In vitro digestion of mixed protein matrices in semi-dynamic system

Abstract

This proposal aims to be a contribution to the study of the in vitro digestion of mixed protein matrices (animal proteins + vegetable proteins), a theme practically unexplored in the literature. The approach chosen for the study was the semi-dynamic in vitro digestion, which is composed of a gastric stage that simulates the emptying of the stomach followed by a static stage simulating the duodenum. The main objective of the present proposal is to evaluate the effect of the presence of plant proteins on the digestive behavior of mixed protein matrices (MPM). In vitro digestion is proposed to evaluate the impact of food matrices on the restructuring of biopolymers in the gastric phase. In addition, the impact of this restructuring on the bioaccessibility of an incorporated bioactive (curcumin) will also be evaluated. The plant protein to be studied will be the soy protein isolate (SPI), and whey protein isolate (WPI) will be the source of animal protein. Mixed protein matrices (MPM) will contain different SPI/WPI ratios in their composition, and will be structured as: (i) gels: these MPM will be produced by heating; (ii) emulsion-loaded gels. In vitro digestion experiments will be performed completely static in a first stage (stomach and small intestine) to identify the most promising MPM in terms of absorbable proteins and lipids. The MPM chosen will be submitted to semi-dynamic in vitro digestion in the second stage of the project. In both steps will be obtained profiles of protein digestibility and profiles of lipid digestibility as well as bioaccessibility of curcumin, the bioactive chosen to be incorporated into the emulsions of filled geis. (AU)