Impact of pectin properties on lipid digestion under simulated gastrointestinal conditions: Comparison of citrus and banana passion fruit (Passiflora tripartita var. mollissima) pectins

Abstract

Medium methoxylated pectin (52% mol/mol, MMP) was isolated from banana passion fruit (Passiflora tripartita var. mollisima) by hot acidic extraction. The impact of MMP on lipid digestion was compared to that of commercial citrus pectins with high (71% mol/mol, HMP) and low (30% mol/mol, LMP) methoxylation degree. A static in vitro digestion model was used to elucidate the impact of pectin properties (methoxylation degree and molecular weight) on the gastrointestinal fate of emulsified lipids. A 2.0% (w/w) corn oil-in-water emulsion stabilized with 0.2% (w/w) Tween 80 was prepared, mixed with 1.8% (w/w) pectin samples, and then subjected to the static in vitro digestion model (37 °C): initial (pH 7.0); oral (pH 6.8, 10 min, mucin); gastric (pH 2.5, 120 min, pepsin); and intestinal (pH 7.0, 120 min, bile salts, and pancreatic lipase) phases. The impact of the three pectin samples on surface particle charge (ζ-potential), particle size distribution of lipid droplets, microstructure, rheology, and lipid digestion (free fatty acids (FFAs) released) was determined. The rate and extent of lipid digestion decreased with increasing simultaneously both the molecular weight and pectin methoxylation, with the FFAs released after 120 min of intestinal digestion being 47, 70, and 91% (w/w) for HMP, MMP, and LMP, respectively. These results have important implications for understanding the influence of pectin on lipid digestion. The control of lipid digestibility within the gastrointestinal tract might be important for the designing and development of novel functional foods to control bioactive release or to modulate satiety.