Abstract:

Zuoqing is a critical step in the process of making oolong tea, which is significantly impacted by various factors,
including sunshine withering, tossing number and tossing time. In this work we studied the impact of the Zuoqing parameters
on the sensory quality of summer oolong tea. These parameters were optimized through L9 (33) orthogonal experiments. The
best Zuoqing results, providing a sensory score of 90.150, a tea polyphenol content of 19.907%, a free amino acid content
of 2.095% and a Green value of 0.260 were achieved when the weight reduction resulting from sunshine withering was 15%
and tossing was performed three times for 14 min each time. The sensory quality of oolong tea was affected in decreasing
order of importance by the weight reduction resulting from sunshine withering, tossing time and tossing number. These
findings in this study may provide references for studying the Zuoqing process of summer oolong tea.

Key words: summer oolong tea, sunshine withering, tossing, quality