Beijing Laboratory for Food Quality and Safety, Key Laboratory of Agricultural Product Detection and Control for Spoilage Organisms and Pesticides, Food Science and Engineering College, Beijing University of Agriculture, Beijing 102206, China.
Beijing Laboratory for Food Quality and Safety, Key Laboratory of Agricultural Product Detection and Control for Spoilage Organisms and Pesticides, Food Science and Engineering College, Beijing University of Agriculture, Beijing 102206, China.
Food Res Int. 2022 Apr;154:111029. doi: 10.1016/j.foodres.2022.111029. Epub 2022 Feb 17.
This study aimed to investigate the role of stability of low density lipoprotein (LDL) spherical particles as well as oxidation of lipids and proteins on formation of off-odor in heated egg yolk (EY). Off-odor attributes and volatile components of EY with different thermal temperature (25 °C-90 °C) were investigated by sensory evaluation, gas chromatography-mass spectrometry (GC-MS) and GC-ion mobility spectrometry (IMS). The off-flavor and volatile compounds increased significantly when EY were heated at 60 °C-65 °C. Destruction of LDL particle structure was presented by confocal laser scanning microscopy with thermal treatment at 60 °C. A positive correlation (r = 0.899, p < 0.05) was shown between oil exudation and off-odor of heated EY. Moreover, oxidation of lipids and proteins, protein aggregation, and changes of protein secondary structure (increased β-sheets and decreased α-helices) in LDL particles were all found when heating temperature rose to 65 °C. It was speculated that unstability of LDL particles resulted in the leakage of lipids; then oxidative products of lipids took part in the formation of off-odor volatiles in heated EY.
本研究旨在探讨低密度脂蛋白（LDL）球形颗粒的稳定性以及脂质和蛋白质的氧化在加热蛋黄（EY）产生异味中的作用。通过感官评价、气相色谱-质谱联用（GC-MS）和气相离子迁移谱（GC-IMS）研究了不同热温度（25°C-90°C）下 EY 的异味属性和挥发性成分。当 EY 在 60°C-65°C 下加热时，异味和挥发性化合物显著增加。通过共聚焦激光扫描显微镜显示 LDL 颗粒结构在 60°C 热处理时被破坏。加热 EY 的油渗出与异味之间存在正相关（r=0.899，p<0.05）。此外，当加热温度升高到 65°C 时，发现 LDL 颗粒中的脂质和蛋白质氧化、蛋白质聚集以及蛋白质二级结构的变化（增加的β-折叠和减少的α-螺旋）。推测 LDL 颗粒的不稳定性导致脂质泄漏；然后脂质的氧化产物参与了加热 EY 中异味挥发性物质的形成。
