High internal phase emulsions stabilized solely by alkali-extracted bamboo leaf polysaccharide conjugates

Bamboo leaf polysaccharides have a variety of biological activities, such as antioxidation and immunomodula-tion, but their emulsifying properties have rarely been involved. In this study, polysaccharide conjugates were extracted from bamboo leaf residue under alkaline conditions, referred to as BLPC-A. BLPC-A aqueous solution and medium-chain triglycerides (MCT) were used as the raw materials to prepare oil-in-water (O/W) high in-ternal phase emulsions (HIPEs). As a single emulsifier, BLPC-A could stabilize 80% (w/w) MCT. With the increase in the BLPC-A concentration (1.00-2.50%, w/w), the average particle size (APS) (d3,2) of the HIPEs gradually decreased, while the viscoelasticity of the HIPEs gradually increased. Furthermore, all HIPEs had good stability during a 30-day storage period at 25 celcius. Among them, after the BLPC-A HIPEs (2.00%, w/w) underwent heat treatment at 40-90 degrees C, the APS (d3,2) increased from 10.51 & mu;m to 13.01 & mu;m, the tightly packed structure was well maintained, and the HIPEs had good storage stability and enhanced viscoelasticity. When the BLPC-A HIPEs (2.00%, w/w) were exposed to different concentrations of Na+ (0.50-1.00 M) and Ca2+ (0.01-0.05 M), the APS (d3,2) decreased from 8.55 & mu;m to 7.53 & mu;m, and increased from 10.62 & mu;m to 36.54 & mu;m, respectively, while the viscoelasticity was enhanced for each, though HIPEs exposed to Na+ had superior storage stability. These results show that BLPC-A can be used as a natural emulsifier with a good emulsifying effect, while further providing support for the effective utilization of bamboo leaf resources.

Automated summary

In this study, polysaccharide conjugates extracted from bamboo leaf residue were used to prepare oil-in-water high internal phase emulsions (HIPEs). The polysaccharide conjugates showed good emulsifying properties and could stabilize medium-chain triglycerides. The stability and viscoelasticity of the HIPEs were enhanced with increasing polysaccharide concentration, and they exhibited good stability during storage and exposure to heat and ions.