Maillard Reaction Modification of Walnut Gluten Antioxidant Peptides: Process Optimization, Conformational...

Area of Science:

• Food Science
• Biochemistry
• Nutritional Science

Background:

• Walnut gluten peptides possess potential functional properties but require enhancement for improved flavor and bioactivity.
• The Maillard reaction is a promising method for modifying peptide characteristics.

Purpose of the Study:

• To improve the flavor quality and antioxidant activity of walnut gluten peptides.
• To optimize Maillard reaction conditions for peptide modification.
• To characterize the structural and functional changes in modified peptides.

Main Methods:

• Extraction and hydrolysis of gluten from defatted walnut meal.
• Maillard reaction modification using various sugar sources and optimized conditions (peptide-to-sugar ratio, temperature, pH, time).
• Characterization using UV-Vis, fluorescence spectroscopy, DSC, FTIR, SEM, amino acid analysis, sensory evaluation, and DPPH radical scavenging assay.

Main Results:

• Fructose was identified as the optimal sugar source for Maillard modification.
• Optimal reaction conditions yielded a sensory score of 8.5 and 66.92% DPPH radical scavenging activity.
• Maillard modification altered peptide conformation, microstructure, and increased antioxidant activity, while largely preserving essential amino acids.

Conclusions:

• Maillard reaction with fructose effectively enhances the flavor and antioxidant capacity of walnut gluten peptides.
• The modification process alters peptide structure and microstructure, leading to improved functional properties.
• This study presents a feasible strategy for the high-value utilization of walnut gluten peptides, though further research on digestibility and bioavailability is needed.