Role of pectin in the delivery of β-carotene embedded in interpenetrating emulsion-filled gels made with soy protein isolate.

This study investigated the effects of different matrices on gel properties, lipid digestibility, β-carotene bioaccessibility, released free amino acids and gel network degradation. Microstructure studies have proven that sugar beet pectin/soy protein isolate-based emulsion-filled gel (SBP/SPI-E) with interpenetrating networks was formed. SBP/SPI-E exhibited higher hardness (2.67 N, p < 0.05) and released lesser free amino acids (269.48-μmol/g SPI) than soy protein isolate-based emulsion-filled gel (SPI-E) in simulated intestinal fluid (SIF); however, both had similar free amino acids contents in simulated colonic fluid. SBP has the potential to delay gel network degradation in SIF, as evidenced by the sugar stain strips of SDS-PAGE and microstructure observation. Furthermore, SBP/SPI-E and SPI-E exhibited similar β-carotene bioaccessibility in SIF, suggesting that SBP from composite gel could not affect the aforementioned bioaccessibility. The study provides useful information for the design of functional gels in the application of fat-soluble nutrient delivery.