EFFECT OF STEAM PELLETING AND REGRINDING ON THE DIGESTIBILITY OF PROTEIN IN CEREAL GRAINS, SOYBEAN MEAL AND WHEAT BRAN BY THE RAT

1968 ◽  
Vol 48 (1) ◽  
pp. 35-39 ◽  
Author(s):  
E. M. Olsen ◽  
S. J. Slinger

The effect if steam pelleting and regrinding on digestibility of protein in corn, wheat, barley, oats, soybean meal and wheat bran was tested with rats. Percentage amino acid absorption and net protein utilization (NPU) were determined for the wheat bran. Pelleting and regrinding improved the digestibility of protein in bran but had no effect on the digestibility of protein in the other ingredients tested. Increased absorption of amino acids caused by the increased digestibility of protein in bran varied considerably for individual amino acids, being greatest for isoleucine, lysine, methionine and threonine of the essential amino acids. The improvement in protein digestibility and amino acid availability was reflected in a higher NPU.

1965 ◽  
Vol 45 (2) ◽  
pp. 63-70 ◽  
Author(s):  
J. D. Summers ◽  
S. J. Slinger ◽  
G. C. Ashton

Feather meal when used as the sole source of protein in a ration would not support weight gain in growing chicks. Supplementation of feather meal protein with the essential amino acids, in which it is reported deficient, improved rate of gain, but did not improve net protein utilization. One may thus conclude that besides being in imbalance, the protein of feather meal is poorly absorbed.Four commercially available meat meal samples were markedly enhanced by supplementation with the amino acids in which previous work had indicated that meat meal protein was deficient. Meat and feather meal protein when used to supply 3% of the protein in practical-type corn–soybean meal rations gave equally as good results as soybean meal protein. The results obtained using feather meal protein in practical-type rations can not be explained entirely on the basis of excess protein in these diets.


1991 ◽  
Vol 58 (4) ◽  
pp. 431-441 ◽  
Author(s):  
Thérèse Desrosiers ◽  
Laurent Savoie

SummaryThe effect of heat treatments, at various water activities (αw), on digestibility and on the availabilities of amino acids of whey protein samples in the presence of lactose was estimated by an in vitro digestion method with continuons dialysis. Four αw (0·3, 0·5, 0·7 and 0·97), three temperatures (75, 100 and 121 °C) and three heating periods (50, 500 and 5000 s) were selected. The initial lysine: lactose molar ratio was 1:1. Amino acid profiles showed that excessive heating of whey (121 °C, 5000 s) destroyed a significant proportion of cystine at all αw, lysine at αw 0·3, 0·5 and 0·7, and arginine at αw 0·5 and 0·7. At αw 0·3, 0·5 and 0·7, protein digestibility decreased (P < 0·05) as the temperature increased from 75 to 121 °C for a heating period of 5000 s, and as the heating time was prolonged from 500 to 5000 s at 121 °C. Excessive heating also decreased (P < 0·05) the availabilities of ail amino acids at αw 0·3, 0·5 and 0·7. The availabilities of lysine, proline, aspartic acid, glutamic acid, threonine, alanine, glycine and serine were particularly affected. Severe heating at αw 0·97 did not seem to favour the Maillard reaction, but the availabilities of cystine, tyrosine and arginine were decreased, probably as a result of structural modifications of the protein upon heating. Heating whey protein concentrates in the presence of lactose not only affected lysine, but also impaired enzymic liberation of other amino acids, according to the severity of heat treatments and αw.


1997 ◽  
Vol 272 (4) ◽  
pp. E592-E599 ◽  
Author(s):  
B. B. Poindexter ◽  
C. A. Karn ◽  
J. A. Ahlrichs ◽  
J. Wang ◽  
C. A. Leitch ◽  
...  

To determine how increased amino acid availability alters rates of whole body proteolysis and the irreversible catabolism of the essential amino acids leucine and phenylalanine throughout the neonatal period, leucine and phenylalanine kinetics were measured under basal conditions and in response to intravenous amino acids in two separate groups of healthy, full-term newborns (at 3 days and 3 wk of age). The endogenous rates of appearance of leucine and phenylalanine (reflecting proteolysis) were suppressed equally in both groups and in a dose-dependent fashion (by approximately 10% with 1.2 g x kg(-1) x day(-1) and by approximately 20% with 2.4 g x kg(-1) x day(-1)) in response to intravenous amino acid delivery. Insulin concentrations remained unchanged from basal values during amino acid administration. The irreversible catabolism of leucine and phenylalanine increased in a stepwise fashion in response to intravenous amino acids; again, no differences were observed between the two groups. This study clearly demonstrates that the capacity to acutely increase rates of leucine oxidation and phenylalanine hydroxylation is fully present early in the neonatal period in normal newborns. Furthermore, these data suggest that amino acid availability is a primary regulator of proteolysis in normal newborns throughout the neonatal period.


