EFFECTS OF THE LENGTH OF POLYSACCHARIDE CHAINS ON THE FUNCTIONAL-PROPERTIES OF THE MAILLARD-TYPE LYSOZYME-POLYSACCHARIDE CONJUGATE

The effect of the length of polysaccharide chains on the functional pr operties of Maillard-type protein-polysaccharide conjugates was invest igated using the lysozyme as a model protein, various sizes of galacto mannan as a polysaccharide, and xyloglucan as an oligosaccharide. The emulsifying properties of the lysozyme-galactomannan conjugates increa sed in proportion to the length of polysaccharide chains. On the other hand, the heat stability of the lysozyme-galactomannan conjugates gre atly increased in the range of 3.5-24 kDa galactomannan, regardless of its molecular mass. In addition, the effects of the binding number of polysaccharide to lysozyme on the emulsifying properties of the lysoz yme-galactomannan conjugates were further investigated using 1 and 2 m ol of the galactomannan (24 kDa)-attached lysozyme. The 2 mol of the p olysaccharide-attached lysozyme showed better emulsifying properties t han 1 mol of the polysaccharide-attached protein. The residue most sen sitive to the Maillard reaction in a lysozyme was identified as the 97 -lysine using the lysozyme-xyloglucan conjugate.