摘要

Beta-carotene is important for fortification of nutritional products while its application is limited by instability. The influence of maltodextrin (MDX) on physicochemical properties and stability of beta-carotene emulsions stabilized by sodium caseinate (SC) was investigated. The emulsions were characterized by dynamic light scattering (DLS), laser diffraction (LD), transmission electron microscopy (TEM), rheometer, and turbiscan lab expert. The effects of pH, ionic strength, and freeze-thaw on stability of emulsions were observed. The emulsions could tolerate up to 2 mol/L NaCl or 10 mmol/L CaCl2 and showed Newtonian behavior. The droplet diameter, polydispersity index, and zeta-potential did not change obviously after 3 months storage at 4 degrees C in dark conditions. The emulsions with MDX showed excellent freeze-thaw stability and gave favorite protection for beta-carotene. The retention ratio of beta-carotene in the emulsions with MDX was above 92.1% after 3 months storage while that in the one without MDX was only 62.7%. The study may provide a promising strategy to improve stability of sensitive nutraceuticals without adding synthetic antioxidants. The findings obtained could provide fundamental basis for rational design of emulsion delivery systems when freeze-thawing is required during manufacturing process or storage period.