Revealing the relationship between vegetable oil composition and oxidative stability: A multifactorial approach

A detailed composition analysis was performed for 22 diverse oils and fats and included determination of tocopherols (α, γ and δ), β-carotene, chlorophyll, total phenolic compounds (TPC) and fatty acid (FA) composition, as well as the determination of their oxidative stability (Rancimat test). Principal components analysis was applied to obtain an overview of the sample variations and to identify behavioural patterns. Linear regression correlations and a multiple linear regression model were performed to quantify the relationship between the composition of oils and fats and their oxidative stability. The TPC and saturated FA were the main individual factors that correlated positively with oxidative stability (r2 = 0.417, r2 = 0.321 respectively, p < .01), whereas unsaturated FA, polyunsaturated FA and total tocopherols correlated negatively (r2 = 0.304, r2 = 0.264, r2 = 0.223 respectively, p < .01). Saturated, monounsaturated and polyunsaturated FA together accounted for 67% of variability and are considered the most important parameters to affect oxidative stability. Results of this study provide a better understanding of the complex relationship between oil and fat composition and their oxidative stability, which is an essential step for designing strategies to increase stability and shelf-life of culinary oils.