烫漂时间对香椿嫩芽颜色及挥发性风味成分的影响研究

为了研究香椿嫩芽烫漂过程中颜色热降解规律及挥发性风味成分的变化,分别采用分光光度法和光电反射光度法对香椿嫩芽叶绿素含量和色差进行测定,同时利用顶空固相微萃取及GC-MS联用技术对不同烫漂时间下香椿嫩芽的挥发性成分进行鉴定,并对各种处理后的风味物质进行主成分分析。结果表明,香椿嫩芽叶绿素降解和绿色损失均属于一级动力学反应,且叶绿素的减少与绿色损失相关性较好,呈极显著水平。烫漂后香椿嫩芽挥发性成分种类增多,含硫类等呈刺激性气味的化合物相对含量减少,烯类等呈柔和气味增加,提升了香椿的香味品质。综合颜色及挥发性成分随烫漂时间的变化规律,确定最佳烫漂时间为30s。主成分分析结果显示,第1、第2和第3主成分累积贡献率达98.742%,能够较好的代表原始数据所反应的信息。第1主成分包含噻吩类、烯类、醇类和醛类,贡献率大小为噻吩类烯类醇类醛类;第2主成分包含酮类和其它类,贡献率大小为酮类其它类;第3主成分为烃类。本研究结果为香椿嫩芽精深加工过程中颜色和风味的控制提供了理论依据。

Effects of Blanching Time on Color and Volatile Components of Toona sinensis Buds

In order to investigate thermal degradation kinetics of green color and changes of volatile components of Toona sinensis during blanching,the effects of different blanching time on chlorophyll contentand green value determined by spectrophotometric/photoelectric reflection spectrophotometry and volatile components analyzed by Head Solid-phase micro-extraction as well as GC-MS technology were studied.Results showed that chlorophyll degradation and green color loss followed a first-order reaction.Meanwhile significant correlation between chlorophyll destruction and green color loss was found.The species of volatile component in blanched Toona sinensis increased.The relative contents of excitant odour,such as sulfocompounds were greatly reduced and mid aroma such as alkenes were just the opposite,which improved flavor quality of Toona sinensis.Considering of the variation law of color and volatile components with blanching time,the optimum blanching time was 30 minutes.The results of principal component analysis showed that cumulative rate of three principal components was 98.745％,which could represent the original data information better.The first principal components included thiophenes,alkenes,alcohols and aldehydes,and the order of effect from high to low was thiophenes ＞ alkenes ＞ alcohols ＞ aldehydes.The second principal components included ketones and others,and the order of effect from high to low was ketones ＞ others.The third principal components were hydrocarbons.This study provided theoretical basis for the control of color and flavor buds during the deep processing of toona sinensis buds.