萎凋温度对鲜叶物性及呼吸特性的影响

为研究萎凋工艺参数对鲜叶物性及呼吸特性的影响机制，设置20℃、28℃、36℃的温度梯度，研究萎凋温度对萎凋叶含水率、容重、柔软性、弹塑性、色差等物理特性，呼吸特性以及感官品质的影响。研究显示：随着萎凋过程中鲜叶含水率的降低，鲜叶的容重、柔软性、塑性等呈先升后降的趋势，以28℃处理最高；弹性呈先下降后增加的趋势，不同处理间以28℃处理样的弹性相对最低；色差明亮度L值总体呈下降趋势，红绿度a值呈逐渐上升的趋势，以28℃处理下a值最小，即保绿特性最好，感官审评结果也表明28℃处理的干茶样汤色、外形等得分最高，品质最优；CO₂释放量总体呈“降-升-降”的变化趋势，以36℃处理样的释放量相对最大。

The Effect of Withering Temperature on Physical Characteristics and Respiration of Tea Fresh Leaves

In order to study the response of tea fresh leaves physical characteristics and respiration to the withering process parameters, setting three different withering temperature (20℃, 28℃, 36℃), the water content, bulk destiny, flexibility, elasticity, plasticity and color value, the released amount of CO₂ of the withering leaves and the sensory evaluation of made tea were evaluated. The results showed that with the increasing of withering time, moisture content of tea fresh leaves decreased gradually, bulk destiny, plasticity and elasticity of leaves increased at first and then decreased during withering, and were the highest at 28℃; elasticity decreased at first and then increased, the elasticity of tea leaves were relatively lowest when the withering light intensity was 28℃; the L value (luminosity) declined generally, the a value (red and green degree) increased gradually, and it had the lowest value at 28℃, namely the green keeping was the best, the results of sensory evaluation also showed that the liquor color and shape of black tea at 28℃had the highest score, with the best quality; the released amount of CO₂ decreased at first, then increased and decreased finally, and the amount was the largest when the withering light intensity was 36℃.