Effect of microwave treatment on glycation extent of lysozyme-maltodextrin maillard conjugates

Lysozyme- maltodextrin conjugates were prepared by microwave heating of the mixtures at different times. The formation of the protein- polysaccharide conjugates was confirmed by SDS–polyacrylamide gel electrophoresis, free amino group content, browning intensity and UV absorbance measurement and determination enzyme activity. SDS-PAGE profile showed that lysozyme– maltodextrin conjugates were formed. The results of free amino group content indicated that increasing microwave heating time caused an increased in glycation degree. Browning and intermediate maillard products, as monitored by absorbance at 420 nm and absorbance at 294 nm, sharply increased compared to control sample. Enzymatic activity of glycosylated lysozymes were reduced compared with unmodified lysozyme. Significant changes in browning intensity, free amino group content and SDS-PAGE profile indicated that lysozyme–maltodextrin conjugates were successfully formed using microwave heating treatment. Moreover, higher microwave heating intensity enhanced the extent of glycosylation. All data showed that microwave heating treatment could be an effective and promising method for linking polysaccharides to proteins.