Evaluation of Protein in Foods. X. A Comparison of Methods for Assessing the Protein Contribution of Five Middle Eastern Meals

1964 ◽  
Vol 47 (2) ◽  
pp. 377-382
Author(s):  
Z I Sabry ◽  
A B Morrison ◽  
J A Campbell
Keyword(s):  
Protein Quality ◽  
Middle Eastern ◽  
The Other ◽  
Protein Ratio ◽  
Retention Efficiency ◽  
Protein Retention ◽  
Chemical Score ◽  
Complete Protein ◽  
Net Protein

Abstract Protein quality of five Middle Eastern meals was evaluated by using simplified chemical score (SCS), protein efficiency ratio (PER), net protein ratio (NPR), protein retention efficiency (PRE), and net protein utilization (NPU). The meals consisted of Arabic bread in combination with sesame (Halaweh), with sesame and chickpea (Hommos tehineh), with rice and lentil (Rice Mujaddarah), with parboiled wheat and lentil (Burghul Mujaddarah), or with parboiled wheat, yoghurt, and meat (Kishk). Halaweh, Hommos tehineh, and Kishk were limiting in lysine, while the other two meals were limiting in methionine. Lysine and methionine appeared to be fully available in all meals with the exception of Halaweh, in which lysine was partially unavailable. All methods ranked the meals in the same order, with Halaweh as the poorest, Hommos tehineh the best, and the other three meals slightly inferior to Hommos tehineh in quality. Methods for determining the protein contribution of meals which took into account both quantity and quality of protein, i.e., net dietary protein calories per cent (N.D-p. Cals %), protein rating (PR), and per cent complete protein (% CP), were also tested. Values for N.D-p. Cals % and PR correlated closely with each other and relatively poorly with % CP. Values for SCS × % protein calories correlated closely with N.D-p. Cals % and PR.

The Relative Nitrogen Utilization Method for Evaluating Protein Quality

1976 ◽  
Vol 59 (1) ◽  
pp. 42-45 ◽  
Author(s):  
J Murray McLaughlan
Keyword(s):  
Protein Quality ◽  
Poor Quality ◽  
Nitrogen Utilization ◽  
The Other ◽  
Efficiency Ratio ◽  
Protein Ratio ◽  
Test Protein ◽  
Reference Protein ◽  
Net Protein

Abstract A single-dose rat assay for protein quality called relative nitrogen utilization (RNU) is described. The method includes a factor for the protein utilized for maintenance. The protein quality of the test protein is expressed as a per cent of the value for Iactalbumin, the reference protein. For good quality proteins RNU gives results that are similar to those obtained by net protein ratio and relative protein value; for poor quality proteins RNU results fall between values by the other 2 methods. The protein efficiency ratio (PER) gives much lower values for poor quality proteins than any of the other 3 aforementioned methods and is influenced more by both level of protein and lipid in the diet. RNU is a more precise assay than PER as judged by the coefficient of variation.

The effect of methods of sterilization on the nutritive value of protein in a commercial rat diet

1976 ◽  
Vol 35 (2) ◽  
pp. 267-276 ◽  
Author(s):  
D. J. Ford
Keyword(s):  
Amino Acids ◽  
Nutritive Value ◽  
Protein Quality ◽  
Point Of View ◽  
Chemical Methods ◽  
True Digestibility ◽  
Complete Protein ◽  
Net Protein ◽  
Total Amino Acids

1. The effect on protein quality of treating a commercial rat diet by autoclaving at various temperatures for different periods of time, or by irradiation with 2.5 or 10 Mrd, was studied. True digestibility (TD) and biological value (BV) were measured and the available and total amino acids in the diets were estimated using microbiological and chemical methods..2. Autoclaving at 121° for 60 min reduced BV, TD and net protein utilization (NPU) more than autoclaving at 134° for 3 min. Availability of amino acids was reduced by both treatments but to a greater extent by autoclaving at 121° for 60 min. Total amino acids were essentially unaffected. Irradiation had no effect on BV, TD, NPU or total amino acids, and the availability of amino acids was also unaffected, with the exception of lysine which was slightly reduced..3. When the diet was autoclaved at 115 or 121° for 15, 30 or 60 min, or at 134° for 3 min the availability of the amino acids was reduced with increasing time and temperature of treatment. Treatment at 134° for 3 min had an effect on available amino acids similar to treatment at 121° for 15 or 30 min..4. Ethylene oxide fumigation of the diet caused reduced availability of histidine, methionine and tryptophan but had negligible effect on arginine, leucine and lysine..5. It is concluded that from a practical point of view irradiation causes least damage to proteins in rodent diets. If such diets are to be autoclaved they should be supplemented with complete protein to counteract amino acid destruction.

