基于HS-SPME-GC-MS与电子舌分析冷藏冠玉枇杷的风味特性

Flavor Characteristics of Guanyu Loquat Based on HS-SPME-GC-MS and Electronic Tongue during Cold Storage

目的探讨冷藏对枇杷果实风味品质的影响。方法采用顶空固相微萃取-气相色谱质谱联用(HS-SPME/GC-MS)、液相色谱和电子舌检测技术,研究冠玉枇杷在温度为(6±0.5)℃,相对湿度为90%~95%的环境下果实的滋味特性、酸度、糖组分含量及挥发性物质的变化情况。结果电子舌检测结果表明,在贮藏过程中枇杷的酸味下降明显,贮藏14 d后味觉指标发生显著变化,主成分1的方差贡献率达到85.17%,酸味、甜味与可溶性固形物、pH值呈高度相关性,与可溶性糖缺乏关联性。蔗糖含量在冷藏过程中表现为持续下降趋势,质量损失率为56.7%。HS-SPME/GC-MS结果表明,在枇杷果实中共检测出37种挥发性物质,其中醛类化合物为枇杷的主要挥发性成分,相对含量接近40%。挥发性物质的种类和含量随着贮藏时间会发生变化,己醛的相对含量会降低,(E)-2-己醛含量显著增加。结论在冷藏过程中,冠玉枇杷果实的酸味明显下降,蔗糖含量显著减少,主要香气成分己醛和(E)-2-己醛可以作为枇杷采后贮藏品质评价的重要指标,并且在贮藏14~21 d期间是风味变化较为明显的阶段。

The work aims to study the effect of cold storage on flavor and quality of loquat fruit.HS-SPME/GC-MS,liquid chromatography and electronic tongue detection technology were used to study changes of flavor characteristics,acidity,sugar content and volatile substances of the fruit at(6±0.5)℃,relative humidity 90%-95%.The results of electronic tongue showed that the acidity of loquat decreased significantly during storage,and the taste index changed significantly after 14 d of storage,the variance contribution rate of principal component 1 was 85.17%.The acidity and sweetness were highly correlated with soluble solids and pH value,and lack of correlation with soluble sugar.The sucrose decreased continuously during cold storage and the loss rate was 56.7%.The results of HS-SPME/GC-MS showed that 37 kinds of volatile compounds were detected in loquat fruit,among which aldehydes were the main volatile components,and the relative content was close to 40%.The variety and content of volatile matter changed with storage time,the relative content of hexanal decreased,and the content of E-2-hexanal increased significantly.The acid taste and sucrose content of Guanyu loquat fruit decreases significantly during cold storage and the main aroma components hexanal and(E)-2-hexanal can be used as an important index to evaluate the quality of loquat in postharvest storage.Moreover,the 14th day to the 21st day is the most obvious stage of fruit flavor change.