Lycopene trans-isomer undergoes geometrical isomerization into cis-isomers with thermal treatment. Influences of three isomerization method including ethyl acetate reflux,microwave assisted reflux and ultrasound/microwave assisted reflux were investigated. The results showed that proportion of cis-isomers in 6% oleoresin samples were higher than that in 90% lycopene samples after ethyl acetate reflux. Nitrogen had insignificant effects on the isomerization of lycopene. Although microwave and ultrasound-microwave assisted reflux had no significant difference with each other,both showed significance influence over refluxing in ethyl acetate reflux,proportion of cis-isomers reached more than 54.7% after S h procession. Consequently,microwave was the best way to isomerization of lycopene.%番茄红素在受热的情况下会发生反式异构体(all-trans)向顺式异构体(ci-isomers)的转化.本文研究了乙酸乙酯热回流、微波法及超声-微波协同法对番茄红素异构化的影响.结果表明:乙酸乙酯热回流处理后,6％番茄红素油树脂中顺式异构体占比高于90％番茄红素中顺式异构体占比；氮气保护对番茄红素的异构化无明显保护作用；微波对番茄红素异构化有较强的促进作用,处理5h后顺式占比可以高达54.7％,但超声-微波协同法对番茄红素异构化的影响与微波单独使用时无明显变化.所以微波是较好的番茄红素热处理异构化方法.
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