Proximate composition, globulin, albumin, nonprotein nitrogen and amino acid contents wemdetermined in four varieties of dry bean. Protein and nonprotein nitrogen contents were similar in all four varieties. The lysine was higher in the varieties Rico 23 and Rosinha -G2. The sulfur-containing amino acids were higher in Rico 23. PER, apparent biological value, nitrogen retention and methionine availability were highest in Rico 23 and lowest in the variety Carioca. For these two varieties PER values ranged from 1.32-0.75, apparent biological value from 58.9-39.4%, nitrogen retention from 36.1-21.0 mg N retained/rat/day and methionine availability from 40.6-29.3%, respectively. Apparent digestibility was lowest for Rico 23 and highest for Pirata-1. Pirata-1 ranked second in all biological parameters, except for methionine availability. Cooking the raw bean did not raise digestibility beyond 66%. Availability of iron was in the range 4-5% for all varieties.

Proximate composition, amino acid pattern, and toxicity of an unheated dry bean flour and of six other materials obtained by fractionation of the flour were studied. When fed to weanling rats the flour and all six fractions were toxic. Most of the toxicity was eliminated by heating the soaked beans 2.5 min at 97 °C, but maximum PER was attained after 10 min at the same temperature. Not all trypsin inhibitor and phytohemagglutinin activities had been eliminated by any of these treatments. Autoclaving (121 °C, 15 min) decreased the availability of lysine in the whole flour and in the water-insoluble solids by 36.7 and 29.3%, respectively, whereas it did not affect significantly that of the other fractions. Heating at 121 °C for 7.5 min was deleterious to the nutritive value of the isolated protein fractions.Leguminous seeds constitute an important source of food protein and energy for a large sector of the world population. The increasing interest in the food legumes has been demonstrated by several international symposia on this topic in the last decade (Milner, 1973;Wall, 1973;Jaffe, 1977).

The influence of storage on dry bean was studied for 6 months under three different conditions of temperature and relative humiditv (RH): A. 12°C. 52% RH: B. 25°C. 65-10% RH: and C. 37°C. 76% RH. Then hydration capacity of rhe seeds remained constant under condition A, increased slightly under condition C and decreased to less than 50% of the original under condition B. Changes in the percentages of hardshell beans were inversely proportional to the hydration capacity. The texture (hardness) of the cooked beans increased from 200 to 250 kg force in the Instron apparatus for the conditions A and B but it reached values greater than 500 kg after 4 months of storage under condition C. Cooking time increased from 60 min to 95, 116 and 300 min for the conditions A, B and C, respectively. The PER value dropped from 1.01 to 0.66, 0.43 and 0.10 under storage conditions A, B and C, in this order. Biological availability of methionine dropped from 46.3% to 43.1, 38.2 and 27.6%, whereas cysteine availability decreased from 51.6% to 45.8, 43 and 30% under the conditions A, B and C, respectively. Protein digestibility changed from 62.4% to 58.9, 57.1 and 54.4% for the conditions A, B and C, in the same order. Addition of methionine to the beans stored for 6 months under the conditions A, B and C, raised the PER from 0.66, 0.43 and 0.10 to the values 2.45, 2.46 and 2.40, respectively, without significantly affecting the digestibility.

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