Comparison of Interlaboratory Variation in Amino Acid Analysis and Rat Growth Assays for Evaluating Protein Quality

1985 ◽  
Vol 68 (1) ◽  
pp. 52-56 ◽  
Author(s):  
Ghulam Sarwar ◽  
Robert Blair ◽  
Mendel Friedman ◽  
Michael R Gumbmann ◽  
Ross L Hackler ◽  
...  

Abstract Estimates of inter- and intralaboratory variation of protein efficiency ratio (PER), relative PER (RPER), net protein ratio (NPR), relative NPR (RNPR), and nitrogen utilization (NU) were compared with those of amino acid analysis in the same batches of 7 protein sources (ANRC casein, egg white solids, minced beef, soy assay protein, rapeseed protein concentrate, pea flour, and whole wheat flour). Interlaboratory variation (estimated as between-laboratories coefficients of variation, CV) of NPR and RNPR (up to 6.0%) was lower than that of PER (up to 20.2%) and RPER (up to 18.5%). The interlaboratory determination of NPR and RNPR was also more reproducible than that of most essential amino acids (CV up to 10.0%), especially tryptophan (CV up to 23.7%), cystine (CV up to 17.6%), and methionine (CV up to 16.1%). Intralaboratory variation (estimated as within-laboratories CV) of amino acid analysis (up to 4.7%), however, was comparable to that of protein quality indices in most protein sources (up to 6.0%). The significant (P <0.01) positive correlations (r = 0.68-0.74) between amino acid scores and protein quality indices based on rat growth were further improved when amino acid scores were corrected for digestibility of protein (r = 0.73-0.78) or individual amino acids (r = 0.79- 0.82).

2020 ◽  
Vol 4 (3) ◽  
Author(s):  
Lauren M Reilly ◽  
Patrick C von Schaumburg ◽  
Jolene M Hoke ◽  
Gary M Davenport ◽  
Pamela L Utterback ◽  
...  

Abstract Increased consumer interest in high-quality and novel protein sources has driven the demand for the inclusion of protein-rich ingredients in companion animal diets. Novel protein concentrates, with protein contents of at least 50%, have been used to satisfy these consumer demands. However, minimal information is available regarding the macronutrient composition and protein quality of these ingredients that is needed for proper formulation of pet foods. Therefore, the objectives of this study were to determine the macronutrient and amino acid compositions, standardized amino acid digestibility according to the precision-fed rooster assay, and protein quality using digestible indispensable amino acid score (DIAAS like) of pea protein (PP), potato protein (POP), faba bean protein (FBP), soy protein concentrate (SPC), and dried yeast (DY). Precision-fed rooster assays were conducted using cecectomized roosters to calculate standardized amino acid digestibility and true metabolizable energy corrected for nitrogen (TMEn). For all five protein concentrates, all essential amino acids were highly digestible (88.0% to 96.3%, dry matter basis) with differences (P < 0.05) in only lysine, methionine, and tryptophan digestibilities. The TMEn values were highest for POP (4.22 kcal/g) and DY (3.61 kcal/g). The DIAAS-like values for adult dogs indicated that methionine was the first-limiting amino acid in all protein concentrates except POP, where the first-limiting amino acid was tryptophan. Using Association of American Feed Control Officials (AAFCO)-recommended values for adult cats, DIAAS-like values for methionine were lowest (P < 0.05) for FBP at 81.5%, with all other amino acids for all protein concentrates over 100%. The National Research Council (NRC)-recommended allowances for adult cats indicated that DIAAS-like methionine values for PP (92.7%) and FBP (73.8%) were significantly lower (P < 0.05) with these being the first-limiting amino acids, with the remaining amino acids above 100% for the other protein concentrates. The protein quality and high essential amino acid digestibility of these protein concentrates indicate that they would be viable protein sources in canine and feline diets. However, additional complementary protein sources should be included to meet the requirements of all essential amino acids.


