1. Relationship between PAH4 formation and thermal reaction products in model lipids and possible pathways of PAHs formation.
- Author
-
Xu, Xiangxin, Liu, Xiaofang, Wang, Shuai, Zou, Yongping, Zhang, Jixian, Liang, Li, Wen, Chaoting, Li, Youdong, Xu, Xiaowei, He, Xudong, Liu, Guoyan, and Xu, Xin
- Abstract
Lipids are closely related to the generation of PAHs during food thermal processing. During heating, lipids mainly triglycerides undergo hydrolysis, oxidation and decomposition. The relationship between the various products and the formation of PAHs is still unclear. This paper investigated the effect of different lipid standards on PAH4 production, and explored their thermal stability and reaction products to delve into nature of the differences in PAH4 production. Fatty acids were more prone to generate PAH4 than glycerides. The higher the degree of esterification of glycerides, the higher its thermal stability and the lower the content of PAH4 generated, implying that hydrolysis of glycerides promoted the generation of PAH4. In addition, there was a positive correlation between unsaturation in lipids and the PAH4 production. After heat treatment, hydroperoxides, unsaturated fatty alcohols and aldehydes, alkenes and aromatic substances were abundant in oleic acid and linoleic acid which produced the most PAH4. Thermal decomposition of lipid hydroperoxides was the pathway for the generation of conjugated hydrocarbon radicals, alcohols, aldehydes, and alkenes. The intramolecular cyclization and Diels-Alder reaction acted as ring-forming reactions, with consequent dehydrogenation, decarboxylation, side-chain breaks and radical reorganization, ultimately facilitating the amplification of the aromatic rings and the formation of PAHs. [Display omitted] Hydrolysis of glycerides is an important factor in promoting the formation of PAH4. The unsaturated lipids contributed to the production of PAHs especially heavy PAHs. Hydroperoxides may be regarded as precursors for the formation of PAHs. The secondary oxidation products of lipids served as intermediates in PAHs formation. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF