Construction And Application Of Corn Protein Hydrolysate Based Food-grade Colloidal Structures

Food-grade colloidal structures can be generated by utilization of molecular interactions between food macromolecules and small molecular weight compounds or mutual interactions of two macromolecules.They have shown good potential for applications in the food,beverage,and dietary supplement industries.These novel structures used for the formulation and delivery of bioactive molecules.Recently,naturally occurring surface-active substances have attracted increased interest in the food fields.In this study,we first found that corn protein hydrolysate(CPH)can be developed into a new type of natural surfactants.We constructed different food-grade colloidal structures based on the noncovalent interaction with vitamin D3(VD3),tannic acid(TA)and calcium phosphate particles(CaP),and then evaluated and investigated their potentials as the novel vehicle for hydrophobic active substances,natural and efficient foaming agents,emulsifiers,respectively.These findings would provide the theoretical and technical supports for the development of natural ingredients in functional food applications.The main conclusions are as follows:(1)We prepared corn protein hydrolysate-based VD3 nanocomplexes.UV and FT-IR spectra indicated the existence of non-covalent interactions(i.e.hydrogen bonding)between CPH and VD3.The result from X-ray diffraction further suggested the formation of amorphous structure of VD3 after its complexation with CPH.Additionally,dynamic light scattering and transmission electron microscope showed that the CPH-VD3 complexes exhibited a spherical structure with a size scale from 102 to 121 nm.The encapsulation and loading efficiency of VD3 could reach 97% and 9%,respectively.Furthermore,the complexation obviously avoided spontaneous particle aggregation of VD3 against ionic strength([NaCl] = 200 mmol/L).The remaining ratio of the encapsulated VD3 after exposure to high levels of UV light was as high as 72%.More importantly,in vitro bioaccessibility of VD3 could be up to 95% for the complexes.This study demonstrated that CPH could serve as a novel nano-vehicle for VD3 and it opens up the possibility of using CPH to construct the colloidal delivery system.(2)We investigated the interation between CPH and TA,and evaluate the potential ofCPH-TA complexes as novel foaming agents.Serious aggregation could happen for CPH and TA in water solution,and this was dominated mainly by the noncovalent interactions(hydrophobic interactions or hydrogen bound)between CPH and TA.Compared to CPH,CPH–TA complexes in appropriate CPH/TA ratio(CPH/TA=1:0.3)formed strong viscoelastic interfacial film,which had stable oscillatory elasticity.These surface properties were positively reflected in foams produced by the CPH–TA complexes,which exhibited good foaming capacity and considerable stability probably due to better response to external stresses.But the structure of CPH–TA complexes prepared with too high TA concentration(CPH/TA=1:0.5)is too dense,which decreased the surface elasticity of layers dramatically,and the resultant foams became less stable.(3)We investigated the synergistic interfacial properties of CPH-CaP complexes at the oil-water interface.Results showed that,with the addition of CPH,synergistic effects in interfacial tension decays were clearly observed.The decoration of CaP particles with CPH enhanced their hydrophobic wettability simultaneously.These interfacial properties were positively reflected in the emulsions prepared by the complexes.The Pickering emulsions exhibited a fine formation ability and long-term stability.Whatmore,the balance between different noncovalent interactions of CPH and CaP can be modulated via pH and concentration ratio.Hence,the surface modified CaP particles facilitate to construct interfacial crystal architecture and resulting stable Pickering emulsions and gels.