GB428048A - Improvements in or relating to edible fats and fatty oils - Google Patents

Abstract

Cooking-fat derived from fatty acids of molecular formula containing predominantly not fewer than 16 carbon atoms is improved by forming therein free fatty acid either by partially saponifying the fat and then acidulating or by subjecting the fat to limited reaction with water in the presence of a catalyst. The saponification may be with a caustic alkali, preferably a concentrated solution of sodium hydroxide, and the subsequent acidulation with a strong acid, preferably sulphuric or phosphoric, the fat being finally washed with water to remove the alkali salt formed, together with any excess of acid. The hydrolysis may be effected by the use of enzymes, by treatment in an autoclave in the presence of a soap catalyst which is subsequently washed out, or by the Twitchell process using a water-soluble sulphonic acid catalyst. The fats used include common fats, such as lard, peanut oil or hydrogenated cotton-seed oil processed to be of edible grade. During and after the process contact of the free fatty acid with air is avoided by packing the fat in air-tight containers or by employing an inert gas such as nitrogen. In an alkali-refined fat for use both for frying and in baked goods the final free fatty-acid content is preferably 0,25-2 per cent. For a shortening to be used only in baked products an edible fat, alkali-refined or not, containing less than one per cent of free fatty acid is so treated that the free fatty acid content is 2-10 per cent. Specification 414,916, [Group VI], is referred to.