气相色谱-离子迁移谱结合多元统计学分析不同包装对香椿粉品质的影响

Effect of Different Packaging Materials on the Quality of Toona sinensis Powder Analyzed by Gas Chromatography-Ion Mobility Spectrometry Combined with Multivariate Statistical Analysis

为延长真空冷冻干燥香椿粉的货架期,分别采用聚乙烯(polyethylene,PE)密封袋、铝箔密封袋、复合真空袋、铝箔真空袋对香椿粉进行包装,在(55±1)℃高温、(40±3)%相对湿度条件下进行加速实验,研究香椿粉贮藏期间感官、水分、色泽、风味成分及菌落总数的变化。结果表明:随着贮藏时间延长,采用PE密封包装贮藏的香椿粉吸潮、褐变严重,菌落总数显著上升;而铝箔真空包装贮藏的香椿粉中水分含量、色泽及菌落总数未发生明显变化;不同包装贮藏的香椿粉中共鉴定出56种挥发性化合物,包括醇类13种、醛类11种、酸类3种、萜烯类3种、酮类7种、酯类9种、醚类1种、含硫类2种、烷烃类3种、杂环类4种;挥发性化合物的主成分分析表明,不同包装贮藏的香椿粉样品可显著区分;通过正交偏最小二乘判别分析,结合变量投影重要性(variable importance in projection,VIP),共筛选出14种差异挥发性化合物(VIP>1),其聚类热图也可对不同包装贮藏样品进行较好分类。以铝箔真空包装形式效果最佳,铝箔密封、复合真空包装次之,PE密封包装的香椿粉水分、色泽、风味及微生物品质变化最大。

To extend its shelf life,vacuum freeze-dried Toona sinensis(VFDTS)powder was packaged in sealed polyethylene(PE)bags,sealed aluminum foil bags,composite vacuum bags,or aluminum foil vacuum bags.Changes in the sensory quality,moisture content,color,flavor components and total bacterial count of VFDTS powder were monitored during storage under accelerated conditions at(55±1)℃and(40±3)%relative humidity(RH).The results showed that VFDTS powder packaged in sealed PE bags exhibited severe moisture absorption and browning with prolonged storage time,and the total bacterial count significantly increased.On the other hand,the moisture content,color and total bacterial count of the powder stored in aluminum foil vacuum bags remained substantially unchanged.A total of 56 volatile compounds were identified in VFDTS powder stored in the different packaging systems,including 13 alcohols,11 aldehydes,3 acids,3 terpenes,7 ketones,9 esters,one ether,2 sulfur compounds,3 alkanes,and 4 heterocycles.Principal component analysis(PCA)of the volatile compounds showed clear separation among VFDTS powder samples stored in the 4 packaging systems.Based on variable importance in projection(VIP>1)from orthogonal partial least squares discriminant analysis(OPLS-DA),a total of 14 differential volatile compounds were selected,and their clustering heatmaps could be used to effectively classify the samples in different packaging systems.The samples in aluminum foil vacuum bags had the best quality,followed by sealed aluminum foil bags and composite vacuum bags,while the greatest changes in moisture,color,flavor and microbiological quality were observed in VFDTS powder in sealed PE bags during storage.