Synthesis and properties of carbohydrate and alkyl-glycoside fatty acid polyesters: Low calorie oil and fat substitutes

Carbohydrate fatty acid polyesters are synthetic liquid, semi-solid and solid nondigestible, nonabsorbable fat and oil substitutes for dietary fats and oils with the physical and functional properties of conventional fats, vegetable and salad oils. Synthesis of carbohydrate fatty acid polyesters requires the use of fatty acid methyl esters (FAME) and carbohydrate acetates for optimum yield and purity.;A new method devoid of potentially toxic solvents and reagents was developed for the preparation of FAME by transesterification of vegetable oils. The FAME are usable in the synthesis of food quality carbohydrate and alkyl glycoside polyesters.;A one-stage solvent-free low cost interesterification procedure for the synthesis and purification of carbohydrate and alkyl glycoside fatty acid polyesters was developed. Methyl esters of homogeneous and heterogeneous fatty acids in the presence of sodium metal as catalyst were reacted with carbohydrate and alkyl glycoside acetates to obtain excellent yields of food quality polyesters. A variety of nonreducing carbohydrates have been used to produce polyesters: the monosaccharide sugar alcohol, sorbitol; the disaccharides, sucrose and trehalose; the trisaccharide, raffinose; and the tetrasaccharide, stachyose acetate. Reducing saccharides, glucose and galactose converted to nonreducing saccharides as alkyl glycosides were acetylated and interesterified with FAME to produce methyl glucoside, methyl galactoside and octyl glucoside fatty acid polyesters.;The structures of carbohydrate and alkyl glycoside polyesters were confirmed by both infrared and C-13 NMR spectroscopy. The degree of substitution was determined by C-13 NMR spectroscopy. The physical properties of the carbohydrate and alkyl glycoside polyesters were similar to conventional fats and oils.;In vitro enzymatic hydrolysis by lipolytic enzymes and in vivo mice feeding trials indicated the carbohydrate and alkyl glycoside polyesters are neither digested nor absorbed and may serve as low calorie oils and fats substitutes.