Abstract
To satisfy consumers’ requirement of less smoke, vegetable oils should possess certain thermal stability, which was evaluated by smoke point and dependent on the content of the minor compounds. As the proposal of the moderate refining technology, contents of the minor compounds such as free acid, peroxide, phosphorus, solvent, water and other volatile matters under the condition would change interactively, leading the establish of the vegetable oil standards difficult. The purpose of this work was to investigate the effects of the minor compounds on the smoke point. Soybean oil and rapeseed oil samples with different contents of free fatty acid, peroxide, phosphorus, solvent, moisture and volatile matter were collected and their mathematical relationships with smoke point was analyzed by principal component regression. Based on these results, a regression equation was obtained: Ln smoke point=4.790–0.021×Ln (acid value) + 0.014×Ln(peroxide value)–0.051×Ln (content of phospholipids)–0.105×Ln (moisture and volatile matter) (R2=0.848).
Furthermore, according to the correlation coefficient of the calculated and measured smoke point (0.972), the suitability of the regression model in terms of its ability to predict the smoke point of different oil samples was good.
