高温条件下亚麻籽油二次氧化产物的动态变化

Dynamic change of secondary oxidation products in flaxseed oil at high temperature

探讨了亚麻籽油在100~200℃条件下加热1~5 h的过程中过氧化值、酸价、羰基值以及二次氧化产物脂肪族醛类化合物的动态变化。结果表明:亚麻籽油在100℃条件下加热时,过氧化值随加热时间的延长而升高;在120~200℃条件下加热时,过氧化值随加热时间的延长呈现先升高后降低的趋势。酸价和羰基值均随加热温度的升高和加热时间的延长而升高。亚麻籽油高温氧化过程中亚麻酸产生的特征二次氧化产物含量最高,其次是亚油酸,油酸最少。亚麻酸特征二次氧化产物中丙醛最易生成且含量最高,反-2-戊烯醛和反-2-己烯醛产生较晚、较慢,亚油酸特征二次氧化产物中己醛最先生成,反-2-壬烯醛和反,反-2,4-癸二烯醛生成较晚、较慢;油酸特征二次氧化产物中壬醛在120℃加热1 h没有生成,之后其含量随加热温度升高而增加,随加热时间延长先增加后降低。

The dynamic changes of peroxidation value,acid value,carbonyl value and secondary oxidation products aliphatic aldehyde compounds in flaxseed oil heating at 100-200℃for 1-5 h were investigated.The results showed that the peroxide value of flaxseed oil increased with the extension of heating time at100℃,and it increased first then decreased at 120-200℃,while the acid value and carbonyl value of flaxseed oil increased with heating time extension and heating temperature rising.Linolenic acid produced the most characteristic secondary oxidation products during the oxidation of flaxseed oil at high temperature,followed by linoleic acid and oleic acid.Among the secondary oxidation products of linolenic acid,propionaldehyde was easily formed and had the highest content,in contrast,trans-2-pentenal and trans-2-hexenal produced later and slower.Hexanal first produced in the secondary oxidation products of linoleic acid,and the trans-2-nonenal and trans-and trans-2,4-decadienal produced later and slower.The secondary oxidation product of oleic acid nonanal was not detected when reacting at 120℃for 1 h,later nonanal content increased with heating temperature rising,and first increased then decreased with heating time prolonging.