EVALUATION OF THE HYDROLYTIC STABILITY OF HEAT-PROCESSED OAT PRODUCTS

Abstract

It was studied the hydrolytic stability of oat products heat-processed by drying and extrusive cooking. Oat kernels with 18% moisture were dried to level of 14.2-5.8%. The material was ground in a roll-mill and three fractions, > 532 µm, 532-150 µm, and <150 µm were separated and analyzed. For the extrusion experiments, the fractions >532 µm and <532 µm were conditioned to the total moisture level of 15.5-25.5%, then extruded in a single-screw laboratory extruder, using temperatures between 77.6 and 162.4° C for the second and third zones, respectively, while the temperature of the first zone was kept at 80°C. After extrusion, the material was dried, ground and wrapped into plastic bags. The acidity index of the extruded products, unlike observed in the milling study, did not range significantly (p>0.05) after 126 days of storage, showing a good hydrolytic stability.