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.

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. 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.

Enzymatic Determination of the Protein Quality of Individual Rumen Bacteria

1967 ◽  
Vol 92 (3) ◽  
pp. 357-364 ◽  
Author(s):  
W. G. Bergen ◽  
D. B. Purser ◽  
J. H. Cline
Keyword(s):  
Protein Quality ◽  
Rumen Bacteria ◽  
Enzymatic Determination

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.

scholarly journals The nutritional value and quality of squid (Illex illecebrosus) meal as source of dietary protein for broiler chicken

1979 ◽  
Vol 41 (1) ◽  
pp. 163-173 ◽  
Author(s):  
H. W. Hulan ◽  
F. G. Proudfoot ◽  
C. G. Zarkadas
Keyword(s):  
Fish Meal ◽  
Protein Quality ◽  
Control Diet ◽  
Biological Response ◽  
New Approach ◽  
Protein Supplements ◽  
Fish Meat ◽  
Amino Acid Profiles

1. Squid meal (SqM), produced by grinding and drying the whole squid (Illex illecebrosus) common to the northeast Atlantic and Mediterranean, contained 645 g protein/kg and appeared limiting with respect to lysine, methionine and cystine.2. Although a comparison of the essential amino acid profiles of SqM with other protein concentrates indicated that SqM was higher than fish meal andsoya-beanmeal but lower than casein or whole-egg protein, these tests could not accurately predict protein quality.3. A new approach is reported for evaluating protein quality of SqM. It was based on the direct chromato-graphic determination of its collagen content, from the amounts of 5-hydroxylysine or 5-hydroxyproline present, and elastin, from the amounts of desmosine or iso-desmosine present. This method can alsobe routinely used to assess the connective tissue content and protein quality of animal protein supplements such as fish, meat-and-bone meals.4. A nutritional evaluation of SqM as a source of protein for poultry was carried out using 320 male and 320 female Cobb chicks fed from I-d-old to 48 d, a control diet containing 50 g/kg fish meal or test diets containing 50 g, 100 g or 150 g SqM/kg.5. Feeding of SqM at a rate of up to IOO g/kg diet resulted in optimum biological response and monetary returns.

scholarly journals Protein quality of autoclaved cowpea varieties as influenced by anti-nutritional factors

2021 ◽  
Vol 31 (1) ◽  
pp. 17-21
Author(s):  
D. B. Oke ◽  
O. A. Adeyemi ◽  
M. O. Oke
Keyword(s):  
Phytic Acid ◽  
Tannic Acid ◽  
Trypsin Inhibitor ◽  
Positive Relationship ◽  
Protein Quality ◽  
Nutritional Factors ◽  
Cowpea Varieties ◽  
Net Protein ◽  
Cowpea Variety

One hundred and ten (110) weanling male winstar strain rats were used to determine the protein efficiency ration (PER) and net protein ration (NPR) of five cowpea samples. PER ranged from 1.06 in IT 81D-1137 to 1.91 in 1784E-1-108 while values in autoclaved samples ranged from 1.55 in IT81D-1137 to 2.78 in 1784E-1-108. for NPR, raw samples gave values that ranged between 2.44 and 3.57 in 1781D-1137 and 1784E-1-108 respectively. Autoclaved samples gave NPR values that ranged from 2.72 to 4.47 in IT 8ID-1137 and IT84E-1-108 respectively. In the raw and autoclaved cowpea diets, trypsin inhibitor, lectin and tannic acid were negatively correlated with PER and NPR while HCN and phytic acid had positive relationship with these indicators of protein quality. In autoclaved samples cowpea variety IT84E-1-108 had the highest PER and NPR values showing that it would support growth to a reasonable extent.

scholarly journals Determination of the protein quality of almonds ( Prunus dulcis L.) as assessed by in vitro and in vivo methodologies

2019 ◽  
Vol 7 (9) ◽  
pp. 2932-2938 ◽  
Author(s):  
James D. House ◽  
Kristen Hill ◽  
Jason Neufeld ◽  
Adam Franczyk ◽  
Matthew G. Nosworthy
Keyword(s):  
Protein Quality ◽  
Prunus Dulcis
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