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Biomedical subjects

R Bressani

Publications and source records attributed to R Bressani.

At least 109 records · Page 6Linked to original sources
PubMed1981

[Effect of vitamin and mineral supplements on the protein utilization of mixtures of corn and beans].

The present study was undertaken to establish the effect of some vitamins and minerals on protein utilization of maize:bean mixtures fed in an 87:13 and 70:30 weight ratio. The experiments were carried out by feeding such diets without thiamine, niacin, pyridoxin, riboflavin and vitamin A and without iron, zinc, iodine and magnesium, alone or in combination. Completely supplemented diets were used as reference. The results indicated better protein utilization from the 70:30 maize:bean mixture than from the 87:13. Even though it was not possible to detect significant differences due to the lack of single nutrients, either vitamins or minerals, probably due to the relatively short experimental period, the results strongly suggest the importance of these nutrients in increasing protein utilization. The same result was true when both mixtures were supplemented with their limiting amino acids lysine, methionine and tryptophan. Furthermore, the addition of these amino acids without vitamins or minerals did not improve protein utilization, suggesting that nutrition is not due to single nutrients but to a nutrient balance. Chemical carcass composition of the rats showed an increased fat accumulation for the animals fed the 70:30 mixture over those fed the 87:13 blend. No explanation was given, and this should be a subject of further research.

Amino Acids↗
PubMed1980

[Chemical evaluation of morro or jícaro (Crescentia alata) flours prepared by ensilaging and/or dehydration].

The chemical composition, nutritive value and potential use of the morro fruit (Crescentia alata) has received little attention. The purpose of the present study was: a) to determine appropriate conditions for processing and conservation of the morro fruit without hulls, since a significant part of the production is lost due to inadequate storage conditions, and b) to evaluate, by means of chemical analysis, the whole fruit and its products. For the preparation of dehydrated meals, the content of the fruit was subjected to sun drying and tray drying dehydration with two air temperatures, 60 degrees and 90 degrees C. The method used for the storage of the whole fruit was anaerobic fermentation achieved by ensilaging the fruit in small concrete experimental silos for 90, 145 and 180 days. At the end of each period, the silos were opened. The ensilaged material was of very good appearance and apparently free from unfavorable contaminations; it was dehydrated in tray dryers at an air temperature of 60 degrees C. Independent of processing, the chemical analysis showed the meals to contain on the average 17% crude fat, 11% crude fiber and 18% crude protein. From the amino acid content and using the 1973 FAO/WHO scoring pattern it was found that such flours were limiting in their sulfur amino acid, lysine and threonine content in the order.

Amino Acids↗
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↗
PubMed1978

[Evaluation of coffee pulp as a possible substitute for corn in poultry rations].

A study was conducted to determine the possibility of using coffee pulp as an ingredient of chick rations. Another objective of the study was to evaluate the biological effect of adding sodium metabisulfite on the nitritive value of the agricultural by-product. Fifteen day-old chicks were fed rations containing 10, 20 and 30% coffee pulp, untreated and treated with 1 and 2% solutions of sodium metabisulfite. After three weeks on these rations, the animals were switched to one containing 30% coffee pulp, for five weeks. Results of the first experimental period showed a negative effect of coffee pulp on weight gain, feed conversion and water consumption on a water intake/weight basis. Apparently, treatment of coffee pulp with a 2% solution of sodium metabisulfite improved the above parameters but without reaching those attained by the control ration. In the second part of the study, the groups fed 30% coffee pulp, with and without metabisulfite treatment, gained less weight and showed lower feed conversion efficiencies than the control group. An interesting fact was the absence of mortality even in those groups fed 30% coffee pulp in the first part of the study. From these data it is concluded that coffee pulp at levels of 10% can be used with no problem in chick rations. It is necessary, however, to carry out additional studies before recommending the use of this by-product in poultry rations.

Animal Nutritional Physiological Phenomena↗
PubMed1977

Some Nutritional Characteristics of a Naturally Occurring Alga (Microcystis sp.) in a Guatemalan Lake.

The nutritional characteristics of an alga (Microcystis sp.) that occurs naturally in a Guatemalan lake were determined. The sun-dried material proved to have a high protein content (55.6%) and to be a possible good source of calcium and phosphorus (1, 169.1 and 633.4 mg/100 mg, respectively). Amino acid analysis showed that total sulfur amino acids were the most deficient ones, giving a protein score of 42 to the material. The in vitro protein digestibility of the material was 69.5%. Biological trials demonstrated that when the material was offered as the only protein source, very low consumption and a high mortality rate were obtained whether or not the diet was supplemented with 0.4% dl-methionine. However, when the material supplied 25% of the total protein of a corn-algae diet, the protein quality of the cereal was significantly improved (P < 0.05).

Journal Article↗