No abstract

Acidic hydrolysis of starch, in contrast to enzymatic hydrolysis, gives a very low degree of multiple attack. By making use of this property it seems possible to prepare polysaccharide mixtures with very narrow ranges of molecular weight distribution. In a commercial sample of soluble starch the ratio of weight to number average molecular weights (M̄w/M̄n), which is a direct measure of polydispersity, is decreased from 3.1 to 1.2 by acid hydrolysis followed by ethanol‐water precipitation.

No abstract

Carboxymethylcellulose activated to varying extents by cyanogen bromide was used in insolubilizing Bacillus subtilis α‐amylase. The retention of native activities in the resulting derivatives toward soluble starch and the amounts of bound enzyme were determined. The effect of enzyme concentration in the coupling medium on the retention of activity was also investigated. The results are shown to accord with the hypothesis that the enzyme molecules tend to concentrate more on the surface of the carrier than inside the pores as the reactivities of the components in the coupling reaction are increased.