Bioavailability of tryptophan in selected foods by rat growth assay

1989 ◽  
Vol 39 (1) ◽  
pp. 85-91 ◽  
Author(s):  
F. E. McDonough ◽  
C. E. Bodwell ◽  
P. A. Wells ◽  
J. A. Kamalu
Keyword(s):  
Rat Growth ◽  
Growth Assay

scholarly journals Preparation, properties and metabolism of retro-3-dehydroretinyl acetate

1968 ◽  
Vol 109 (2) ◽  
pp. 293-299 ◽  
Author(s):  
A. Krishna Mallia ◽  
M. R. Lakshmanan ◽  
K. V. John ◽  
H. R. Cama
Keyword(s):  
Small Intestine ◽  
Vitamin A ◽  
Hydrobromic Acid ◽  
The Body ◽  
Rat Intestine ◽  
Retinyl Acetate ◽  
Major Site ◽  
Rat Growth ◽  
Growth Assay ◽  
Biological Potency

1. Treatment of 3-dehydroretinyl acetate with aqueous hydrobromic acid resulted in the formation of retro-3-dehydroretinyl acetate, which, on alkaline hydrolysis, gave the corresponding alcohol. 2. retro-3-Dehydroretinyl acetate was isomerized to 3-dehydrovitamin A when fed to vitamin A-deficient rats. 3. When retro-3-dehydroretinyl acetate was administered orally, it was hydrolysed to retro-3-dehydroretinol in the rat intestine, isomerized to 3-dehydroretinol and esterified before being transported to the liver for storage. 4. When administered intraperitoneally, both 3-dehydrovitamin A and retro-3-dehydrovitamin A were accumulated in liver and other tissues, whereas after enterectomy 3-dehydrovitamin A was not detected anywhere in the body. 5. The small intestine was shown to be the major site of conversion of retro-3-dehydrovitamin A into 3-dehydrovitamin A. 6. The extent of conversion of retro-3-dehydroretinyl acetate into 3-dehydrovitamin A was much smaller than that of the conversion of retro-retinyl acetate into vitamin A. 7. The biological potency of retro-3-dehydroretinyl acetate, determined by the rat-growth assay, was 2·6% of that all-trans-retinyl acetate, when given orally.

EVALUATION OF PROTEIN IN FOODS: III. A STUDY OF BACTERIOLOGICAL METHODS

1959 ◽  
Vol 37 (11) ◽  
pp. 1351-1360 ◽  
Author(s):  
C. G. Rogers ◽  
J. M. McLaughlan ◽  
D. G. Chapman
Keyword(s):  
Amino Acid ◽  
Protein Quality ◽  
Animal Origin ◽  
Rat Growth ◽  
Amino Acid Requirements ◽  
Growth Assay ◽  
Assay Methods ◽  
Limiting Amino Acid ◽  
Egg Powder

Bacteriological methods for the determination of protein quality were evaluated by comparison with protein efficiency ratio (P.E.R.) values determined by a standardized rat growth assay. Enzyme or acid hydrolyzates of foods were used as the source of amino acids with hydrolyzed whole egg powder as the reference standard. With Streptococcus faecalis A.T.C.C. 9790 autolysis occurred in media containing hydrolyzates of proteins deficient in lysine, and was largely responsible for results which did not agree with P.E.R. values. In methods employing Leuconostoc mesenteroides P-60 A.T.C.C. 8042, growth was influenced only by the most limiting amino acid relative to the requirements of the test organism.Results with enzyme hydrolyzates correlated poorly with P.E.R. values, whereas, with acid hydrolyzates, a good correlation was obtained for cereal proteins. A difference in amino acid requirements was largely responsible for the lack of agreement between the P.E.R. assay and methods employing L. mesenteroides, particularly for legumes and foods of animal origin. It was concluded that bacteriological assay methods which have been proposed for protein evaluation are unsatisfactory as screening procedures for the evaluation of protein in foods.

Rat Growth Assay for Vitamin B12

1949 ◽  
Vol 72 (1) ◽  
pp. 102-106 ◽  
Author(s):  
D. V. Forst ◽  
H. H. Fricke ◽  
H. C. Spruth
Keyword(s):  
Vitamin B12 ◽  
Rat Growth ◽  
Growth Assay

Rat Growth Assay for Vitamin B12. Correspondence with Collaborative Microbiological Assay Results on U.S.P. Liver Extracts

1953 ◽  
Vol 49 (1) ◽  
pp. 107-120 ◽  
Author(s):  
Douglas V. Frost ◽  
Howard H. Fricke ◽  
Henry C. Spruth
Keyword(s):  
Vitamin B12 ◽  
Microbiological Assay ◽  
Rat Growth ◽  
Growth Assay

EVALUATION OF PROTEIN IN FOODS: III. A STUDY OF BACTERIOLOGICAL METHODS

1959 ◽  
Vol 37 (1) ◽  
pp. 1351-1360 ◽  
Author(s):  
C. G. Rogers ◽  
J. M. McLaughlan ◽  
D. G. Chapman
Keyword(s):  
Amino Acid ◽  
Protein Quality ◽  
Animal Origin ◽  
Rat Growth ◽  
Amino Acid Requirements ◽  
Growth Assay ◽  
Assay Methods ◽  
Limiting Amino Acid ◽  
Egg Powder

Bacteriological methods for the determination of protein quality were evaluated by comparison with protein efficiency ratio (P.E.R.) values determined by a standardized rat growth assay. Enzyme or acid hydrolyzates of foods were used as the source of amino acids with hydrolyzed whole egg powder as the reference standard. With Streptococcus faecalis A.T.C.C. 9790 autolysis occurred in media containing hydrolyzates of proteins deficient in lysine, and was largely responsible for results which did not agree with P.E.R. values. In methods employing Leuconostoc mesenteroides P-60 A.T.C.C. 8042, growth was influenced only by the most limiting amino acid relative to the requirements of the test organism.Results with enzyme hydrolyzates correlated poorly with P.E.R. values, whereas, with acid hydrolyzates, a good correlation was obtained for cereal proteins. A difference in amino acid requirements was largely responsible for the lack of agreement between the P.E.R. assay and methods employing L. mesenteroides, particularly for legumes and foods of animal origin. It was concluded that bacteriological assay methods which have been proposed for protein evaluation are unsatisfactory as screening procedures for the evaluation of protein in foods.

