EVALUATION OF PROTEIN QUALITY IN WHEAT BY-PRODUCTS: DIGESTIBILITY OF PROTEIN AND ABSORPTION OF AMINO ACIDS BY THE RAT

1968 ◽  
Vol 48 (2) ◽  
pp. 215-220 ◽  
Author(s):  
E. M. Olsen ◽  
S. J. Slinger ◽  
J. D. Summers

Two experiments were conducted with rats to evaluate the protein quality of a series of wheat by-products, which served as the sole source of protein in diets calculated to contain 10% protein. Digestibility of nitrogen and percentage absorption of amino acids were compared with weight gain, feed efficiency and net protein utilization (NPU) as criteria. Percentage absorption of different amino acids was found to vary considerably in the same protein. Of the essential amino acids, lysine, threonine, methionine and isoleucine had the lowest percentage absorption in all of the products tested. The results indicate that the amount of amino acids absorbed, as measured by the excretion method, may be a more satisfactory measure of protein quality than total amino acid content.

2004 ◽  
Vol 79 (2) ◽  
pp. 231-240 ◽  
Author(s):  
A. I. García ◽  
J. C. de Bias ◽  
R. Carabaño

AbstractTwenty-eight New Zealand White X Californian doe rabbits weighing 3791±141 g were surgically fitted with a glass T-cannula at ileum level. Animals were given ad libitum access to either a casein-based diet (C) or a protein-free diet (PF). The only difference in the ingredient composition of the diets was the substitution of 160g/kg of maize starch by casein in the C diet. Animals were randomly allotted to each experimental diet. Seven rabbits per diet were not allowed to practice caecotrophy. The C diet resulted in higher food dry matter (DM) intake (DMI) (111-5 v. 51-5 g/day), food nitrogen intake (3-12 v. 0-20 g/day), ileal flow of DM (56-0 v. 23-8 g/day) and ileal flow of nitrogen (0-72 v. 0-24 g/day) but lower soft faeces DMI (21-7 v. 41-4 g/day) than the PF diet. A linear relationship between ileal endogenous nitrogen flow and total DMI was found for animals given the C but not for the PF diet. The ingestion ofC diet led to a higher (proportionately 0-41, on average), endogenous ileal amino acid flow than PF diet for all amino acids except for glycine. The ileal flow of glycine was proportionately 0-25 higher in animals given the PF diet than in animals given the C diet. The C diet resulted in higher content of nitrogen, threonine and proline in soft faeces than the PF diet. In contrast, the ingestion of the PF diet led to a higher content of lysine and methionine in soft faeces than the C diet. Within the C diet, animals practising caecotrophy showed higher ileal flow of DM (73-4 v. 56-0 g/day) and phenylalanine (0-834 v. 0-677 g/kg DMI) than animals not practising it. Caecotrophy led to a higher endogenous proportion of some of the most important limiting essential amino acids in rabbits, such as arginine, lysine, phenylalanine and threonine. In rabbits, the use of PF diets has limited practical application in the estimation of nitrogen endogenous losses as the low food DMI and the high soft faecesDMI leads to abnormal food: soft faeces intake ratio. Moreover, due to the important effect of caecotrophy on the amino acid composition of endogenous losses, it is important to correct the total amino acid content of the ileal chyme by the undigested amino acid residue coming from the soft faeces intake. This correction could be made, without the methodological complexity implied, by fitting animals with a wooden collar and thereby avoiding caecotrophy as in the present trial.


Author(s):  
Walid Elfalleh ◽  
Nizar Tlili ◽  
Ma Ying ◽  
He Sheng-Hua ◽  
Ali Ferchichi ◽  
...  

Chemicals from fresh pomegranates were established. Total sugar of juice extracts are mainly fructose (ca. 7.27 g/100 ml) and glucose (ca. 8.11 g/100 ml). Pulp minerals, expressed as mg/100g are potassium (351.26), magnesium (10.02), calcium (9.26), sodium (7.25), iron (0.15), Zinc (0.10), copper (0.08) and manganese (0.04). Juice proteins are about 7.95 g/l and dry pulp proteins are 24% on a dry-weight basis DW (Kjeldhal assays). Seed proteins are ca. 16.87% DW. Globulins (62.4 mg/g DW) and albumins (54.12 mg/g DW) are the major storage protein fractions, followed by glutelins (33.2 mg/g DW) and prolamins (18.08 mg/g DW). Seed total amino acid content is 14.45 g/100 g DW. Seeds are rich in Glu, Arg, Asp, Leu and Gly amino acids. Essential amino acids average 33.54% of total amino acid. Essential amino acids are mostly all much higher than the requirement of FAO/WHO for adults (but none for preschool children). Most other amino acids have content slightly fewer. All of these findings implied that the content of sugar, mineral and protein maybe included in pomegranate as supplements for commonly diets.


2020 ◽  
Vol 1 (2) ◽  
pp. 145-153
Author(s):  
Idriss Lawane Abakar ◽  
◽  
Tidjani Abdelsalam ◽  
Parkouda Charles ◽  
François Tapsoba ◽  
...  

