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Biomedical subjects

J E Braham

Publications and source records attributed to J E Braham.

At least 19 recordsLinked to original sources
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 the treatment of coffee pulp, fresh or ensilaged, with calcium hydroxide, on its nutritive value].

This study was carried out to determine the effects of the addition of calcium hydroxide on the chemical composition and nutritive value of fresh or ensilaged coffee pulp. Fresh or ensilaged pulp were mixed with 1, 2 and 3% of calcium hydroxide. The process was carried out during 0 and 16 hr, after which time the treated pulp was sun-dried for 36 hr until moisture content reached 12%. These samples were then analyzed for their proximate chemical composition and for some minerals (Ca, P, Na, K), as well as for caffeine, tannins and chlorogenic and caffeic acids content. Diets were then prepared from these materials, containing 15% protein and 15 or 30% fresh or ensilaged coffee pulp, and offered to weanling rats during six weeks. Information required on weight gain, food conversion, apparent digestibility and toxicity of the diets was recorded. Results of the chemical analysis revealed that the main changes found in both types of pulp as a result of the calcium hydroxide treatment were the following: a decrease in ether extract (from 4.0 to 2.5 g/100 g), crude fiber (from 18.3 to 11.9 g/100 g) and protein content (from 12.3 to 8.6 g/100 g) in an inverse relation to the amount of calcium hydroxide used. The amount of ash increased, fluctuated between 5.5 and 15.4%, depending on the amount of calcium hydroxide used. The latter affected the Ca:P ratio in the diets, where an average ratio of 7.2:1 was found in the control pulp (0% calcium hydroxide) and 59.0:1 in those treated with the highest amount of calcium hydroxide (3%). Regarding the caffeine, tannins and chlorogenic and caffeic acids contents, calcium hydroxide was effective in decreasing only tannins, more so in the fresh than in the ensilaged pulp; the decrease was in direct proportion to the amount of calcium hydroxide added and to the length of the Ca(OH)2 treatment. The results of the biological assays showed that the addition of Ca(OH)2 in either of the two time periods used and at either of the concentrations studied, did not improve the nutritive value of coffee pulp. There was always a better performance in the animals that consumed ensilaged pulp than in those fed fresh pulp. The animals fed 15% coffee pulp either fresh or ensilaged performed better than those consuming 30% coffee pulp.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1986

[Chemical composition and evaluation of the protein quality of beans in adult humans by the short-term nitrogen balance method].

Three varieties of common beans were chemically analyzed and their protein quality was evaluated in 12 human male adult subjects by the short-term nitrogen balance method. Chemical analyses were performed for both raw and cooked grains. Cooking reduced the trypsin inhibitors in 28 to 73%, hemagglutinins, 100%, tannins as acid tannic equivalents, 9 to 72%, and 55 to 75% as catequin equivalents, and alkali-soluble nitrogen in 65%. Red and black beans contained more residual trypsin inhibitors and tannins than white beans, while the latter contained more alkali-soluble nitrogen. Although cooked colored beans had more antinutritional factors that affect protein digestibility, their protein quality was similar to that of white beans. This could be explained by the fact that the amino acid composition and/or balance of red and black beans absorbed nitrogen is better than that of white beans, so that the final nutritional value will be determined by the sum of interactions between all factors. In this study, each of the three varieties presented at least one protein quality depressor in higher concentration than the other two varieties. Therefore, the overall differences found between treatments and residual effect, were small or non existent, while significant differences (p greater than 0.05) were found between subjects and nitrogen balance periods. A level of 0.65 g of bean protein/kg/day was not enough to maintain nitrogen balance in subjects fed a diet where beans were the only protein source. According to calculations, 0.9-1.0 g of bean protein/kg/day are necessary for nitrogen balance in male adults, and 1.2-1.3 g of protein bean would be the recommendation for a normal population.

Adult↗
PubMed1985

Studies on the development of infant foods from plant protein sources. Part I. Effect of germination of chickpea (Cicer arietinum) on the nutritive value and digestibility of proteins.

For the purpose of developing an infant food of improved dispersibility characteristics and high nutritive quality, different treatments and technologies were applied to chickpea (Cicer arietinum). Samples were germinated for two and four days at room temperature (25 - 27 degrees C). One portion of each germinated chickpea sample was boiled for 40 min and the other portion was autoclaved at 15 psi for 15 min. These processed samples were then compared with the corresponding value of raw germinated and ungerminated samples as well as with the ungerminated processed ones for the following characteristics: chemical composition, contents of antiphysiological factors, solubility of proteins, lysine availability, net protein ratio (NPR), and digestibility of proteins. Germination caused an increase in the protein content of the seeds. No appreciable changes were observed in the trypsin inhibitor and tannin contents during germination. Availability of lysine was found slightly lower in the germinated seeds. The solubility of the nitrogenous constituents was markedly increased during germination. Along with processing, germination had no beneficial effect in improving protein quality, although digestibility of the proteins was increased. Boiling was more advantageous in the case of germinated seeds than autoclaving, whereas the reverse was true in the case of ungerminated seeds.

Animals↗
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

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

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↗
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

[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

[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↗
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↗
PubMed1983

[Biological behavior of protein fractions isolated from the common bean (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.

Amino Acids↗