The differences in the formation kinetics of trans linolenic acid in linolenic acid triglycerides during heating and the effects of linolenic acid at different acylation positions in the glycerides on the types of thermally isomerized trans products were studied.Using GC-FID to analyze the trans isomers of linolenic acid,it was found that there were 7 trans isomers in the linolenic acid triglyceride and 6 trans isomers in linseed oil,and the reaction was zero-order.The kinetic parameters of linolenic acid triglyceride and linseed oil were compared,and it was found that in linolenic acid triglyceride and linseed oil,the activation energies of C18:3-9t,12c,15c,C18:3-9c,12t,15c and C18:3-9c,12c,15t were 79.39,106.49 and 82.33 kJ/mol,and 86.04,115.84 and 102.85 kJ/mol,respectively;the activation energies of C18:3-9t,2c,15t and C18:3-9t,12t,15c were 180.57 and 233.55 kJ/mol,and 164.36 and 165.38 kJ/mol,respectively;the activation energies of C18:3-9t,12t,15t were 211.79 and 140.30 kJ/mol,respectively.with the comparison on the the isomer contents of monolinolenin,dilinolein and 1,3-dilinolenin revealed that Sn-1 and Sn-2 were more stable than Sn-1 and Sn-3;Sn-1 was more stable than Sn-1 and Sn-3,and Sn-1 and Sn-2.Therefore,the energy barrier of linolenic acid triglyceride was basically higher than that of linseed oil;In terms of acylation sites,Sn-1 and Sn-2 was more stable than Sn-1 and Sn-3,and Sn-1 was more stable than Sn-1 and Sn-3,and Sn-1 and Sn-2.
关键词
亚麻酸/反式异构体/动力学/气相色谱-火焰离子化检测器/酰化位置
Key words
linolenic acid/trans isomer/kinetic/GC-FID/acylation site
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