2020 ◽  
Vol 25 (2) ◽  
pp. 30
Author(s):  
Ayodeji Ahmed Ayeloja ◽  
W. A. Jimoh ◽  
T. O. Uthman ◽  
M. O. Shittu

Effect of storage time on the quality of smoked heteroclarias was studied. 108 samples of heteroclarias (average weight 210 + 15g) was used. Analysis carried out include: proximate, mineral composition (Ca, Na, Fe and Mg), biochemical, amino acid and sensory evaluation. Data obtained was subjected to Analysis of Variance (ANOVA) while the sensory data was subjected to nonparametric test (Kruskal Wallis test). Smoked heteroclarias have good nutritional quality in terms of proximate, mineral and amino acids all of which decrease with increase in duration of storage at ambient temperatures. Glutamic acid  was the most predominant amino acid and the highest non-essential amino acid (NEEA), lysine was the most predominant EAA. There was higher concentration of non-essential amino acids than essential amino acids, EAA/NEAA ratio (0.86 – 0.93) recorded indicates that the fish have excellent protein quality; its the predicted protein efficiency ratio (P-PER) ranged between 3.44-3.61 and its biological value ranged between 79.84 -75.04. Its chemical score and TEAA decrease with increase in storage time. Its texture quality reduced significantly (χ2 = 12.207, p<0.01) with increased storage period. It is therefore recommended that smoked heteroclarias be consumed as soon as it is smoked and regularly for good healthy conditions especially among children, aged and other vulnerable groups.


2019 ◽  
Vol 110 (2) ◽  
pp. 255-264 ◽  
Author(s):  
Paolo Tessari

ABSTRACT Background Essential amino acids (EAAs) are key factors in determining dietary protein quality. Their RDAs have been estimated. However, although nonessential amino acids (NEAAs) are utilized for protein synthesis too, no estimates of their usage for body protein replenishment have been proposed so far. Objective The aim of this study was to provide minimum, approximate estimates of NEAA usage for body protein replenishment/conservation in humans. Methods A correlation between the pattern of both EAAs and NEAAs in body proteins, and their usage, was assumed. In order to reconstruct an “average” amino acid pattern/composition of total body proteins (as grams of amino acid per gram of protein), published data of relevant human organs/tissues (skeletal muscle, liver, kidney, gut, and collagen, making up ∼74% of total proteins) were retrieved. The (unknown) amino acid composition of residual proteins (∼26% of total proteins) was assumed to be the same as for the sum of the aforementioned organs excluding collagen. Using international EAA RDA values, an average ratio of EAA RDA to the calculated whole-body EAA composition was derived. This ratio was then used to back-calculate NEAA usage for protein replenishment. The data were calculated also using estimated organ/tissue amino acid turnover. Results The individual ratios of World Health Organization/Food and Agriculture Organization/United Nations University RDA to EAA content ranged between 1.35 (phenylalanine + tyrosine) and 3.68 (leucine), with a mean ± SD value of 2.72 ± 0.81. In a reference 70-kg subject, calculated NEAA usage for body protein replenishment ranged from 0.73 g/d for asparagine to 3.61 g/d for proline. Use of amino acid turnover data yielded similar results. Total NEAA usage for body protein replenishment was ∼19 g/d (45% of total NEAA intake), whereas ∼24 g/d was used for other routes. Conclusion This method may provide indirect minimum estimates of the usage of NEAAs for body protein replacement in humans.


Author(s):  
Radha Palaniswamy ◽  
Dhanyasri Selvaraj ◽  
Sandhiya Renganathan

Objective: To determine the protein quality, especially the amino acid content of 8 tropical fruits both raw and boiled samples. Eight different tropical fruits were used in the study (Apricot, Jamun, Dragonfruit, Pomegranate, Mangustan, Litchi, Jackfruit, and Kiwi.Methods: Ninhydrin method was used for the estimation of the concentration of amino acids present in the above fruits. Raw and boiled fruits were used for the study.Results: Both raw and boiled forms which showed thats Jamun and Mangustan contained highest concentration amino acids whereas apricot shows the lowest concentration of amino acids except in Jamun which showed higher values in the raw fruit whereas in others the boiled samples showed higher values.Conclusion: It was evident that tropical fruits have a good balance of the essential amino acids (both raw and boiled fomr) which provide significant sources of protein in our diet.


2020 ◽  
Vol 98 (6) ◽  
Author(s):  
Lauren M Reilly ◽  
Patrick C von Schaumburg ◽  
Jolene M Hoke ◽  
Gary M Davenport ◽  
Pamela L Utterback ◽  
...  

