基于电子鼻和全二维气相色谱质谱联用法分析不同稳定化米糠挥发性成分差异

Analysis of the Differences in Volatile Components of Different Stabilized Rice Brans Based on Electronic Nose and Comprehensive Two-dimensional Gas Chromatography-mass Spectrometry

摘要:

为了探究不同稳定化处理对米糠风味成分的影响，该研究采用电子鼻与全二维气相色谱-质谱联用技术（Comprehensive Two-dimensional Gas Chromatography-time-of-flight Mass Spectrometry, GC×GC-TOFMS），结合偏最小二乘判别分析（Partial Least Squares Discriminant Analysis, PLS-DA）和相对气味活度值（Relative Odor Activity Value, ROAV）对米糠挥发性风味物质的变化进行了系统分析。结果表明：不同稳定化处理方法对米糠风味的影响存在显著差异，共检测到99种挥发性香气化合物，包括6种醛类、10种酮类、22种烷烃类、12种醇类、28种萜烯类、8种酯类及13种其他化合物。其中，红外处理对米糠风味影响不大，而高压蒸汽处理有效降低了米糠的异味（吲哚）。变量重要性投影（Variable Importance in Projection, VIP）共筛选出23种潜在差异性物质，4种不同稳定化处理后米糠中的香叶基丙酮和(-)-柠檬烯等潜在差异性物质相对含量显著减少。ROAV值表明，烘烤、微波和高压蒸汽稳定化处理后米糠关键风味物质（ROAV>1）均减少，2-正戊基呋喃、甲庚基烯酮和香茅烯等8种物质为不同稳定化米糠风味差异的关键风味物质。该研究对不同稳定化处理的米糠挥发性风物质进行差异分析，为提升米糠产品附加值及品质提供理论依据。

Abstract:

To explore the impacts of different stabilization treatments on the flavor components of rice bran, this study employed an electronic nose and comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry (GC×GCTOFMS), combined with partial least squares discriminant analysis (PLS-DA) and relative odor activity value (ROAV) evaluation to systematically analyze the changes in volatile flavor compounds of rice bran. The results indicated that there were significant differences in the effects of different stabilization methods on the flavor of rice bran. A total of 99 volatile aroma compounds were detected, including 6 aldehydes, 10 ketones, 22 alkanes, 12 alcohols, 28 terpenes, 8 esters, and 13 other compounds. Among them, infrared treatment had minimal impact on rice bran flavor, while high-pressure steam treatment effectively reduced the off-flavor (indole) in rice bran. Variable Importance in Projection (VIP) identified 23 potential differential substances, with significant decreases being found in the relative contents of potential differential substances such as geranylacetone and (-)-limonene in the rice bran after four different stabilization treatments. The ROAV values revealed that the key flavor substances (ROAV>1) in rice bran decreased after the stabilization treatments like baking, microwaving, and high-pressure steaming. Eight substances, including 2-n-pentylfuran, methylheptenone, and citronellene, were identified as the key flavor compounds contributing to the differences in flavor among the rice bran samples subjected to different stabilization methods. This study conducted a differential analysis of volatile flavor substances in rice bran subjected to different stabilization methods, providing a theoretical basis for enhancing the added value and quality of rice bran products.