文献类型： 外文期刊

作者： Lu, Huimin ¹ ; Li, Yongfu ¹ ; Qiu, Ju ¹ ;

作者机构： 1.Inst Integrated Agr Dev, Guizhou Acad Agr Sci, Guiyang, Peoples R China

2.Guiyang Coll, Coll Food Sci & Engn, Guiyang, Peoples R China

关键词： Linseed oil; Electron spin resonance; Free radicals; Trans -fatty acids; Gas chromatography

期刊名称：HELIYON （ 影响因子：4.0； 五年影响因子：4.1 ）

ISSN：

年卷期： 2024 年 10 卷 6 期

页码：

收录情况： SCI

摘要： Various studies have demonstrated that employing ESR spin trapping to detect free radicals yields valuable insights into the vulnerability of bulk oils to oxidation. Consequently, this method can be employed to assess and compare the oxidative stability of different samples. This study was conducted to investigate the production and transformation of free radicals and trans isomers in linseed oil when subjected to different temperatures and durations of heating. These analyses revealed that the peak levels of free radicals PBN adducts were evident in linseed oil heated to 120 degrees C, while these levels decreased within 90 min and were absent at a higher temperature of 180 degrees C. Free radical PBN adducts were readily degraded at 180 degrees C. Levels of heat-induced trans isomers rose in linseed oil samples with rising temperatures but began to degrade at temperatures exceeding 240 degrees C partially. The content examination of these trans isomers revealed that the double bonds located at positions 9 and 15 exhibited a higher susceptibility to isomerization compared to the double bond at position 12. Furthermore, the values of k and Ea indicated that the synthesis of tri-trans-alpha-linolenic acid (TALAs) was more challenging compared to doubleTALAs, and double-TALAs were more challenging than single-TALAs. This was because the triTALAs has a higher Ea value than the mono-TALAs and double-TALAs. The study has demonstrated that subjecting linseed oil to high-temperature heating leads to the production of free radicals and trans isomers. And PBN radical adduct is unstable at 180 degrees C and the double bonds at positions 9 and 15 could be isomerized more easily than that at position 12. These results indicated that controlling the formation of free radicals and single-TALAs isomers may be the key way to reduce the trans isomers of linolenic acid during cooking oil heating. In the follow-up study, we found that VE, VK3, ethyl caffeic acid and resveratrol had significant inhibitory effects on the formation of TALAs of linolenic acid, and the highest inhibitory rate of resveratrol with 5% addition could be reached to 30.86%. The above substances can be applied to the thermal processing of linseed oil to prevent the formation of TALAs.