酪蛋白-海藻酸钠基乳液凝胶性质及其在姜黄素负载中的应用OA北大核心CSTPCD

Curcumin(Cur)is a natural bioactive molecule with antioxidant,anti-inflammatory,hypolipidemic,and other biological activities,but the poor stability and low oral bioavailability of which limit its application in food and pharmaceutical industries.Emulsion gel has both emulsion and gel structures,as well as good stabilities,which is widely used in functional food and pharmaceutical industry as a carrier of natural bioactive molecules.In this paper,a O/W emulsion gel with an oil phase fraction of 80％was prepared by the one-step homogenization method using casein(CN)and sodium alginate(SA)as the matrix to loading Cur to improve its stability and bioavailability.The effect of CN to SA volume ratio on the formation and structure of emulsion gel was studied,and the storage,freeze-thaw,dilution,thermal and centrifugation stability of emulsion gels loading Cur were analyzed.The simulated gastrointestinal release characteristics of Cur loaded by emulsion gel were explored.The results showed that emulsion gels could be formed with CN(mass fraction of 4％)alone as matrix.After combined with SA(mass fraction of 2％),the emulsion gel could be formed at the CN to SA volume ratio of 9∶1 to 7∶3.The average particle size of oil droplets in emulsion gels loading Cur was reduced from(86.00± 6.31)μm without SA to(47.00±0.97)μm.The average particle size of oil droplets in CN emulsion gel was(107.00±7.54)μm and the oil phase separated after 15 d storage,while the addition of SA significantly improved the storage stability of the emulsion gels which remained stable after 750 d storage.However,the freeze-thaw stability of CN-SA emulsion gels was poor.With the aqueous dilution at pH 1.5,4.5 and 7.5,the emulsion gels with CN to SA volume ratio from 9∶1 to 7∶3 kept stable.Moreover,the emulsion gels had good centrifugation stability,which water holding capacity increased with the increasing of SA addition.The emulsion gels based on CN-SA had high thermal stability,which microstructure remained stable after heat treatment at 65 or 85 ℃ for 1 h.Compared with free Cur,the gastrointestinal release rate and bioaccessibility of Cur loaded in emulsion gels based on CN-SA were significantly increased,and the emulsion gel with a CN to SA ratio of 7∶3 had the highest gastrointestinal release rate and bioaccessibility of Cur.The results could provide theoretical basis for loading and delivery of Cur,as well as the technical reference for system construction of high stable emulsion gels.