The Effect of Potassium on the Organic Acid and Nonprotein Nitrogen Content of Plant Tissue

2015 ◽  
pp. 165-188
Author(s):  
Merle R. Teel
Keyword(s):  
Organic Acid ◽  
Nitrogen Content ◽  
Plant Tissue ◽  
Nonprotein Nitrogen

Determination of Protein Nitrogen in Plants

1977 ◽  
Vol 60 (3) ◽  
pp. 590-593 ◽  
Author(s):  
T Powell Gaines
Keyword(s):  
Acetic Acid ◽  
Plant Tissue ◽  
Nonprotein Nitrogen ◽  
Protein Nitrogen ◽  
Aoac Method ◽  
The Mean

Abstract A method is described for determining protein nitrogen (PN) in plants. Plant tissue extracted with 0.5% acetic acid to remove nonprotein nitrogen (NPN) prior to Kjeldahl analysis gave results very close to true PN, whereas AOAC crude PN method 2.049 gave results much too high. True PN was determined as the mean of 3 independently derived values and was used as the basis for comparing the proposed PN method with AOAC method 2.049. Failure of the AOAC method to differentiate between NPN and/or inorganic ammoniacal N and actual PN causes values derived from this method to be too high when it was used to determine PN in plants.

Direct and Indirect Determination of True Protein Content of Milk by Kjeldahl Analysis: Collaborative Study

1991 ◽  
Vol 74 (2) ◽  
pp. 281-288 ◽  
Author(s):  
David M Barbano ◽  
Joanna M Lynch ◽  
J Richard Fleming
Keyword(s):  
Nitrogen Content ◽  
Protein Content ◽  
Total Nitrogen ◽  
Collaborative Study ◽  
Total Nitrogen Content ◽  
Nonprotein Nitrogen ◽  
Protein Nitrogen ◽  
Nitrogen Determination ◽  
True Protein

Abstract Currently, the reference procedure for determination of the "protein" content of milk is based on measurement of the total nitrogen content of milk by the Kjeldahl method (AOAC method, 920.105). About 6% of the total nitrogen content of milk Is nonprotein nitrogen. Therefore, total nitrogen multiplied by the conversion factor 6.38 overestimates the true protein content of milk on average by about 6%. In the present study, new direct and Indirect methods were developed for measurement of the true protein content of whole milk by Kjeldahl nitrogen determination. Both new methods are sample preparation procedures used to fractionate the nitrogen-containing compounds In milk prior to measurement of the nitrogen content of these fractions by Kjeldahl analysis. The collaborative study consisted of 9 pairs of blind duplicate milk samples that were analyzed for total nitrogen, nonprotein nitrogen, and protein nitrogen by each of 10 laboratories. Both methods for true protein measurement (direct and Indirect) gave acceptable statistical performance characteristics and good agreement between methods. The new direct method requires about half the laboratory analysis work of the indirect method (i.e., total minus nonprotein nitrogen). The methods have been adopted official first action by AOAC as (1) a new method for nonprotein nitrogen determination in milk, (2) a new method (direct) for determination of protein nitrogen content of milk, and {3) an alternative method (indirect) for determination of protein nitrogen content of milk.

Total nitrogen, nonprotein nitrogen, and protein content in largemouth bass (Micropterus salmoides) with reference to quantitative protein estimates

1972 ◽  
Vol 50 (12) ◽  
pp. 1607-1610 ◽  
Author(s):  
A. J. Niimi
Keyword(s):  
Body Weight ◽  
Nitrogen Content ◽  
Protein Content ◽  
Total Nitrogen ◽  
Largemouth Bass ◽  
Micropterus Salmoides ◽  
Total Nitrogen Content ◽  
Nonprotein Nitrogen ◽  
Feeding Level

Nonprotein nitrogen (NPN) content in largemouth bass accounted for 9% of the total nitrogen content. This level was influenced by feeding level and probably body weight. A consideration for NPN is essential for quantitative protein estimates.

SEROLOGICAL EFFECTS OF ETHIONINE IN THE RABBIT

1954 ◽  
Vol 32 (2) ◽  
pp. 126-130 ◽  
Author(s):  
Christine E. Rice ◽  
P. Boulanger ◽  
E. Annau
Keyword(s):  
Body Weight ◽  
Protein Synthesis ◽  
Serum Albumin ◽  
Nitrogen Content ◽  
Guinea Pigs ◽  
Total Serum Protein ◽  
Total Serum ◽  
Serum Complement ◽  
Nonprotein Nitrogen ◽  
Normal Limits

In relation to body weight, rabbits were found to tolerate a much lower dosage of ethionine than guinea pigs. Serum complement titers fell, however, even in rabbits receiving small daily doses of ethionine, an indication of a basal disturbance in the processes of protein synthesis. Total serum protein values remained within normal limits but globulin tended to increase in relation to albumin, whereas in many of the ethionine-injected guinea pigs previously studied, serum albumin had increased in relation to globulin. In rabbits given 250 mgm. daily doses of ethionine, a definite increase in the nonprotein nitrogen content of the serum was recorded.

SEROLOGICAL EFFECTS OF ETHIONINE IN THE RABBIT

1954 ◽  
Vol 32 (1) ◽  
pp. 126-130
Author(s):  
Christine E. Rice ◽  
P. Boulanger ◽  
E. Annau
Keyword(s):  
Body Weight ◽  
Protein Synthesis ◽  
Serum Albumin ◽  
Nitrogen Content ◽  
Guinea Pigs ◽  
Total Serum Protein ◽  
Total Serum ◽  
Serum Complement ◽  
Nonprotein Nitrogen ◽  
Normal Limits

In relation to body weight, rabbits were found to tolerate a much lower dosage of ethionine than guinea pigs. Serum complement titers fell, however, even in rabbits receiving small daily doses of ethionine, an indication of a basal disturbance in the processes of protein synthesis. Total serum protein values remained within normal limits but globulin tended to increase in relation to albumin, whereas in many of the ethionine-injected guinea pigs previously studied, serum albumin had increased in relation to globulin. In rabbits given 250 mgm. daily doses of ethionine, a definite increase in the nonprotein nitrogen content of the serum was recorded.

scholarly journals Determinations of Nonprotein Nitrogen Content of Cheese Whey

1975 ◽  
Vol 58 (10) ◽  
pp. 1521-1523 ◽  
Author(s):  
S.S.H. