A Critical Review on Vegetable Oils Refining: A Case for Local Reagents Application

Abstract

Vegetable oils contain impurities such as free fatty acids, phospholipids, and pigments that require removal through refining to improve its quality and usability. In Nigeria, traditional methods are mostly applied as a result of non-availability of required technology. Also, industrial refining methods often rely on imported chemical reagents, which increase production costs and limit local processing capacity. This review explores procedures, benefits and limitations of both traditional and industrial methods of vegetable oils refining. Also, the potential of locally sourced reagents, such as agricultural waste, as viable alternatives in the chemical and physical refining of vegetable oils are discussed. This will encourage circular economy and promote many of United Nations Sustainable Development Goals (UN SDGs), by using renewable materials in separation processes and adding values to the agricultural wastes. Emphasis is placed on the probable effectiveness, economic advantages, and environmental impact of using indigenous materials such as plant-based precipitants, agricultural waste-based alkali solutions and natural adsorbents for vegetable oils refining. Process optimization would help in providing the best condition at each stage of the refining operation and as well alternative routes based on different refining agents.