[How I got to study legumes]. / Como llegué al estudio de las leguminosas.

In this paper the author presents a brief account of his involvement in the study of legume seeds form a nutritional and toxicological perspective. After observing that the Venezuelan peasants ate diets which often included cooked black beans and a form of corn bread called arepas, he performed nutritional trials which led him to recognize that raw beans contained thermolabile antinutritional factors and that their proteins were complementary to those of corn. Among the antinutritional factors, he isolated a hemagglutinating fraction which later was further characterized. Based on their properties he recognized the existence of four different types of Phaseolus vulgaris cultivars. Research on the nutritive value of bean diets also got him involved in the identification of a growth factor later called vitamin B12.

Selenium status of children living in seleniferous areas of Venezuela.

Selenium was measured in red blood cells, serum and hair of children and in breast milk of mothers in seleniferous areas of Venezuela by means of neutron activation analysis. Signs of selenosis were observed only in a few cases. Reduction in the rate of growth is discussed with respect to unequal local nutritional conditions during the growth period.

[Nutrition yesterday and today]. / Nutrición ayer y hoy.

The history of human nutrition from primitive times to actuality is briefly outlined. Many of the modern nutritional problems can be traced back to changes caused by the introduction of agriculture and, more recently, food technology. These developments have changed the composition of the diet to which the primitive hunter-gatherers had adapted themselves during millions of years. Changes in food habits and the beginning of the science of nutrition are discussed, and a brief review of nutritional recommendations is provided. The terms of nutritional goals and rules, so much used today, are of recent introduction. Nevertheless, norms, normal allowances and other similar expressions have since long ago been in use. Nutritional goals should be based on the vital habits of the population for which they are intended, and should be adapted to the ever emerging new findings in nutritional sciences.

[Requirements of nutrients which participate in erythropoiesis]. / Requerimientos de nutrientes que participan en la eritropoyesis.

Proteins, some minerals and vitamins, play important roles in erythropoiesis and the survival of the red blood cell. This article deals specifically with the physiological requirements and recommended intakes of iron, folate and vitamin B12. A comparison of the physiologic iron requirements according to age and sex, and the amount of iron which is actually absorbed from the diets consumed by the lower socioeconomic strata of the Venezuelan population; indicates that these diets do not satisfy the requirements at all ages. Such disparity is most marked in children below three years of age, in adolescents and in women during their reproductive age. Failure to do so leads to varying degrees of iron deficiency. This low bioavailability of the Venezuelan diet is also observed in other Latin American diets consumed by the same low socioeconomic strata, which explains the high prevalence of iron-deficiency anemia in the vulnerable groups. The low intake of fruits and vegetables by the lower socioeconomic strata of the Latin American population prevents these sectors from consuming an adequate intake of folate, failing to fulfill the daily recommended intake (3.3 - 3.6 micrograms/kg body weight). This situation is aggravated in pregnant and lactating women who require an additional intake of 300 micrograms and 100 micrograms, respectively. Prevalence of folate deficiency in the first stage may be in the order of 30% in some regions. In the second stage of deficiency, characterized by megaloblastic changes in the bone marrow and an erythrocyte folate concentration of less than 50 micrograms/lt, it could be as high as 40% in pregnant women. Nutritional vitamin B12 deficiency does not constitute a health problem in Latin America. Various surveys in the lower socioeconomic strata have reported normal or higher than normal serum B12 concentrations, compared to well-nourished populations.

[Hematologic profile and absorption of iron from diets consumed by a population of low socioeconomic level of 2 Venezuelan states]. / Perfil hematológico y absorción del hierro de dietas que consume la población de estrato socioeconómico bajo de dos estados de Venezuela.

Hematologic studies carried out in inhabitants of the State of Carabobo revealed that 19% of the subjects studied presented iron deficiency, this being more prominent in women and in children. Iron deficiency anemia was absent in men, while in the other groups its frequency, as registered, was from 5 to 13%. Tests for iron absorption from foods which form the average diet of the population in the Carabobo State, and the diet consumed by adults from the low socioeconomic strata in the States of Carabobo and Yaracuy, demonstrated that in normal subjects, bioavailability is lower than physiological requirements of men, women and children. In the iron-deficient subjects, its bioavailability can cover physiological needs. It is estimated that an important proportion of the population strata consuming such diets, suffer from iron nutritional deficiency, especially women during the reproductive age, and children.

