Insights into multi-component digestion and antioxidant release from plant protein-seaweed-based Maillard conjugate-MRP systems

Abstract

Maillard conjugation to modify protein functionality results in the formation of a protein-polysaccharide complex. The resultant conjugate mixture is rich in different Maillard reaction products (MRP) and unreacted components. The investigation pertaining to the digestion and intestinal fate of these components is challenging due to the multitude of effects and interactions between different components. This study attempts to understand gastrointestinal behaviour and diffusion/release patterns of different components from a complex system made of the amaranth-Gracilaria seaweed system. Data acquired from in-vitro INFOGEST protocol and intestinal dialysis absorption model were used to investigate the amino acid release and antioxidant diffusion during different phases of digestion. The analysis suggests a significant improvement in the radical scavenging capacity of overall antioxidants released from the conjugate-MRP system compared to that of amaranth protein alone based on different antioxidant assays (DPPH, FRAP, ICred) during each stage of digestion. The permeability and overall intestinal absorption ratio of antioxidants through a dialysis membrane shows an improvement of up to 55 % compared to that of the plant protein. Moreover, amino acid and phyto-compounds release patterns of the conjugate-MRP system exhibit selective shielding effects towards the gastric phase, which can potentially be investigated for targeted release of bioactive compounds.