Content uploaded by Gilson Teles Boaventura
Author content
All content in this area was uploaded by Gilson Teles Boaventura on Jul 16, 2014
Content may be subject to copyright.
A preview of the PDF is not available
Evaluation of the effects of flaxseed when used as a protein source for the growth and maintenance phases of rats
Abstract and Figures
OBJETIVO: O objetivo deste trabalho foi avaliar a qualidade protéica da linhaça quando usada nas fases de crescimento e manutenção em ratos. MÉTODOS: Na primeira etapa utilizaram-se 18 Rattus norvegicus, Wistar, fêmeas, recém-desmamadas, recebendo água e ração à vontade. Estas foram distribuídas em 3 grupos (n=6): grupo linhaça - com dieta à base de linhaça, grupo controle - com dieta à base de caseína, grupo controle modificado - com dieta à base de caseína, com maior concentração de fibras e óleo. Na segunda etapa (após 28 dias de experimento) a dieta do grupo linhaça foi modificada, acrescentou-se 5,4% de caseína. Os demais grupos permaneceram com as mesmas dietas. Todas eram isoenergéticas e continham 10% de proteína. Os animais foram acompanhados até 180 dias de vida. Foram determinados o quociente de eficiência protéica e a albumina nas duas fases do experimento. RESULTADOS: Na primeira etapa, o grupo linhaça obteve quociente de eficiência protéica (0,8, DP=0,05) significantemente menor que o grupo controle (2,3, DP=0,1) e o controle modificado (2,3, DP=0,2). A concentração de albumina do grupo linhaça (3,0, DP=0,04g/dL) foi menor (p<0,01) que a do grupo controle (3,9, DP=0,06g/dL) e a do controle modificado (3,9, DP=0,01g/dL). Já na segunda etapa, o grupo linhaça modificado (1,2, DP=0,1) obteve maior (p<0,01) quociente de eficiência protéica que grupo controle (0,9, DP=0,02) e o controle modificado (0,9, DP=0,05). Não houve diferença significante no teor de albumina entre os grupos, caracterizando a recuperação da desnutrição. CONCLUSÃO: Conclui-se que a linhaça não deve ser utilizada como fonte exclusiva de proteína, principalmente na fase de crescimento.
Figures - uploaded by Gilson Teles Boaventura
Author content
All figure content in this area was uploaded by Gilson Teles Boaventura
Content may be subject to copyright.
ResearchGate has not been able to resolve any citations for this publication.
The literature on the protein content, amino-acid composition, fractionation, and functional properties of flaxseed proteins is reviewed and summarized. The discussion on the fractionation centers on the methods for isolation of the various protein fractions and on the physico-chemical characteristics of high- and low-molecular-weight fractions. Most interesting are the favorable functional properties of flaxseed proteins and the wide range of potential products in which they can be incorporated.
A prevalência de desnutrição protéico-energético em pacientes com insuficiência renal crônica submetidos à terapia de hemodiálise é elevada. Dentre os diversos parâmetros disponíveis para a avaliação do estado nutricional, a albumina tem sido o mais comumente utilizado para este fim visto a sua estreita associação com a morbidade e mortalidade nesta população. No entanto, vários fatores como idade, comorbidades, hipervolemia e perdas corpóreas podem influenciar as concentrações séricas de albumina. Além disso, na vigência de inflamação, condição comumente presente neste grupo de pacientes, o metabolismo da albumina pode encontrar-se alterado, influenciando os seus níveis plasmáticos. Sendo assim, esta comunicação tem como objetivo abordar os aspectos gerais da albumina e discutir a sua utilização na avaliação do estado nutricional de pacientes com insuficiência renal crônica submetidos à hemodiálise.
For sixteen years, the American institute of Nutrition Rodent Diets, AIN-76 and AIN-76A, have been used extensively around the world. Because of numerous nutritional and technical problems encountered with the diet during this period, it was revised. Two new formulations were derived: AIN-93G for growth, pregnancy and lactation, and AIN-93M for adult maintenance. Some major differences in the new formulation of AIN-93G compared with AIN-76A are as follows: 7 g soybean oil/100 g diet was substituted for 5 g corn oil/ 100 g diet to increase the amount of linolenic acid; cornstarch was substituted for sucrose; the amount of phosphorus was reduced to help eliminate the problem of kidney calcification in female rats; L-cystine was substituted for DL-methionine as the amino acid supplement for casein, known to be deficient in the sulfur amino acids; manganese concentration was lowered to one-fifth the amount in the old diet; the amounts of vitamin E, vitamin K and vitamin B-12 were increased; and molybdenum, silicon, fluoride, nickel, boron, lithium and vanadium were added to the mineral mix. For the AIN-93M maintenance diet, the amount of fat was lowered to 40 g/kg diet from 70 g/kg diet, and the amount of casein to 140 g/kg from 200 g/kg in the AIN-93G diet. Because of a better balance of essential nutrients, the AIN-93 diets may prove to be a better choice than AIN-76A for long-term as well as short-term studies with laboratory rodents.
