Effect of Maillard reaction conditions on the solubility and molecular properties of wheat gluten–maltose conjugates

Abstract In this experiment, the conjugation reaction between gluten and maltose via Maillard reaction under dry‐heated condition was studied. The process conditions for the preparation of protein–maltose conjugates with optimum solubility were optimized by using Box‐Behnken model. The conjugation reaction and the structure changes of the protein–maltose conjugates were confirmed by infrared spectroscopy (FTIR) and scanning electron microscopy ( SEM ). The results showed that the process conditions for the preparation of protein–maltose conjugates with optimum solubility were as follows: temperature 50.72°C, time 1.92 days, and gluten/maltose (W/W) 267.36%. The infrared spectroscopy showed that the structure of the modified protein had a very obvious change, including the decrease in β‐fold and β‐turn and the increase in α‐helix at a certain degree. But the conjugation reaction has little effect on the irregular coiled structure. The scanning electron microscopy showed that the microstructure of gluten is small grainy, but gluten–maltose conjugate looks sheet with bigger volume.