Biomedical subjects

R Bressani

Publications and source records attributed to R Bressani.

At least 73 records · Page 4Linked to original sources

PubMed1985

[A new alternative for estimating recommendations of protein intake in humans. Protein requirements of an adult population fed with a diet based on rice and beans].

This paper proposes a new approach to estimate the protein needs of a population; recommendations are also made on the protein intake of adults fed diets based on rice and beans. For this purpose, the nitrogen balance data previously reported for 40 adult human subjects who had participated in 160 nitrogen balance periods fed diets based on rice and beans, with and without animal protein and/or energy supplementation were used. The proposed method is based on the curvilinear response between nitrogen intake and its nitrogen balance. The second degree equation describing the relationship between nitrogen balance and intake is calculated. Using the mathematical concept of the first and second derivatives, the point of inflexion is obtained, and interpreted as that condition wherein the individual utilizes with maximum efficacy the ingested nitrogen; nitrogen ingestion, which corresponds to that point, is therefore taken as the dietary nitrogen recommendation for the individual. When the values obtained by means of the quadratic equation are compared to those obtained by the traditional linear equation, values were found to be statistically equal (p less than 0.05) for both calculation methods. The recommended protein intake of an adult population fed a diet based on rice and beans was 0.80 and 0.77 g/kg/day for the quadratic approach, and for the conventional method, respectively. When this diet was supplemented with 10% milk protein and with the same energy level, the calculated values were 0.64 and 0.71 g protein/kg/day for both methods, in this same order. The essential amino acid intake and absorption values were also calculated from the protein levels recommended by both methods to be in nitrogen balance, from a diet based on rice and beans. Findings revealed, in all cases, that the intakes of each and all essential amino acids met those levels indicated by FAO/WHO, with the exception of isoleucine and the sulphur-containing amino acids, which apparently limit the quality of the diet.

Adult↗

PubMed1985

[Relationship between the included levels of coffee pulp and the protein content in rations for monogastric animals].

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.

Animal Feed↗

PubMed1985

[Biochemical and nutritional studies of germinated soybean seeds].

The purpose of this work was to determine the biochemical and nutritional changes of soybean seeds during germination. Soybean seeds were soaked for a period of eight hours and then germinated for 0, 1, 3 and 5 days. Part of them was subjected to an autoclave process. Then, both the raw and cooked seeds were dried, ground and analyzed. During the germination process an increase in the percentage content of protein and fiber in the seeds occurred; cooked seeds, in contrast, showed a slight decrease with respect to the former. Ether extract increased in percentage until the third day, and then decreased on the fifth. In the cooked seeds, higher values than in the raw seeds were obtained, due to the fact that when seeds were autoclaved, protein and carbohydrate losses occur. In regard to ash content, this diminished in percentage as germination advanced; the same happened to the free-protein extract. The raffinose and stachyose sugars, factors which cause flatulence, disappeared on the third germination day. As to nitrogen extraction, a greater percentage was obtained using distilled water as solvent, both for the raw and cooked seeds, than when using NaOH and NaCl. The trypsin inhibitors content increased on the first day of germination and then decreased. Ungerminated, autoclaved seeds, showed no trypsin inhibitors activity, whereas in the germinated cooked seeds, it increased slightly as germination days went by. Regarding protein efficiency ratio (PER), seeds with 0, 1 and 3 germination days presented no significant differences among them, the cooked seeds exhibiting higher values than the raw seeds. Apparent digestibility increased as the germination period advanced, having obtained better values when they were autoclaved. In the soybean milk acceptability test, no significant differences were observed between milk from ungerminated soybean seeds, and milk from the 3-day germinated seeds.

Animals↗

PubMed1985

Studies on the development of infant foods from plant protein sources. Part II. Effect of processing conditions on the chemical and nutritive properties of chickpea (Cicer arietinum).

