[Nutritional quality of pigeon pea protein, immature and ripe, and its supplementary value for cereals]. / Calidad nutricional de la proteína del gandul, tierno y maduro, y su valor suplementario a los cereales.

The purpose of the present research was to determine the differences which could exist between immature and mature pigeon pea in gross chemical composition and protein quality, raw and cooked, as well as their respective supplementary value to rice, and to mature and immature corn and sorghum. The chemical composition data showed only small differences in proximate composition between the mature and immature grain. The cooking process did not affect chemical composition. Based on the FAO/WHO amino acid reference pattern, immature pigeon pea was more deficient in threonine than mature pigeon pea, which was limiting in valine. Both grains were limiting in sulfur amino acids. The protein quality of the immature grain was higher than that of the mature grain, and both responded positively to cooking, suggesting the presence of antiphysiological substances in both. Amino acid supplementation studies demonstrated that both the immature and mature grain responded to methionine addition, the first limiting amino acid, and to tryptophan, the second limiting amino acid. The effects were more marked when samples were cooked. Both types of grains were good supplements to rice, when added in amounts of 10-20%. Mature pigeon peas supplemented relatively well the proteins of sorghum, immature and mature corn, at the 20, 30 and 20% levels, respectively. The differences found could be explained on the basis of the amino acids limiting cereal grains and pigeon peas protein.

[Evaluation of a device to measure the hardness of the bean grain (Phaseolus vulgaris) and its use in the determination of cooking time]. / Evaluación de un aparato para medir la dureza del grano de frijol (Phaseolus vulgaris) y su utilización para la determinación de tiempos de cocción.

A simple equipment named DUR-INCAP was developed to study the factors responsible for the hard-to-cook beans and for other purposes related to this problem. The instrument measures objectively the hardness of individual beans, expressing the result as gram-force. The document describes the equipment. As a first step in establishing the usefulness of the equipment, a study using four white, four black and four red-colored beans, purchased in the market, was undertaken. Likewise, a black bean (Tamazulapa) harvested in January, 1983, and stored for one year at 5 degrees and 25 degrees C, and the same cultivar harvested in January, 1984, were also used. All beans were cooked in boiling water (95 degrees C) at atmospheric pressure for 30, 60, 100, 140 and 180 min. At each cooking time, a sample was withdrawn and its hardness measured individually on 25 kernels, with the DUR-INCAP. With the help of experienced persons in cooking, the hardness at each cooking time was classified into soft cooked beans (less than 100 g-force), medium (between 100-200 g-force) and hard (above 200 g-force). Results were as follows: white and black beans reached softness at 140 min of cooking, with the exception of one black sample which required 180 min. Two of the four red beans required 180 min, and the other two, needed 40 additional min. The effects of storage time and temperature on hardness became evident in the study with the black bean Tamazulapa. The sample stored for one year at 25 degrees C needed 140 min cooking time, while the sample stored at 5 degrees C and the one harvested in January, 1984, required 100 min. These initial results suggest that the DUR-INCAP instrument may be useful for the study of the hard-to-cook bean problem; however, additional analyses are required.

[Relationship between the included levels of coffee pulp and the protein content in rations for monogastric animals]. / Relación entre los niveles de inclusión de pulpa de café y contenido proteínico en raciones para animales monogástricos.

The purpose of this research was to determine the effect of including fresh and ensilaged coffee pulp in rations for monogastric animals, and find the best protein and coffee pulp levels in rations for rats. Fresh coffee pulp and pulp ensilaged for 12 months were used; both kinds of pulp were sun-dried before incorporating them into the rations. The chemical analyses of the pulps revealed a lower content in caffeine, tannins, chlorogenic acid and caffeic acid in the ensilaged pulp than in fresh coffee pulp. Thirty-two experimental rations were prepared, 16 with fresh coffee pulp and 16 with the ensilaged by-product, distributed into four different protein levels (10, 15, 20 and 25%), and three levels of pulp (15, 30 and 45%) for each protein level. The rations thus prepared were fed to Wistar albino rats for a six-week period. The parameters used to measure the effect of the two types of pulp were mortality rate, food consumption, weight gain, food conversion and apparent digestibility of the rations. Ensilaged pulp had a higher nutritive value, lower toxicity and better digestibility than fresh pulp. The increase in the protein level of the ration resulted in partial protection against the negative effects of coffee pulp on the performance of animals, since this improved as the protein level of the ration increased.

[Effect of various solvents on the extraction of protein fractions of beans (Phaseolus vulgaris)]. / Effecto de varios solventes sobre la extracción de las fracciones proteínicas del frijol (Phaseolus vulgaris).

A study was carried out to determine the effect of different solvents on the extraction of protein fractions in beans. Black bean protein was extracted with the following solvents: distilled water, 0.01 M sodium hydroxide, 0.05 M sodium chloride, and 70% ethanol. By using each solvent under different conditions, it was possible to establish the optimum ones for the best extraction and fractionation of proteins from leguminous seeds. These conditions were the following: one hour agitation at room temperature, three successive extractions with the same solvent, and a ratio of solid to solvent of 1:20 W/V. The effect of 24 different sequences of solvents upon the extraction of protein was also investigated. From the extraction point of view, the best sequence of solvents for extracting the protein was that where NaOH constituted the first solvent used; this sequence, however, has the disadvantage of extracting all the protein from the seed, making it impossible to separate other protein fractions by another solvent. If the purpose of the extraction is to separate different protein fractions, the best sequence of solvents is distilled water or sodium chloride in the first place, followed by ethanol and sodium hydroxide. The need for using standardized methodology for the fractionation of protein from seeds in order to obtain comparable data between research laboratories is emphasized.

