Preparation process optimization and volatile components analysis of Osmanthus fragrans Qingzhuan tea

The Osmanthus fragrans Qingzhuan tea was prepared by fermentation with Qingzhuan loose tea and O. fragrans as main raw materials. Using sensory score as evaluation index, the preparation process conditions were optimized by single factor and orthogonal tests, and the sensory quality and physicochemical indexes of O. fragrans Qingzhuan tea were analyzed, and the volatile flavor components were analyzed by solid phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS). The results showed that the optimum preparation conditions were as follows: O. fragrans addition 7%, fermentation temperature 35 ℃ and time 24 h. Under these optimal conditions, the sensory score of O. fragrans Qingzhuan tea was 91.20, the contents of water extract, tea polyphenols, total free amino acids, and caffeine were 27.35%, 11.48%, 1.13%, and 4.05%, respectively. A total of 64 volatile flavor components were detected. O. fragrans Qingzhuan tea had moderate tightness, smooth surface, red and bright color, pure aroma, osmanthus fragrance and coordination, and mellow taste.