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Biomedical subjects

R Bressani

Publications and source records attributed to R Bressani.

At least 19 recordsLinked to original sources
PubMed1992

[Comparative study of the chemical composition and nutritive value of runner bean (Phaseolus coccineus) and of common bean (Phaseolus vulgaris)].

Scarlet beans (Phaseolus coccineus) is an important food grain legume in the diet of rural populations living in the highlands of México, Guatemala and other countries of Latin America. The present study was conducted to obtain more chemical and nutritive data on this grain legume, because of its importance in agricultural production systems and due to the role it plays in rural diets. Ten samples were purchased in the highland markets of Guatemala, to compare their physical, chemical and nutritive characteristics with three samples of common beans (Phaseolus vulgaris). A sample of 10 kg was used for nutritional studies, fed alone and in mixtures with maize. The results indicated that P. coccineus has greater weight as compared to P. vulgaris (0.74 vs. 0.18 g) and are larger in size (0.60 vs. 0.14 cc/grain). Seed coat percentage was 10.2% for P. coccineus as compared to 9.0% for P. vulgaris. The cooking time was 231 minutes for P. coccineus and 180 minutes for common beans. Seed coat thickness and permeability are different when comparing P. coccineus with P. vulgaris, since at 24 hr soaking time, P. coccineus absorbed 80% of its water weight as compared to 100% for common beans. In chemical composition) small differences were found between P. coccineus and P. vulgaris. The first had slightly more ether extract, crude fiber and ash content than the second. Amino acid content among the six samples of P. coccineus was quite variable, but its pattern was rich in lysine and limiting in sulfur amino acids. Cooking time at 3 hr gave a higher NPR than when cooked at atmospheric pressure for 5 hr, with protein values relative to casein of 69.2 and 60.0%, respectively. P. coccineus protein quality was improved by methionine supplementation, and it appeared to be better digested than that of P. vulgaris. Mixtures of high protein quality were obtained with 15% P. coccineus and 85% maize while common beans and maize mixed in a 30 to 20 ratio showed maximum protein efficiency. The digestibility of the P. coccineus/maize mixtures was higher than that of common beans and maize.

Amino Acids↗
PubMed1992

[Relation between various physical characteristics of sorghum varieties (Sorghum vulgare) and their popping capacity].

The purpose of this study was to attempt to establish a possible relationship between the physical characteristics of grain sorghum and its capacity to expand. Eleven national varieties of sorghum were studied and were characterized for color, weight of 100 grains, number of grains in 40 grams, grain density and texture. Before subjecting the samples to the popping process, the method was standardized with respect to the experimental load. These tests helped to select a 62-gram load. Likewise, the effect of grain moisture content was studied. Results indicated that a soaking time of 45 minutes gave the best percent expansion. Highly statistical significant differences were found in the physical characteristics among the eleven sorghum varieties, as was also the case with respect to change in volume, popped grains and percentage of popped grains, which varied between 7.42 to 89.29%. The initial volume of the grain was negatively associated to the percentage of expanded grains. The initial grain volume was significantly negatively related to the unpopped grain. The final volume significantly correlated with the number of grain in 40 grams, with endosperm texture and grain density. Even though physical structure is important in grain expansion, other factors like chemical composition may also be of significance.

Edible Grain↗
PubMed1992

[Chemical composition of 11 varieties of sorghum (Sorghum vulgare) before and after popping the kernels].

The effect of the popping process on the chemical composition, on lysine and tryptophan and on the in vitro protein digestibility of eleven sorghum varieties was evaluated. The popping of the grain was conducted in a popcorn popper previous adjustment of conditions. There were statistically significant differences in chemical composition both, in the raw grain and in the processed grain. The chemical composition was affected by the process and with the exception of protein content, it reduced the content of ether extract (3.43 to 2.75%) and increased significantly the level of crude fiber (2.47 to 4.45%). The concentration of available lysine and of tryptophan in the raw grain was reduced significantly by the process, with lysine losses of 9 to 57% and for tryptophan of 26 to 64%. A decrease was also observed in amylose as percentage of starch. In a number of samples the popping process significantly reduced in vitro protein digestibility.

Amylose↗
PubMed1991

[Effect of reheating on iron availability and the protein nutritive value of cooked black bean (Phaseolus vulgaris)].

