Outline
- Abstract
- Keywords
- 1. Introduction
- 2. Vegetable Oils and Degradation Process
- 3. Experimental Part: Thermal Degradation Monitoring
- 3.1. Materials
- 3.2. Raman Spectroscopy and Raman Instrumentation
- 4. Results
- Conclusion
- Acknowledgements
- References
رئوس مطالب
- چکیده
- کلید واژه ها
- 1. مقدمه
- 2. روغن های گیاهی و فرآیند تخریب
- 3. بخش تجربی : پایش تخریب حرارتی
- 1.3. مواد
- 2.3. ابزار دقیق و طیف سنجی رامان
- 4. نتایج
- نتیجه گیری
Abstract
The paper deals with measuring of structural changes in edible oils during their heating giving arise to unsafe degradation products. The attention is paid to the major decomposition product of heated oxidized linoleate and content of carotenoids with antioxidant effects. Analysis is based on Raman spectral data that provide unique information about the structure of the oils. Raman spectroscopy offers effective and rapid way for oils quality control with respect to their health benefits and in terms of processes in food technology. Three most common vegetable oils were used for the thermal degradation study: sunflower, canola and olive oil. Measured were both, extra virgin and refined oils. Mathematically processed spectral data indicate the least action of thermal load for olive oils. Then due to a significant content of antioxidants it is canola oil. The worst effect in terms of thermal decomposition products formation and the loss of cis double bonds arise for sunflower oils.
Keywords: measurement - Raman Spectroscopy - scarotenoids - Thermal degradation - vegetable oilConclusions
Raman spectroscopic study of oxidative degradation of edible oils shows that thermal stress of vegetable oils can be monitored via the amount of rising degradation products. Multivariate statistical method PCA and PLS are an efficient tool for spectral data evaluation. Analyses carried out for sunflower, canola and olive oils leads to the conclusion that the most evident degradation occurs for polysaturated sunflower oils. Canola oils give better results due to negligible content of carotenoids and the best results exhibit olive oils. These two represent greater health benefits as rather monosaturated oils and are more suitable for thermal stress. However, prolonged heat load of all types of cooking oils causes the formation of degradation products that may undesirably affect the human health. Raman spectroscopic evaluation of discussed features brings advantages over traditional methods mainly in sense of rapidity, simplicity and no need of chemical reagents and sample preparation, what saves time and costs.