Study on Construction and Self-Emulsifying of Rice-Casein Complex

Abstract:

The purpose of this study was to fabricate rice protein/casein complexes（CPS）and to explore their self-emulsifying behavior. By mixing rice proteins and casein at a mass ratio of 1:1 at pH = 12 and readjusting the pH to 7，soluble CPs can be obtained. The solubility and hydrophobic characteristics of CPs were measured. The results showed that rice proteins and casein were merged by hydrophobic interactions and the solubility of rice proteins was enhanced by 50 times. In addition，isothermal titration calorimetry（ITC）showed that there was a spontaneous exothermic reaction between the CPs and eugenol. The eugenol can be self-emulsified with different proportions of CPsto form nanoemulsions that had an average particle size<200 nm and Zeta-potential intensity >-30 mV. The recovery of CPs in the emulsions can be as high as 79.75%，the maximum efficiency of encapsulation of eugenol was 28.54 μg/mL，and the maximum binding capacity of eugenol is 336.78 μL/g CPs. The data illustrated by particle size and the zeta-potential of emulsions indicated that the emulsions had strong storage stabilities during the 28-day storage. Release studies showed that the emulsion can control the release rate of eugenol，which followed a style of first-order release kinetics. The results demonstrated that the CPs prepared by this study are promising food ingredients in food industry and the CPs-eugenol emulsions can be potential candidates for delivery of lipophilic bioactives for their controlled release attributes.