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.

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.