In Guatemala, at the rural level, beans are prepared for family consumption every two days. Beans are cooked again every 12 hours for 15 minutes prior to their consumption. Due to the adverse effect that the process causes on nutritive value, the present study evaluated the method and preparation practice of beans on protein value; tannin and soluble and ionizable iron content. As to the effect of re-cooking on protein level, findings revealed that there were no significant statistical effects on net protein ratio (NPR) or in protein efficiency ratio (PER) and number of bean cooking. Nevertheless, a constant effect in quality in the first and second cooking procedure was detected. The second cooking gave a similar value as the first. Also, the first and second heating reduced protein digestibility, but the third gave a value similar to the initial one. No changes were observed in the digestibility of dry matter. Relatively high amounts of protein were found in the cooking broth, which was not affected by the number of heating. It was also found that the bean broth contained high levels of tannins in the initial heating, decreasing later significantly. The same was observed in the cooked beans alone and in beans with their broth. With respect to iron, findings showed a relatively high transference of beans to broth, in total iron as well as in soluble, ionizable and insoluble iron. No changes were observed in whole beans without broth caused by number of heatings, on total, soluble or ionizable iron. In beans with their broth, a similar effect was observed, although a slight increase in insoluble iron was detected at the end of heating. A decrease in soluble and insoluble iron was observed in broth with number of heatings. Correlations were calculated among the parameters studied, which suggested an effect of tannins on the bioavailability of iron caused by tannins.

Fabaceae↗
PubMed1991

[Bioavailability of amino acids in beans (Phaseolus vulgaris)].

Biological availability of amino acids of three common bean (Phaseolus vulgaris) varieties was evaluated in four, healthy adult subjects, consuming bean-based diets by the amino acid absorption technique and the short-term nitrogen balance method. The amino acid composition was determined according to the ionic interchange method, and tryptophan was estimated by a colorimetric procedure. The essential amino acid (EAA) and non-essential amino acid (NEAA) pattern suggests that no significant differences in content exists in the three bean varieties. When the EAA patterns were compared with those of FAO/WHO, the limiting AA in decreasing order were found to be: tryptophan, valine and threonine (sulfur AA are not considered because the hydrolysis used in this study destroys them); and the AA surpassing the reference pattern were the aromatic AA and isoleucine. Apparent (AD) and true (TD) digestibilities of the EAA fluctuated between 33 and 59% and 60 and 85%, respectively, for black beans. With red beans, these results diminished: 29 and 55% AD and 64 and 81% TD, while for white beans the limits extended: 18 and 57% AD and 36 and 86% TD. Valine proved to be the EAA of lower biological availability, and lysine and phenylalanine the most available. It is suggested that the low digestibility of valine could be due to the amino acid imbalance existing in the bean protein, since this contains an excess of isoleucine and leucine in relation to valine. The AD and TD of the AAE with respect to the NEAA were of 0.89 and 0.98 for black bean, 0.89 and 0.96 for the red and 0.77 and 0.90 for the white, which indicates that biological availability of the NEAA is higher than that of the EAA. Findings thus confirm that biological determination of the TD of protein permits prediction of the TD of the AA, since a positive correlation (r = 0.93) statistically significant was found (p less than 0.05) among them. Utilization of the TD parameter instead of that of AD to estimate the protein quality is therefore recommended.

Adult↗
PubMed1991

[Evaluation of two methods to determine the polyphenol content in raw and cooked beans and its effect on protein digestibility].

