砍收期与白肋烟游离氨基酸含量变化及品质的关系

Effect of Stalk Cutting Time on Free Amino Acid Content in Burley Tobacco

用日立835-50型氨基酸自动分析仪,探索白肋烟砍收期游离氨基酸变化及对烟叶品质的影响。结果表明,检测的16种氨基酸中,谷氨酸、天冬氨酸、脯氨酸含量较高,三者合计占总量的63.6%～74.33%,其它13种较低合计占25.67%～36.40%。不同砍收期各部位叶总游离氨基酸含量差异较大,下部叶以3周时最高,5周时最低,中部叶、上部叶分别是4周、5周最高,均以6周时最低,三部位平均以4周最高,5周最低。砍收期对各部位氨基酸含量的影响为下部叶>上部叶>中部叶,对丝氨酸、组氨酸、异亮氨酸的影响较大,而对苯丙氨酸、谷氨酸、总游离氨基酸的影响较小。以打顶后下部3周、中部4周(或全整株收晾)、上部5周收晾,更有利于各部位烟叶品质的提高。

A better understanding of the effects of stalk cutting time on free amino acid is necessary to further improve the leaf quality of burley tobacco.The objective of this study was to investigate whether there were differences in the free amino acid contests of three stalk leaves among the harvest time of 3,4,5 and 6 weeks after topping in burley tobacco.The results showed that out of 16 free amino acid types,three free amino acids,Glu,Asp,Pro,had a ratio of 63.60% to 74.33% to total amino acids.The total contents of other 13 types were lower,about 25.67% to 36.40%.Significant differences were observed in the content of free amino acids among different stalk leaves.The highest and lowest values were found in the harvest time of 3 and 5 weeks after topping in lugs,respectively.Although it had the lowest contents of free amino acids in the treatments of the harvest time of 6 weeks after topping in both cutters and leaves,the highest values were observed in the treatments of the harvest time of 4 and 5 weeks after topping,respectively.Average across three stalk leaves,it was greatest and lowest in the treatments of the harvest time of 4 and 5 weeks after topping,respectively.The impact of stalk cutting time on free amino acids was greatest in lugs,followed by leaves and cutters.Stalk-cut period also had a higher effect on the contents of ser,his,ile than those of phe,glu and FAA.It was concluded that the best harvest time to obtain good quality in burley tobacco was 3,4 and 5 weeks after topping for lugs,cutters and leaves,respectively.