In order to improve the taste, flavor and nutritional quality of chickpea (Cicer arietinum), various processing conditions were studied. The decorticated samples were processed under various conditions, either by presoaking or non-soaking in water or sodium carbonate solution. The proteins were also isolated from water or carbonate-presoaked chickpea and subjected to various processing. Carbonate-presoaked samples gave slightly lower protein and ash values. No major changes in other constituents were observed. Subjective analysis of the intensity of characteristic chickpea flavor in processed samples was carried out, indicating some improvement in the carbonate-presoaked samples. Carbonate-treated samples exhibited a lighter color. The carbonate presoaking procedure had no adverse effect on the availability of lysine and nitrogen solubility index (NSI), as compared to the water-presoaking procedure. The time required to inactivate trypsin inhibitors in carbonate-presoaked chickpea at boiling temperature, was half that required in the case of water-presoaked ones. Under the conditions used in treating chickpea with sodium carbonate, no beneficial effect was observed in reducing the tannin content. No significant differences were observed in net protein ratio (NPR) among the various processed chickpea samples, even though in some cases isolated protein gave significantly lower NPR values. Digestibility values were higher for isolated protein than for whole chickpea samples.

Animals↗

PubMed1985

[Evaluation of a device to measure the hardness of the bean grain (Phaseolus vulgaris) and its use in the determination of cooking time].

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.

Fabaceae↗

PubMed1985

Studies on the development of infant foods from plant protein sources. Part III. Preparation, processing and properties of various products developed.

Studies have been carried out on the development of a low-cost, high-quality infant food of low paste viscosity from rice, chickpea (Cicer arietinum) and cow's milk. In order to improve the overall quality of the product, chickpea was processed by different methods prior to its incorporation. A number of formulations was prepared by mixing 52% rice, 30% each, the processed chickpea sample, and 18% whole milk powder. These mixtures were processed by extrusion cooking or drum drying. In the case of the extrusion cooking method, from the nutritional and technological points of view, it was found advantageous to incorporate milk powder after cooking a mixture of rice and chickpea. The values of net protein ratio (NPR) of the products developed, whether processed by extrusion cooking or drum-drying methods, were statistically equal, and not significantly different from those of casein. Supplementing the product with methionine and threonine showed no effect in improving the NPR value, suggesting that these amino acids were not limiting. There were slight differences in the digestibilities of proteins in the products developed and all were lower than that of casein. Depending on the processing method, differences were observed in paste viscosities of the products. After partial hydrolysis of the products with pounds amylase, both the cold and hot paste viscosities were greatly reduced and were comparable with those of whole milk powder. From the results herein reported, it can be concluded that the drum-dried product prepared using rice:chickpea (carbonate presoaked):milk (52:30:18) is the best of all the products developed. Its amino acid composition compares favorably with that of the milk proteins.

Amino Acids↗

PubMed1985

Effects of cone opening, initial moisture content and multiple extrusion on the protein quality of extruded soybean using the Brady Crop Cooker.

In the present study, three cone openings (0.133; 0.106, and 0.080 cm) and three initial moisture content values (9%, 15% and 21%) were used as treatments to evaluate their effects on the protein quality of full-fat soybean flour, extruded in the Brady Crop Cooker. The specific volume, protein and oil contents as well as available lysine content characteristic of the final product, were not affected by the treatments used. Processing temperatures, however, decreased when the initial moisture content of the material was increased. The nitrogen solubility index was affected by the cone opening but not by the moisture content of the material. With respect to the trypsin inhibitors content, the increase in the initial moisture content in soybeans gave conflicting results. At the 21% moisture treatment, the amounts of trypsin inhibitors were higher than those present in the raw material; a similar effect was also observed with urease activity. At the other two moisture contents (9 and 15%) the amounts of trypsin inhibitors and urease activity were decreased by heat treatment, mainly at the 9% moisture level, which were related to the cone opening of the extruder. PER values in rats were influenced by the moisture content and were not affected by the cone opening. Results obtained in the biological assays with chicks, both for weight gain and conversion efficiency, were favored by a decrease in cone opening. Nevertheless, the increase in the moisture content induced a decrease in weight gain at the 5- and 8-week periods, without affecting the conversion efficiency. The effect of consecutive passes of the material through the extruder was also studied. The product obtained with two extrusions presented a good biological value, probably as a consequence of the low values in the trypsin inhibitors and urease activities. When the material was extruded three times, results proved to be poor, due to a reduction to significant low levels of available lysine content--which becomes limiting--, and nitrogen solubility index of the full-fat soybean flour.

Animals↗

PubMed1984

[Protein digestibility and energy in diets based on rice and beans in human adults].

