Enzymatic synthesis of carbohydrate esters of fatty acid (1) esterification of sucrose, glucose, fructose and sorbitol

The authors attempted to synthesize carbohydrate esters of fatty acids enzymatically in order to overcome the problems associated with the chemical processes for the synthesis of commercial sucrose esters. The enzymes used were lipases from microorganisms belonging toRhyzopus, Enterbacterium, Aspergillus, Pseudomonas, Chromobacterium, Candida, Mucor andPenicillium. Fatty acids (stearic, oleic and linoleic) and carbohydrates (sucrose, glucose, fructose and sorbitol) used for the reaction were obtained from commercial sources. The enzyme reaction was performed by mixing the enzyme and the substrates in the buffer solution and incubating at 40 C; after freeze‐drying the mixture, the products were extracted and subjected to thin layer chromatography (TLC) and high performance liquid chromatography (HPLC). It was observed by TLC and HPLC that carbohydrate esters of fatty acid were produced by the enzyme reaction, and their structures were confirmed by infra red (IR) and nuclear magnetic resonance (NMR) spectrometries. The lipase fromCandida cylindracea was the most enzyme active on the synthesis of carbohydrate esters. The optimum conditions for its activity were as follows: molar ratio of carbohydrate to fatty acid: 0.05mol/l : 0.2mol/l; amount of lipase: 4g/l; pH of the reaction mixture: 5.4 in phosphate buffer; reaction period: 72 hr.