基于HS-SPME-GC-MS和E-nose分析不同温湿度贮藏条件下变质毛椰子果中椰肉的挥发性物质变化

Volatile Compound Changes in Spoiled Dehusked Coconut Meat Stored at Different Temper atures and Humidities Based on HS-SPME-GC-MS and E-nose

摘要:

该研究利用顶空固相微萃取技术结合气相色谱-质谱联用（Headspace Solid-phase Microextraction-gas Ghromatography-mass Spectrometry, HS-SPME-GC-MS）和电子鼻（Electronic nose, E-nose）对未贮藏正常新鲜毛椰子果椰肉和三种不同温湿度（25 ℃/70%、35 ℃/80%和45 ℃/90%）贮藏条件下的变质毛椰子果椰肉中挥发性物质进行测定，并借助主成分分析（Principal Component Analysis, PCA）和正交偏最小二乘判别分析（Orthogonal Partial Least Squares-Discriminant Analysis, OPLS-DA）进行差异和特征挥发性物质分析。结果显示，利用HS-SPMEGC-MS分析变质后椰肉的挥发性物质种类和含量都有所增加（种类从30种分别增加到45、40和39种，总含量从50.51分别增加到53.32、50.21和90.16 μg/g），而酯类物质含量却降低（从15.30 μg/g分别降到7.71、7.94和13.92 μg/g）。PCA和OPLS-DA均能将四种椰肉进行有效区分，并分别筛选出5、9、6和9种特征挥发性物质。E-nose结果表明变质果椰肉在W2W（对芳香成分和有机硫化物敏感）的响应值（13.19、5.16和5.39）显著高于FCM（4.80）。通过利用E-nose对芳香成分和有机硫化物的分析有望进行变质毛椰子果椰肉的筛选。该研究为探索变质毛椰子果快速筛选的方法提供了一定的理论基础，对提高后续产品品质有重要的指导意义。

Abstract:

Headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) and electronic nose (E-nose) technology were used to analyze the volatile compounds in the coconut meat of normal fresh dehusked coconut fruit (FCM) and spoiled dehusked coconut fruit (DCM-25, DCM-35, and DCM-45) stored under three different temperature and humidity conditions (25 ℃ /70%, 35 ℃ /80%, and 45 ℃ /90%, respectively). Principal component analysis and orthogonal partial least squares-discriminant analysis were performed to analyze the differential and characteristic volatile compounds. HS-SPMEGC-MS results showed that, compared with those in FCM, both the types and contents of volatile compounds in DCM increased (the number of types increases from 30 to 45, 40, and 39, respectively, and the total content increased from 50.51 to 53.32, 50.21, and 90.16 μg/g, respectively). The contents of esters decreased in DCM (from 15.30 to 7.71, 7.94, and 13.92 μg/g, respectively). The four types of coconut meat were distinguished via principal component analysis and orthogonal partial least squares-discriminant analysis, and five, nine, six, and nine characteristic volatile compounds were identified, respectively. The E-nose results suggested that the response values of the W2W sensor (sensitive to aromatic compounds and organic sulfides) of DCM (13.19, 5.16, and 5.39) were significantly higher than those of FCM (4.80). The analysis results of aromatic compounds and organic sulfides via E-nose may be useful in identifying coconut meat of spoiled dehusked coconut fruit. This study provides a theoretical basis for exploring rapid screening methods for spoiled dehusked coconut fruit and can guide improvements in the quality of related products.