Improving physicochemical and biological properties of gelatin-xylooligosaccharide conjugates by Maillard reaction

Abstract Maillard reaction can enhance the functional characteristics of the protein. Herein, we investigated changes in the physicochemical and biological properties of gelatin (GA)-xylooligosaccharide (XOS) conjugates following Maillard reaction. The results showed that the browning intensity of the conjugates increased with the prolongation of heating time. Additionally, sodium dodecyl sulphate-polyacrylamide gel electrophoresis revealed some macromolecule polymer formed, and the grafting degree of GA was augmented to 40.05% with prolongation of heating time. GA glycation with XOS decreased α-Helix content and increased level of β-Turn level, and exerted a slight impact on contact angle. Moreover, the results of in vitro simulated gastrointestinal digestion analysis showed that the GA-XOS mixture enhanced resistance to digestion after Maillard reaction for 60 min, affording hydrolysis ratios ranging from 17.86–27.79% and 25.03–35.47% in simulated gastric fluid and intestinal fluid, respectively. The antioxidant ability and heat stability of the conjugates was visibly enhanced following heating treatment. Additionally, increasing the mass of XOS accelerated the antioxidant capacities of GA-XOS conjugates. The finding will assist the fabrication of GA-XOS conjugates with highly functional properties by Maillard reaction.