Effect of enzyme types on emulsifying properties of walnut emulsion

Abstract

In order to explore the efficient investigate and utilization of emulsion produced by enzyme-assisted aqueous extraction of walnut oil, the effects of different enzyme treatment (including Alcalase 2.4L, Ban 480L α-amylase, Neutrase 0.8L, Pectinex SP-L, Celluclast 1.5L) on the characteristics of emulsion were studied to characterize its emulsifying characteristics The emulsion composition, particle size distribution, Zeta potential, rheological properties and protein surface hydrophobicity of emulsion were determined to characterize its emulsifying properties. The results showed that the particle size of the emulsion obtained from enzymatic hydrolysis showed a smaller trend and the absolute value of Zeta potential showed a larger trend in the presence of enzymes. On emulsion protein, hydrophobicity of emulsion protein was obtained by hydrolysis with different enzymes showed that the trend followed the order: Celluclast 1.5L> Ban 480L >Neutrase 0.8L >Pectinex SP-L >control> Alcalase 2.4L. The particle size, zeta potential, ability to increase emulsion viscosity and interfacial hydrophobicity of emulsion proteins affected the emulsion physical stability and the effect of demulsification. The results of rheological analysis show that emulsions from Ban 480L α-amylase, Neutrase 0.8L and Celluclast 1.5L hydrolysate still maintained their elastic structure damaged by shear rate and were more stable, and the emulsions obtained by Alcalase 2.4L and Pectinex SP-L were unstable which was easy to be broken.