College of Food and Health, Beijing Technology and Business University (BTBU), Beijing 100048, China.
Oil Crops and Lipids Process Technology National & Local Joint Engineering Laboratory Wuhan, Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Wuhan 430062, China.
Food Funct. 2022 Oct 31;13(21):10956-10969. doi: 10.1039/d2fo01990f.
The present study focused on the role of roasting pretreatment in improving the flavor of WOs. In total, 71 volatile compounds were detected, 35 odorants were perceived, and 17 aroma-active compounds were identified in WOs by using headspace-solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) and aroma extract dilution analysis of gas chromatography-olfactometry (AEDA/GC-O). The results indicate that extended roasting pretreatment is effective in generating aldehydes and pyrazine aroma-active compounds in WOs. The correlation between the aroma-active compounds and chemical composition was identified by Pearson correlation analysis. The branched-chain aldehyde, 3-methylbutanal, is a Maillard reaction product with ribose as a precursor. Pyrazine aroma-active compounds were also related to ribose, with absolute correlation coefficients of 0.85 to 0.96; among pyrazine compounds, 2-ethyl-5-methylpyrazine showed strong correlation with isoleucine and arginine, while 2-methylpyrazine and 2,3,5-trimethylpyrazine showed strong correlation with glycine, lysine, and histidine. The determination of the effect of roasting on aroma-active compound alteration and the study of aroma precursors will be helpful for walnut oils' flavor quality control, which directly enable their industrial application.
本研究重点探讨了烘焙预处理对改善 WO 风味的作用。采用顶空固相微萃取-气相色谱-质谱联用（HS-SPME-GC-MS）和气相色谱-嗅觉测量法的香气萃取稀释分析（AEDA/GC-O），共检测到 71 种挥发性化合物，感知到 35 种气味物质，鉴定出 17 种 WO 的香气活性化合物。结果表明，延长烘焙预处理可有效生成 WO 中的醛类和吡嗪类香气活性化合物。采用 Pearson 相关分析确定了香气活性化合物与化学成分之间的相关性。支链醛，3-甲基丁醛，是一种美拉德反应产物，以核糖为前体。吡嗪类香气活性化合物也与核糖有关，其绝对相关系数为 0.85 至 0.96；在吡嗪类化合物中，2-乙基-5-甲基吡嗪与异亮氨酸和精氨酸呈强相关性，而 2-甲基吡嗪和 2,3,5-三甲基吡嗪与甘氨酸、赖氨酸和组氨酸呈强相关性。烘焙对香气活性化合物变化的影响的确定和香气前体的研究将有助于控制核桃油的风味质量，这直接使它们能够应用于工业生产。
