Microwave and Conventional Heating Effects on Some Physical and Chemical Parameters of Edible Fats

Abstract

Effects of microwave energy and conventional heating on physical and chemical parameters of five edible oils and fats (virgin olive oil, olive oil, sunflower oil, high oleic sunflower oil, and lard) were investigated. These fats and oils were subjected to three well-controlled treatments: heating in conventional electric oven, heating by microwave energy, and exposure to microwave energy, respectively. The effect of microwave heating on the visible spectrum, K 232 and K 270, density, viscosity, and squalene and trans -isomer contents of fats and oils was worse than that produced by heating the same fats in a conventional oven at the same temperature, time, surface/volume ratio, and light conditions. Subjecting fats and oils to microwave energy under the same conditions, but below 40 °C, did not produce considerable variations in the same parameters when compared to the original ones. Keywords: Microwave oven; heating effect; chemical and physical parameters; edible fats and oils