[Biochemical and nutritional value of seeds of the lima bean (Phaseolus lunatus) in comparison with those of the common bean (Phaseolus vulgaris)]. / El valor bioquímico y nutricional de las semillas del haba de lima (Phaseolus lunatus) en comparación con las del frijol común (Phaseolus vulgaris).

Composition in nutrients and antinutritional factors, digestibility and growth in rats fed diets prepared with raw and cooked beans of Ph. vulgaris, cultivar "Tacarigua", and Ph. lunatus cultivar "Tapiramo", are compared. Grains from both cultivars are similar in appearance, taste, nutritional value, and acceptability. Protein and phosphorus contents were greater in Ph. vulgaris than in Ph. lunatus seeds. The chemical score and availability of lysine were better in Ph. lunatus. Diets prepared with raw beans from Ph. lunatus resulted non toxic for the rats during a 12-day period of feeding. All rats fed with raw beans from Ph. Vulgaris died in the same period of time. Protein efficiency was better with cooked beans of Ph. lunatus. The cultivar "Tapiramo" (Ph. lunatus) is recommended for autoconsumption by small farmers.

Inhibition of trypsins and chymotrypsins from different animal species: a comparative study.

The effect of 3 purified trypsin inhibitors and 4 legume seed extracts on teh trypsins and chymotrypsins of the activated pancreata of 11 animal species, including man, was measured. The activation was performed by either homologous enterokinase or by bovine trypsin. Several trypsinogens were not activated by the latter. Rabbit trypsin was the most sensitive to all inhibitor preparations, while the human trypsin was the most resistant, except to the black bean extract. The response of the chymotrypsins was more variable and those of capybara and rabbit showed extreme sensitivity. Considerable differences between the extracts of black and white garden beans, both Phaseolus vulgaris, with respect to their reactivity toward different animal enzymes were detected. No relation between relative pancreas weight and susceptibility toward soybean trypsin inhibitor could be observed.

[Obtaining protein fractions from commercial sesame cakes (Sesamum indicum)]. / Obtenção de frações protéicas a partir de tortas comerciais de gergelim (Sesamum indicum).

Sesame press cake represents an important potential protein source for human consumption. Some of the limiting factors are its high crude fiber content, oxalic acid content, and its bitter taste. By fractionation of solvent-extracted sesame meal, several preparations were obtained which were analyzed for their nutrient content, protein utilization and digestibility. PER values were low, and supplementation with lysine, skim-milk powder, soymeal or fish meal, improved the PER values considerably. Based on these findings, formulas for use as a protein supplement for children are presented.

Obtencao de fracoes proteicas a partir de tortas comerciais de gergelim (Sesamum indicum). / Obtention of protein fractions from commercial cakes of sesame (Sesamum indicum)

As farinhas de gergelim obtidas comercialmente como subproduto da extracao do oleo representam um potencial muito grande como fonte de proteina para consumo humano.Neste trabalho, estudaram-se os fatores que tem limitado seu uso na alimentacao humana e apresentam-se as bases que permitam utiliza-las em forma pratica. Sao apresentados resultados para o conteudo de fibra, proteina, vitaminas, minerais, acido oxalico, aminoacidos e tambem do valor nutritivo pela eficiencia proteica e digestibilidade em ratos. Nossos resultados demonstraram que se pode obter uma reducao significativa no conteudo de fibra e acido oxalico e aumento de proteinas, mediante moagem e peneiragem, por descascado ou por obtencao de concentrados. Evidenciouse uma eficiencia proteica baixa (aproximadamente 1), pelo que se recomenda a suplementacao das farinhas com lisina ou com uma boa fonte deste aminoacido, especialmente com proteinas de leite em po desnatado, proteinas de soja ou farinha de peixe. Nestas duas ultimas, os resultados foram muito bons (2.5 e 2.7) quando cada fonte fornece 50% das proteinas. Sao apresentados algumas formulacoes contendo 20 a 40% de farinha com uma concentracao final de proteina entre 16 e 24% e que deram como PER valores de 2.2 e 2.8

Partial characterization of a subtilisin inhibitor from black bean seeds.

