Effects of cone opening, initial moisture content and multiple extrusion on the protein quality of extruded soybean using the Brady Crop Cooker.

In the present study, three cone openings (0.133; 0.106, and 0.080 cm) and three initial moisture content values (9%, 15% and 21%) were used as treatments to evaluate their effects on the protein quality of full-fat soybean flour, extruded in the Brady Crop Cooker. The specific volume, protein and oil contents as well as available lysine content characteristic of the final product, were not affected by the treatments used. Processing temperatures, however, decreased when the initial moisture content of the material was increased. The nitrogen solubility index was affected by the cone opening but not by the moisture content of the material. With respect to the trypsin inhibitors content, the increase in the initial moisture content in soybeans gave conflicting results. At the 21% moisture treatment, the amounts of trypsin inhibitors were higher than those present in the raw material; a similar effect was also observed with urease activity. At the other two moisture contents (9 and 15%) the amounts of trypsin inhibitors and urease activity were decreased by heat treatment, mainly at the 9% moisture level, which were related to the cone opening of the extruder. PER values in rats were influenced by the moisture content and were not affected by the cone opening. Results obtained in the biological assays with chicks, both for weight gain and conversion efficiency, were favored by a decrease in cone opening. Nevertheless, the increase in the moisture content induced a decrease in weight gain at the 5- and 8-week periods, without affecting the conversion efficiency. The effect of consecutive passes of the material through the extruder was also studied. The product obtained with two extrusions presented a good biological value, probably as a consequence of the low values in the trypsin inhibitors and urease activities. When the material was extruded three times, results proved to be poor, due to a reduction to significant low levels of available lysine content--which becomes limiting--, and nitrogen solubility index of the full-fat soybean flour.

Cultivation of two varieties of winged bean (Psophocarpus tetragonolobus, L. DC) in Jaboticabal, São Paulo.

Winged bean was recently introduced in the region of Jaboticabal, and the behavior of varieties "UPS-31" and "UPS-122" in different planting seasons was studied. Plantings were spaced 15 days, and the experiment started October 16, 1978 and ended December 15 of the same year. Plantings were made in rows, spaced 1.50 m from each other, leaving a distance of 0.60 m between plants. Their growth was tutored by bamboo poles which led them to a single wire placed horizontally at 1.70 m from the soil. An effect of the planting season was observed on flowering and fructification, since late plantings presented lower values for these characteristics and also decreased the harvesting period of the dry pods. Early plantings led to a higher development of the plants, and also to higher yield values as yield is a consequence of the number of pods per plant, with a high content of seeds per pod. Variety "UPS-122" was somewhat late in flowering and more vigorous than "UPS-31". The planting season did not affect the protein and oil contents, and average values in seeds of 43% and 17% were obtained, respectively.

[Agronomic, nutritional and processing characteristics of soybean germ plasm with colored seed coats]. / Características agronómicas nutricionais e de processamento de germoplasma de soja com tegumentos coloridos.

Ten soybean varieties with colored seed coats were evaluated in Jaboticabal, with the objective of obtaining information as to color preference in the direct use of soybeans in human consumption. The above-mentioned material showed good adaptation to the local environmental conditions: plant cycles were smaller than the Santa Rosa (121 days), varying from 107 to 119 days, in spite of the fact that some varieties started blooming later than Santa Rosa. All materials are within the minimum standards for local planting; however, some of them showed a lodging problem, and all varieties are susceptible to bacterial pustule. They have smaller seeds than Santa Rosa, and in relation to yield, varieties as the NC-55, Aksarben 1S (Black), Aksarben 1S (Brown) and Chi kei 13 did not statistically differ from the Santa Rosa. Protein content showed a variability of 37.90 to 43.90% and oil varied from 14.72 to 21.34%. Methionine content was between the known limits (0.907 to 1.644 g/16 g N), but lysine was higher than any reported data (7.584, to 10.877 g/16g N). The Tanner, Chi kei 13 and Chi kei 15 presented a high percentage of hard beans. This fact had a positive influence on the seed hydration characteristics, but their experimental cooking times were very low, varying from 51 and-a-half to 122 minutes. The term "hydration time" is being introduced here, which is defined as the time, in hours, required for a seed to double up its weight when submerged in water.