BACKGROUND: Modification with carbohydrates usually changes the functional properties of proteins. Such modification might make non-conventional food proteins (such as plant and microbial proteins) more applicable for human consumption. The purpose of this research was to conjugate glucosamine to lysozyme and casein using a water-soluble carbodiimide and to investigate the effect of conjugation on the functional properties of these proteins. RESULTS: Glycosylation with glucosamine converted casein to high-molecular-weight species which appeared as diffuse bands in sodium dodecyl sulfate polyacrylamide gel electrophoresis. Approximately 2 and 0.11 mol of glucosamine was attached to 1 mol of casein and lysozyme respectively. Both conjugated proteins exhibited improved solubility at different pHs (3 and 6) and different temperatures (25, 45 and 60 ◦C), increased heat stability and better emulsifying activity, emulsion stability and foaming capacity compared with the unmodified proteins (P < 0.05). CONCLUSION: These changes might increase the applicability of lysozyme as a natural antimicrobial and casein as a protein ingredient in different food systems.
کلید واژگان :casein; lysozyme; glucosamine; glycosylation; functional properties; carbodiimide
ارزش ریالی : 600000 ریال
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