[Biological behavior of protein fractions isolated from the common bean (Phaseolus vulgaris)]. / Comportamiento biológico de fracciones proteínicas aisladas del frijol común (Phaseolus vulgaris).

The purpose of this study was to determine the factors responsible for the low digestibility of bean proteins. To this effect, protein fractions were isolated from black beans through sequential extraction with distilled water, 70% ethanol and 0.01 M sodium hydroxide. Since the amount of protein extracted with the solvents was very low, it was practically impossible to carry out its biological evaluation in rats. Therefore, the protein fractions were added to casein diets in order to determine the decrease in casein digestibility due to the particular protein fraction added. The extracts and residues were heated and dehydrated prior to their incorporation in the rations. Nine rations were prepared. The first one was the control with casein only; 20% of whole bean flour was added to the 2nd; rations 3, 4 and 5 contained the water extraction residue, the water extract, and both, respectively; rations 6, 7 and 8 contained the ethanolic residue, the ethanol extract, and both, respectively. Finally, ration 9 was prepared with the NaOH residue. All the materials used as well as the rations were analyzed for their proximate composition and amino acid pattern. The results of the biological evaluation were as follows: casein and dry matter digestibility decreased significantly with the 2nd ration which contained 20% whole bean flour, effect which was significant also in rations containing either the water or the ethanol extract. This effect is attributed to the antiphysiological factors present in the beans which are resistant to heat treatment. The protein efficiency ratio was lower for the rations prepared with the residues from water and ethanol extractions (3 and 6) than for casein; these results are attributed to the lysine and methionine deficiency in the protein fractions, complicated by a lower protein intake. The lowest nutritive value was found in group 7, which was fed the ration containing the ethanol extract, but when the latter was added together with its residue (ration 8), the PER was superior than for ration 7, possibly due to a higher content of methionine and lysine in ration 8. Finally, it is suggested that better results could be obtained by using higher amounts of beans and their protein fractions in the ration.

Efecto de varios solventes sobre la extraccion de las fracciones proteinicas del frijol (Phaseolus vulgaris). / Effect of different solvents on the extraction of protein fractions of beans (Phaseolus vulgaris)

En el presente trabajo se informa de un estudio relacionado con el fraccionamiento por solubilidad de las proteinas del frijol negro (Phaseolus vulgaris), variedad S-19N, usando diferentes solventes: agua, hidroxido de sodio 0.0l M, cloruro de sodio 0.05 M, y etanol al 70%

[Chemical evaluation of morro or jícaro (Crescentia alata) flours prepared by ensilaging and/or dehydration]. / Evaluación química de harinas de morro o jícaro (Crescentia alata) preparadas por ensilaje y/o deshidratación.

The chemical composition, nutritive value and potential use of the morro fruit (Crescentia alata) has received little attention. The purpose of the present study was: a) to determine appropriate conditions for processing and conservation of the morro fruit without hulls, since a significant part of the production is lost due to inadequate storage conditions, and b) to evaluate, by means of chemical analysis, the whole fruit and its products. For the preparation of dehydrated meals, the content of the fruit was subjected to sun drying and tray drying dehydration with two air temperatures, 60 degrees and 90 degrees C. The method used for the storage of the whole fruit was anaerobic fermentation achieved by ensilaging the fruit in small concrete experimental silos for 90, 145 and 180 days. At the end of each period, the silos were opened. The ensilaged material was of very good appearance and apparently free from unfavorable contaminations; it was dehydrated in tray dryers at an air temperature of 60 degrees C. Independent of processing, the chemical analysis showed the meals to contain on the average 17% crude fat, 11% crude fiber and 18% crude protein. From the amino acid content and using the 1973 FAO/WHO scoring pattern it was found that such flours were limiting in their sulfur amino acid, lysine and threonine content in the order.

[Effect of various processes on the protein quality of food based on corn and soybeans]. / Effecto de varios procesos sobre la calidad proteinica de un alimento a base de soy a y de maiz.

The present study deals with the effect of various processing methods on the protein values of Maisoy, a blend of 30% whole soybean and 70% corn. The processes evaluated were: a) lime cooking using calcium hydroxide; b) toasting, and c) extrusion cooking, using an equipment known as the Brady Crop Cooker. The same blend of soybean/corn was processed by the same three methods. In addition, a sample of Maisoy--blend produced in Bolivia with the extrusion equipment previously indicated--was also evaluated. The evaluation of all products was carried out using the protein efficiency ratio method (PER). The capacity of two of the blends, with and without amino acid supplementation, of causing changes of deoxiribonucleic acid, ribonucleic acid, and protein in the content of muscle and liver was also measured. Lime cooking as well as extrusion cooking yielded a food with a protein efficiency ratio which varied from 2.30 to 2.60. Both processes destroyed the antiphysiological factors of soybean.