unique to pan frying fixation. Overall, there are differences in the quality of Polygonatum cyrtonema tender bud tea prepared by different fixation methods, among which microwave fixation is more suitable for the preparation of Polygonatum cyrtonema tender bud tea.