EVALUATION OF PROTEIN IN FOODS: 1. A METHOD FOR THE DETERMINATION OF PROTEIN EFFICIENCY RATIOS

1959 ◽  
Vol 37 (1) ◽  
pp. 679-686 ◽  
Author(s):  
D. G. Chapman ◽  
Raul Castillo ◽  
J. A. Campbell
Keyword(s):  
Protein Quality ◽  
Corn Starch ◽  
Sole Source ◽  
Male Rats ◽  
Protein Retention ◽  
Wistar Strain ◽  
Bioassay Procedure ◽  
Net Protein

A bioassay procedure for the evaluation of the nutritional quality of the protein in foods is described. This method involves measurement of the protein efficiency ratio (grams gain per gram protein consumed) under standardized conditions. Male rats of the Wistar strain 20–23 days of age are fed ad libitum an otherwise adequate reference diet containing 10% protein supplied by a standard sample of casein. Foods to be assayed are added to the diet as the sole source of protein at the expense of the casein and corn starch to maintain a protein level of 10%. Protein efficiency ratios (P.E.R.'s) are calculated after 4 weeks and are adjusted to a constant value of 2.5 for casein. Although influenced by the age of rat and subject to certain inherent criticisms, determination of P.E.R. values was found to be a simpler method for evaluating protein quality than determination of net protein retention or net protein utilization and equally sensitive.

EVALUATION OF PROTEIN IN FOODS: 1. A METHOD FOR THE DETERMINATION OF PROTEIN EFFICIENCY RATIOS

1959 ◽  
Vol 37 (5) ◽  
pp. 679-686 ◽  
Author(s):  
D. G. Chapman ◽  
Raul Castillo ◽  
J. A. Campbell
Keyword(s):  
Protein Quality ◽  
Corn Starch ◽  
Sole Source ◽  
Male Rats ◽  
Protein Retention ◽  
Wistar Strain ◽  
Bioassay Procedure ◽  
Net Protein

A bioassay procedure for the evaluation of the nutritional quality of the protein in foods is described. This method involves measurement of the protein efficiency ratio (grams gain per gram protein consumed) under standardized conditions. Male rats of the Wistar strain 20–23 days of age are fed ad libitum an otherwise adequate reference diet containing 10% protein supplied by a standard sample of casein. Foods to be assayed are added to the diet as the sole source of protein at the expense of the casein and corn starch to maintain a protein level of 10%. Protein efficiency ratios (P.E.R.'s) are calculated after 4 weeks and are adjusted to a constant value of 2.5 for casein. Although influenced by the age of rat and subject to certain inherent criticisms, determination of P.E.R. values was found to be a simpler method for evaluating protein quality than determination of net protein retention or net protein utilization and equally sensitive.

Protein quality evaluation in vivo of cricket flour (Gryllus assimilis) reared in Brazil

2021 ◽  
pp. 1-8
Author(s):  
R.R.S. Araújo ◽  
M.M.A. Fagundes ◽  
A.M.F. Viana ◽  
A.H.S. Paulino ◽  
M.E. Silva ◽  
...  
Keyword(s):  
Weight Gain ◽  
Biochemical Parameters ◽  
Protein Quality ◽  
Control Group ◽  
Protein Ratio ◽  
Protein Utilisation ◽  
Chemical Score ◽  
Net Protein Utilisation ◽  
Net Protein

This study aimed to evaluate the chemical and biological quality of Gryllus assimilis flour, through the analysis of nutritional and biochemical parameters of tests on young rats (Rattus norvegicus – Fischer). The most deficient essential amino acid was methionine, with a chemical score of 56.40%. For the net protein ratio (NPR) and net protein utilisation (NPU) ratio, the diet containing unsupplemented cricket flour was not enough to reach the NPR and NPU levels of the control group and was insufficient to promote weight gain in the rats. The addition of methionine and wheat bran increased the digestibility of the cricket flour, which resulted in a significant improvement in the levels of cricket protein utilisation, increasing the rates mentioned above and promoting weight gain in the rats. Based on our results, we can state that considering the age of the study animals, cricket meal was a sufficient source of protein for maintenance of body weight, but not for weight gain. Based on biochemical parameters (total protein, albumin, alanine transaminase, aspartate transaminase, creatinine, urea), the cricket meal did not compromise the general health of the study animals. We therefore conclude that the addition of other sources of methionine to cricket flour can be a fundamental strategy for better use of cricket proteins in the diet.

