Amphiphilic Esterified Xylo-Oligosaccharide: Surface-Active Properties and Anti-Microbial Activities

Abstract

Background and Objective: The lipase catalyzed-esterification of native xylo-oligosaccharide (Xylo) and lauric acid (C-12) was used to synthesize amphiphilic esterified xylo-oligosaccharide laurate (Xylo_L). This study was designed to investigate the surface-active properties and antimicrobial activities at different concentrations of Xylo_L [0-15% (w/w)], compared to Xylo. Materials and Methods: Emulsifying activity, emulsifying stability, foamability and foaming stability of Xylo_L was determined, compared to Xylo. The antimicrobial activities of Xylo and Xylo_L were evaluated against Escherichia coli (a Gram-negative bacterium) and Staphylococcus aureus (a Gram-positive bacterium). Results: Esterified modification of Xylo improved the emulsifying ability and prolonged the stability of emulsions, when soybean oil was used as the dispersed phase. Xylo exhibited antimicrobial activities for both E. coli and S. aureus at all concentrations [5-15% (w/w)]. Xylo_L was less effective at E. coli and S. aureus inhibition than Xylo at all concentrations [5-15% (w/w)]. Conclusion: The antimicrobial activities decreased after the esterification of Xylo to Xylo_L. Xylo_L may suitable as an ingredient of emulsion foods, as an emulsifier and stabilizer with a slight antimicrobial function.