6533b7dbfe1ef96bd12712ae
RESEARCH PRODUCT
Determination of unsaturation grade and trans isomers generated during thermal oxidation of edible oils and fats by FTIR
D Mendoza OlivaresJ. V. Gimeno AdelantadoM.c.m. Moya MorenoF.j Amézquita LópezF. Bosch Reigsubject
chemistry.chemical_classificationDegree of unsaturationfood.ingredientChemistrySunflower oilOrganic ChemistrySunflowerAnalytical ChemistryInorganic ChemistryAbsorbancefoodOrganic chemistryFood scienceCanolaSpectroscopyCorn oilCis–trans isomerismPolyunsaturated fatty aciddescription
Abstract The oxidative deterioration of culinary oils and fats during episodes of heating associated with normal usage (80°C–300°C, 20–40 min) was monitored by FTIR spectroscopy. The thermal oxidation of polyunsaturated fatty acids during heating was studied by the determination of unsaturation percentage and trans isomers at various temperatures and heating times. Oils frequently used in food frying such as olive oil, sunflower oil, corn oil and seeds oil (sunflower, safflower and canola seed), and lard were studied. The Absorbance Correction Method is proposed to correct the spectral interference and allows the analytic use of signal which would not be initially valid for quantitative analysis. The results show that there is a decrease in unsaturation and an increase in trans isomers starting at 150°C and becomes more pronounced at temperatures around 250°C. This variation in unsaturation grade and conformation provides evidence of the transformation of essential polyunsaturated fatty acids and subsequent decrease in the oils’ nutritional value.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 1999-05-01 | Journal of Molecular Structure |