scholarly journals The effect of dietary protein on reproduction in the mare. VI. Serum progestagen concentrations during pregnancy

1998 ◽  
Vol 69 (4) ◽  
Author(s):  
F.E. Van Niekerk ◽  
C.H. Van Niekerk
Keyword(s):  
Dietary Protein ◽  
Protein Quality ◽  
Amino Acid Content ◽  
Protein Supplementation ◽  
The Other ◽  
Protein Diet ◽  
Sharp Decline ◽  
High Quality Protein ◽  
Essential Amino Acid Content

Sixty-four Thoroughbred and Anglo-Arab mares aged 6-12 years were used, of which 40 were non-lactating and 24 lactating. Foals from these 24 mares were weaned at the age of 6 months. Non-lactating and lactating mares were divided into 4 dietary groups each. The total daily protein intake and the protein quality (essential amino-acid content) differed in the 4 groups of non-lactating and 4 groups of lactating mares. The mares were covered and the effect of the quantity and quality of dietary protein on serum progestagen concentrations during pregnancy was studied. A sharp decline in serum progestagen concentrations was recorded in all dietary groups from Days 18 to 40 of pregnancy, with some individual mares reaching values of less than 4 ng/mℓ. Serum progestagen concentrations recorded in some of the non-lactating mares on the low-quality protein diet increased to higher values (p<0.05) than those of mares in the other 3 dietary groups at 35-140 days of pregnancy. A similar trend was observed for the lactating mares on a low-quality protein diet at 30-84 days of pregnancy. No such trends were observed in any of the other dietary groups. High-quality protein supplementation increased serum progestagen concentrations during the 1st 30 days of pregnancy. Lactation depressed serum progestagen concentrations until after the foals were weaned.

Assessment of Protein Quality Methodology for Infant Formulas

1985 ◽  
Vol 68 (4) ◽  
pp. 680-683
Author(s):  
Geraldine Vaughan Mitchell ◽  
Mamie Young Jenkins
Keyword(s):  
Quality Evaluation ◽  
Protein Quality ◽  
Reference Standards ◽  
Infant Formulas ◽  
Casein Diet ◽  
Reference Standard ◽  
Powdered Milk ◽  
The Third ◽  
Net Protein

Abstract Rat bioassay was used to assess the protein quality of powdered infant formulas and to evaluate the feasibility of using modified casein diets (containing the same source and level of fat and carbohydrate contributed by the infant formulas) as reference standards. Modification of the casein diet to match the milk-based formulas caused a significant reduction in weekly protein efficiency ratios (PER) and net protein ratios (NPR) at the third and fourth weeks. Modification of the casein diet to simulate the soy-based formulas had no significant effect on NPR values; PER values were more varied. When PER and NPR values of the powdered milk-based formulas were expressed relative to the unmodified reference standard, the relative values were lower than when each matched reference was used. With few exceptions, the relative weekly PER values of the soy-based formulas were similar regardless of the standard used. The relative NPR values of the formulas had a pattern similar to the relative PER values. The data indicate that protein quality evaluation of infant formulas using rat bioassay warrants the use of matched casein reference diets for each type of formula.

scholarly journals Fortifying pork liver mixture: Evaluation of protein quality and iron bioavailability – Part 2

2017 ◽  
Vol 30 (6) ◽  
pp. 817-826
Author(s):  
Silvana Mariana SREBERNICH ◽  
Gisele Mara Silva GONÇALVES ◽  
Semíramis Martins Álvares DOMENE
Keyword(s):  
Ferrous Sulfate ◽  
Protein Efficiency Ratio ◽  
Protein Quality ◽  
Iron Bioavailability ◽  
Standard Diet ◽  
Efficiency Ratio ◽  
Protein Retention ◽  
Pork Liver ◽  
Significant Difference ◽  
Net Protein

ABSTRACT Objective To evaluate the protein quality and iron bioavailability of a fortifying mixture based on pork liver. Methods Determinations of protein efficiency ratio, net protein utilization, true digestibility and hemoglobin regeneration efficiency by depletion and repletion were performed. In the depletion phase, the animals (male Wistar rats) received an iron-free AIN–93G diet and in the repletion phase they received the following diets: standard AIN–93G diet, fortifying mixture and standard diet containing heptahydrated ferrous sulfate for comparison. Results For standard AIN–93G diet and fortifying mixture the results were 3.75 and 4.04 for protein efficiency ratio and 3.53 and 3.63 for net protein retention, showing that the presence of pork liver in the diet promoted an increase in protein efficiency ratio and net protein retention (not statistically significant). True digestibility results obtained with the fortifying mixture (97.16%) were higher than those obtained with the standard AIN–93G diet (casein), but without significant difference. The hemoglobin regeneration efficiency values obtained for standard AIN–93G diet, fortifying mixture and standard diet containing heptahydrated ferrous sulfate were 50.69, 31.96 and 29.96%, respectively, showing a statistically significant difference between the control (standard AIN–93G diet) and test (fortifying mixture and standard diet containing heptahydrated ferrous sulfate) samples, but not between the test samples. Conclusion The fortifying mixture showed a high protein efficiency ratio value of 4.04 and a high relative biological value (108%) and it can be added to soups, creams and meats in day-care centers for the prevention of iron-deficiency in children of school age.