OBJETIVOS: O propósito deste estudo foi analisar experimentalmente a eficiência da suplementação alimentar da dieta do Município de Quissamã, RJ, em recuperar a desnutrição durante o período de crescimento. MÉTODOS: Foram utilizados 42 Rattus norvegicus, desmamados ao 26º dia e induzidos à desnutrição por 21 dias (ração hipoprotéica 2%, ad libitum). Os animais foram distribuídos em sete grupos, alimentados com suas respectivas dietas, todas isoprotéicas (10%) e isoenergéticas (350Kcal/100g). Foi registrado o peso dos animais e, após o sacrifício, foram coletados e pesados fígado, rins, baço e intestino. RESULTADOS: O ganho ponderal médio no 28º dia do controle suplemento alimentar (75,33g) foi significativamente inferior aos demais grupos, e o do controle suplemento alimentar e vitaminas+minerais foi o mais elevado (213,17). Quase todos os grupos diferenciaram-se estatisticamente no peso médio de fígado, rins e baço; os órgãos do controle suplemento alimentar apresentaram o menor peso (respectivamente 3,34g; 0,97g; 0,24g) sendo significativamente inferior aos demais grupos. O controle suplemento alimentar e vitaminas+minerais apresentou o maior peso médio do fígado (13,85g). O Controle vitaminas+minerais apresentou o maior peso médio dos rins (1,88g) e do baço (0,87g). O número de placas de Peyer/animal variou de nove a treze, sem diferenças entre os grupos; o tamanho das placas de Peyer do controle suplemento alimentar (2,6mm) foi significativamente inferior aos demais grupos. O Quissamã suplemento alimentar apresentou as maiores placas de Peyer (4,4mm). O controle suplemento alimentar apresentou sempre valores inferiores para todos os parâmetros estudados comparativamente, já que não foram adicionados à sua ração vitaminas e minerais. CONCLUSÃO: A dieta de Quissamã, RJ experimentalmente alcança as necessidades mínimas para promover a recuperação da desnutrição, sendo desnecessária a adição de vitaminas e minerais e/ou suplemento alimentar.
The nutritional value or quality of structurally different proteins varies and is governed by amino acid composition, ratios of essential amino acids, susceptibility to hydrolysis during digestion, source, and the effects of processing. To optimize the biological utilization of proteins, a better understanding is needed of the various interrelated parameters that influence their nutritive value. This review attempts to contribute to this effort. It discusses methods used for protein quality evaluation, research needs to facilitate labeling foods for protein quality, and factors influencing protein quality including amino acid analysis, digestion, food processing, antinutrients, and protein-energy relationships. Recent studies on the nutritional quality of more than 50 common and uncommon protein sources including cereals, legumes, other seeds, meat, seafood, insects, leaves, mushrooms, and potatoes are reviewed. Also described are advantages of consuming low-quality proteins fortified with essential amino acids, nutritional benefits of mixtures of complementary protein sources, plant genetic approaches to improving the nutritive value of foods, problems associated with liquid diets for adults and infants, socioeconomic aspects of new protein foods, and the influence of protein type and quality on lactation, the immune system, and serum lipids. This integrated overview is intended to stimulate interest in the introduction and use of new protein sources for feeding the ever-growing world population. Keywords: Amino acids; digestibility; food protein sources; health; malnutrition; mixed proteins; nutritional quality; protein quality
From the nutritional point of view, soybeans can play a significant role in at least three aspects: as a source of supplementary
and complementary protein, as a source of calories, and as a source of nitrogen. The protein role is probably the most important
for food systems of developed and underdeveloped populations, while the role as a source of protein and calories applies more
to food systems of developing populations. Soy protein efficiently supplements cereal grain protein, because it corrects the
lysine deficiency of cereals. In some cases, for example with maize, it also corrects the tryptophan deficiency. On the other
hand, the essential amino acid pattern of soybean protein complements that of other protein sources, for example cereal grains,
cottonseed flour, and, in general, lysine deficient protein sources. This makes feasible the preparation of foods of optimum
protein quality and of a high protein content. Because of its quality, soybean protein can replace animal protein without
a significant decrease in nutritive value, for example as milk and meat extender; for diets low in quantity and quality of
protein and deficient in calories, soybeans, as full-fat flour, provide both. Because of cultural eating habits, it is difficult
to conceive the use of soybeans as complete substitutes of common beans; therefore, efforts should be made to use soy protein
in combination with common foods used by populations to whom soybeans are foreign food. Examples of the nutritional benefits
derived from the use of soybean protein as flour or protein concentrate or as full-fat soybean flour are given, particularly
for foods consumed in Latin American countries. Besides the role soybeans play in human foods, they also play a significant
role in the animal industry as a very important component of diets. The efficiency of the swine and poultry industry would
be lower if it were not for the nutritional contribution of soybeans.