Abstract: In order to improve the solubility and bioavailability of β-carotene, a stable β-carotene-loaded oil-in-water (O/W) emulsion system was constructed using Pseudosciaena crocea roe protein isolate (PRPI) as an emulsifier. The stability of the emulsion system with different storage times was investigated. The digestion process and absorption capacity were determined by in vitro simulated digestion. The results showed that the average particle size and appearance of the emulsion system did not change significantly after 14 days of storage. Simulated oral digestion had little effects on the microstructure of the emulsion system. However, during simulated gastric digestion, the emulsion system was hydrolyzed and the droplets were aggregated, the average particle size increasing from (255.46 ± 7.41) nm to (9 749.25 ± 406.66) nm (P < 0.05). After simulated intestinal digestion, the degree of droplet aggregation decreased significantly, the average particle size decreasing to (3 654.36 ± 527.91) nm (P < 0.05), but the retention rate and bioavailability of β-carotene remained at high levels of (81.64 ± 2.72)% and (93.13 ± 3.59)%, respectively. Therefore, PRPI could be used as an emulsifier to construct an emulsion delivery system with improved stability for improved β-carotene bioavailability.

Key words: Pseudosciaena crocea roe protein isolate; β-carotene; emulsion system; in vitro digestion; bioavailability