Research On The Stability And Digestion Proterties Of Filled Hydrogel Particles Loading With ?-carotene Emulsions

?-carotene has many beneficial physiological functions to human,but its poor physicochemical properties and solubility will lead to its low bioavailability and high degradation rate,which can greatly limit the application of?-carotene in the food industry.Consequently,more and more researches are focus on fabricating various delivery systems to encapsulate?-carotene in order to widen its application.In this article,we firstly prepared?-carotene-loaded protein emulsion and then fabricated hydrogel particles to encapsulate?-carotene-loaded protein oil droplets.Aimed at the physicochemical,stability and digestion properties of?-carotene-loaded emulsions and hydrogel particles,we have carried out a series of experiments.The preparation and physicochemical properties of?-carotene-loaded hydrogel particles:The successful fabrication of?-carotene-loaded hydrogel particles could be proved by the measurement of particle size and microstructure analysis.?-carotene-loaded hydrogel particles have a particle size about 1.87?m and showed shear thinning behavior which were belonged to pseudoplastic fluid.There were no significant difference in the particle size of hydrogel particles cross-linked with Ca²⁺?0-4 mM?.However,Ca²⁺could promote the formation of hydrogel particles,and both the viscosity and gel strength of hydrogel particles were strengthened with the increase of Ca²⁺concentration.The encapsulation rate of?-carotene in hydrogel particles was up to 99.5%.Thestabilitypropertiesof?-carotene-loadedhydrogelparticles:?-carotene-loaded hydrogel particles had poorer centrifugal stability,but with the cross-link effect of Ca²⁺,the centrifugal stability could be improved.The phase separation was obvious in emulsions at pH 3-5 while?-carotene-loaded hydrogel particles were relatively stable to droplet aggregation across pH 3-7.?-carotene-loaded emulsions remained stable at all salt levels?0-4 M?,and there were slight phase separation in hydrogel particles cross-linked with Ca²⁺?0-2 mM?at high salt levels?>2 M NaCl?.However,?-carotene-loaded hydrogel particles could be stable at different salt levels when the concentration of Ca²⁺was up to 2-4 m M.In the storage and heating stability experiments,the retention of?-carotene in hydrogel particles was higher than in emulsions and was improved after the cross-linked with Ca²⁺.The digestive properties of?-carotene-loaded hydrogel particles:After an in vitro simulated digestion model experiment,it was found that there were a large amount of aggregation in stomach in both?-carotene-loaded emulsions and hydrogel particles.Then after digestion in the small intestine,there were still some undigested lipid in emulsions but the aggregates of hydrogel particles would be almost disassemble,which was in favour of lipid digestion.What's more,free fatty acid?FFA?released rate suggested there was a higher FFA rate in hydrogel particles than emulsions.The retention rate of?-carotene in hydrogel particles after the digestion was up to 80%and the bioaccessibility was up to 60%,which were higher than those of emulsions.The addition of Ca²⁺in hydrogel particles could promote the digestion of lipids,but to some extent it would reduce the bioaccessibility of?-carotene.