Biological protein quality and phytic acid content of domesticallyprocessed kidney beans (Phaseolus Vulgaris)

2016 ◽  
Vol 35 (4) ◽  
Author(s):  
Rajni Modgil ◽  
K. Mankotia ◽  
Ranjana Verma ◽  
Anupama Sandal
Keyword(s):  
Phaseolus Vulgaris ◽  
Phytic Acid ◽  
Phosphorus Content ◽  
Protein Quality ◽  
Protein Digestibility ◽  
Efficiency Ratio ◽  
Phytate Phosphorus ◽  
Kidney Beans ◽  
Net Protein

Effect of domestic processing techniques i.e. soaking, sprouting and cooking was seen on the anti nutrient constituents of kidney beans (Phaseolus vulgaris). Biological protein quality of sprouted and cooked grains was also estimated. Anti nutrient analyzed was phytic acid. Phytate phosphorus and non phytate phosphorus content was also estimated. Rats were fed on domestically processed kidney beans for estimation of protein efficiency ratio(PER), food efficiency ratio(FER) ,apparent protein digestibility(APD), true protein digestibility(TPD), Biological value(BV), net protein utilization(NPU) and net protein retention (NPR). Cooking of kidney beans resulted in a significant decrease in phytic acid and phytate phosphorus content as compared to sprouting. Sprouting and cooking resulted in an increase in FER and PER. Cooking resulted in an increase in biological protein quality of kidney beans. Domestically processed kidney beans have better biological protein quality.

PROTEIN QUALITY EVALUATIONS OF SELECTED CULTIVARS OF WHEAT, MEASURED BY CHEMICAL SCORES AND MOUSE BIOASSAYS

1984 ◽  
Vol 64 (1) ◽  
pp. 127-137
Author(s):  
J. M. BELL ◽  
D. M. ANDERSON
Keyword(s):  
Amino Acids ◽  
Crude Protein ◽  
Protein Quality ◽  
Growth Index ◽  
Wheat Cultivars ◽  
Protein Ratio ◽  
Relative Growth ◽  
Key Words Wheat ◽  
Limiting Amino Acid ◽  
Net Protein

Wheat cultivars, Glenlea, Inia-66, Neepawa, Pitic-62 and Twin, and Bonanza barley, were fed to mice in digestibility and protein quality evaluation trials. In the digestibility trial each diet contained 94.7% test grain, plus mineral and vitamin supplements and 0.55% chromic oxide fecal marker. Digestibility of energy ranged from 79.3% (Twin) to 83.4% (Neepawa). Digestibility of protein ranged from 71.0% (Twin) to 84.4% (Neepawa). Crude protein (CP) (N × 6.25) ranged from 11.8% (Twin) to 15.8% (Neepawa) and affected the protein apparent digestibility coefficients. In the 14-day growth trials the grains were compared in four ways: (a) as 94.7% of the diet, (b) in diets containing 9% CP, (c) in diets containing 9% CP plus amino acids to meet the requirements for growth of the mouse and (d) in diets containing 7% CP. Casein control diets were used. In (a) mice fed Twin wheat and Bonanza barley gained less than all others. In (b) all wheats resulted in slower growth than barley or casein but Twin had better protein than Inia-66 and Pitic-62, reflecting lysine contents. In (c) all wheats supplemented with amino acids equalled casein in terms of growth. In (d) the responses to 7% CP diets were inferior but parallel to those from 9% CP diets. In the protein quality evaluations barley ranked highest in relative growth index, protein efficiency ratio and net protein ratio. Twin wheat ranked second and Pitic-62 ranked last. Lysine was the first-limiting amino acid in all wheats, having from about 59 to 64% of the level required by 20- to 35-kg pigs. Isoleucine was second-limiting except for Glenlea with threonine. Key words: Wheat, cultivars, protein quality, mouse assays, digestibility

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