Effect of frying conditions on fatty acid profile and total polar materials via viscosity

This work investigates how the temperature dependence of soybean oil viscosity varies with frying conditions and chemical composition, to develop a model that predicts oil degradation directly from process parameters. The temperature dependence of frying oil viscosity is described using Lioumbas et al. (2012) non-linear model, which is confirmed with satisfactory accuracy (r2 > 0.9998). Two models, predicting viscosity separately from frying conditions and chemical composition, are established, both with an overall accuracy of greater than 95.0%. Using the viscosity parameter as a medium, multiple quasi-linear regression analysis was applied to derive an expression that predicts fatty acid composition and total polar materials from the average oil temperature and the frying time (r2 = 0.930). This final expression quantifies the relationship between the frying conditions and the chemical composition of the oil, which is convenient for on-site quality control.