1985 ◽  
Vol 54 (2) ◽  
pp. 349-353 ◽  
Author(s):  
Elisabeth Kindt ◽  
Halvor Holm ◽  
Sverre Halvorsen ◽  
Sverre O. Lie

1. In a previous study (Kindt et al. 1983, 1984) it was assumed that a protein hydrolysate, devoid of phenylalanine, together with intact protein as given to children with phenylketonuria (PKU), was equivalent to egg or milk protein. One group of children was given this ‘PKU protein’ in amounts corresponding to the Joint FAO/WHO ad hoc Expert Committee (1973) recommendations. The results indicated that the Joint FAO/WHO ad hoc Expert Committee (1973) recommended levels of protein intake were marginal.2. The purpose of the present study was to evaluate whether the quality of the protein hydrolysate, together with intact protein (‘PKU protein’), is equivalent to egg or milk protein. This was done using a rat bioassay. Four protein sources were used: (1) egg protein, (2) protein hydrolysate, (3) protein hydrolysate diluted with non-essential amino acids, (4) protein hydrolysate mixed with food proteins (‘PKU protein’), comparable with the diet previously used (Kindt et al. 1983, 1984).3. The results indicated that the ‘PKU protein’ was of very high qua1ity: net protein utilization (NPU) > 90. The protein hydrolysate alone and the protein hydrolysate diluted with non-essential amino acids gave a NPU > 80.4. The conclusion drawn from the present study is that the ‘PKU protein’, as used in the treatment of children with PKU, is equivalent to egg or milk protein. This supported the view that the Joint FAO/WHO ad hoc Expert Committee (1973) recommended levels of intake were marginal.


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.


1996 ◽  
Vol 271 (4) ◽  
pp. E733-E741 ◽  
Author(s):  
P. Tessari ◽  
R. Barazzoni ◽  
M. Zanetti ◽  
M. Vettore ◽  
S. Normand ◽  
...  

Whether tracers of different essential amino acids yield the same estimates of body protein turnover is still uncertain. Therefore, we have simultaneously determined leucine (Leu; using [14C]Leu), phenylalanine (Phe; using [13C]Phe), and tyrosine (Tyr; using [2H2]Tyr) rates of appearance (Ra) from proteolysis (PD), as well as Leu and Phe disposal, into protein synthesis (PS) both before and after an anabolic stimulus in healthy volunteers. Protein anabolism was stimulated by insulin plus a branched-chain amino acid-enriched aromatic amino acid-deficient amino acid solution, which increased Leu (from 145 +/- 9 to 266 +/- 10 mumol/l) but decreased Phe (from 57 +/- 2 to 46 +/- 3) and Tyr (from 58.7 +/- 5.5 to 21.0 +/- 2.2) concentrations. Postabsorptive endogenous Leu Ra (2.04 +/- 0.12 mumol.kg-1.min-1), Phe Ra (0.66 +/- 0.03), and Tyr Ra (0.45 +/- 0.06), as well as rates of PS determined with the leucine (1.65 +/- 0.10 mumol.kg-1.min-1) and the phenylalanine tracer (0.57 +/- 0.03), agreed well with the known abundance of these amino acids in body protein(s). After insulin and amino acids, PD was suppressed (P < 0.001) using all tracers. However, although percent suppression of endogenous Leu Ra (-->1.49 +/- 0.10 mumol.kg-1.min-1, 26 +/- 5%) and Phe Ra (-->0.53 +/- 0.02 mumol.kg-1.min-1, -20 +/- 2%) were comparable, endogenous Tyr Ra was suppressed to a larger extent (-->0.23 +/- 0.02 mumol.kg-1.min-1, -46 +/- 3% P = 0.038). PS was stimulated using the Leu (+24 +/- 7%, P < 0.02) but not the Phe (+6 +/- 4%, not significant) data. We conclude that isotopes of different essential amino acid: provide comparable estimates of PD and PS in the postabsorptive state. However, their responses to an anabolic stimulus may differ, possibly depending on exogenous amino acid availability and/or the resulting plasma levels.


2020 ◽  
Vol 33 (7) ◽  
pp. 1148-1155
Author(s):  
Su A Lee ◽  
Jong Young Ahn ◽  
Ah Reum Son ◽  
Beob Gyun Kim

Objective: The objective was to determine standardized ileal digestibility (SID) of crude protein (CP) and amino acids (AA) in cereal grains and various co-products fed to growing pigs.Methods: Ten feed ingredients tested were barley (9.3% CP), lupin kernels (31.1% CP), and wheat (11.3% CP) as cereal grains, and 2 sources of corn gluten feed produced in China (21.6% CP) and Korea (24.6% CP), corn gluten meal (65.3% CP), lupin hulls (11.6% CP), rice bran (14.5% CP), soybean meal (44.8% CP), and wheat bran (15.4% CP) as co-products. Ten experimental diets were formulated to contain each ingredient as a sole source of N and an N-free diet was used to correct basal endogenous losses of CP and AA. All diets also contained 0.5% Cr2O3 as an indigestible index. A replicated 11×6 incomplete Latin square design with 11 dietary treatments, 6 periods, and 22 animals was employed. Twenty-two barrows with an initial body weight of 64.6±4.9 kg were equipped with a T-cannula in the distal ileum. An experimental period consisted of a 4-d adaptation period and a 2-d collection period.Results: The SID of CP in the barley, lupin kernels, wheat, 2 sources of corn gluten feed, corn gluten meal, lupin hulls, rice bran, soybean meal, and wheat bran were 84.7%, 90.5%, 90.4%, 77.4%, 74.6%, 89.5%, 90.4%, 74.4%, 86.9%, and 63.4% (standard error of the mean [SEM] = 5.3, p = 0.006), respectively. The respective SID values of Lys were 75.5%, 88.4%, 83.9%, 74.7%, 62.4%, 80.3%, 83.9%, 78.5%, 88.0%, and 71.2% (SEM = 3.3, p<0.001), and the SID values of Met were 83.6%, 88.7%, 89.4%, 85.7%, 78.3%, 88.9%, 89.4%, 85.3%, 91.1%, and 77.0% (SEM = 2.4, p<0.001), respectively.Conclusion: The ileal digestibility of protein and amino acids varies among the feed ingredients fed to pigs.


