A Novel Method for Extracting Steryl Glucosides From Soy Lecithin

In this study, a novel method utilizing enzyme and involving simple solvent extraction steps, is developed to yield an extract with high content of steryl glucosides (SG) and acyl steryl glucosides (ASG) from soy lecithin - the by-product of vegetable oil refining. Phospholipase A(1) is used to convert phospholipids in soy lecithin into more hydrophilic hydrolysates, from which SG and ASG are separated by solvent extractions. A 3x3 full factorial design is employed to investigate the effects of two parameters (enzyme dose and reaction time) on three responses (yield of extract, SG/ASG content of extract, and recovery of SG/ASG). There are significant enzyme dose - reaction time interaction effects on all the responses, except for yield of extract. The highest SG (including ASG) content of more than 90% in the extract is achieved at enzyme dose of 0.03g and reaction time of 16h, where the yield of extract obtained is 1.43%.Practical Applications: Conventionally, steryl glucosides and acyl steryl glucosides are isolated from lipid extract and purified by chromatographic methods, which result in a small amount of high purity steryl glucosides and acyl steryl glucosides, and thus is not economic to scale up. The method revealed in this study employed an enzymatic reaction followed by simple solvent extractions, and can be easily scaled up to produce high purity steryl glucosides and acyl steryl glucosides, making them more affordable for researchers. In addition, the method also presents a new application for soy lecithin or lecithin of other plant origins, whose current applications are mostly related to the main component-phospholipids. In this study, a novel method utilizing enzyme and involving simple solvent extraction steps is developed to yield an extract with high content of steryl glucosides (SG) and acyl steryl glucosides (ASG) from soy lecithin - the by-product of vegetable oil refining.