| Gliadin has the advantages of non-toxicity,biodegradability and good biocompatibility.Its special amino acid composition and structure give it unique amphiphilicity,which could self-assembly into nanoparticles in antisolvent process.In this study,gliadin was used as a transport carrier for phloretin and a stabilizer in the in-situ synthesis of silver nanoparticles.The co-assembly of gliadin,phloretin and silver nanoparticles significantly improved the stability of phloretin and silver nanoparticles,and the antioxidant and antibacterial composite colloidal particles were prepared.Then,the interfacial antioxidant and antibacterial Pickering emulsions were constructed using the functional gliadin particles as stabilizer,and the stability,antioxidant activity and antibacterial activity of the emulsions were investigated.The main research results of this paper are as follows:1.The composite colloidal particles(G/CMC) of gliadin and carboxymethyl cellulose(CMC)were prepared by the anti-solvent method,and it was used as the transport carrier for phloretin(Phl).The stability and structure of these composite particles,as well as the effects of G/CMC on the stability,bioavailability and antioxidant activity of phloretin were investigated.The results showed that gliadin and CMC were mainly combined by electrostatic and hydrogen bond interactions,and the prepared G/CMC had good stability in p H range of 4.0-8.0,which could significantly improve the thermal stability and UV stability,as well as the bioaccessibility of phloretin increased from 23%to 55%.In addition,phloretin-loaded G/CMC nanoparticles(G/CMC-Phl)had strong antioxidant activity,which could inhibit the production of reactive oxygen species(ROS)in erythrocytes induced by AAPH,and had a protective effect on erythrocytes hemolysis.2.The interfacial antioxidant Pickering high internal phase emulsions(Pickering HIPEs)were prepared using G/CMC-Phl composite colloidal particles as emulsifier.The stability and rheological properties of Pickering HIPEs,as well as the effects of distribution of phloretin on the oxidation stability and digestive properties of the emulsions were investigated.The results showed that G/CMC-Phl-stabilized Pickering HIPEs is a gel-like emulsion with elasticity and has excellent storage stability.Through the co-assembly of gliadin and phloretin could achieve the interfacial delivery of antioxidants,and the prepared Pickering HIPEs could inhibit the production of primary and secondary oxidation products during the lipid oxidation reaction.What’s more,the emulsion system could protect phloretin from the influence of extreme environment and digestive enzymes in the digestive tract,thereby improved the bioaccessibility of phloretin.3.Based on the advantages of self-assembly and binding to Ag~+of gliadin and the strong antioxidant activity of phloretin,gliadin-Ag NPs-phloretin composite colloidal particles(G-Ag-Phl)were prepared through in-situ synthesis method using gliadin as stabilizers and phloretin as reducing agent.And then Pickering emulsions were prepared using G-Ag-Phl as emulsifier.The stability,antibacterial activity and mechanism of G-Ag-Phl colloidal particles and emulsions were investigated.The results showed that the size of synthesized Ag NPs was 20-30nm,and the co-assembly of gliadin and Ag NPs could achieve the stable state of Ag NPs,the prepared G-Ag-Phl could significantly inhibit the growth of Staphylococcus aureus and Escherichia coli.In addition,G-Ag-Phl-stabilized Pickering emulsions also exhibited good antibacterial activity,which could destroy the morphology of bacterial,changing the integrity and permeability of bacterial cell wall/membrane and resulting in increased of intracellular ion leakage,as well as inducing the overproduction of intracellular ROS in bacterial cells and interfering with the normal oxidative metabolism.Moreover,The Ag NPs and phloretin could exert synergistic antibacterial effect. |
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