For glucanase assay, we recommend the medium viscosity beta-glucan.  We now offer low, medium and high viscosity wheat arabinoxylans, and we think that the low viscosity material will be best (easiest) to use in the reducing-sugar assay.

The substrates are enzymically treated to yield the required viscosity (20 ~ 30 cSt). Modification of the viscosity of beta-glucan is required for IOB viscometric malt beta-glucanase test (which works well).

We suggest that you dry the β-glucan powders further in a vacuum oven at about 50˚C.  This will lower the moisture content to approximately 1-2%.

The polymer you require is barley beta-glucan (medium viscosity).  The beta-glucan that we supply is pure 1,3:1,4-beta-D-glucan.  Barley β-glucan is also susceptible to hydrolysis by cellulase.

The content of 1,3 bonds in barley beta-glucan is about 32% (from literature).  We would not expect this to change much (if at all) over different batches.

The MW’s were determined by Multiangle laser light scattering technique.

Barley beta-glucan lot 30108 would contain about 3-4% arabinoxylan (this was produced in 1993).  Material supplied post 1995 contains < 0.5% arabinoxylan.  Carob galactomannan is quite pure (> 96%).

The high molecular weight beta-glucan is the naturally occurring; this is enzymically modified to give the other viscosities.