Monitoring by 1H nuclear magnetic resonance of the changes in the composition of virgin linseed oil heated at frying temperature. Comparison with the evolution of other edible oils
- 作者：Maria D. Guillé ; n ; mariadolores.guillen@ehu.es ; Patricia S. Uriarte
- 关键词：Linseed oil ; Omega 3 groups ; Thermodegradation process ; Frying temperature ; 1H nuclear magnetic resonance (1H NMR) ; Acyl groups ; Aldehydes ; Iodine Value ; Polar Compounds ; Sunflower oil ; Extra virgin olive oil
- 刊名：Food Control
- 出版年：2012
- 期刊代码：49_09567135
- 类别：abs
- 出版时间：November, 2012
- 卷：28
- 期：1
- 页码：59-68
- 文件大小：540 K
摘要
Linseed oil was heated at frying temperature in an industrial fryer for 20聽h. The evolution of its composition was monitored by 1H Nuclear magnetic resonance. The composition parameters determined simultaneously were: the molar percentage of the different acyl groups, the Iodine Value, the concentration of the total aldehydes as well as of the different kinds of aldehydes; in addition, the percentage in weight of Polar Compounds was also determined at different heating times. When heating this oil the molar percentage of linolenic groups diminishes at an important rate while that of linoleic or diunsaturated groups increases, as does that of saturated plus modified groups, that of oleic or monounsaturated groups remaining unchanged. The main aldehydes formed were (E,E)-2,4-alkadienals together with n-alkanals and (E)-2-alkenals. This oil reached the safety limit of 25%in weight of Polar Compounds very early with a very small degradation level of acyl groups and a very low content of aldehydes. The changes undergone by this oil were compared with those of sunflower oil and of extra virgin olive oil submitted to the same degradative conditions.