Abstract: Setting three different withering light intensities, the water content, bulk destiny, flexibility, elasticity, plasticity and color value, the released amount of CO₂ of the withering leaves were evaluated, and the effects of different withering light intensity on physical characteristics of rolled leaves, fermented leaves and fired tea were also analysed. The results showed that with the increasing of withering time, moisture content of tea fresh leaves decreased gradually, bulk destiny and elasticity of leaves increased at first and then decreased during withering, and were the highest at 6 000 lx in moderate range (the moisture content was between 60% and 65%), elasticity decreased at first and then increased, the elasticity of tea leaves were relatively highest when the withering light intensity was 6 000 lx, and the variation of plasticity was opposite, the L value (luminosity) declined generally, the “a” value (red and green degree) decreased at first and then increased, and it had the lowest value at 6 000 lx, namely the green keeping was the best, the results of sensory evaluation also showed that the liquor color and shape of black tea at 6 000 lx had the highest score, with the best quality, the released amount of CO₂ decreased at first, then increased and was stable finally, the urning point occurred during withering at 6 h, and the amount was the largest when the withering light intensity was 6 000 lx.

Key words: withering, light intensity, flexibility, elasticity and plasticity, color value, the released amount of CO₂