RELEASE OF MIXED LINKAGE (1-]3),(1-]4)-BETA-D-GLUCANS FROM BARLEY BY PROTEASE ACTIVITY AND EFFECTS ON ILEAL EFFLUENT

The behaviour of barley beta-glucans in the upper gut has been assesse d using ileal effluents recovered from a barley-based test meal. Resul ts have been compared to in vitro treatments used to extract beta-gluc ans. In vitro, exposure to endogenous proteases led to a solubilisatio n of beta-glucan, ranging from 28% in the untreated to 83% following N SP isolation. In ileal effluent 60% of the beta-glucan was solubilised , similar to the in vitro treatment. However, the viscosity of the ile al effluent was low, comparable to a mucin standard. Although beta-glu can can be solubilised in the upper gut its viscosity would appear to have only a limited potential to affect nutrient bioavailability. (C) 1997 Elsevier Science B.V.