基于GC-IMS技术分析糙米速食粥米储藏过程中风味物质的变化

Analysis of Flavor Changes of Instant Brown Rice Porridge Rice during Storage based on Gas Chromatography-Ion Mobility Spectrometry

为探究糙米速食粥米储藏期间品质的变化规律,从风味化学的角度采用气相离子迁移谱技术(gas chromatography-ion mobility spectrometry,GC-IMS),结合动态主成分分析(principal component analysis,PCA)研究糙米速食粥米储藏过程中特征挥发性有机物组成及含量的变化,并通过风味信息指纹图谱评价样品间挥发性有机物(volatile organic compounds,VOCs)的差异性。结果表明,GC-IMS联用技术可定性定量地快速鉴别不同储藏环境和储藏时间的糙米速食粥米挥发性物质的单体和二聚体,共识别59种VOCs。其中,鲜制糙米速食粥米的VOCs主要包括醛类、酮类和酯类,相对含量分别为24.44%、20.40%和43.59%。室温储藏时,随着储藏时间的延长,糙米速食粥米中醇类、醛类、吡嗪类、呋喃类含量增加,酮类、酯类含量降低;真空度对糙米速食粥米风味品质影响较小。高湿环境下,随着储藏时间的延长,有机酸类物质逐渐产生,醛类和醇类物质含量增幅较大,酮类、酯类物质减少,且随储藏温度的升高,挥发性物质变化加剧。

In order to explore the quality changes of instant brown rice porridge rice during storage,gas chromatographic ion mobility spectrometry(GC-IMS)and dynamic principal component analysis(PCA)were used to study the changes of the composition and content of characteristic volatile organic compounds during the storage of instant brown rice porridge rice,the difference of volatile organic compounds(VOCs)between samples was evaluated by the flavor information fingerprint.The results showed that GC-IMS combined technology can quickly and qualitatively identify the monomers and dimers of volatile substances of instant brown rice porridge rice in different storage environments and storage times,and a total of 59 VOCs have been identified.The VOCs of fresh instant brown rice porridge rice mainly include aldehydes,ketones and esters,with relative contents of 24.44%,20.40%and 43.59%respectively.When stored at room temperature,the relative contents of alcohols,aldehydes,pyrazines and furans in instant brown rice porridge increased,while the contents of ketones and esters decreased with the extension of storage time.Vacuum condition had little effect on flavor quality of instant brown rice porridge.In high humidity environment,with the extension of storage time,organic acids were gradually produced,aldehydes and alcohols increased greatly,ketones and esters decreased,and volatile substances changed significantly with the increase of storage temperature.