Study on Preparation of Purple Sweet Potato Protein-Glucose Maillard Reaction Product and Its Interaction with Anthocyanin

The Maillard reaction product was successfully prepared and its interaction with anthocyanin was analyzed.The molecular weight of the product was determined by SDS-PAGE.The structural characteristic of the Maillard reaction product was characterized by FTIR,DSC and fluorescence spectrometric method.The results showed that the molecular weight of the main Maillard reaction product was 25 kDa.Compared with purple sweet potato protein-anthocyanin complexes,the FTIR absorption strength of Maillard reaction product was generally lower,especially in the amido I band,and maillard reaction product had higher denatured peak temperature(76℃),but its denaturation enthalpy(366.7 J/g)was lower.The maximum emission wavelength of the Maillard reaction product was 340 nm,and the results showed that purple sweet potato athocyanin quenched the fluorescence of Maillard reaction product via a combination quenching which had the features of the static and dynamic quenching,and static quenching was the main process.There was a strong force of interaction between anthocyanin and Mailard reaction product.The interaction was mainly expressed as van del Waals force and hydrogen bond force.The binding site between purple sweet potato anthocyanin and the Maillard reaction product was closer to tryptophan residue.