GB1025265A - Method of making edible polyglycerol and polyglycerol fatty acid esters - Google Patents

Abstract

Polyglycerols and fatty acid esters thereof are prepared by heating glycerol with an interesterification catalyst in an amount not exceeding 5% by weight of the glycerol to a sufficiently high temperature above 100 DEG C. to cause polymerization, simultaneously removing water formed in the reaction by distillation, cooling the reaction, adding an amount of water at least 30% by weight of, but less than the amount of, the polyglycerol, introducing a solid bleaching agent in an amount not exceeding 20% by weight of said polyglycerol, maintaining a temperature above room temperature and below 100 DEG C. for a sufficient time to bleach said polyglycerol, separating said polyglycerol from said water and, if desired, esterifying the bleached polyglycerol by heating with saturated or unsaturated fatty acids having 2-22 carbon atoms in the molecule, and/or with their glycerides or anhydrides to polyglycerol esters. The polymerization reaction can be stopped at the desired degree of polymerization, usually when the polyglycerol contains 2-30, preferably 3-8, glyceryl units, by determining the specific gravity, refractive index and the viscosity at suitable times during the source of the reaction. All or only one, but preferably 1-4, of the hydroxyl groups of the polyglycerol may be esterified with the fatty acids. Specified interesterification catalysts are the alkyl metal oxides and hydroxides, iodine, sodium acetate and sodium glyceroxide and specified bleaching agents are carbon black, activated clay and bleaching earths. In modifications of the process (a) the esterification is effected with a glyceride which is a vegetable or animal fat or oil and (b) a polyglycerol ester with a fatty acid is reacted with acetic acid to form the acetate.ALSO:Polyglycerols and fatty acid esters thereof are prepared by heating glycerol with an interesterification catalyst in an amount not exceeding 5% by weight of the glycerol to a sufficiently high temperature above 100 DEG C. to cause polymerization, simultaneously removing water formed in the reaction by distillation, cooling the reaction, adding an amount of water at least 30% by weight of, but less than the amount of, the polyglycerol, introducing a solid bleaching agent in an amount not exceeding 20% by weight of said polyglycerol, maintaining a temperature above room temperature and below 100 DEG C. for a sufficient time to bleach said polyglycerol, separating said polyglycerol from said water and, if desired, esterifying the bleached polyglycerol by heating with saturated or unsaturated fatty acids having 2-22 carbon atoms in the molecule, and/or with their glycerides or anhydrides to polyglycerol esters. The polymerization reaction can be stopped at the desired degree of polymerization, usually when the polyglycerol contains 2-30, preferably 3-8, glyceryl units, by determining the specific gravity, refractive index and the viscosity at suitable times during the course of the reaction. All or only one, but preferably 1-4, of the hydroxyl groups of the polyglycerol may be esterified with the fatty acids. Specified inter-esterification catalysts are the alkyl metal oxides and hydroxides, iodine, sodium acetate and sodium glyceroxide and specified bleaching agents are carbon black, activated clay and bleaching earths. In modifications of the process (a) the esterification is effected with a glyceride which is a vegetable or animal fat or oil and (b) a polyglycerol ester with a fatty acid is reacted with acetic acid to form the acetate.ALSO:A composition for intravenous injection contain 0.01 to 5% preferably 0.12 to 0.18%, by weight of a polyglycerol-fatty acid ester prepared by a novel process (see Division C2). The esters may also be included in creams and ointments.