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Biomedical subjects

R Bressani

Publications and source records attributed to R Bressani.

At least 37 records · Page 2Linked to original sources
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

Limiting amino acids in raw and processed amaranth grain protein from biological tests.

Amino acid supplementation studies with young rats were carried out using raw and processed amaranth grain (A. cruentus) of dark- and cream- or light-colored seeds. The results of various studies repeatedly indicated that threonine is the most limiting amino acid in raw and processed, dark and cream-colored grain. Protein quality as measured either as NPR or PER was improved by threonine addition alone or with other amino acids and decreased liver fat to values similar to those measured with casein. This finding contradicts the reports that state that leucine, determined by chemical score, is the most limiting amino acid. Leucine addition alone or with other amino acids did not improve protein quality. The study confirmed cream-colored grain to be nutritionally superior to dark grain and that properly processed grain, light- or dark-colored, has higher protein quality than raw grain.

Amaranthus↗
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↗
PubMed1989

[Acid- and neutro-detergent fiber and minor mineral contents in maize and its tortilla].

The present study was carried out to complete available information on the nutrient contents of corn tortilla particularly mineral elements and acid and neutro-detergent fiber. Results indicated that the tortilla weight should be considered in dietary surveys. Protein and ash contents are slightly higher in tortillas than in maize, in the first case due to carbohydrate losses that occur during the process, and in the case of ash, due to the lime used during the cooking process. The process also induces changes in the acid- and neutro-detergent fiber in maize. Similar yields related to the decrease of neutro-detergent and the increase of acid-detergent fiber were found in both products. The cell walls content decreases in the tortilla, with an increase in cellular content. With respect to minerals, an increase in calcium content was found, giving a better Ca:P balance, as well as increases in Fe, Cu and Zn.

Dietary Fiber↗
PubMed1989

[Intake of dietary fiber in the Central American isthmus: nutritional implications].

Mean intakes of dietary fiber (DF) were estimated in the population of Central America and Panama, using the results of dietary surveys conducted in 1969 and 1986 both in rural and urban areas, as well as data on the DF content of foods as consumed in the region. Data on preschool children were also estimated. The results indicated that DF intake in urban areas is lower than that of rural areas, particularly in Costa Rica and Panama. In 1969, intake varied from 32g in El Salvador to 15g in Panama in urban areas, while in rural areas intake was from 45g in El Salvador to 13g in Panama. The foods which contributed most to the total intake in Guatemala, El Salvador and Honduras were tortillas and beans, while in Costa Rica and Panama, beans provided the largest intake. In preeschool children, intake was 12.5g in El Salvador and 5.4g in Costa Rica in 1969, which is the same tendency as that found for adults. From more recent data on food intake, it was found that DF intake had decreased in the rural areas of El Salvador, Honduras and Costa Rica, being between 4 and 9% in the first two countries and 12% in Costa Rica. In the urban area of the latter, from 1969 to 1986 a decrease in DF intake of around 20% has taken place.

Adult↗
PubMed1989

[Effect of the seed coat on the hardening of common beans (Phaseolus vulgaris)].

Samples of cotyledons and whole black beans (Phaseolus vulgaris), Tamazulapa variety were stored during six weeks at 37 degrees C and 90% relative humidity to establish chemical and physical changes which occur during storage, and to determine the role played by the seed coat in the hard-to-cook phenomenon. After the storage period, samples of whole beans were divided in two subsamples, with and without the seed coat. These two samples and the cotyledons were analyzed for cooking time, water absorption, dietary fiber, tannic acid, soluble pectins and phytic acid. Cooking time of the whole beans increased from 99 to more than 480 minutes in the six-weeks period; for the cotyledons this value increased from 45 to 111 minutes. Cooking time of the dehulled bean, stored as whole bean, increased from 45 to 111 minutes. Cooking time of the dehulled bean, stored as whole bean, increased from 45 to 103 minutes. Water absorption in the whole beans and the cotyledons decreased, although in the cotyledons it was higher, due perhaps to the great absorption capacity to the seed coat. No changes were observed in the dietary fiber content of the cotyledons nor in the beans dehulled after storage. However, in the whole grains neutro-detergent fiber decreased, while acid detergent fiber, cellulose and lignin did not present significant changes. On the other hand, soluble pectates decreased in the whole bean and in the cotyledons; nevertheless the tannin content (as tannic acid) decreased only in the whole beans (from 3.28 to 1.64 mg/g). The data obtained suggest that the seed coat plays a significant role in the hard-to-cook process of hardening of the bean, before and during storage.

Dietary Fiber↗
PubMed1988

Preliminary study of the factors that determine nutrient composition of bean-cooking broth.

Bean cooking broth or liquor is a food preparation that results from cooking beans under a number of circumstances. This preparation is the first bean-derived food provided by mothers to their children as young as two months of age. Because of this, bean cooking plays an important nutritional role that must be evaluated. The present study attempted to evaluate, through a number of experiments, the significance of cultivars, method of cooking--either under atmospheric or vapor pressure--cooking time, salt addition, soaking and grain size on bean broth content. This was established mainly by solid content, and also by protein, ash and tannin content in different experiments. The results indicated that cultivars, but mainly cooking and soaking time, cooking method, and seed size were all important factors in determining brean-broth composition, mainly of total solids. Protein and ash contents were less affected. Prolonged cooking of the bean-broth resulted in a decrease in polyphenolic content. The relative nutritional importance of the above factors should be studied further.

