GB989540A - Interesterification process for fatty glycerides - Google Patents

Abstract

Fatty glyceride esters containing not more than 0.1% free fatty acid are randomly interesterified by (a) forming a dispersion in the ester of 0.02-0.08%, by weight of the ester, of alkali metal, preferably sodium, hydroxide in the form of a 1-12% aqueous solution containing also at least 0.1%, but preferably not more than 0.3% glycerol, while maintaining the temperature high enough to melt all solids present but not so high as to flash off the glycerol, i.e. generally not above 160 DEG C.; (b) maintaining the temperature at least 120 DEG C. but below that at which the glycerol will boil off, and usually not above 200 DEG C., until the desired degree of molecular rearrangement has been attained; (c) destroying the hydroxide catalyst by addition of an edible acidic material, suitably citric or phosphoric acid, capable of splitting alkali metal soaps, in an amount of 1-5 equivalents of the alkali metal hydroxide present, but preferably in an amount no greater than that which would produce a free fatty acid content in the rearranged esters of 0.7%; and (d) removing the oil-insoluble material thereby formed. If required, steps (a) and/or (b) may be carried out under reduced pressure. If the glycerides to be randomized contain more than 0.1% free fatty acid, they may be pretreated to reduce the level below 0.1% by adding sufficient aqueous alkali metal hydroxide solution containing 1-12% hydroxide, and thereafter removing water by heating under vacuum. Glycerides suitable for interesterification comprises mixture of soyabean oil with tallow or lard, and of palm oil and coconut oil. The free fatty acid present in the product may subsequently be removed by a conventional deodorization process. Specification 802,129 is referred to.