Four studies were carried out for the purpose of measuring the digestibility of diets based on rice and beans (Phaseolus vulgaris), and in order to quantify the effect of their supplementation with animal protein (milk) and energy (oil), on the energy and protein digestibility of such diets in human adults. Diets were offered so that they supplied 46, 72, and 103 mg N/kg/day. When the basal diet--where rice provided 60% of the protein and beans 40%--was administered at a level of 102.5 mg of nitrogen/kg/day and 49.5 Kcal/kg/day of gross energy, an apparent and true nitrogen, energy and metabolizable energy digestibility of 59.1, 70.8, 93.8 and 92.5%, respectively, were observed. When substituting 10% of the vegetable protein by milk protein in the same diet, the same indicators revealed a digestibility of 65.3, 76.8, 93.5 and 92.1%, respectively. The information indicates that supplementation with animal protein improves nitrogen absorption at any of the energy levels studied. In contrast, caloric supplementation does not have any positive effect on nitrogen or energy absorption. It was also found that nitrogen apparent digestibility increases significantly when the N level in the diet is raised, and stabilizes when intake exceeds 100 mg nitrogen/kg/day. It is therefore proposed that for digestibility studies in diets where animal protein is utilized at a nitrogen level of around 120 mg/kg/day, true digestibility remains constant, no matter what nitrogen level is used in the diet.

Adult↗

PubMed1984

[Evaluation of the protein quality of meat flour from the tollo shark (Squalus acanthias)].

The protein quality of tollo flour evaluated by various biological methods, including digestibility, is reported. The product contained 91.52% crude protein and 69.86% true protein, the difference being non-protein nitrogen, mainly urea. Due to this reason the biological evaluations were carried out with different shark flour concentrations and evaluated at different lengths of time with each method. Diets containing 0, 3, 6, 9 and 12% shark flour were prepared and evaluated by the PER, NPR, and NGI methods. Casein was used as reference protein. The protein digestibility was 91.2%, not corrected for non-protein nitrogen. On this same basis, PER and NPR--at a protein level of 9.97% in the diet--were 2.58 and 2.05, respectively. The casein control diet gave a PER of 2.93 and an NPR of 4.52. NGI was calculated by using the non-protein diet, or without it, with values of 3.32 and 2.95, respectively. As expected, all values corrected for non-protein nitrogen were higher for protein digestibility. The differences were significant at the 5% level. Apparently, urea influenced negatively the biological evaluations. It can be concluded, therefore, that the tollo shark meat is of excellent quality.

Animals↗

PubMed1984

[Relation between the digestibility and protein value of the common bean (Phaseolus vulgaris)].

The main nutritional limitations of common beans are the low digestibility of their protein and the deficiency of the latter in sulfur amino acids. Analysis of the information presented indicates that with 57 samples of different color (23 red, 21 black, 10 white and 3 brown), no relationship was found between protein digestibility and its quality as measured by NPR. Nevertheless, white beans have a higher protein digestibility than black, red and brown. The greater digestibility of white beans, however, does not increase the protein quality when mixed with cereal grains above that observed with black and red, probably because the protein that gives the higher digestibility is highly deficient in its sulfur amino acids content. These aspects require further research for programs aimed at increasing the nutritive value of food grain legumes.

Amino Acids, Sulfur↗

PubMed1984

[Effect of animal protein supplementation and energy on the protein quality of diets based on rice and beans in adult males].

Four short nitrogen balance index studies were carried out in adult subjects to evaluate the biological quality of a mixture based on rice and beans, and also to measure the effect of animal protein and/or energy supplementation on the nutritive value of the mixture. In the first study, rice supplied 60% and beans, 40% of the protein's diet, which was administered at an energy level of 45.5 kcal/kg/day of metabolizable energy. A regression coefficient of 0.76 +/- 0.11 was found between ingested nitrogen and nitrogen balance, and a value for nitrogen maintenance of 96.2 +/- 13.7 mg/kg/day. When this same diet was administered in the second study at a 51.2 kcal/kg/day of metabolizable energy, the regression coefficient was 0.80 +/- 0.13, and that of nitrogen for maintenance, 90.1 +/- 8.7 mg/kg/day, without differences being significant (P less than 0.05) for any of the two measures. In the third study, 10% of the mixture's protein was substituted by milk protein, and given at a level of 45.2 kcal/kg/day of metabolizable energy. In this case, the regression coefficient found was 0.96 +/- 0.08, and that of nitrogen for maintenance, 78.6 +/- 10.2 mg/kg/day. These values do differ significantly (P less than 0.05) from those found in the two previous studies. When the diet of the third study was administered to the same subjects at a level of 48.9 kcal/kg/day of metabolizable energy, the regression coefficient of the equation was 0.86 +/- 0.17, and that for maintenance nitrogen, 82.4 +/- 10.2 mg/kg/day. These values are statistically equal to those found in the third study and do differ significantly from those of the first two studies. Information indicates that the supplementary effect of protein and milk occurs mainly at the digestive level. It is therefore concluded that when rice and beans are consumed jointly, in the adequate proportions, they constitute an excellent-quality food for adult humans.

