Comparative Physical Characterization, Physio-Chemical and Fatty Acid Composition of Some Edible Vegetable Oils

Abstract

Edible vegetable oils which include red palm oil, coconut oil, groundnut oil, sesame oil (Beniseed oil), soybean oil, palm kernel oil, etc. are derived from seeds or fruits of different plants. These oils are consumed not only for their supply of lipids in the diets but for their distinct aromas, colours, palatability and availability. Vegetable oils are rich in essential nutrients such as vitamins and anti-oxidant compounds. The type of diet and in particular the nature of dietary fats has been found to raise or lower the blood cholesterol in man. This study was therefore necessary as it will assess and ascertain the physiochemical and fatty acid characteristics of the various vegetable oils available in the Nigerian markets. The various physiochemical and fatty acid parameters were estimated using standard procedure. Results indicate that red palm oil had high levels of palmitic and oleic acids as well as peroxide and iodine values, with high fire and boiling points. Coconut oil had high peroxide, saponification and acid values, high concentrations of capric, lauric, palmitic, myristic, stearic and linoleic acids with high smoke point. Palm kernel oil had high iodine, saponification and acid values, high contents of capric, lauric and myristic acids with high flash, fire and boiling points. Oleic and stearic acids were in turn very high in soybean, sesame. In conclusion, results indicate that red palm oil, soybean and sesame oil would be safer for consumption since there are less atherogenic compared with the other vegetable oils.