Meeting Abstract
P-332
The use of a very low cost extruder on the inactivation of phytohemagglutinin activity in red kidney beans (Phaseolus vulgaris L.). G. NYOMBAIRE (1). (1) Michigan State University.
A significant part of the world relies on dry beans as a staple food for subsistence, particularly in combination with cereals. However, beans contain phytohemagglutinins (PHA), protease inhibitors and amylase inhibitors. These antinutrients must be inactivated, the starch must be gelatinized, and the beans must be ground or softened before consumption. Lack of fuel wood for cooking dry beans is a major problem facing over-populated developing countries and continued deforestation alters local and global climate. The existing extrusion equipment is not suited to the context of countries with low income, as it requires considerable financial investment. The objective of this study was to test the performance of a very low cost extruder on the inactivation of phytohemagglutinin activity in red kidney beans. Extrusion of raw ground red kidney beans was accomplished using a low cost laboratory co-rotating twin-screw extruder model JS30A manufactured in China by Qitong Chemical Industry Equipment Co., Ltd. The screws are 30 mm in diameter and the barrel has a L/D of 16. Red kidney bean flour was extruded at 25% and 36% moisture content wet basis; screw speed was 118, 194 and 255 r.p.m; feed rate was 85 and 120 g/min and extrusion barrel temperature was 105 and 125°C (die end). Phytohemagglutinin activity in the extruded samples was determined in triplicate by enzyme-linked immunosorbent assay (ELISA). Significant reduction (more than 90%) of PHA was observed in samples extruded under 25% moisture. The very low cost extruder manufactured in China can be used by both developed and developing countries in the production of safe and low cost nutritional bean products such as infant flours and bean snacks.