Abstract The rising consumer demand for alternative and sustainable protein sources drives the popularity of the use of plant-based proteins in the pet food industry. Pulse crops, which include beans, peas, lentils, and chickpeas, have become an important addition to both human and animal diets due to their protein content and functional properties. However, knowledge of their nutrient composition and protein quality is necessary for the proper formulation of these ingredients in pet foods. The objective of this study was to determine the macronutrient composition and standardized amino acid digestibility and to describe the protein quality through the use of digestible indispensable amino acid scores (DIAAS-like) of five pulse ingredients. Black bean (BB) grits, garbanzo beans (GB), green lentils (GL), navy bean (NB) powder, and yellow peas (YP) were analyzed for dry matter (DM), ash and organic matter (OM), crude protein (CP), gross energy (GE), acid hydrolyzed fat (AHF), and total dietary fiber (TDF) to determine the macronutrient composition. Precision-fed rooster assays were conducted using cecectomized roosters to calculate standardized amino acid digestibility and true metabolizable energy corrected for nitrogen (TMEn). The essential amino acids, with the exception of methionine, were highly digestible with digestibility values of 80% to 90% (dry matter basis) for all selected pulse ingredients. BB grits had the lowest (P &lt; 0.05) digestibility of arginine (86.5%) and histidine (80.6%) in contrast to GB (94.9% and 89.9%, respectively). The TMEn of GB was highest (P &lt; 0.05) at 3.56 kcal/g compared with the other pulses. The DIAAS-like values for adult dogs were consistently the lowest for methionine for all pulses, making it the first-limiting amino acid in these ingredients. The DIAAS-like values for adult cats showed GL had lowest (P &lt; 0.05) score in tryptophan compared with other pulses when using both AAFCO values and NRC recommended allowances as reference proteins. Methionine was the first-limiting amino acid for YP and tryptophan for GL. Based on macronutrient composition, protein quality, and amino acid digestibility, it can be concluded that pulse ingredients have the required nutritional characteristics to be viable protein sources in canine and feline foods. However, the use of complementary protein sources is recommended to counterbalance any potential limiting amino acids in pulse ingredients.


2012 ◽  
Vol 108 (S2) ◽  
pp. S333-S336 ◽  
Author(s):  
Gertjan Schaafsma

PDCAAS is a widely used assay for evaluating protein quality. It is a chemical score, which is derived from the ratio between the first limiting amino acid in a test protein and the corresponding amino acid in a reference amino acid pattern and corrected for true faecal N digestibility. Chemical scores exceeding 100 % are truncated to 100 %. The advantages of the PDCAAS are its simplicity and direct relationship to human protein requirements. The limitations are as follows: the reference pattern is based on the minimum amino acid requirements for tissue growth and maintenance and does not necessarily reflect the optimum intake. Truncated PDCAAS of high-quality proteins do not give any information about the power of these proteins to compensate, as a supplement, for low levels of dietary essential amino acids in low-quality proteins. It is likely that faecal N digestibility does not take into account the loss from the colon of indispensable amino acids that were not absorbed in the ileum. Anti-nutritional factors, such as lectins and trypsin inhibitors, in several plant protein sources can cause heightened endogenous losses of amino acids, an issue which is particularly relevant in animal feedstuffs. The assumption that amino acid supplementation can completely restore biological efficiency of the protein source is incorrect since the kinetics of digestion and absorption between supplemented free amino acids and amino acids present in dietary proteins, are different.


2012 ◽  
Vol 108 (S2) ◽  
pp. S59-S68 ◽  
Author(s):  
Shane M. Rutherfurd ◽  
Kiran Bains ◽  
Paul J. Moughan

Cereals and legumes are staple foods in India and are limiting in lysine and sulphur amino acids, respectively. Available lysine loss, due to Maillard-type reactions that may occur during food preparation, exacerbates the problem of lysine deficiency particularly in cereals. Consequently, determining the contents of digestible essential amino acids, particularly lysine, is important. True ileal digestibilities of most amino acids (including total and reactive lysine) were determined for ten food ingredients and eleven foods commonly consumed in India. Semi-synthetic diets each containing either an ingredient or the prepared food as the sole protein source were formulated to contain 100 g kg− 1protein (75 g kg− 1for rice-based diets) and fed to growing rats. Titanium dioxide was included as an indigestible marker. Digesta were collected and the amino acid content (including reactive lysine) of diets and ileal digesta determined. Available (digestible reactive) lysine content ranged from 1·9–15·4 g kg− 1and 1·8–12·7 g kg− 1across the ingredients and prepared foods respectively. True ileal amino acid digestibility varied widely both across ingredients and prepared foods for each amino acid (on average 60–92 %) and across amino acids within each ingredient and prepared food (overall digestibility 31–96 %). Amino acid digestibility was low for many of the ingredients and prepared foods and consequently digestibility must be considered when assessing the protein quality of poorer quality foods. Given commonly encountered daily energy intakes for members of the Indian population, it is estimated that lysine is limiting for adults in many Indian diets.


