Glycation of sunnhemp protein with dextran via dry heating: Thermal, micro-structural characterization, and amino acid profiling.

Abstract

This study aims to obtain sunnhemp protein isolate (SHPI) and dextran conjugates by dry heating method of Maillard conjugation. The effects of different incubation time (0, 1, 3, 5, 7, and 9 days) on the molecular flexibility, available lysine content, antioxidant properties, molecular structure, and thermal and micro-structural properties of conjugates were compared with SHPI (no conjugation) at 60°C and 79% relative humidity. The results indicated the formation of SHPI-dextran conjugates as confirmed by the change in molecular flexibility, lysine content, antioxidant activities, color, and water activity values. The molecular structure revealed the confirmation of covalent bonding between SHPI and dextran. Differential scanning calorimetry and thermo-gravimetric analysis results exhibited improvement in the thermal stability of SHPI when conjugated with dextran. The microstructural characterization showed that Maillard conjugation changed the surface structure of SHPI. The analysis of amino acid composition displayed that lysine, arginine, and phenylalanine were the dominant Maillard reaction sites of SHPI and dextran. Among all the conjugated samples, 5 days of incubation time was selected as an optimum condition for the development of SHPI-dextran conjugates on the basis of the aforementioned characterization. Overall, it was concluded that Maillard conjugation of sunnhemp protein with dextran via dry-heating technique could modify and improve its various attributes. PRACTICAL APPLICATION: The conjugation of plant proteins with polysaccharide through the Maillard reaction under dry heating conditions represents a natural and green technique for improving the techno-functional properties of proteins. The study has the potential to establish framework for the utilization of Sunnhemp protein isolate-dextran conjugates. This approach offers the potential for cost-effective production of emulsifiers and development of effective encapsulating matrices. The investigation expands on an underutilized plant protein source facilitating an alternative to animal-based proteins and contributing to the development of a sustainable circular bioeconomy.