Zhang Hexin, Wu Caiyun, Zhang Mengmeng, Li Mei, Xu Huaide, Zhao Wenge, Zhang Ting, Lei Hongjie
College of Food Science and Engineering, Northwest A&F University, Yangling 712100, China.
College of Food Science and Engineering, Northwest A&F University, Yangling 712100, China.
Food Chem. 2025 Feb 28;466:142197. doi: 10.1016/j.foodchem.2024.142197. Epub 2024 Nov 24.
The susceptibility of walnut lipids to deterioration constitutes challenges for industry development, and the oxylipins formed during this process remain to be explored. This study employed lipidomics to reveal the dynamic evolution of lipid characteristics and identify oxidation markers from oxylipins in walnuts during accelerated storage. Glycerophospholipid (GP) content continuously declined in the initial and severe deterioration stages. The accumulation of diglycerides and partial lysophospholipids characterized initial deterioration. Triglycerides were prone to direct oxidation, while GPs tended to be first hydrolyzed. GP metabolism especially phosphatidylethanolamine degradation triggered walnut deterioration. Moreover, ten oxylipins derived from linoleic acids were identified in walnuts. Trans-EKODE-(E)-Ib, 13-HODE, 9-HODE, and 9(S),12(S),13(S)-TriHOME were screened as oxidation markers. The cellular structure exhibited the cell membrane and oil body membrane rupture during deterioration. Potential mechanisms of lipid deterioration were proposed, providing a scientific basis and guidance in optimizing quality control strategies and assessing practical deterioration degrees of walnuts.
核桃脂质易发生劣变，这对产业发展构成挑战，且在此过程中形成的氧化脂质仍有待探索。本研究采用脂质组学方法揭示核桃在加速储存过程中脂质特征的动态演变，并从氧化脂质中鉴定出氧化标志物。在初始和严重劣变阶段，甘油磷脂（GP）含量持续下降。甘油二酯和部分溶血磷脂的积累是初始劣变的特征。甘油三酯易于直接氧化，而甘油磷脂则倾向于先水解。GP代谢尤其是磷脂酰乙醇胺降解引发了核桃劣变。此外，在核桃中鉴定出了十种源自亚油酸的氧化脂质。筛选出反式-EKODE-(E)-Ib、13-HODE、9-HODE和9(S),12(S),13(S)-TriHOME作为氧化标志物。细胞结构在劣变过程中表现出细胞膜和油体膜破裂。提出了脂质劣变的潜在机制，为优化质量控制策略和评估核桃实际劣变程度提供了科学依据和指导。