The polyphenolic compounds present in raw and cooked, and dried, with and without the cooking broth of common white, black and red beans (Phaseolus vulgaris) were measured by the Folin-Denis method for total polyphenols, and by the protein precipitation method of Hagerman-Butler, which measures their biological activity. The polyphenol content was measured during 20 consecutive days on the same sample, using three different extracts of volume from each sample. Statistical analysis of the results by the Folin-Denis method indicated that variability among the three aliquots was different for each bean color. A non-parametric analysis, however, indicated that the average in the three levels of concentration for beans of all colors, was the same. A similar analysis of the results by the Hagerman-Butler method demonstrated that variability and average values for the three aliquots were equal for black and red beans but not for white beans. The coefficient of variation was lower for the higher aliquot of the extract. A significant correlation (r = 0.72, P less than 0.05, n = 60) was found between the two methods for all beans using the larger aliquot of the extract. The correlation was highly significant (r = 0.84, P less than 0.05) when white bean values were eliminated. The polyphenolic content varied with seed color and the thermic process reduced their content, as measured by the two methods. The losses in polyphenolics as measured by the Folin-Denis in the cooked beans dried with broth, varied from 31.4 to 36.3%, and from 39.8 to 51.1% for the cooked bean flour dried without broth. The losses by the Hagerman-Butler method were from 25.0 to 93.5% in the cooked bean flours dried with cooking broth, and from 33.3 to 95.7% when dried without the broth. The higher losses were recorded for red beans. In vivo digestibility for cooked bean flours, dried and without broth, were 73.2, 69.6 and 64.5%, and 71.9, 71.9 and 68.8% for white, red and black beans, respectively. A negative correlation (r = -0.39) and significant (p less than 0.05) was found between polyphenolic content in the diet and in vivo protein digestibility.

Analysis of Variance↗
PubMed1990

Effect of processing on the nutritive value of Canavalia Jackbeans (Canavalia ensiformis L).

A comparative study of roasting, cooking with and without calcium hydroxide and extrusion cooking on the protein quality of Canavalia was conducted. The results suggested both extrusion and pressure cooking with lime to be equally effective in improving the protein quality of Canavalia and superior to pressure cooking alone and roasting, the latter effective possibly in destroying the antiphysiological factors in Canavalia but possibly also damaging its protein quality. The individual effects of roasting, cooking with different levels of calcium hydroxide, and with water under pressure at different times on the protein quality of Canavalia were also studied. These indicated a beneficial effect of calcium hydroxide added at a level of 0.45% by weight of seed, for 30 minutes under pressure. Cooking in water under pressure for 30 minutes with and without lime added was slightly better than cooking for longer periods of time. Roasting was also effective in improving the quality of Canavalia particularly when the T was adjusted at 170 degrees C, and roasting conducted for 15 minutes. A significant improvement in the protein quality of processed Canavalia was obtained by methionine supplementation.

Analysis of Variance↗
PubMed1990

[Dietary fiber content and nitrogen digestibility in Central American foods: Guatemala].

The study herein reported presents information on the dietary fiber content of four food groups consumed in Central America. These are: cereals, grains and products; raw and processed beans; raw and processed vegetables, and starchy foods such as potatoes, cassava and plantain. Besides data on soluble and insoluble fiber, data on in vitro protein digestibility are included. The total dietary fiber content of the wheat flour products varied from 1.62 to 2.83% on a fresh basis, with the exception of whole-wheat bread, which showed a 7.57% content. The maize tortilla presented values ranging from 3.96 to 5.21% in respect to beans, and the values for cooked and raw beans fluctuated between 6.36 and 7.00%, independent of the color; however, fried beans reported values from 15.28 to 17.58%. Vegetables contained total dietary fiber values of 1.51 to 4.34, and the tubers, from 1.31 to 2.86%.

Dietary Fiber↗
PubMed1989

[Bean grain quality].

As the title states, the present document is a review of the factors which may influence the bean grain quality. This quality is determined by factors such as acceptability by the consumer, cooking characteristics and by its nutritive value. At the same time, these factors are affected by the genetic constitution of the grain as well as by the environmental conditions of production. Therefore, the improvement obtained on the bean-grain quality will be measured through the interaction established among the different disciplines, such as geneticists, agronomists and scientists in food science and nutrition. The above-mentioned factors are influenced by the events that occur in the different links of the food chain. This article analyzes the effect of processing on the nutritive quality of the grain and, likewise, a brief review of the hard-to-cook problem which affects the acceptability of the grain by the consumer is made. It also considers the low protein digestibility problem and the effects that have been associated to tannin content, as well as the carbohydrate utilization. Finally, some recommendations are suggested to improve the nutritional quality of beans, which is the most important protein source for large segments of the worldwide population.

Digestion↗
PubMed1989

[LATINFOODS].

