[Preparation of flour processed with pigeon pea seed]

Pigeon pea is a legume grain of good production capacity and of a relatively high nutritive value, which has not been used in Latin America on the basis of the potential it offers. In this study experiments were conducted to learn about the possibility of processing pigeon pea to yield an intermediate flour with good functional characteristics for food product development. The intermediate pigeon pea flour was produced through a selection of a process to efficiently dehull the grain followed by a thermic process to improve its functional properties and nutritive value. The best dehulling process was subjecting the grain to a vapor treatment for five minutes, followed by a 2-hour dehydration of surface moisture with air at 60 degrees and dehulling with an 8-disc dehuller for 10 minutes. Yield was 84% with 70.7% dehulling efficiency. Pigeon pea flours were prepared by three thermic processes: pressure cooking at 15 lb (121 degrees C) for 5 and 10 minutes as a reference product; cooking and drying with a drum dryer at 120 degrees C and 4 rpm and by extrusion-cooking with the material with 18 and 21% moisture at 270 and 300 degrees F, respectively. Process selection was based on the functional properties such as water absorption index, water solubility index, soluble nitrogen and viscosity, through chemical analysis of protein, available lysine and methionine and residual trypsin inhibitors, and through a biological evaluation of protein digestibility and quality. Both pressure cooking products had similar functional and chemical characteristics, however, the 5-minute cooked product has higher protein quality than the 10-minute product.(ABSTRACT TRUNCATED AT 250 WORDS)