Preparation And Characterization Of Oxidized Starch Carriers To Controlled Uptake And Release Of β-carotene

β-Carotene is a natural antioxidant that is beneficial for human health. β-carotene is well known for its aqueous insolubility and its sensitivity to environmental stimuli. The carrier was used to improve the dispersion state of β-carotene and protect it from hazard conditions. Oxidized potato starch polymers were used to prepare microgels and microspheres to encapsulate β-carotene.Microsphere was made of DO30% oxidized potato starch polymers chemically cross-linked by sodium trimetaphosphate (STMP) through the inverse emulsion and membrane emulsification menthods. Positively charged WPI emulsified β-carotene emulsions were prepared by ultrasonic emulsification. Negetively charged oxidized starch microshoeres can absorb positively charged P-carotene emulsions through electrostatic attraction in order to encapsulate P-carotene. The absorption between oxidized starch microspheres and β-carotene emulsions can be influenced by salt concentration and pH.Microgel was made of oxidized potato starch polymers chemically cross-linked by sodium trimetaphosphate (STMP). In this study, the absorption capacity of β-carotene nanoemulsion by oxidized starch microgel of various degrees of oxidation (DO) and the cross-link density (R cross-linkenpolymer(w/w)) are investigated as a function of pH and salt concentrations. It was found that DO30% with R cross-linker/polymer(w/w)= 0.1 were the optimal gel type for nanoemulsion absorption, and pH 3 and ionic strength of 0.06 M were the optimal conditions for nanoemulsion absorption. Swelling capacity and zeta-potential of the microgels were dominant in governing the absorption capacity. The in vitro release experiment under stimulated gastrointestinal fluids suggested that P-carotene emulsions remained stable at the gastric condition and were majorly released under the intestinal condition.β-carotene loaded oxidized starch microspheres were made of DO90% oxidized starch polymers where the carboxyl (COO-) groups are physically cross-linked via ferric ions (Fe3+). O/W/O double emulsion was used to prepare β-carotene loaded oxidized starch microspheres. It was found that 10% DO90% oxidized starch polymers with molar ratio of cross-linker to polymer 6.17 were the optimal condition in which to prepare β-carotene loaded oxidized starch microspheres. The highest Loading Efficient is 2.2935±0.003536 mg-g1. In addition, the average size of the microsphere is 39.021μm in pH 3 HCl solution. The zeta-potential of microsphere is -20.9mV in pH 3 HCl solution. The in vitro release experiment under stimulated gastrointestinal fluids, the percentage of β-carotene is only 10.5% in simulated gastric fluids, the percentage of β-carotene is 83.61%. The results suggested that the oxidized starch microsphere could be used to target delivery of β-carotene to the intestine. Moreover, the oxidized starch microsphere could be used to protect β-carotene activity under heat.Oxidized starch microgels and microspheres can be used to improve the dispersion state and stability of poorly soluble active compounds, and target delivery them to the intestine. The carriers prepared by oxidized starch will have broad application.