晾制湿度对雪茄茄衣烟叶颜色的影响

Influence of air-curing humidity on color of tobacco leaves for cigar wrapper

为揭示影响雪茄茄衣烟叶颜色的主要因素,采用常规晾制、分阶段取样的方法研究了不同晾制湿度处理雪茄烟叶含水率、叶绿素含量(质量分数)、酶活性、化学成分和色度值的变化规律。结果表明:晾制过程中低湿度处理的雪茄茄衣烟叶失水速度较快,其次为中湿度处理,高湿度处理较慢。在高湿度条件下,雪茄茄衣烟叶叶绿素a和叶绿素b降解较快,类胡萝卜素含量增加较快。过氧化物酶(POD)和多酚氧化酶(PPO)活性高湿度处理高于中湿度和低湿度处理,在晾制后期(20~30 d)更加明显。高湿度处理晾制后雪茄茄衣烟叶色度值较高,中湿度和低湿度处理色度值较低。相关及逐步回归分析表明,雪茄茄衣烟叶还原糖和总氮含量与色度值的相关系数达到极显著(P≤0.01)水平,是影响晾制后茄衣颜色的重要因素。

In order to reveal the main factors influencing the color of tobacco for cigar wrapper,conventional air-curing and phased sampling methods were used to study the changes of moisture content,chlorophyll content(mass fraction),enzyme activities,chemical composition and colorimetric values of cigar tobacco at different air-curing humidity.The results showed that the moisture loss rate of cigar tobacco leaves in the process of air-curing under low humidity treatment was higher than that under medium humidity treatment,and that of high humidity treatment was the lowest.Under high humidity treatment,the degradation of chlorophyll a and chlorophyll b,and the increasing rates of carotenoid in cigar tobacco leaves were faster.The activities of peroxidase and polyphenol oxidase in cigar tobacco leaves under high humidity treatment were higher than those under low humidity and medium humidity treatments,especially at the later stage of air-curing(20-30 d).The colorimetric values of cigar tobacco leaves after air-curing were the highest under high humidity treatment,followed by medium humidity treatment and low humidity treatment.Correlation and stepwise regression analyses indicated that the correlation coefficients between the reducing sugar,total nitrogen and colorimetric values reached extremely significant(P≤0.01)levels,and reducing sugar and total nitrogen were the important factors affecting the color of tobacco for cigar wrapper after air-curing.