Chemical Stability and in vitro release properties of β-carotene in emulsions stabilized by Ulva fasciata polysaccharide.

The aim of the present study was to examine how factors (pH, temperature, iron chelators, and free radical scavengers) influence on the chemical stabilities of β-carotene encapsulated by Ulva fasciata polysaccharide (UFP)-stabilized emulsions and the bioaccessibility under in vitro oral-gastro-intestinal digestion conditions. The concentration of β-carotene in emulsions under different environments was determined. Changes in droplet properties, particle size and microstructure, throughout the oral-gastric-intestinal model were measured and the rate and extent of lipid digestion were recorded in the simulated small intestine fluid. Our results suggested that the pH had a significant effect on the stability of β-carotene, a rapid degradation at acidic environment and a relatively higher stability at high pH (6.0 and 7.0) were observed. β-carotene in emulsions was highly sensitive to extreme temperature (80°C, 90°C, and 100°C). Addition of EDTA or α-tocopherol significantly increased the stability of β-carotene. Meanwhile, digested UFP-stabilized emulsions showed higher lipid digestion rate than GA-stabilized emulsions and BP-stabilized emulsions. UFP was capable of increasing the bioaccessibility of β-carotene in emulsions compared to GA and BP. Therefore, UFP-stabilized emulsion is a promising delivery system to promote applications of β-carotene in functional food and beverage system.