Nutrients ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1360 ◽  
Author(s):  
Il-Young Kim ◽  
Sanghee Park ◽  
Ellen T. H. C. Smeets ◽  
Scott Schutzler ◽  
Gohar Azhar ◽  
...  

Heart failure in older individuals is normally associated with a high body mass index and relatively low lean body mass due to, in part, a resistance to the normal anabolic effect of dietary protein. In this study we have investigated the hypothesis that consumption of a specially-formulated composition of essential amino acids (HiEAAs) can overcome anabolic resistance in individuals with heart failure and stimulate the net gain of body protein to a greater extent than a commercially popular protein-based meal replacement beverage with greater caloric but lower essential amino acid (EAA) content (LoEAA). A randomized cross-over design was used. Protein kinetics were determined using primed continuous infusions of L-(2H5)phenylalanine and L-(2H2)tyrosine in the basal state and for four hours following consumption of either beverage. Both beverages induced positive net protein balance (i.e., anabolic response). However, the anabolic response was more than two times greater with the HiEAA than the LoEAA (p < 0.001), largely through a greater suppression of protein breakdown (p < 0.001). Net protein accretion (g) was also greater in the HiEAA when data were normalized for either amino acid or caloric content (p < 0.001). We conclude that a properly formulated EAA mixture can elicit a greater anabolic response in individuals with heart failure than a protein-based meal replacement. Since heart failure is often associated with obesity, the minimal caloric value of the HiEAA formulation is advantageous.


2020 ◽  
Vol 98 (8) ◽  
Author(s):  
Maryane S F Oliveira ◽  
John K Htoo ◽  
Hans H Stein

Abstract An experiment was conducted to test the hypothesis that values for standardized ileal digestibility (SID) of amino acids (AA) in corn, wheat, and wheat middlings obtained using the direct procedure are not different from values obtained using the difference procedure. Sixteen ileal-cannulated barrows (initial BW: 69.5 ± 5.0 kg) were allotted to a replicated 8 × 4 Youden Square design with 8 diets and 4 periods. Each period consisted of 5 d of adaptation to the diet and 2 d of collection of ileal digesta. Four diets were based on soybean meal (SBM), corn, wheat, or wheat middlings as the only AA-containing ingredients. Three additional diets were based on a mixture of SBM and corn, SBM and wheat, or SBM and wheat middlings, and an N-free diet was also used. The apparent ileal digestibility (AID) and the SID of crude protein (CP) and AA for the 4 diets containing SBM, corn, wheat, or wheat middlings as the sole source of AA were calculated using the direct procedure. The AID and SID of CP and AA for the 3 mixed diets containing SBM and corn, wheat, or wheat middlings were also calculated and the contribution of digestible AA from SBM was subtracted from the AID or SID values for the diets. The AID or SID of AA in corn, wheat, and wheat middlings were subsequently calculated by difference. Results indicated that the AID values for a few AA were lower (P &lt; 0.05) if the direct procedure was used instead of the difference procedure, regardless of ingredient. The AID of Trp was greater in corn and wheat middlings, and the SID of Trp in corn and wheat middlings tended to be greater, if the direct procedure rather than the difference procedure was used, but that was not the case for wheat (interaction, P &lt; 0.05 and P &lt; 0.10, respectively). However, for all other indispensable AA, and for most of the dispensable AA, the SID of AA in corn, wheat, and wheat middlings was not different between the difference procedure and the direct procedure. Therefore, values for SID of AA in cereal grains and fiber-rich ingredients may be determined using either the direct or the difference procedure.


1981 ◽  
Vol 46 (1) ◽  
pp. 159-171 ◽  
Author(s):  
M. R. Taverner ◽  
I. D. Hume ◽  
D. J. Farrell

1. Pigs prepared with re-entrant ileal cannulas were used to determine the ileal availability of amino acids in nine cereal grains including five wheats, sorghum (Sorghum vulgare Pers.), maize, barley and Triticale.2. The average true availability of amino acids in these grains was 0·88 but there were consistent differences in availability among amino acids. Generally, lysine and threonine were among the least available amino acids while glutamic acid and arginine were among the most available amino acids in cereal protein.3. There was as much variation in amino acid availability within a grain species (wheat) as among the other grains.


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