Bleaching of Vegetable Oil using Organic Acid Activated Fuller’s Earth (Bentonite Clay)

Vegetable oil is one of the basic food items which is consumed by almost every human being in this universe. Therefore quality of vegetable oil should be good enough so that it accounts for healthy life. In vegetable oil manufacturing there are four major steps involved which are neutralization, degumming, bleaching and deodorization. Among these steps bleaching is the very important and critical step because it ensures the good color and odor of vegetable oil. The famous method of bleaching in Pakistan is adsorption by inorganic acid activated fuller’s earth (bentonite clay). Treatment with inorganic acid (Sulfuric acid and hydrochloric acid) activated bentonite clay is very efficient and shows satisfactory results. But there is a major disadvantage associated with its use. Fumes of hydrochloric acid or sulfuric acid are very dangerous for both the equipment and labor involved in manufacturing of vegetable oil. Therefore the safety of the labor and equipment is compromised. The major purpose of this research work is to give the alternative method for activation procedure of bentonite clay and this method should be the safest method for both the labor and equipment used in vegetable oil industry. So safety is the major motivation for this research. Some organic acids showed good and compatible results as compared to inorganic acids and these acids are highly safe for both the equipment and labor. Key words—Bentonite clay; Surface activation; Organic acids; Adsorption; Fourier Transform Infrared Spectroscopy (FT-IR)