Gorduras vegetais hidrogenadas : produtos da termoxidação e ação antioxidante dos tocoferois

AUTOR(ES)
DATA DE PUBLICAÇÃO

2002

RESUMO

Frying is one of the most widely used practices in the food industry and in domestic food preparation. Analyses of frying fats in severaI countries have shown that a significant number of used fats and oils are beyond the alteration limit considered reasonable and/or established by legislation. Two of the most commonly used analytical procedures to evaluate the quality of frying fats and oils are the determination of polar compounds and of polymeric triacylglycerols. Values of polar compounds in the range of 25 - 30% and levels of polymeric triacylglycerols of 10 or 16% have been established in different regulations as the maximum limit for the rejection of used fats or oils. The objective of this research was to study the behaviour of partially hydrogenated vegetable fats submitted to high temperatures (thermoxidation). Samples of partially hydrogenated vegetable fats of two sources - soybean and cottonseed oils - were thermoxidated at 180°C during 10 h. The evolution of polar compounds and of polymeric triacylglycerols was determined by SPE (solid phase extraction), followed by HPSEC (high performance size-exclusion chromatography), and by HPSEC with direct injection of the sample. Effects of the degree of unsaturation and of the addition of tocopherols on thermal and oxidative degradation were also studied ...Note: The complete abstract is available with the full electronic digital thesis or dissertations

ASSUNTO(S)

antioxidantes polimeros oleos e gorduras - analise deterioração

ACESSO AO ARTIGO

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