Study On The Construction Of Edible Dock Protein Delivery System And The Encapsulation Of Flavonoids

Edible dock is rich in protein and is a new type of edible resource.Flavonoids have various biological health effects,but their poor water solubility and low stability greatly limit their application in food.In order to improve the stability of flavonoids,edible dock protein was extracted using alkali solution and acid precipitation method,and its physicochemical properties were characterized.We used edible dock protein to embed four flavonoids with different phenolic hydroxyl positions（chrysin,baicalein,apigenin and galangin）,and analyzed the interaction between flavonoids with different phenolic hydroxyl positions and editable dock protein;Then,a binary composite micelle system of apigenin-edible dock protein was constructed,and yeastβ-glucan was added.Preparation of apigenin-edible dock protein-yeastβ-glucan.The physicochemical properties,structural properties,and interaction mechanism of the ternary composite micelles of dextran were analyzed.The main results are as follows:1.Analysis of physicochemical properties of edible dock proteinThe protein content in edible dock is 35.67%.We used a combination of alkalidissolution and acid precipitation and dialysis methods to isolate and purify edible dock protein,with an extraction rate of 44.61%and a purity of 82.57%.The average molecular weight of the protein measured by volume exclusion chromatography was approximately44.53 k Da.Using an automatic amino acid analyzer,the edible dock protein is rich in 18amino acids,of which the content of hydrophobic amino acids accounts for 45.52%of the total amino acids,providing a good hydrophobic cavity for flavonoids.2.Preparation and characterization of flavone-EDP composite micellesWe used edible dock protein to embed four flavonoids with different phenolic hydroxyl positions.The results showed that the encapsulation efficiency was in the order of apigenin>galangin>baicalin>chrysin.As temperature increases,K_SV decreases,while K_q is significantly higher than the maximum diffusion collision quenching constant of 2.0×10¹⁰L·（mol·s）^-1,indicating a static quenching between the edible dock protein and flavonoids.Thermodynamic parameters?H<0,?S<0 and?G<0 indicate that the binding between editable dock protein and flavonoids is a spontaneous endothermic process,and hydrogen bond and van der Waals force are the main driving forces for self-assembly.The results of in vitro digestion experiments indicate that the edible dock protein has a sustained release effect on all four flavonoids.After three months of storage,the retention rates of flavonoids were above 60%,indicating that the edible dock protein micelles significantly improved the stability of flavonoids.3.Preparation and characterization of ternary complexOn the basis of the above,select the apigenin-edible dock protein with the bestembedding effect as a representative binary composite micelle to further explore yeastβ-glucan stabilizing and synergistic effects of dextran on binary micelles.The results showed that when yeastβ-glucan addition amount of dextran was 0.5%（w/w）,the embedding rate of apigenin increased to 89.23%.During the self-assembly process of ternary composite micelles,yeastβ-glucan induces the spatial structure expansion of the edible dock protein,exposing it to more endogenous fluorescent groups.FT-IR map shows that yeastβ-glucan hydrogen bonding interactions occurred between dextran and apigenin-edible dock protein composite nanocapsules.Thermodynamic parameters indicate that apigenin-edible dock protein-yeastβ-glucan.The formation of dextran ternary composite micelles is a spontaneous endothermic process,and hydrogen bond and van der Waals force are the main driving forces.The simulated digestion experiment results show that yeastβ-glucan can effectively slow down the degradation of apigenin in the stomach and enable its efficient and sustained release in the intestinal tract,which is conducive to exerting the true nutritional value and health effects of apigenin.To sum up,the edible dock protein based delivery system has a good embedding effect and stabilization effect on flavonoids,and the phenolic hydroxyl structure of flavonoids is the key to regulating the functional characteristics of self-assembled micelles.The research results will provide theoretical guidance for the development of food functional factor delivery vectors and the high value utilization of editable dock proteins.