Generalized linear model describes determinants of total antioxidant capacity of refined vegetable oils
2012
CasteloâBranco, Vanessa Naciuk | Torres, Alexandre Guedes
The total antioxidant capacity of edible oils corresponds to the integrated action of antioxidant compounds. The antioxidant capacity may be used as a proxy of the chemical antioxidant activities of components in oils, but this hypothesis has not been tested by multivariate statistical analysis. Tocols, fatty acids, artificial antioxidants, peroxide value, conjugated dienes, and total antioxidant capacity were determined in samples of refined oils of soybean, corn, canola, and sunflower. Generalized linear models and multiple regression models were adjusted to estimate the integrated association between the total antioxidant capacity and chemical components of oils. The generalized linear model of antioxidant capacity better adjusted to the data because the descriptive variable type of oil was a significant predictor. The type of oil, γâ and δâtocopherols, and peroxide value explained 95% of the variability of antioxidant capacity in the model (pâ=â0.0006). Besides, γâtocopherol was the most important predictor variable for the model considering the pâvalue and the estimated relative weight for the model. Therefore, γâtocopherol was the major determinant of total antioxidant capacity of refined oils of soybean, corn, canola, and sunflower. Practical applications: Direct spectrophotometric assay of antioxidant activity can be used to determine the antioxidant quality of fresh refined oils. Furthermore, the statistical evaluation of chemical determinants of vegetable oils based on generalized linear models might contribute to our understanding of the antioxidant quality and the stability of oils.
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