Kawal is made by a natural or uncontrolled fermentation of Senna obtusifolia leaves. It is a food condiment, and appreciated because of its particular flavor. It is also used as a meat or fish substitute. Kawal is an important source of protein in the diet of low-income families. The present work was done to determine the total amino acid content in raw and fermented Senna obtusifolia leaves. The high performance liquid chromatography (HPLC) with The Pico-Tag method was used for the analysis and determination of amino acid profiles. The results obtained showed that the kawal protein is rich in essential amino acids and semi-essential for humans, with different concentrations. Leucine gave a maximum value of 208.56 mg/100 g (DM) and 538,29 mg/100 g (DM); valine showed the value of 173,46 mg/100 g (DM) and 476.25 mg/100 g (DM), for lysine this value is 205.58 mg/100 g (DM) and 456.13 mg/100 g (DM). In the background, we have histidine, threonine, tyrosine, isoleucine and phenylalanine, whose best concentrations are between 157.36 mg/100 g and 397.93 mg/100 g (DM) in fermented leaves. For semi-essential amino acids, the fermented leaves have concentrations of between 121.96 mg/100 g and 1260.92 mg/100 g (DM).


2020 ◽  
pp. 58-63
Author(s):  
K.B. Gurieva ◽  
N.A. Khaba ◽  
E.A. Tarasova ◽  
S.L. Beletskiy

The results of the research on the assessment of the biological value of wheat after storage by the composition and ratio of amino acids are presented. It is shown that after 6.5 years of storage in elevator silos, the protein content in wheat met the requirements of the standard for class 3 wheat. The sum of all amino acids was from 11.5 to 13.1 g / 100 g, including essential amino acids — 4.0-4.5g/100g and non-essential — 7.8-8.7 g / 100 g. The proportion of essential amino acids was 33.7-35.3% of the total amino acid content. The calculation of the amino acid score demonstrated that the main amino acid limiting the nutritional value of wheat after storage is lysine with an amino acid score of 45-53%. The essential amino acids threonine, valine, isoleucine, and leucine are also classified as deficient, but with a higher value of the amino acid score, close to the complete protein.


Proceedings ◽  
2020 ◽  
Vol 70 (1) ◽  
pp. 4
Author(s):  
Sara Bautista-Expósito ◽  
Elena Peñas ◽  
Albert Vanderberg ◽  
Juana Frias ◽  
Cristina Martínez-Villaluenga

Legumes are alternative protein sources that have been successfully used to develop diverse meatless foods. Although these plant-based products have a lower impact on the environment than equivalent animal-based products, they have lower protein digestibility. Germination could be a useful bioprocess to enhance protein digestibility in legumes, although its effect at different times of seedling development has been little studied in lentils and faba beans. This work investigated the effect of germination time (4 and 6 days after full seed imbibition) on the proteins of three types of Canadian lentils (“gray zero tannin”, G; “caviar black”, B; and “red dehulled”, D) and faba beans (“zero vicin/convicin”, F). Germination increased total nitrogen (4–14% increase) and total levels of some amino acids: Asp in all the sprouts studied; Ser, Pro, Ala, Cys, His and Lys in G; and Met and Tyr in B. A concurrent degradation of the 7S and 11S globulin subunits, the accumulation of peptides below 20 kDa and free essential and non-essential amino acids (4- to 6-fold increase) were observed after germination in all the legumes studied. These effects were attributable to the increased protease activity observed after sprouting. Trypsin inhibitory activity was lower in legume sprouts, except for D, where a small increase was detected. Time, legume type and their interaction showed significant effects on the parameters studied. Germination effects were generally more remarkable at longer stages of seedling development. Among the legumes studied, D showed a differential behavior characterized by a faster protein degradation and release of small peptides, probably due to its higher protease activity as indicated by principal component analysis. These results evidence the positive effects of germination on the protein digestibility of different lentil types and faba beans. The protein quality of plant-based foods could be improved through the selection of legume species with higher germination-induced proteolytic rates and optimized germination times.


Author(s):  
Lata . ◽  
Narender Singh Atri

Objective: In this paper amino acid profile of Lentinus sajor-caju (Fr.) Fr., a basidiomycetous mushroom has been investigated.Methods: During the evaluation 15 amino acids (lysine, aspartic acid, serine, threonine, glutamic acid, cysteine, glycine, alanine, valine, methionine, isoleucine, leucine, tyrosine, phenylalanine and histidine) were determined from the dried sample of Lentinus sajor-caju by following the standard technique of biochemistry using ion-exchange chromatography.Results: The total amino acid content has been evaluated at 18.82 g/100g. Amongst the evaluated amino acids, exogenous amino acid lysine (6.66 g/100g) is preponderantly present in comparison to all other amino acids. The essential amino acid (EAA) index (44.64%) and biological value (BV=36.93%) has also been determined for the examined sample.Conclusion: Lentinus sajor-caju (Fr.) Fr. is a potential source of quality protein with a substantial proportion of exogenous and endogenous amino acids.


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.


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.


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