Evaluation of different sugars for glycation modifications of chitosan to improve its functionality for food preservation

Abstract

The modification of chitosan's amino groups through the Maillard reaction (MR) presents a pioneering approach to enhance its functional and biological properties. The present study aimed to understand the association between sugar-specific glycation-induced modifications and Chitosan-based Maillard Reaction Products (CMRPs) functionality. CMRPs were prepared by treating chitosan (CHO) with different saccharides, namely fructose (Fru), galactose (Gal), glucose (Glc), lactose (Lac), maltose (Mal), and methylglyoxal (MGO) at 80 °C for 6 h. These CMRPs were characterized by assessing 1) glycation markers, 2) structural modifications, and 3) functional properties. CMRPs formation was higher in aldohexoses (Gal, Glc) as compared to ketohexose (Fru) and disaccharides (Mal and Lac). Notably, fructosamine content, carbonyl adducts, and β-amyloid aggregates were highest in Gal CMRPs (46 mM/mg, 52 mM/mg, 6 M/mg) and Glc CMRPs (45 mM/mg, 15 mM/mg, 3 M/mg). Furthermore, MR of chitosan with aldohexoses at 100 °C for 8 h accelerated CMRPs synthesis with improved emulsifying activity, surface hydrophobicity, antioxidant potential, and substantial gel formation. The thermogravimetric analysis assessed the thermal stability and residual weight, while field emission scanning electron microscopy revealed a compact, nonporous morphology compared to chitosan alone. FTIR and HPLC analysis confirmed the structural changes, primarily due to the binding of the carbonyl group of sugars with the NH2 group of chitosan. Differential scanning calorimetry of CMRPs indicated shifts in peak temperatures and endothermic transitions in terms of enthalpy. Overall, Glc CMRPs exhibited improved functional, thermal, antioxidant, and emulsifying properties indicating their potential application in food preservation and packaging.