Effect of elevated drying temperature on rapeseed oil quality

Effect of rapeseed drying temperature on oil quality was investigated over the range 50–250°C. Total oil content was not significantly affected at 5% probability. Amounts of free fatty acids were significantly affected but remained much below the maximum permissible limit. Oil color was also significantly affected but had no specific trend of variation with temperature, and visual differentiation was difficult. Further, visual cracks and blackening were observed in rapeseeds dried at 250°C. Based on this study, elevated drying temperature up to 200°C was recommended for rapeseed without adversely affecting oil quality. This would save up to 80% drying time compared to the present practice of drying rapeseed at a maximum temperature of 93°C.