Preparation And Characterization Of ?-carotene Dispersion System Based On Biomacromolecules

?-Carotene?BC?is a kind of natural tetraterpene compound,which widely exists in vegetables and fruits,covering a series of bright colors from yellow to red.Because of its high vitamin A activity and strong antioxidant properties,BC is widely used in food system.BC has many physiological functions,such as preventing cancer,improving human immunity and reducing the incidence of some chronic diseases.However,there are only C=C bond and C-H bond in BC molecular structure,which is very hydrophobic and easy to degrade under the stress of light,high temperature and oxygen.In this study,BC dispersion system was constructed by using food grade biomacromolecule polysaccharides and proteins to explore the interaction of OSA modified starch,whey protein isolate?WPI?nanofibrils and nanofibril WPI with Inu and HA composite BC particles,as well as encapsulation efficiency,physicochemical stability and simulated release in vitro of BC loaded in dispersion were compared.In this paper,the physical modification of WPI was carried out to prepare long and thin nanofibrils?amyloid protein?,which are then complexed with polysaccharides using self-assembled WPI.Synthetic emulsifier and oil phase were not used in this paper.Main conclusions are as follows:1?Study the protection and delivery of BC by OSA modified starch.The results of FTIR and particle size distribution showed that BC successfully entered the hydrophobic region of OSA modified starch.Zeta potential shows a neutral charge due to the ionization inhibition of carboxyl at pH 3.2.Therefore,the stability of the dispersion mainly depended on the steric hindrance of starch and the hydrophobic interaction between OSA group and BC.The encapsulation efficiency of OSA modified starch/BC was about 81.44%.In addition,OSA modified starch/BC dispersion showed good light,salt ion,pH and temperature stability,and had good color protection effect.2?WPI can be self-assembled into nanofibrils by heating for a long time under low pH and salt ion concentration,and form short peptides along with hydrolysis,which has better emulsification.Through a series of WPI with different nanofibril degrees loaded BC,the structure-activity relationship between the molecular structure of WPI and BC was studied.It was found that with the extension of heating time,the viscosity of the dispersion system increased,and the hydrophobic groups of proteins were exposed more.This may be that there are hydrolyzed peptides in WPI₂₄4 nanofibrils,which has better emulsification.Accordingly,a series of WPI nanofibrils combined with BC showed higher and higher storage stability and encapsulation efficiency,the encapsulation efficiency of WPI₂₄/BC dispersion was 92.11%.DSC showed that BC exists in an amorphous state,not in a crystal structure,which proved that BC exists in the hydrophobic region.Through FTIR spectrum,it was concluded that hydrogen bond and hydrophobic force were the main forces to form the complex.The rheological results showed that with the increase of shear rate,the solution appears shear thinning phenomenon.3?The degradation mechanism of WPI₂₄/Inu/BC and WPI₂₄/HA/BC showed a first-order kinetic curve,and they all showed better encapsulation efficiency,thermal stability,light stability,oxidation resistance and storage stability than WPI₂₄/BC.Among them,the presence of Inu made the system showed better thermal stability,and the presence of HA made the system showed better encapsulation efficiency,UV stability and storage stability.The above results showed that WPI₂₄/Inu/BC and WPI₂₄/HA/BC can be used as stabilizers to make the system more stable,and the bioavailability of functional substances can be significantly improved.