Ebony (Phitecellobium flexicaule Benth) and proteins fractionation, solubilization, characterization and production of an isolate

Different combinations of pHs (2 to 12) and temperatures (25, 30 and 35 degrees C) were tested to obtain a protein isolate from ebony (Pithecellobium flexicaule, Benth) seeds. Seed proteins contained 54.6 per cent albumins, 32 per cent globulins, 5.7 per cent glutelins and 1.3 per cent prolamins. The isoelectric points for albumins, globulins and glutelins were in the pH range of 2.3-2.7. The average molecular weight of albumins ranged from 92 to 100 kDa and for the four globulin subunits in the range of 28.4 to 57.3 kDa. For isolate production, proteins were sequentially extracted with distilled water and a 5 per cent NaCl solution. The resulting supernatants were mixed. The best extraction was achieved at pH 11 and 25 degrees C. 45.6 per cent of the total seed protein was precipitated at pH 2.6 yielding an isolate with 90 per cent protein (N x 6.25). The isolate contained high quantities of lysine, leucine, threonine and phenylalanine but were low in sulfur containing amino acids methionine and cysteine. The extraction process reduced tannins, phytates and trypsin inhibitor in 53, 70 and 70 per cent, respectively. In vivo protein digestibility of the protein isolate was 85.4 per cent and the corrected digestibility essential amino acid score was of 44 per cent due to the lack of sulfur containing amino acids. In order to upgrade the protein quality of ebony isolate it is recommend to supplement with methionine or sulfur containing rich foods.

Effects of temperature, moisture and residence time in the properties of full fat soybean flour produced in a twin extruder / Efectos de temperatura, humedad, y tiempos de residencia en las propiedades de harinas de soya integral producidas en un extrusor gemelo

soybeans were dehulled, roll-milled into grits, conditioned to 18 or 21 per cent moisture and continuously cooked in a twin extruder at three temperature programs and two residence times. The resulting extrudates were further dired and rool-milled into flour and characterized for their physical, chemical and funtional properties. The urease activity and nitrogen solubility index (NSI) decreased with increased extrusion temperature, residence time and soybean grits moisture content. The best pre-cooked full fat flours had a urease activity lower than 0.2 and a NSI higher than 15 per cent

Effects of dehulling and storage conditions on cooking requirements and chemical composition of soybeans / Efecto del descascarado y de las condiciones de almacenamiento en los requerimientos de cocción y composición química de la soya

Changes in cooking requirements and chemical composition of whole and dehulled soybeans, stored in 2 different environments [25ºC/75 per cent RH. (Environment 1) and 38ºC/90 per cent RH. (Environment 2)], were studied. Rate of water absorption and solid losses during cooking were higher for the dehulled soybeans at both storage conditions. However, cooking requirements to archieve the same degree of texture cotyledons were similar for whole and dehulled seeds. Cooking time increased with prolonged storage; the effect was more noticeable in samples stored under Environment 2. Samples kept for 6 months almost twice as much cooking than control samples. dehulled soybeans had a lower fiber content, relatively higher amounts of protein and fat, but similar amino acid compositions than whole soybeans. Cooking caused losses of carbohydrates and ash and, therefore, significantly increased levels of protein and fat reflected by losses of solids during soaking and cooking. Among the amino acids, only cysteine suffered subtantial decrease as a result of cooking. Cooking and storage inactivated 90 per cent and from 20-35 per cent of the trypsin inhibitors, respectively; the latter effect was more accentuated in samples stored under Environment 2

Effects of dehulling, cooking and storage conditions on protein quality and digestibility of soybeans / Efecto del descascarado, cocción y almacenamiento sobre la calidad de la proteína y digestibilidad de la soya

Soybeans were debulled, stored under two environmental conditions [25ºC/75 por ciento RH (Env. 1) and 38ºC/90 por ciento RH (Env. 2)], optimally cooked and assayed for trypsin inhibitor and protein quality with laborary rats. Dehulling not significantly effects protein quality (PER and NPR) and protein digestibility of raw and cooked soybeans. Raw soybeans diets were significantly poorer in protein quality and digestibility when compared with cooked counterparts. PER values of dehulled-cooked soybean diets decreased significantly (p<0.05) as seeds were stored for up to 3 months under either environment. These were no significant differences in PER values due to etorage suring the period from 3 a 6 months. PER values for whole-cooked soybean diets exhibited a significant decline only when stored for 6 months under Env. 2

The effect of soaking time on water time on water absorption and solid losses of whole and dehulled soybeans / Efecto del tiempo de remojo en la absorción de agua y pérdida de sólidos en soya entera y descascarada

Dehulled entire soybean cotyledons are required for the preparation of many interesting products. Removing hulls had a dramatic effect on the rate of water uptake during soaking. Maximum uptake was reached in only 3 hr compared to the 12 hr needed by whole beans. This saves time and reduces microbial groeth during soaking. The amount of water absorbed by beans, with and without hulls, was similar once corrected for solid losses and surface water. Removal of fibrous shells during dehulling increased both the protein and oil contents by 2 per cent. Dehulled beans steadily lost solids during soaking. Losses were 8.6 per cent compared to 0.7 per cent whole beans when maximum uptakes were first reached. Way of avoiding or reducing these losses are discussed

The tortilla making properties of two improved maicillo cultivars from Honduras

Grains of two improved maicillo hybrids (Sorghum bicolor (L) Moench) and their criollo (Landrace) counterparts grown at two farmsites in Honduras were lime-cooked and processed into table tortillas. Kernels from the criollos were less dense and softer than kernels from the improved cultivars. The improved maicillos had straw or red plant and glume colors while the criollos were less dense and softer than kernels from the improved cultivars. The improved maicillos had straw or red plant and glume colors while the criollos had purple colored plants with black or purple glumes. The soft textured criollo kernels required less cooking than their harder improved counterparts. Nixtamals cooked to contain 53-55 moisture were the most suitable for processing into tortillas. Both improved maicillos compared favorably with Sureño (used as positive control during processing). The criollos produced darker, less acceptable tortillas. Masa and tortillas from criollos darkened during lime-cooking especially during baking. All sorghums and their respective tortillas had similar chemical composition. The improved maicillos bred in Honduras have a significantly improved plant and glume color with white pericarp. The sorghum improvement was also observed in the overall tortilla quality.