Analysis of the process and quality characteristics of green tea and black tea from Babu Ziya

【Objective】 This study aimed to investigate processing parameters and quality characteristics of green tea and black tea from Babu Ziya，and screen the suitable processing techniques for these tea products，which provided a theoretical basis for the development and utilization of Babu Ziya as well as production of distinctive tea products.【Method】 Using the fresh tea leaves （one bud and two leaves） from the ZY-1 lines selected from the Babu Ziya resources as test materials，microwave fixation and drying temperature tests for green tea （microwave power set at 1050， 800，and 600 W，and microwave duration set at 1.0，1.5，2.0，and 2.5 min） were performed； fermentation time and final drying temperature tests for black tea （fermentation time set at 2.0，2.5，3.0，and 3.5 h，and drying temperature set at 65，75，85，and 95 ℃） were conducted. The optimal processing techniques and quality characteristics of green tea and black tea from Babu Ziya were comprehensively analyzed from both quality components and sensory evaluation.【Result】 In the processing of green tea from Babu Ziya， the comprehensive scores of sensory quality of green tea obtained by microwave fixation at 800 W for 2.0 min and drying at 85 ℃ were relatively high，reaching 95.30 and 92.70 respectively，which were significantly higher than those in other treatments（P<0.05，the same below）. The green tea treated with microwave fixation at 800 W for 2.0 min had the highest anthocyanidin content at 7.40 mg/g； the green tea dried at 85 ℃ exhibited the highest contents of free amino acids， tea polyphenols，and anthocyanidin，at 4.68%，31.19%，and 8.69 mg/g， respectively. The black tea showed higher comprehensive sensory quality scores when fermented for 3.0 h and dried at 75 ℃ and 85 ℃， reaching 94.90， 93.70， and 93.95， respectively，which were significantly higher than those in other treatments. The theaflavin and thearubigin contents of black tea processed with a fermentation time of 3.0 h were highest at 0.85% and 6.60%， respectively， significantly higher than those of other treatments. Black tea processed at a drying temperature of 75 ℃ exhibited higher levels of tea polyphenol，total flavonoids，theaflavins，and thearubigins，at 25.64%，3.41%，0.82%，and 6.93%，respectively. Principal component analysis，orthogonal partial least squares-discriminant analysis，and cluster analysis results indicated that theaflavins，thearubigins，soluble sugars，and water extracts were the key components responsible for quality differences in black tea due to fermentation time，whereas tea polyphenols，theaflavins，thearubigins，and theabrownins were the critical components contributing to quality variations caused by the drying temperature.【Conclusion】 The key processing parameters and quality characteristics for producing green tea and black tea from high-anthocyanin ZY-1 purple bud tea are clarified， and both the green tea and black tea exhibit unique characteristics.