Adult↗

PubMed1984

[Nutritive value of diets based on tubers and legumes consumed in 3 different proportions].

This study was an attempt to determine the nutritional value of diets based on mixtures of manioc and cowpea flours. The proportions analyzed were 87/13, 70/30 and 50/50, respectively. The effect of supplementing these diets with methionine was also investigated. The nutritional value of the diets was evaluated using as a basis the percentage of utilizable protein. Findings revealed that the protein was best utilized when the percentages of manioc and cowpea flours were 50/50, with significant differences observed among the proportions analyzed. In contrast, no significant differences were observed with methionine supplementation to diets of manioc and cowpea flours mixed in the proportion of 87/13. However, when the proportions were 70/30 and 50/50, the addition of methionine induced significant differences, with the highest protein value in both mixtures. It was also observed that the percentage of utilizable protein increased as the proportions of cowpea in the diets also increased.

Animals↗

PubMed1984

The complementation effects on dietary protein of ungerminated and germinated mung bean (Phaseolus aureus) with rice.

Biological evaluations using rats were carried out to determine the complementation effects on dietary protein of cooked mung bean/rice and cooked germinated mung bean/rice mixtures. On an isoproteic basis, mung bean protein was found to be of a lower quality than rice protein. Upon complementation with rice, however, the protein quality of the ungerminated and germinated mung bean/rice mixtures steadily increased when rice was incorporated to provide 25, 50 and 75% of the protein in the diet. A comparison study between germinated and ungerminated mung bean/rice mixtures indicated that the latter mixture was of a better protein quality. Nevertheless, replacement of 75% of the dietary protein of mung bean by rice showed no difference between the germinated and ungerminated mung bean.

Amino Acids, Essential↗

PubMed1984

[The protein quality of commercial products of texturized soybean protein and meat mixtures].

The purpose of the present study was to evaluate the protein quality of eight commercial samples of texturized soybean protein (TSP) collected in the food markets of various Latin American countries. The study also included experiments designed to establish the limiting amino acids in those products, and studies to evaluate the process of texturization by extrusion cooking. Finally, experiments were also carried out to evaluate the effect of replacement of meat by TSP as well as the supplementary value of the latter to tortilla flour. The eight samples were characterized for their functional properties and protein quality. The results obtained indicate that all samples were different in density, water absorption, and nitrogen solubility. Likewise, all samples were different in their lysine, methionine and threonine content, with PER values ranging from 1.75 to 2.31. Protein quality standard value is 2.3. The amino acid supplementation studies showed a positive significant response to methionine addition, particularly in those products exhibiting low PER values. The addition of both lysine and threonine to the methionine-supplemented product, increased PER significantly. The data also demonstrated that replacement of more than 25% of meat protein by TSP protein decreased protein quality of the product, even when a TSP with an accepted protein quality value was used. This product was also found to supplement the quality of tortilla protein. Finally, it was established that the texturization process did not reduce the protein quality of soybean protein. Based on these results, it is concluded that the variability in the protein quality measured in the eight TSP samples was due to the initial quality of the soy flour texturized, which was already damaged before texturization. For this reason, it is recommended that Latin American countries establish TSP quality standards when this product is used as a protein extender for meat, and that appropriate systems be implemented for the quality control of such products.

Amino Acids, Essential↗

PubMed1984

Protein digestibility of methionine supplemented common beans (Phaseolus vulgaris) in adult human subjects.

