EXTRUSION OF PINTO BEAN HIGH-PROTEIN FRACTION PRETREATED WITH PAPAIN AND CELLULASE ENZYMES

High protein fraction of pinto bean was pretreated with papain and cellulase enzymes and extruded at a temperature of 120-degrees-C. The effect of enzyme type and concentration, moisture and duration of incubation on expansion, texture, color, water absorption and solubility, pH, sugars, nitrogen solubility index and in vitro protein digestibility of the extrudate were investigated. Enzymatic modification had differential effects on nitrogen and carbohydrate components and on some physical and functional properties of extrudates, depending on type of enzyme and incubation conditions. Results indicated the possibility of controlling protein and fiber hydrolysis at low moisture to obtain a desirable degree of modification to improve extruded products. This method may be used in food applications to obtain new snack type products from beans or their fractions.