Cooking↗
PubMed1988

Relationship between content and intake of bean polyphenolics and protein digestibility in humans.

The purpose of this study was to determine the effect of bean polyphenolics on bean protein digestibility in humans. Steam pressure cooking decreased tannic acid in beans by: 38.2 (white), 23.9 (red), 38.5 (white:black mixture, 50:50), 20.5 (Ipala black) and 44.4% (Jalpatagua black). The reduction in catechin was: 57.5, 97.6, 83.0, 78.7 and 88.4%, respectively. The content of tannic acid in dried cooked beans was: 284.9 in white, 834.5 in red, 620.2 in the white:black mixture, 1,021 in Ipala black and 1,009 mg/100 g in the Jalpatagua black bean. These percentages correlate significantly with fecal nitrogen (r = 0.29, p less than 0.05). Catechin of the dried cooked beans was 7.5 in white, 27.4 in red, 25.4 in the white:black mixture (50:50), and 60.1 and 55.5 mg/100 g in each of the black cultivars, and correlated significantly with fecal nitrogen (r = 0.34, p less than 0.01), absorbed nitrogen (r = -0.37, p less than 0.01) and protein digestibility (r = -0.35, p less than 0.01). It was concluded that one of the factors that reduces bean protein digestibility is the polyphenlic compound.

Adult↗
PubMed1988

[Effects of processing by granular heated beds on the chemical and functional properties of legume grains].

The present research compares the effect of cooking cowpea, canavalia and lupine by pressure cooking and by a granular bed roaster, on chemical and physical characteristics. The wet cooking process was carried out by pressure cooking at 121 degrees C for 30 min at 15 psi, using a bean-to-water ratio of 3 to 1. The cooked samples were dried with heated air (60 degrees C). The granular bed roasting was carried out at 200 and 250 degrees C for contact times of 2 and 2.5 minutes, at a 5 to 1 sand:bean ratio. For this process, a granular bed roaster was designed and constructed. This process induced in the grain temperatures which varied from 90-128 degrees C, and thermic efficiencies which fluctuated between 38 and 60%. The wet and the dry processes did not affect protein and fat content, although available lysine values decreased slightly. The two processes did not affect water absorption and water solubility. The nitrogen solubility index, however, decreased as roasting temperatures increased in the case of the granular bed roaster, and it also decreased in the wet-cooking procedure. Both processes affected color of the cooked flours, with a light orange color, suggesting non-enzymatic browning due to the high temperatures used.

Fabaceae↗
PubMed1988

Culinary practices and consumption characteristics of common beans at the rural home level.

A survey was carried out on housewives of rural bean-producing areas for the purpose of collecting information on bean selection procedures, culinary practices and bean consumption in rural homes from four departments of northeastern Guatemala. The study sample consisted of 10 families selected at random from each of 19 municipalities. The questionnaire used had been pretested in two rural communities not included in the study sample. As already shown by other INCAP surveys of this nature, it was found that all families consumed common black beans, and on rare occasions beans of different color or species. With respect to cooking practices, it was found that beans are not usually soaked prior to cooking, and that few housewives add salt at the beginning of cooking. Two fractions are usually obtained, the cooked beans and the cooking broth. Another finding was that beans are consumed in four preparations: cooked whole, strained and fried, ground and fried, and cooked and fried. Bean broth is consumed by both adults and children, and a thick broth is preferred since it is considered to be more nutritious and better tasting. Children begin to consume bean broth as early as two months of age, and beans at 14 months. The average amount of broth ingested was 62 g, and whole cooked beans, 70 g. Mothers surveyed indicated that broth was administered to children because: it was nutritious (56% of the mothers); in order to teach children how to eat (15%); or because of its taste (9%). Regarding the hard-to-cook phenomenon, 32% of the housewives indicated that storage time was responsible for it, while 17% attributed this condition to bad seeds, and 18% to sun-drying or inadequate postharvest practices and to their preparation for consumption. Although the survey confirmed the importance that common beans have in rural diets, the main finding was that the first bean food product fed to children is the bean-cooking liquor or broth, which on the average contains 8.52% of total solids and 1.48% protein.

Cooking↗
PubMed1988

[Evaluation of the protein quality of legume flours obtained by roasting in heated beds].

Roasted flours from cowpea, canavalia and washed lupin were prepared by a thermic treatment in fluid sand beds at 150, 200 and 250 degrees C for 2.0 and 2.5 minutes, followed by dehulling and grinding. A flour produced by pressure cooking at 121 degrees C for 30 min followed by drying was used as reference. The flours were evaluated through residual levels of antitryptic activity, tannin content, available lysine, NPR and protein digestibility. The roasting and the pressure cooking processes increased NPR values. Nevertheless, the NPR values of all legume flours were significantly lower than the NPR casein values. The roasting process carried out under the conditions indicated inactivated trypsin inhibitor activity significantly. A small decrease in tannin content was also observed, with small insignificant changes in available lysine. The protein digestibility of all products was high with lupin, digestibility being equal to that observed for casein. The roasting process in a fluid granular bed allows the production of products of acceptable protein quality with low levels of antiphysiological factors.

Animals↗