Abstract:In order to improve the Yihong black tea quality in summer, different polyphenol oxidases from Jinshui NO1, Fengshui, Huanghua and E,li NO2 Pyrus pyrifolia Nakai were utilized to ameliorate the fermentation, and the sensory quality, chemical components and aroma of Yihong black tea in summer were compared in present paper. Results indicated the notable differences in oxidation kinetics curves of polyphenol oxidase from different Pyrus pyrifolia Nakai. The Jinshui NO1 and Fengshui had high enzyme activities, the maximum reaction rate achieved the highest at 3 minutes and 5 minutes respectively, it could complement the low enzyme activities of tea at the initial stage of fermentation and promote the Yihong black tea permention in summer. Meanwhile, the PPO in Jinshui NO1 could obviously improve the sensory quality(84.05), compared with the control, the brightness of tea increased significantly (p<0.01), the tea brew hue also increased by 12.00% (p<0.01), the contents of theaflavins, the thearubigins and soluble sugar in black tea increased significantly (p<0.01), and the contents of aroma components also increased, such as phenylacetaldehyde, (E,E)-2,4-heptadienal, safranal, nerol, cis-linalool oxide, β-Ionone, trans-geranylacetone, α-Copaene etc. All the results indicated that the application of polyphenol oxidase in Jinshui NO1 provided a useful way on quality improvement of Yihon black tea in summer.
