GB670899A - Refining of solvent-extracted vegetable oils - Google Patents

Abstract

A process for refining and decolorizing solvent-extracted vegetable oils by agitating with aqueous sodium hydroxide is carried out in the presence of at least one non-ionic ether of a polyhydric alcohol containing two to three hydroxy groups and from two to eight carbon atoms or a non-ionic derivative of such of said ethers as contain an unreacted hydroxyl group, such compounds being liquid at about 80 DEG F. The ether may be a polyglycol containing at least two glycol units, such as polypropylene glycol having a molecular weight of about 400, and may have one or both of the hydroxyl groups etherified by alkyl groups of from 1 to 18 carbon atoms or substituted by carboxylic, phenolic, amino or mercapto groups. The addition of the non-ionic ethers improves the colour removal and permits reduction in the quantity of alkali used and in the time of treatment. Examples are given showing the colour reduction obtained when extracted cottonseed or soya bean oils containing about 40 per cent oil and 60 per cent hexane are agitated with aqueous alkali and polypropylene glycol of about 400 molecular weight at about 130 DEG F, and with a number of other ethers and ether esters of the polyglycol type.