Studies were carried out to determine the possible relationship between the color of the seed coat of beans and the nutritive value of its protein. Beans with white, red and black seed coats and a black coated bean and its white mutant were chosen for the study. Hemagglutinin activity was located in the cotyledons of all samples with low activity in the seed coat. No activity was found in the cooked beans or in the cooking broth. Trypsin activity was influenced by a heat labile factor (true trypsin inhibitor) and by a heat resistant factor (tannins). The heat labile factor or true trypsin inhibitor was higher in the cotyledons (16-18 TUI/mg sample) than in the seed coat, while the heat resistant factor was found in highest concentration in the seed coat. Red and black seed coats had a higher concentration (23-31 TUI/mg sample) of the heat resistant factor than the white seed coat of the normal white bean and of the mutant (7-9 TUI/mg sample). Cooked beans and their broth showed trypsin inhibitor activity of the heat resistant type. Cooked cotyledons had 5-9 TUI/mg sample. Tannin concentration was high in colored seed coats (38-43 mg/g) and low in white coated beans (1.3 mg/g) while values ranged from 3.8-5.9 mg/g in the cotyledons. A highly significant correlation (r = 0.88) was found between tannin concentration in the seed coat and trypsin inhibitor activity. No correlation between these two components was found in the cotyledons. Samples of cooked beans supplemented with methionine without the cooking broth had higher protein quality values (2.9-3.3) than samples fed with the broth (1.7-2.1). Protein digestibility was lower for red (70.4%) and black beans (75.0%) fed with the broth than beans fed without the broth (78.7% and 77.9% respectively), but the broth had no effect on the protein digestibility of white coated beans (81.3 and 81.4%). The data suggest that color of the seed coat is related to the protein quality of beans.

A BSTRA CTCanavalia ensiformis is a grain legume that offers good possibilities for its use, but reports on its chemical composition and nutritive quality are not readily available. This study presents chemical and nutritional data on C. ensiformis, C . gladiata and C. maritima grains. The three species varied in protein content mainly because of differences in crude fibre content. Protein varied from 26.9 to 22.4%, and crude fibre varied from 8.5 to 17.3%. This was due to differences in seed-coat percentage. The amino acid content in C. ensiformis and C. gladiata was essentially the same, and both were deficient in sulphur-containing amino acids but rich in lysine. Pressure cooking and roasting reduced lysine levels. Mineral content in the three species was essentially the same, with high potassium levels as is the case with most food legumes. Feeding trials indicated low nutritional quality for the raw grain, which was significantly improved by pressure cooking and roasting. Protein digestibility was 47.9%, and cooked and roasted samples had 76-4 and 78-7%, respectively. Both C. ensiformis and C. gladiata had the same protein quality , and it was significantly improved with methionine supplementation.

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A BS T R A CTA set of 14 selections of four amaranth species were studied. Six yielded over 10 kg 36 m-2, and three below 5 kg 36 m-2. Grain size varied from 1.55 to 2.14 mm, and seed weight from 0.46 to 1-18 mg seed-'. There was n o relationship between seed weight and yield. Protein content varied f r o m 12.5 to 16.0%, while fat varied from 7.7 to 12.8%. The content of P, K , Ca, Mg, Na, Fe, Cu, M n and Z n was similar among all selections. Trace amounts of C14 fatty acids were found, while C16 acids varied from 16.83 to 23.83% of the oil. The Cl8:O fatty acids varied from 1-86 to 4.11%, the C18:l from 20.29 to 35.46%, while the C18:2 fatty acids varied from 38.25 to 57.86%. Lysine varied from 0.73 to 0.84%, with tryptophan values ranging from 0-18 to 0.28%. Seeds from all selections were processed by hot-water soaking for 20 min followed by drum-dryiiig, f o r protein quality evaluation.The three A. caudatus had an average protein efficiency ratio (PER) of 2-45; A. hybridus a PER of 2-34; A. cruentus 2-36 and A. hypochondriacus 2-33. Differences were not statistically different. Light and dark coloured seeds had the same average value of 2.36. the study showed important genetic differences in chemical composition.

Condensed tannins and related phenols in 13 samples of red Guatamalan common beans (Phaseolus vulgaris) were determined by four chemical assays. The results were highly correlated although the degree of variation among the samples differed greatly according to the assay. In rat feeding trials, tannin content was negatively correlated with net protein ratio, a measure of protein quality, and positively correlated with protein digestibility. Neither correlation was statistically significant due primarily to the low tannin content of the diet. Methionine supplementation not only improves the protein quality but may also play a role in metabolic detoxification of tannin.