1998 ◽  
Vol 66 (1) ◽  
pp. 285-292 ◽  
Author(s):  
M. García-Gallego ◽  
H. Akharbach ◽  
M. de la Higuera

AbstractThis experiment was conducted to test two different protein sources as alternatives to the commonly used fish meal (FM) in the diet of the European eel (Anguilla anguilla). Six experimental diets were tested in three replicated lots of European eels. All diets contained the same protein and energy content (ca, 300 g crude protein per kg dry matter and 18·5 MJ/kg, respectively) but differed in the nature of the protein source: FM was the only protein source in the control diet and was fully or partially (0–5: 0–5) replaced by meat meal (MM) or sunflower meal (SFM) in four other diets; a sixth diet included SFM as the only protein source but was supplemented with several essential amino acids. Food intake, fish growth and several indices of diet and protein utilization were measured. MM clearly was the poorest protein source while SFM could replace, at least 0·5 of the FM with no significant reduction in performance. In addition, the European eel was able to utilize the supplement of essential amino acids. The full-SFM diet was improved significantly when supplemented and results were not statistically different from the control FM-based diet. Overall, a good correlation was found between the results of each diet and the respective essential amino acid index, calculated using as reference the essential amino acid requirements previously defined for another eel species, Anguilla japonica. This index could be used as a reliable measure for an a priori evaluation of alternative protein sources to be included in commercial foods for eels.


2019 ◽  
Vol 9 (1) ◽  
pp. 32-37
Author(s):  
Jamaluddin ◽  
Nur Atina ◽  
Yonelian Yuyun

In this study used a sample of eel fish species Anguilla marmorata (Q.) Gaimard and Anguilla bicolor from Poso lake that has a high protein content and is a fish endemic to Central Sulawesi. These eels are consumed by the surrounding community of the lake, but the nutritional content remains unknown. The present research was aimed to determine the protein level and amino acid profile of Anguilla marmorata (Q.) Gaimard and Anguilla bicolor eels. The protein level testing used Kjeldahl method, and amino acid profile used High Performance Liquid Chromatography. The results demonstrate the protein level of the two samples Anguilla marmorata (Q.) Gaimard eels have a protein content of 41.84% and Anguilla bicoloreels at 33.75%. Anguilla marmorata (Q.) Gaimard and Anguilla bicolor eels contain 18 types of amino acid, comprised of 9 types of essential amino acids and 9 types of non-essential amino acids. Of the two samples of eel species Anguilla marmorata (Q.) Gaimard and Anguilla bicolor, have complete protein quality because it has all kinds of essential amino acids.


1984 ◽  
Vol 67 (3) ◽  
pp. 623-626
Author(s):  
Ghulam Sarwar

Abstract Amino acid scores corrected for true digestibility of individual amino acids (as determined by rat balance method) were termed “available amino acid scores” in the present investigation. Available amino acid scores were calculated for 7 protein sources and their 10 supplementary or complementary mixtures which have been tested in collaborative amino acid and rat growth assays for evaluating protein quality. The available amino acid scores were as follows: casein + methionine (100); egg white (100); rapeseed protein concentrate, RPC (94); casein (93); beef (89); soya assay protein, SAP (62); pea flour (61); whole wheat flour, WW (38); SAP + methionine (88); pea flour + methionine (72); WW + lysine (67); WW + casein (84); WW + egg white (79); WW + RPC (65); WW + beef (77); WW + SAP (70); and WW + pea flour (75). These scores were similar to the collaborative relative NPR values; the differences were less than 10 units (2–9 units) in most cases. The positive correlation (r = 0.92) between available amino acid scores and relative net protein ratio (RNPR, a rat growth method) values was highly significant (P &lt; 0.01) and the origin of the regression line (y = 0.92x + 1.88) was not significantly different from zero. Amino acid bioavailability has previously been a problem, preventing widespread acceptance of amino acid score. Available amino acid score solves this problem.


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