Assessment of Rancidity and Other Physicochemical Properties of Edible Oils (Mustard and Corn Oils) Stored at Room Temperature

Abstract

Oils may go rancid and develop an unpleasant odor and flavor if incorrectly stored. The main factors that cause rancidity (in addition to moisture, bacteria and enzymes) are light, heat, air and some types of metals. Rancid oil forms harmful free radicals in the body, which are known to cause cellular damage and have been associated with diabetes, Alzheimer's disease and other conditions. Rancid oils can also cause digestive distress and deplete the body of vitamins B and E. Their chemical edible is comprised of saturated and unsaturated fatty acids and glycerides. Temperature affects the quality of edible oils. When edible oils are exposed to high temperatures, unpleasant odours and flavours could result from the deterioration its fatty or oilly portion. The study aimed at assessing rancidity and other physicochemical properties of edible oils (Mustard and Corn oils) at room temperature. Physicochemical properties of edible oils was assesses using standard analytical procedures. The results obtained gave values of density as 8.8512 g/mL for Cord oil (CO) and 9.8779 g/mL for mustard oil (MO) while values of 111.601 millipoise and 116.832 millipoise were obtained for viscosity. The temperatures were 140.02°C and 169.4°C for CO and MO respectively. Saponification value ranged from 152.7 mg for CO to 124.8 mg MO. Iodine value gave 16.56 g for CO and 8.11g in MO respectively while peroxide value recorded 213.459meq/kg in CO and 12.8411meq/kg for MO. The quality of edible oil should be regularly monitored to avoid the use of abused oil due to the health consequences of consuming foods fried in degraded oil and also, to minimize the production costs associated with early disposal of the frying medium.