共轭亚油酸和非共轭亚油酸在加热过程中的氧化修饰。

Oxidative modifications of conjugated and unconjugated linoleic acid during heating.

机构信息

Università degli Studi di Perugia, Dipartimento di Scienze Economico-Estimative e degli Alimenti, Sezione di Chimica Bromatologica, Biochimica, Fisiologia e Nutrizione, Via San Costanzo, 06126 Perugia, Italy.

出版信息

Food Chem. 2013 Oct 15;140(4):680-5. doi: 10.1016/j.foodchem.2012.09.067. Epub 2012 Sep 28.

DOI:10.1016/j.foodchem.2012.09.067

PMID:23692753

Abstract

The oxidative stability of conjugated linoleic (CLA) and linoleic (LA) acids in different chemical forms (free acids, methyl esters and homogeneous triacylglycerols) was compared. All model systems were heated at 180°C for different times (15, 30, 45 and 60min). The primary oxidation products were evaluated by spectrophometric analysis, while the volatile compounds were determined by solid phase micro-extraction (SPME), coupled with gas chromatography-mass spectrometry (HRGC-MS). The isomer profile modifications were investigated by silver-ion high performance liquid chromatography (Ag(+)-HPLC) equipped with an UV detector. Generally, peroxide values decreased during the heating time. Among the volatiles, saturated aldehydes were the most represented compounds. Isomerization of cis,trans and trans,cis CLA to trans,trans isomers was observed mainly for the methyl form of CLA. The three different chemical forms of LA never showed isomerization phenomena.

摘要

比较了不同化学形式（游离酸、甲酯和均相三酰基甘油）的共轭亚油酸（CLA）和亚油酸（LA）的氧化稳定性。所有模型系统均在 180°C 下加热不同时间（15、30、45 和 60min）。通过分光光度分析评估主要氧化产物，通过固相微萃取（SPME）与气相色谱-质谱联用（HRGC-MS）测定挥发性化合物。通过配备紫外检测器的银离子高效液相色谱法（Ag(+)-HPLC）研究异构体谱修饰。一般来说，过氧化物值在加热时间内降低。在挥发物中，饱和醛是最具代表性的化合物。CLA 的甲酯形式主要观察到 cis,trans 和 trans,cis CLA 向 trans,trans 异构体的异构化。三种不同化学形式的 LA 从未表现出异构化现象。