变黄期不同温湿度对烘烤中烟叶蛋白质降解及其相关酶活性的影响

为合理调控烟叶蛋白质含量、提高烟叶质量提供理论依据，对密集烘烤不同变黄温湿度烟叶蛋白质降解和蛋白酶、内肽酶、谷草转氨酶、谷丙转氨酶活性的变化关系进行了研究。研究结果表明，烘烤过程中，不同变黄温湿度下烟叶水分、蛋白质、氨基酸及其相关酶活性的变化规律基本一致；水分和蛋白质含量呈下降趋势，氨基酸含量一直增加，蛋白酶和内肽酶活性呈先升高然后降低而后再升高的“双峰曲线”变化；谷丙转氨酶和谷草转氨酶活性在烘烤开始时有小幅度增加，并出现一个小的峰值，然后呈下降趋势，从60h起急剧升高并达到最大值；且内肽酶活性与可溶性蛋白质相关性显著，和游离氨基酸相关性极显著；谷丙转氨酶只和游离氨基酸相关性显著。密集烘烤不同变黄温湿度，低温中湿变黄处理烟叶中性蛋白酶、内肽酶、谷草转氨酶和谷丙转氨酶活性高且作用时间较长，有利于烟叶内蛋白质的降解和氨基酸的合理转化，改善烟叶质量。 

Effects of different temperature and humility of yellowing stage on protein degradation and related enzyme activities of tobacco leaves during curing tobacco leaves during bulk curing

The effects of different temperature and humility of yellowing stage on the protein degradation, activities of protease, endopeptidase, glutamic oxaloacetic transaminase(GOT) and glutamic pyruvic transaminase(GPT) and their relationship were studied, in order to provide a theoretical basis for controlling the contents of protein and improving the quality feature of tobacco leaves. The results showed that, the variation trends of contents of water, protein and amino acid and related enzyme activities were similar in different temperature and humility of yellowing stage. The contents of water and protein presented the downward trend. The content of amino acid showed rising trend. And the activities of protease and endopeptidase presented the double –peak curve, which was rise-down-rise. The activities of GOT and GPT increased little in the start of yellowing stage. Then, they showed downward trend. And they would increased drastically from 60h. The activity of endopeptidase had a significant and very significant relation with soluble protein and free amino acid respectively. And their was a significant relation between activity of GPT and free amino acid. It would have higher activities and longer action time of protease, endopeptidase, GOT and GPT of tobacco leaves with low temperature and middle humility of yellowing stage. And it could beneficial to the degradation of protein, rational conversion of amino acid, and improving the qualities of tobacco leaves.