The study reports on the protein digestibility of five cultivars of common beans (Phaseolus vulgaris) of different color, tested in young adult human subjects, as the sole dietary protein source. Cheese protein was used as reference protein. The cooked beans provided 0.65 g protein/kg/day, and energy intake was adjusted to 45 kcal/kg/day. Results indicated apparent protein digestibility to vary from 49.6 to 62.1%. White colored beans showed the highest value, while black beans gave the lowest. Cheese protein showed an apparent protein digestibility of 76.2%. The true protein digestibility was calculated using the endogenous nitrogen excretion values obtained in the study, as well as literature values. Digestibility increased as expected, but it is still low as compared to other protein sources. A high correlation was found between dry matter digestibility and protein digestibility. Fecal nitrogen was fractionated between soluble and insoluble nitrogen in a 0.02 N NaOH solution. This assay was also carried out in the cooked beans, and findings revealed that the soluble nitrogen fraction was highly correlated with protein digestibility, with a correlation coefficient of -0.94. This fraction, still to be identified, could very well be responsible for the low digestibility values found for common beans in human subjects.

Adult↗

PubMed1984

[Digestibility, protein value and protein requirements of diets based on plantain/bean and cassava/bean in young adults].

Information is provided on the nitrogen intake for nitrogen equilibrium in young human adults fed a cassava/bean diet and a plantain/bean diet. Ten individuals participating in each study ingested levels of 0, 0.2, 0.4 and 0.6 g protein/kg/day at a constant energy level (45 kcal/kg/day), using the short-term nitrogen balance method with multiple intakes. Even with intakes of 105.7 and 117.4 mg N/kg/day for the cassava/bean and plantain/bean diets, the experimental subjects did not reach a positive balance. The protein digestibility of the diets was low, as had been confirmed previously for beans alone: 55.7% for the cassava/bean study and 50.4% for plantains/beans. The average quantity of nitrogen intake required to reach nitrogen equilibrium for the cassava/bean diet was 114.3 mg N/kg/day and for the plantain/bean diet, 111.9 mg N/kg/day. In the case of the cassava/bean diet, the variability was 81.3 to 172.4, and for plantain/beans, 83.6 to 219.3 mg/kg/day. In four of the five individuals who participated in both studies, the nitrogen intake required to reach nitrogen equilibrium was greater when fed the diet based on plantain/beans than when fed the cassava/beans diet. These data support the assertion that the protein requirement is not a simple figure. Individual variability is so great that, as has been suggested, it is necessary to add two standard deviations to the average figure to cover 97.5% of the population. The results of this investigation support the need to increase protein digestibility and protein quality of beans, since this is a food of major importance for large population segments in the developing countries.

Body Weight↗

PubMed1983

[Chemical composition, amino acid content and nutritive value of the protein of the annatto seed (Bixa orellana, L.)].

On several occasions, many Latin American countries have shown interest in the economic potential of industrializing the exploitation of the pigment in Annatto seed (Bixa orellana, L) used as a natural coloring agent in the food industry. Production of the pigment leaves the seed as a by-product, which once characterized chemically and nutritionally, could contribute to a more profitable exploitation of Annatto seed. The main objective of the present study was to obtain information in regard to this matter. The results of chemical analyses of the seed showed a relatively high amount of protein, which fluctuated between 13 and 17%. Crude fiber levels were also high, about 16%; however, more than 50% of this fiber can be eliminated through sifting of the seed flour. This operation also increases protein content. Annatto seeds have a high phosphorus and a low calcium content. Its protein contains adequate levels of tryptophan and lysine, but is low in methionine, isoleucine, leucine, phenylalanine and threonine. The protein quality of Annatto seed flour was about 65% that of casein, which was used as reference protein. Partly responsible for this low biological value are the amino acid deficiencies, mainly that of methionine, and the low digestibility of the protein. The latter was 57% as compared to 94% for casein, a finding which can be attributed to the crude fiber content of Annatto seed flour, since partial elimination of the fiber resulted in an increase in digestibility up to a value of 65%. In order to utilize more effectively this potential feedstuff in combination with other feeds, further studies should confirm the amino acid deficiencies and digestibility of the Annatto seed protein.

Amino Acids↗

PubMed1983

[Effect of various solvents on the extraction of protein fractions of beans (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.

Ethanol↗