The subtilisin inhibitor (SI), isolated from black beans (Phaseolus vagaris) has a molecular weight of 8918 and it contains four half cystine residues. The N-terminal residue is arginine and the C-terminal is lysine. The subtilisin inhibiting site is composed of an Ala-Leu or Ile bond. This site interacts in addition to subtilisin (S) with elastase from human leukocytes (HLE), both of which compete for the inhibitor. Also, HLE-cleaved SI (SIHLE) is inactive against HLE as well as against S. It was shown that the inhibition of S by SI resembles a temporary inhibition, involving a very slow release of enzyme activity. The trypsin reactive site is a Lys-Val bond, and its interaction with bovine trypsin is very weak. No complexes of SI or trypsin-cleaved SI (SIT) with trypsin could be detected on cellulose-acetate membrane electrophoresis, while SIT forms a clearly visible complex with S.

[Formulation of a rice-based beverage of high nutritive value]. / Formulación de una bebida de alto valor nutritivo a base de arroz.

The purpose of this work was the production of a beverage with a nutritive value similar to that of milk, but available at a lower cost. A traditional beverage in Venezuela, "Chicha de Arroz" (Rice Chicha), was chosen. The various formulas studied were based on rice, non-fat milk and different kinds of soy flour, in addition to sugar, vegetable oil, vitamins, ferrous sulfate and different flavors. A product with protein and caloric values similar to those of milk was obtained. Twenty formulas were prepared and submitted to physico-chemical, microbiological and sensorial evaluations with respect to flavor, color, viscosity and stability during period of refrigeration. The most adequate formula was prepared on a pilot-plant scale. Rat assays gave the same PER results as those of casein. Consumer acceptability was tested on 1,080 school children, and showed to be greater than 95%. The stability was superior to that of milk and the cost, approximately three-fourths that of the latter. In the school-snack program of the National Institute of Nutrition, milk is now being replaced by this Chicha.

[Soluble iron and iron available in vegetable foods]. / Hierro soluble hierro aprovechable en alimentos vegetales.

The relation ship between the quantities of soluble iron and iron available for humans reported by other authors in seven different vegetable foods was investigated. Total iron content, soluble iron, and in some cases also phytic acid were determined. The recovery in soluble form of iron added as iron sulphate to some foods was also studied. The results were compared with those reported in the literature for the amount of iron absorbed in humans from these same foods. In some cases the quantities of soluble iron and available iron were very similar but in some others the values differed considerably. There was a marked variation in the amount of soluble iron in different samples of the some vegetable product and also the iron absorption reported from a single food in different persons. These facts may explain, at least in part, the lack of coincidence mentioned.

[Selection and acceptability of food]. / Selección y aceptabilidad de alimentos.

In this paper the following factors which in one way or the other may have influence on the selection and acceptability of foods are treated: 1. Fisiological and psycological aspects; a) genetic factors, b) neurophysiological factors, c) emotional factors, d) perceptive factors. 2. Physical and ecological aspects. 3. Social and cultural aspects, a) habits and traditions, b) religious believes, c) tabues, d) nutrition faddism, e) prejudice, aversions and perversions, f) social value of foods, g) industrialized foods. 4. Economic aspects. 5. Educational aspects.

[Consumption of selenium in the city of Caracas in comparison with other cities of the world]. / Consumo de selenio en la ciudad de Caracas en comparación con el de otras ciudades del mundo

Ingestion of selenium in Caracas, compared with some other cities. Fourty-two different food products acquired in Caracas were analized for their selenium content and the results compared with those reporte in food from Beltsville, Md. When the selenium level of a normal diet of 2200 cal is calculated, a selenium ingestion of about 220 mcg/d is found for Caracas, compared with several diets from Canada shows that the they contain from 1/3 to 2/3 of the amount of selenium as similar as similar diets in Caracas.