Flavor of the brewed white tea in relation to its constituents of free amino acids (FAA) was studied .The descriptive statistics , ANOVA , principal component analysis (PCA ) , and linear category identification were applied for the analysis .The FAA contents on 46 samples collected from 3 white tea‐producing areas in the province were determined by using an automated analyzer .The results showed that (1) the total FAA in the tea ranged from 16.19 mg?g -1 to 51.00 mg?g -1 ,with an average of 39.36 mg?g -1 ;(2) the highest FAA content of (45.78 ± 8.39) mg?g -1 was found in Kung Mee tea ,followed by that of Silver Needle Pekoe tea at (38.15 ± 6.12) mg?g -1 ,while the lowest was White Peony tea at (34.01 ± 9.16) mg ? g -1 ;(3) theanine in the tea accounted for 52.90% of the total FAA contributing to the cool and delightful taste of the tea ;(4) proline ,glycine ,aspartic ,and threonine were the main source of the sweetness of Silver Needle Pekoe tea ;(5) leucine ,histidine ,and methionine brought about the hint of bitterness in Silver Needle Pekoe tea ;(6) proline ,valine ,aspartic ,and alanine gave the sweet note in Kung Mee tea ;(7) phenylalanine ,isoleucine ,leucine ,and valine tended to be slightly bitter on the taste;and ,(8) glutamic acid might render the umami and sour tastes in Silver Needle Pekoe and Kung Mee teas ;(9) the correct rate in classifying the white teas based on FAA constituents was found to be 100% .Subsequently , using the same model ,27 commercial samples of Kung Mee ,Silver Needle Pekoe ,and White Peony teas were evaluated to show the rates of correct identification to be 100% ,88.89% ,and 88.89% ,respectively .It was ,thus , concluded that FAA composition of the 4 categories of amino acids in tea ,combined with PCA and LDA analytical methods ,could be used to accurately distinguish the white teas .
white teaflavorfree amino aciddiscriminant analysis
国家科技期刊平台
NSTL
万方数据
维普
