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.
The properties of weakly bonded soil have been studied experimentally, mainly by an extension of recent work on artificial bonded sand. Higher stresses were used to fully examine yield of this soil ...when at denser states. Triaxial equipment applying confining pressures of 3.5 MPa and a belt for measuring radial strain on triaxial soil samples were developed. The influence of saturation procedures on test results was investigated. A new loading arrangement has been used and comparative studies carried out to evaluate its influence. The new arrangement improves the stress measurements taken platen to platen. It also reduces premature failure of the sample due to non-uniform stresses. Two natural materials with some degree of cementation were also tested: the Corinth marl (a soft carbonaceous rock from Greece) and the Chemususu Dam soil (a red lateritic soil from Kenya). Both materials have similar characteristics to the artificial soil when tested in triaxial compression. The bonded soils have shown a characteristic variation of stiffness with confining pressure. As the pressure is increased the secant initial stiffness increases initially but, at some threshold value of confining stress, shows stabilization or even a drop on its absolute value, depending on the initial void ratio and the strength of the bonding. The bonded soils have a curved yield locus which is coincident with the failure envelope at low stresses. The failure envelope in the low stress region is dependent of the stress path, being lower for conventional drained compression tests.
The present study was carried out to complete available information on the nutrient contents of corn tortilla particularly mineral elements and acid and neutro-detergent fiber. Results indicated that ...the tortilla weight should be considered in dietary surveys. Protein and ash contents are slightly higher in tortillas than in maize, in the first case due to carbohydrate losses that occur during the process, and in the case of ash, due to the lime used during the cooking process. The process also induces changes in the acid- and neutro-detergent fiber in maize. Similar yields related to the decrease of neutro-detergent and the increase of acid-detergent fiber were found in both products. The cell walls content decreases in the tortilla, with an increase in cellular content. With respect to minerals, an increase in calcium content was found, giving a better Ca:P balance, as well as increases in Fe, Cu and Zn.