Food Composition Tables should be considered as national wealth and as valuable tools for utilization in food and nutrition, in nutritional therapy, in agricultural planning and production, in food guides, and in the food industry for the formulation of information on the product that appears in the label. They should, therefore, be considered as national wealth because they chemically describe the food resources of a country at a very high price, and are considered valuable tools due to their multiple applications. The countries present Tables were published between 1935 and 1961, with analytical data available at that time. So far the Tables have met their purpose, but due to changes that have occurred in raw materials, in analytical methodology, in the new knowledge acquired in nutrition, and in the relationships between food and diseases, in November 1986, representative groups of the Latin American and the Caribbean countries decided to create LATINFOODS. The objective of the program is to promote the development of data banks of foods of the Latin American countries, creating national multidisciplinary groups interested in data production, compilement, publication and utilization, and that eventually, may be homogeneously united to form a data bank for Latin America and the Caribbean Region. During the meeting in favor of the creation of LATINFOODS, detection was made of the constraints of the Food Composition Tables now used as well as the measures needed to correct such problems. These included the number of samples collected as well as the analytical methods used, and the number of nutrients. Due to the observed increase in production and distribution of new food products by the food industry, and to the increased association between foods and diseases, the food industry must participate not only in the generation of data, but in their utilization for food identification, nutrient contribution and nutritional education. Likewise, academic programs in Food Technology should extend the concepts of Food Science with special emphasis on food nutrient contents, to reach an adequate nutritional and health status for the Latin American population.

Databases, Factual↗
PubMed1979

The evaluation of the protein quality of soybean products by short-term bioassays in adult human subjects.

The protein quality of soybean products was determined by a short nitrogen balance index (NBI) assay with 15 adult males. In the first study, a textured vegetable protein (TVP) was tested alone and in a 50:50 mixture with ground beef. Protein was fed at 0.2, 0.4 and 0.6 g/kg body weight/day with a constant energy intake. The protein quality (NBI) was then calculated by regression analysis of nitrogen absorbed to nitrogen retained. The NBI of beef (0.91) and of the mixture (0.87) were similar; however, the protein quality of TVP fed alone (0.77) was significantly lower. In the second study, carried out at an intake level of 0.6 g protein/kg/day, supplementation of the TVP with 0.5% DL-methionine improved nitrogen retention, but the values obtained did not reach statistical significance. Meat alone, or the 50:50 mixture fed at an equivalent protein intake, gave similar nitrogen retention values, both of which differed significantly from those obtained when TVP was fed alone. The addition of wheat gluten, used as a source of methionine, to the TVP: meat mixture, produced nitrogen retention values below those obtained with the 50:50 beef:TVP blend. Ten men participated in another trial, this time to determine the protein quality of a soybean protein isolate, which gave an NBI value of 0.91, indicating the high quality of the protein tested. Comparison of the protein quality values obtained by the short-term NBI assay revealed these were essentially the same as those reported by other workers using the conventional long-term approach.

Adult↗
PubMed1978

Improvement of the protein quality of corn with soybean protein.

In most Central American countries, lime-treated corn provides 31% of the total protein and 45% of the energy intake, and beans 24% of the protein and 12% of the calories. Such diet is low in protein quality and quantity, as well as in energy. To overcome these deficiencies, corn can be supplemented either with its limiting amino acids, lysine and tryptophan, or better still, with whole soybeans which improve not only the amount and quality of the protein consumed but, because of their high oil content, the energy intake as well. In addition, animal experiments have shown that for maximum utilization of these nutrients, adequate vitamin and mineral intake is indispensable. At a level of 15 parts of whole soybean or 8 parts soybean-derived products, to 85--92 parts of corn there were no significant changes in the rheological or organoleptic characteristics of the tortilla prepared there of. Higher levels of soybean products, however, may affect the consistency of the lime-treated corn dough and, therefore, the tortilla acceptability. Since corn is usually cooked, but not ground, at home, the soybean supplement can be successfully added at the wet--milling stage of dough preparation or whole soybeans and corn may be cooked together, when a nutritional intervention is desired at the village level. At an industrial scale, if whole soybeans are used, they may be cooked together with corn, and if soy flour is used, this can be mixed at the end of the process when the cooked corn is ground to a flour. A flow diagram for supplementing corn with 15% whole soybeans is presented. If interventions of this nature are to be successful, there is need for increasing the prestige of corn-based food, as well as of nutrition education programs in these populations.

Amino Acids↗