EXTRACTION OF OAT GUM FROM OAT BRAN - EFFECTS OF PROCESS ON YIELD, MOLECULAR-WEIGHT DISTRIBUTION, VISCOSITY AND (1-]3)(1-]4)-BETA-D-GLUCAN CONTENT OF THE GUM

Different processing technologies were examined for their efficiency i n production of large amounts of good quality oat gum rich in (1-->3)( 1-->4)-beta-D-glucan. Untreated and enzyme-deactivated oat bran concen trate were extracted with aqueous sodium carbonate at pH 10 and 40 deg rees C. Oat gums were subsequently isolated either by dialysis, ultraf iltration, or alcoholic precipitation on small, medium, and pilot plan t scales. It was possible to produce oat gums with a beta-glucan conte nt of approximate to 60-65% with all three methodologies. The viscosit y of solutions of the gums and the molecular weights differed, dependi ng on the production process. Using dialysis, the production of highly viscous gums was possible, whereas ultrafiltration and alcoholic prec ipitation yielded gums with lower solution viscosity. Enzyme-deactivat ed oat bran concentrate gave an oat gum with an increased beta-glucan content and solution viscosity, but in lower yield. To produce large a mounts of oat gum, alcoholic precipitation would be the process of cho ice, but ultrafiltration and dialysis are useful alternatives.