| In recent years,the structure of relevant dosage forms,preparation methods,new raw material development and other innovations have mushroomed with the rapid development of food emulsion delivery system.Among them,the high internal phase emulsions(HIPE)delivery system is a kind of emulsion carrier dosage form with the volume fraction of internal phase(dispersed phase)exceeding 74%,large viscosity and paste like semi-solid structure characteristics.As one of the newly developed food emulsion delivery systems in recent years,it has a wide regulatory potential and application prospect in loading active ingredients.Due to the different solubility and stability of active ingredients and the bioavailability and release requirements for different applications,the load requirements for delivery systems are different.Therefore,it is urgent to develop different types and structures of HIPE delivery systems to meet the diverse demands of active ingredients.In this paper,O/W HIPEs system of protein particles type and protein/polysaccharide complex type,and W/O HIPEs delivery system of polysaccharide synergistic type,capsule shell structure and internal water phase microgel were constructed.The effects of emulsion composition,interface composition,structure and texture properties on the stability,digestion,release,and functional properties of active ingredients were investigated.The main research contents and conclusions are as follows:(1)It constructs protein particle type and protein/polysaccharide complex type O/W HIPEs delivery system.The results showed that the concentration of gliadin nanoparticles(GNPs)and protein/polysaccharide components(ratio,p H value and ionic strength)had important effects on the texture,physical stability and the stability,digestibility and bioaccessibility of β-carotene in HIPEs.Higher protein concentration significantly increased the gel strength and gel rate of O/W HIPEs,and promoted the transformation of O/W HIPEs from the liquid type to the solid gel structure.GNPs endows β-carotene loaded by O/W HIPEs with good bactericidal stability through close coating and arrangement in interface layer(>92%).Compared with the lowest GNPs concentration,the retention rate of O/W HIPEs stabilized by highest GNPs concentration increased from 66.67% to 82.2% after 28 days of storage at 55℃.Also,the retention rate of β-carotene(from 67.0% to 84.1%)under simulated gastrointestinal conditions and the effective bioavailability were improved by gel structure reducing the contact area with digestive enzymes during digestion.The protein/polysaccharide complex formed by lactoferrin with high electric point(p H > 8)and gum arabic is applied to stabilize O/W HIPEs,which can maintain long-term stability in a wide range of p H(3-6)and ionic strength(0-300 m M Na Cl),and protect droplets from coalescence under high temperature or centrifugation conditions.Under weak acid condition(p H=5),the storage stability of β-carotene was the best(about 83.2%),and the retention rate and bioaccessibility were improved.(2)It constructs the polysaccharide synergetic type W/O HIPEs delivery system.Konjac glucomannan and octenyl succinic anhydride starch(OSA-starch)co-stabilized W/O HIPEs based on steric hindrance effect and hydrogen bond interaction,which was successfully stabilized in p H value from 3 to 7,Na Cl concentration from 0 to 400 m M and heat treatment at 90℃ for 30 min.The potential of W/O HIPEs loaded watersoluble(-)-Epigallocatechin-3-gallate(EGCG)was investigated.The W/O HIPEs with polysaccharide synergistic stability had more than 90% encapsulation efficiency in the EGCG concentration range of 2 mg/g.Compared with the weak storage stability of EGCG in aqueous solution and O/W emulsion with the same oil phase content,the retention rate of W/O HIPEs loaded with EGCG reached 71.4% after 28 days of storage at 25℃.In addition,W/O HIPEs can inhibit EGCG from contacting the digestive environment too quickly through the interface barrier and the structure of high viscosity emulsion,which can improve the digestive retention rate and the effective bioavailability of EGCG.(3)It constructs W/O HIPE delivery systems with different structures.The W/O HIPEs carrier with microcapsule-shell structure was constructed by the continuous phase gel shell of W/O HIPEs formed by beeswax and the internal water phase with polysaccharide based material based on W/O emulsion template method,which can achieve long-term protection and controlled digestion of EGCG in the early stage of simulated in vitro digestion.Combined with the mouse colitis model,it was confirmed that W/O HIPEs microcapsule could further reduce the colitis tissue damage,mucosal layer destruction and intestinal oxidative stress in mice,and reduce the intestinal injury caused by colitis by inhibiting the secretion of pro-inflammatory factors and promoting the expression of anti-inflammatory factors compared with EGCG solution.By inducing sodium alginate with glucono-δ-lactone to construct W/O HIPEs carrier with internal water phase microgel structure,the steady loading of curcumin liposome was realized.The results showed that W/O HIPEs loaded with curcumin liposome could further improve the storage stability and photostability of curcumin,and had the potential of slow controlled release,which mainly followed the non-Fickian diffusion release mechanism of Peppas kinetic model. |
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