华富苹果常温贮藏过程中感官品质及挥发性风味物质变化

以华富苹果为实验材料,利用电子鼻、固相微萃取-气质联用技术(SPME/GC-MS)分析苹果在(20±1)℃贮藏1个月的过程中风味物质的变化。结果表明,随着贮藏时间的延长,果皮色泽变暗,逐渐变绿、变黄;果实失重率逐渐增高。苹果糖酸比呈先降后升的趋势;而淀粉含量逐渐降低。利用电子鼻通过主成分分析和线性判别分析均可以对不同贮藏时间的苹果果实进行良好区分,且传感器R2、R6、R8和R9对区分苹果贮藏期内挥发性风味变化效果较好。SPME/GC-MS分析表明,随着贮藏时间的延长,2-甲基丁基乙酸酯、丁酸丙酯、丁酸2-甲基丁酯、异戊酸己酯的含量呈先升后降的趋势,己酸己酯的含量持续下降,2-甲基丁酸乙酯的含量逐渐升高,醇类物质的种类和含量逐渐减少;正己醛的含量成先升高后降低的趋势,2-己烯醛和壬醛的含量均降低;α-法呢烯、双戊烯和甲苯在贮藏期间一直存在。电子鼻有望替代GC-MS对富士苹果货架期内挥发性风味变化进行快速评价。

Changes of Sensory Quality and Volatile Compounds of Huafu Apple Preserved at Room Temperature

"Huafu" apple was selected as the raw material. The changes of volatile compounds were analyzed using electronic nose and solid phase microextraction coupled with gas chromatography and mass spectrometry(SPME/GC-MS)during storage at(20±1)℃ for one month. The results showed that,the color of fruit peel became darker,gradually turned green and yellow along with the prolongation of storage time. The weight loss rate of apple fruit gradually increased. The ratio of sugar to acid decreased firstly and then raised,while the starch content decreased gradually. Electronic nose could distinguish with different storage time of apple fruit by principal component analysis and linear discriminant analysis. The sensors R2,R6,R8 and R9 were better for distinguishing the changes of volatile flavor in apples during storage period. The results of SPME/GC-MS analysis showed that with the prolongation of storage time,the contents of 2-methylbutyl acetate,propyl butyrate,butyl 2-methylbutanoate and hexyl isovalerate tended to increase first and then decrease,and the content of hexyl hexanoate decreased all the time. The contents of ethyl 2-methylbutyrate increased gradually,and the type and contents of alcohols decreased gradually. The contents of hexanal increased first and then decreased,the contents of 2-hexenal and nonanal all decreased,and the contents of α-farnesene,dipentene and toluene existed all the time during storage. Electronic nose expected to replace GC-MS in rapidly evaluation of the volatile flavor changing in Fuji apple during shelf life.