Evaluation of physicochemical characteristics and digestibility of an extrudate with common bean for pigs

Objective. To evaluate the physicochemical properties, In vitro dry matter digestibility, and apparent nitrogen digestibility in fecal matter and urine of pigs of an extruded feed using common bean (Phaseolus vulgaris L.) as a soybean meal substitute. Materials and methods. The standardization of the extrusion process was performed for two formulations of bean flour (Pinto Saltillo), cornflour (Cafime), and soybean meal at different proportions: 20/67/13% and 30/60/10%, respectively. Samples were processed in a single screw extruder at 120-150°C and a moisture content of 18-22%. The evaluated physicochemical properties were expansion index, bulk density, water absorption index, water solubility index, hardness, water activity, and color parameters: L*, a*, and b*. The In vitro dry matter digestibility and apparent nitrogen digestibility in fecal matter and urine of pigs were evaluated using the optimal treatment previously obtained by seeking to decrease processing costs.Results. Optimal conditions for the 20% bean flour formulation were: Temperature of 124.4°C and moisture content of 18.59%. Extrusion temperature decreased bulk density, hardness, and water activity, but increased L* and expansion index. Moisture content decreased bulk density, water activity, hardness, and a*. In vitro dry matter digestibility was higher for the extruded bean diet compared to the control diet (92.33% vs. 85.33%). Conclusions. Results indicated that bean flour is a viable option for animal consumption in terms of nutritional value and digestibility