Aggregation of Aeromonas gum in aqueous solution

Aeromonas (A) gum, a stabilizer, and thickening agent of food, is composed of xylose, mannose, galactose, glucose, and mannuronic acid. Weight average molecular weights M-w and intrinsic viscosities [eta] of the unfractionated A gum and three fractions in water. 0.5 M NaCl aqueous solution and cadoxen were studied by light scattering and viscometry. Experimental results showed that A gum exists as an aggregate in 0.5 M NaCl aqueous solution and mainly as a single chain in cadoxen. The apparent aggregation number (N-sp) of A gum in 0.5 M NaCl aqueous solution was ca. 22, and decreased with increasing sample molecular weight. Change of aggregation and disaggregation of A gum in 0.5 M NaCl aqueous,cadoxen mixtures occurred from 0 to 0.4 of nu(cad) (volume fraction of cadoxen). and was reversible. The stable aggregation of A gum in 0.5 M NaCl aqueous/3% cadoxen mixture was achieved after 150 min.