基于风味特征的大米储藏过程脂肪酸值的预测研究

Prediction of fatty acid values during rice storage based on flavor characteristics

目的 建立大米储藏过程中脂肪酸值的快速预测方法。方法 采用气相色谱-离子迁移谱(gas chromatography-ion mobility spectrometry,GC-IMS)对不同储藏阶段大米的挥发性有机物质(volatile organic compounds, VOCs)进行检测分析,并使用偏最小二乘回归(partial least squares regression, PLSR)法建立脂肪酸与VOCs之间的线性模型。结果 大米在储藏过程中脂肪酸值随时间的延长呈逐渐增加的趋势;储藏过程中,大米VOCs成分主要以醇类和醛类物质为主,除1-辛烯-3-醇物质外,其他VOCs在储藏过程中含量均呈整体下降的趋势;PLSR交叉验证模型的相关系数R~2值为0.9544,均方根误差值为2.4093。结论 基于VOCs特征变量结合化学计量学方法能够准确、快速预测大米不同储藏时期的脂肪酸值,为基于风味信息实现大米品质的快速检测提供了一种新的检测方法。

Objective To establish a rapid prediction method of fatty acid values during rice storage. Methods Gas chromatography-ion mobility spectrometry(GC-IMS) was applied to detect and analyze volatile organic compounds(VOCs) in rice at different stage of storage, and the partial least squares regression(PLSR) algorithm was also used to establish a linear model between fatty acid values and VOCs. Results Fatty acid values increased gradually with the extension of cultivation time during the storage of rice. The composition of rice flavors were mainly alcohols and aldehydes, except for 1-octene-3-alcohol, the content of other VOCs showed an overall downward trend during the storage period;the correlation coefficient of the PLSR cross validation model was 0.9544,and the root mean square error was 2.4093. Conclusion Fatty acid values of rice in different storage periods can be accurately predicted by VOCs characteristic variables combined with chemometric tools, which provides a new detection method for rapid detection of rice quality based on flavor information.