Study On Activity Evaluation And Delivery Systems Of Anthocyanins From Black Soybean Peel

Black soybean peel anthocyanin(BAC)has significant physiological activities,of which cyanidin-3-O-glucoside(C3G)is the main anthocyanin.However,anthocyanins are structurally unstable,sensitive to external environments,easily degraded and have low bioavailability when entering the human body.The application of delivery systems for loading anthocyanins can improve their stability and minimise direct contact between anthocyanins and environmental factors,facilitating the further development and utilisation of anthocyanins in food.The physical and chemical properties of BAC were studied and identified in this work,as well as their physiological activities.Whey protein(WP)-fructo-oligosaccharide(FOS)microcapsules and?-cyclodextrin(?-CD)stabilized double pickering emulsions were successfully prepared to investigate their effects on the stability of anthocyanin.The results have theoretical and practical implications for the application of anthocyanins as solid and liquid ingredients in food products.The main findings are as follows.(1)BAC was purified and its major anthocyanins were identified,and the purity of the purified anthocyanins was increased to 90.68%with the liquid phase peak area of 88.36%.The results showed that the IC₅₀ values of DPPH radical scavenging ability of BAC before and after purification were 0.25 and 0.04 mg/m L,respectively,and the IC₅₀ values of ABTS cation radical scavenging ability were respectively 0.30 and 0.07 mg/m L,and the ferric ion reducing antioxidant power was enhanced.The IC₅₀ values for lipase inhibition were 6.42 and1.62 mg/m L for BAC and 6.46 and 3.17 mg/m L for tyrosinase inhibition before and after purification,respectively.(2)Three different combinations of microcapsules(BAC-FOS,BAC-FOS-WP and BAC-WP)were prepared by freeze-drying technique using BAC as the core material and FOS and WP as the wall material,and the encapsulation rate and drug loading capacity,particle size,appearance and morphology of the microcapsules as well as their stability under simulated gastrointestinal and simulated beverage conditions were investigated.Compared with the single-wall microcapsules,the FOS-WP system showed the highest encapsulation rate(94.21%)and drug loading capacity(5.46%),a good particle size(46.5?m),over 80%retention of anthocyanin in simulated in vitro gastrointestinal digestion,and good protection of anthocyanin in simulated beverage systems(at 4°C or room temperature).(3)?-CD stabilized W/O/W double Pickering emulsions were prepared using BAC as the core material.After orthogonal experiments,the best emulsion was prepared when the emulsion's creaming index,the particle size and particle size distribution span of the emulsion and the encapsulation rate were combined,and the?-CD addition was 4%of the total volume of the emulsion(w/v)and the(W₁/O)to W₂ volume ratio was 6:4.Simulated in vitro gastrointestinal digestion experiments showed that the?-CD stabilized double emulsion limited the release of most of the anthocyanin into the stomach and resulted in a 69%retention of anthocyanin in the intestinal fluid.