Fabrication Of Pickering Emulsions System Stabilized By Gliadin/Tannic Acid Complexes And Its Application

In this study,non-covalent mixture and covalent conjugate were prepared using gliadin and tannic acid(TA).The research compared the differences in structure and functional properties between mixture and conjugate,and revealing the reaction mechanism of two.Then,the emulsification of gliadin nanoparticles(GNPs)and gliadin/TA complexes nanoparticles(GTNPs)was explored,and the emulsification mechanism was studied.Finally,nanoparticles with better interfacial stability were applied to prepare β-carotene Pickering emulsions,and the protection of the physicochemical stability of β-carotene Pickering emulsion was investigated.The main research contents and results are as follows:1.Gliadin and TA can form a non-covalent mixture by simple physical mixing.The results showed that the non-covalent binding between gliadin and TA was mainly driven through hydrogen bond,forming 1:1 gliadin-tannic acid complex.Gliadin and TA can react with Schiff base under the conditions of pH 9.0 and oxygen to form covalent conjugates.The combination of TA caused gliadin to unfold.Furtherly,the complexes formation improved the antioxidant capacity of gliadin.The mixture has a higher antioxidant capacity than conjugate,and conjugate has a higher thermal stability than mixture.2.GNPs and GTNPs were successfully prepared by anti-solvent method.The particlesize of gliadin/TA covalent nanoparticles(covalent NPs)performed polydisperse,while the particlesize of gliadin and gliadin/TA non-covalent nanoparticles(non-covalent NPs)displayed monodisperse.Conjugate increases the hydrophobicity of gliadin,making them closer to neutral wettability.Covalent NPs prefer to locate on the interface and facilitate to stabilize Pickering emulsions with the longer storage period.Covalent NPs-stabilized emulsions could not form the gel-like structure and thus it had an increasing creaming index,while non-covalent NPs-stabilized emulsions could form the gel-like structure.3.GTNPs could significantly improve the physical stability of the β-carotene emulsion during storage compared to GNPs.TA significantly inhibited the degradation ofβ-carotene under UV light,and non-covalent NPs-stabilized emulsion was more effective for preventing degradation of β-carotene.The β-carotene in GTNPs-stabilized emulsionshas higher oxidative retention rate and smaller chromatic aberration change during storage.