EVALUATION OF PROTEIN IN FOODS: VI. FURTHER FACTORS INFLUENCING THE PROTEIN EFFICIENCY RATIO OF FOODS

1960 ◽  
Vol 38 (1) ◽  
pp. 865-869
Author(s):  
E. J. Middleton ◽  
A. B. Morrison ◽  
J. A. Campbell
Keyword(s):  
Protein Synthesis ◽  
Nutritive Value ◽  
Protein Efficiency Ratio ◽  
Plant Protein ◽  
Plant Proteins ◽  
Efficiency Ratio ◽  
Factors Influencing ◽  
Rat Growth ◽  
Growth Assay ◽  
Valid Estimate

Diets containing two levels of protein (10 and 15%) and two levels of fat (10 and 20%) were tested in all possible combinations in a 4-week rat growth assay. Protein was supplied by casein or a mixture of plant proteins. The protein efficiency ratio (P.E.R.) for casein found with a diet containing 10% protein and 10% fat was slightly greater than that found with a diet containing 15% protein and 20% fat, approximating the levels found in the "average" Canadian diet. The value for plant protein was similar under both conditions. Efficiency of carcass protein synthesis was much greater in animals fed casein than in those fed plant protein. With both sources of protein, the efficiency of carcass protein synthesis was similar with diets containing 10% protein and 10% fat to those with 15% protein and 20% fat.In additional studies, no effect of Chlortetracycline or source of carbohydrate on P.E.R. of casein was observed.It was concluded that P.E.R. determinations carried out on a 10% protein diet furnish a valid estimate of the nutritive value of protein and have several practical advantages.

EVALUATION OF PROTEIN IN FOODS: VI. FURTHER FACTORS INFLUENCING THE PROTEIN EFFICIENCY RATIO OF FOODS

1960 ◽  
Vol 38 (8) ◽  
pp. 865-869 ◽  
Author(s):  
E. J. Middleton ◽  
A. B. Morrison ◽  
J. A. Campbell
Keyword(s):  
Protein Synthesis ◽  
Nutritive Value ◽  
Protein Efficiency Ratio ◽  
Plant Protein ◽  
Plant Proteins ◽  
Efficiency Ratio ◽  
Factors Influencing ◽  
Rat Growth ◽  
Growth Assay ◽  
Valid Estimate

Diets containing two levels of protein (10 and 15%) and two levels of fat (10 and 20%) were tested in all possible combinations in a 4-week rat growth assay. Protein was supplied by casein or a mixture of plant proteins. The protein efficiency ratio (P.E.R.) for casein found with a diet containing 10% protein and 10% fat was slightly greater than that found with a diet containing 15% protein and 20% fat, approximating the levels found in the "average" Canadian diet. The value for plant protein was similar under both conditions. Efficiency of carcass protein synthesis was much greater in animals fed casein than in those fed plant protein. With both sources of protein, the efficiency of carcass protein synthesis was similar with diets containing 10% protein and 10% fat to those with 15% protein and 20% fat.In additional studies, no effect of Chlortetracycline or source of carbohydrate on P.E.R. of casein was observed.It was concluded that P.E.R. determinations carried out on a 10% protein diet furnish a valid estimate of the nutritive value of protein and have several practical advantages.

scholarly journals Preparation, properties and metabolism of 5,6-monoepoxy-3-dehydroetinal

1969 ◽  
Vol 111 (1) ◽  
pp. 23-26 ◽  
Author(s):  
A. Krishna Mallia ◽  
M. R. Lakshmanan ◽  
K. V. John ◽  
H. R. Cama
Keyword(s):  
Vitamin A ◽  
Rat Growth ◽  
Growth Assay ◽  
Biological Potency ◽  
Reduction And Oxidation

1. 5,6-Monoepoxy-3-dehydroretinal was synthesized from 3-dehydroretinyl acetate and characterized. 2. When fed to vitamin A-deficient rats, 5,6-monoepoxy-3-dehydroretinal was converted into 5,6-monoepoxy-3-dehydrovitamin A and stored in the liver. 3. It was demonstrated that the rat possesses the necessary enzymes for the reduction and oxidation of 5,6-monoepoxy-3-dehydroretinal to the corresponding alcohol and acid respectively. 4. The biological potency of the epoxy-3-dehydroretinal by the rat-growth assay (determined by USP XIV procedure) was 1·07% of that of vitamin A.

Bioavailability of lysine in selected foods by rat growth assay

1989 ◽  
Vol 39 (1) ◽  
pp. 67-75 ◽  
Author(s):  
F. E. McDonough ◽  
C. E. Bodwell ◽  
A. D. Hitchins ◽  
R. S. Staples
Keyword(s):  
Rat Growth ◽  
Growth Assay
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