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

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.

2017 ◽  
Vol 68 (5) ◽  
pp. 1063-1069
Author(s):  
Cristina Simeanu ◽  
Daniel Simeanu ◽  
Anca Popa ◽  
Alexandru Usturoi ◽  
Dan Bodescu ◽  
...  

Polyodon spathula sturgeon breed is successfully reared in Romania in many fishery farms for meat production and it is capitalized on domestic market as consumption fish. In the current paper were studied a number of 1400 sturgeons from Polyodon spathula breed (1200 individuals of one summer - P.s.0+ and 200 individuals of fourth summers - P.s.3+). From this flock were weighted around 10%, for each age group, and for laboratory determinations were chosen 10 fishes for each age with the corporal mass close to the group mean. After analysing the fillets gathered from the studied fishes for establishing the chemical characteristics, nutritive and biological values of proteins were drawn some interesting conclusions. So, regarding chemical composition we notice that in the meat of analysed fishes water is in a rate of 75.41% at P.s.3+ and 78.37% for P.s.0+; proteins - between 18.08% for P.s.0+ and 19.89% for P.s.3+, values which place those fishes in the group of protein fishes; lipids - between 2.45% and 3.45%, values which situated those sturgeons in category of fishes with a low content in lipids; collagen � 3.83% at P.s.0+ and 4.14% at P.s.3+ which indicate low values for proteins of weak quality in the meat of those sturgeons. Study of nutritive value for the analysed fishes indicate the fact that fishes P.s.0+ have a mediocre nutritive value, having the ratio w/p of 4.33 while sturgeons P.s.3+ were placed in the 2nd category � fishes with a good nutritive value (rate w/p = 3.79). Energetic value of the studied fillets was 97.39 kcal/100 g for P.s.0+ and 114.31 kcal/100 g for P.s.3+, which enlightened an increase of nutritive value with aging, fact especially due to accumulation of adipose tissue. Study of proteins quality, through the presence of those 8 essential amino-acids in the meat of analysed fishes, show the fact that at sturgeons P.s.0+ proportion of essential amino-acids was 20.88% from total amino-acids, while at sturgeons P.s.3+ was 26.23%, fact which enlightened an increasing of proteins� biological value with fish aging. This fact was also shown by calculation of proteins� biological value through chemical methods (EAA index); calculated value for sturgeons P.s.0+ was a little bit lower (118.73) than the one calculated for sturgeons P.s.3+ (118.79).


1982 ◽  
Vol 62 (2) ◽  
pp. 537-545 ◽  
Author(s):  
L. D. CAMPBELL ◽  
B. O. EGGUM ◽  
J. WOLSTRUP

The influence of antibiotics (a 2:1 mixture of bacitracin and neomycin sulfate at 0.7% of the diet) on the availability of energy from barley-fishmeal-based diets was assessed using rats and adult roosters. Changes in estimates of protein quality, as influenced by dietary antibiotics were also determined in the study with rats. Gut biomass content was estimated by measuring the content of adenosine triphosphate (ATP) in gut samples of rats and fresh excreta samples of roosters. Antibiotic addition to the diet significantly (P < 0.01) reduced apparent digestible energy in rats and tended to reduce the true metabolizable energy measured with roosters. Biological value of the protein for rats was increased significantly (P < 0.01) by antibiotics as were net protein utilization values even though true digestibility of protein was decreased significantly (P < 0.01). The availability of some amino acids (e.g. histidine) showed a marked depression (12.1 percentage units) when antibiotics were added to the diet while others were not influenced (e.g. lysine and methionine) or markedly (7.6 percentage units) increased (e.g. alanine). The extent of microbial activity, which was shown to be markedly higher in the hindgut of rats fed no antibiotics as compared to rats fed antibiotics, may have contributed to the positive influence of antibiotic feeding on biological value of dietary protein and to the changes noted in excretion of amino acids by rats and roosters. Key words: Antibiotics, Nitrogen, amino acids, energy, rats, rosters


1964 ◽  
Vol 47 (2) ◽  
pp. 377-382
Author(s):  
Z I Sabry ◽  
A B Morrison ◽  
J A Campbell

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.


1972 ◽  
Vol 27 (3) ◽  
pp. 475-481 ◽  
Author(s):  
Z. Dvořák

1. The amounts of available cystine and tyrosine in the protein of different animal tissues showed a close correlation with the level of hydroxyproline, and may be estimated from hydroxyproline values by regression equations.2. Estimates of ‘chemical score’ have been calculated from the content of hydroxyproline determined in a series of samples for which net protein utilization (NPU) for rats had also been determined. Chemical scores calculated as percentages of the total ‘essential+semiessential’ amino acid content of each material correlated closely with NPU, whereas scores calculated as percentages of total amino acids did not. ‘Methionine+cystine’ were calculated to be first limiting amino acids in every sample.


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.


1972 ◽  
Vol 23 (5) ◽  
pp. 913 ◽  
Author(s):  
AC Kondos ◽  
GL McClymont

The effect on the protein quality of meat meals of processing them under commercial conditions in a continuous dry renderer at maximum temperatures ranging from 116 to 160°C for a running time of 115 min was studied. Although the total levels of amino acids were little affected by processing temperatures, the biological availability of all essential amino acids, as determined by the protozoan Tetrahymena pyriformis, was reduced as the processing temperature increased. At 140 and 160°C the availability of certain amino acids was reduced by 37-56%, lysine, histidine, and methionine being the most severely affected. The availability of essential amino acids in meals produced at temperatures from 121 to c. 138° was not significantly different. The growth-promoting ability of the meat meals for chickens was closely related to the availability of the essential amino acids. __________________ *Part VI, Aust. J. Agric. Res., 19: 171 (1968).


1985 ◽  
Vol 68 (4) ◽  
pp. 680-683
Author(s):  
Geraldine Vaughan Mitchell ◽  
Mamie Young Jenkins

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.


1977 ◽  
Vol 27 (3-4) ◽  
pp. 275-285 ◽  
Author(s):  
I. Marta Evans ◽  
Donald Boulter ◽  
A. R. J. Eaglesham ◽  
P. J. Dart

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.


Author(s):  
Rajni Modgil ◽  
K. Mankotia ◽  
Ranjana Verma ◽  
Anupama Sandal

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.


Sign in / Sign up

Export Citation Format

Share Document