基于气相色谱-离子迁移谱和电子鼻技术研究籼米口腔加工过程中的风味释放

Gas Chromatography-Ion Mobility Spectrometry and Electronic Nose to Detect Flavor Release from Cooked Indica Rice during Oral Processing

为研究籼米米饭在口腔加工过程的风味释放规律,通过志愿者对籼米米饭进行咀嚼制备不同咀嚼阶段食团,采用气相色谱-离子迁移谱(gas chromatography-ion mobility spectrometry,GC-IMS)法和电子鼻技术对比分析籼米在不同口腔加工阶段挥发性成分的差异及标志性差异物。电子鼻结果分析表明,咀嚼前、后籼米米饭风味与咀嚼过程中有显著差异。GC-IMS分析共分离鉴定出33种风味物质。与咀嚼前相比,咀嚼过程中食团的醛类相对含量分别降低了62.01%、47.60%、69.19%和71.78%,醇类相对含量分别增加了59.89%、42.59%、29.94%和17.73%,酮类相对含量分别降低了31.92%、17.87%、34.92%和38.45%。通过偏最小二乘判别分析,共筛选出11种米饭特征性化合物,包括己醛(单体)、己醛(二聚体)、辛醛、庚醛、1-丙醇(单体)、1-丁醇、2,3-戊二酮、2-庚酮、2-戊基呋喃、D-柠檬烯(单体)和D-柠檬烯(二聚体)等。

In order to study flavor release from cooked indica rice during oral processing,boluses of cooked indica rice from volunteers at different mastication stages were collected and analyzed for volatile components by gas chromatographyion mobility spectrometry(GC-IMS)and electronic nose.The differential marker volatile compounds among different mastication stages were investigated.The results of electronic nose indicated that the flavor of cooked rice significantly differed before and after mastication.A total of 33 flavor compounds were identified by GC-IMS.Compared with that before mastication,the content of aldehydes in 25%,50%,75%and 100%boluses decreased by 62.01%,47.60%,69.19%and 71.78%,respectively;the alcohol content increased by 59.89%,42.59%,29.94%and 17.73%,respectively;the ketone content decreased by 31.92%,17.87%,34.92%and 38.45%,respectively.Through partial least squares-discrimination analysis(PLS-DA),11 compounds were selected as characteristic markers,including hexanal and its dimer,octanal,heptanal,1-propanol,1-butanol,2,3-pentanedione,2-heptanone,2-pentylfuran and limonene and its dimer.