Construction And Application Of Corn Protein Peptides Based Food Colloidal Delivery System

Food colloidal delivery system,which based on the interactions of food components,is an embedding and transportation technology for active ingredients by constructing food colloidal microstructure.Protein based colloidal delivery system can not only provide the body with essential nutrients,but can also considerably improve the solubility,chemical stability and biological activity of the active ingredients.In this paper,the noncovalent interactions of corn protein peptides(protein hydrolysate)and polyphenol was successfully used to construct food colloidal delivery system for curcumin(Cur)and alga oil as the model of hydrophobic active ingredients.Moreover,basing on the protein-peptides interactions,corn protein peptides was first used to structural modification or regulation of the protein based emulsions.The main conclusions are as follows:(1)Zein hydrolysate(ZH)was developed as the vehicle for Cur(as the model)to construct composite colloidal particles delivery system.The micelle formation ability and good interfacial activity of ZH was first time reported,and the stable ZH-Cur complexes could be fabricated basing on the strong noncovalent interactions under the antisolvent process of Cur.DLS and TEM results indicated that the complexes were all spherical particles with a hydrodynamic diameter of less than 50 nm,and it showed a good monodispersity and colloidal stability.After noncovalent binding with ZH,water solubility of Cur was considerably increased,also the chemical stability of Cur in long term storage.(2)The effect of xanthophylls(Xan)on the interfacial activity and colloidal delivery capacity of ZH was investigated.The existence of Xan obviously strengthened the interfacial activity and micelle formation ability of ZH,and it could also increase the O/W interface adsorption ability of ZH.The interfacial film of ZH also exhibited higher viscoelasticity compared with the film of the decolored ZH.Moreover,Xan obviously improved the colloidal delivery capacity of ZH.With the presences of Xan,the emulsions stabilized by ZH possessing smaller size and higher physical stability,and the Cur composite particles fabricated in ZH showed smaller size,better monodispersity and higher zeta potential.(3)Similarities and differences of the Cur composite particles fabricated by corn protein hydrolysate(CPH)and traditional NaCas respectively were investigated.Water solubility of Cur could be increased by the formation of Cur composite particles in CPH or NaCas solutions,but CPH was more effective compared with NaCas and the particles in CPH showed smaller size.Moreover,Cur composite particles in CPH also showed higher chemical stability and better bioaccessibility in the simulated digestive process.Additionally,compared with the passive adsorption process of NaCas,CPH could initiatively co-assemble with Cur,forming a new composite micelle structure.(4)Synergistic effect of ZH and soybean soluble polysaccharide(SSPS)in the fabrication of Cur composite particles was studied,and the application of Cur composite particles in various food systems was further expanded.Compared with SSPS,ZH play a leading role in the fabrication of Cur composite particles.However,the presences of SSPS improved the physical stability of Cur composite particles under acidic or high ionic strength conditions.Moreover,SSPS enhanced the sustained release effect of Cur and obviously improved the reconstitution of Cur composite particles after the freeze drying process.Cur composite particles fabricated in ZH-SSPS mixture exhibited high potential in the application of functional food ingredients.(5)Basing on the interactions of ZH and tannic acid(TA),the formed ZH-TA colloidal complexes were applied in the construction of surfactant-free nano-emulsion delivery system for alga oil,as the model of functional oil and lipophilic active component.Serious aggregation could happen for ZH and TA in water solution,and this was dominated mainly by the noncovalent interactions(hydrophobic interactions or hydrogen bound)between ZH and TA.ZH-TA,the noncovalent colloidal complexes,exhibited excellent interfacial activity in the construction of alga oil nano-emulsions(d = 120 nm)delivery system.This delivery system with high encapsulation efficiency for alga oil possesses high physical stability in long term storage.More importantly,this system can effectively inhibited lipid oxidation under accelerated oxidation environment for 15 days,which suggested the super antioxidant protection on alga oil.(6)Structural modification on protein based emulsions was realized by CPH induced aggregation of SPI at high temperature.CPH could induce the cross-linking and aggregation of the unfolded SPI molecule,and this mechanism could be used in the structural modification of SPI stabilized emulsions,transforming the state of the emulsion from fluid to semi-solid.Flocculation of the emulsions could obviously happen due to the presences of CPH under the heating condition,and the flocculation degree was increased with the increasing of CPH content,thus the viscoelasticity and thixotropy of the emulsions could be changed.CPH may play a role of “bridge” in the aggregation of SPI and flocculation of the emulsions,which induced cross-linking of SPI molecular in the bulk phase and interface,and finally resulted aggregation and flocculation of SPI and the emulsions.