Effect of heating time on the physicochemical properties of selected vegetable oils
John Kanayo Chukwu Nduka, Precious Oshiovue Omozuwa, Ojeaga Evans Imanah
Abstract
The determination of oil physicochemical properties is a useful strategy to monitor oil quality to avoid the use of potentially toxic oil. It is relevant in determining the physical and chemical changes that oil undergo during heating. In this work, the effect of prolong heating time from 1–7 h on the physicochemical properties of soybean oil, palmolein oil, groundnut oil and palm kernel oil was examined. Properties such as specific gravity, viscosity, saponification value (SV), iodine value (IV), free fatty acid and peroxide value (PV) were studied to evaluate the compositional quality of oils. Results revealed that heating at the different times did not have any significant effect on the physicochemical properties of the oils. There was however, significant differences of the physicochemical properties on the oil types. Results further reveal that based on the peroxide value, soybean oil was the most stable oil out of the four oils studied while palm kernel oil was found to be the least stable oil; as the stability of palm olein oil was found greater than that of groundnut oil.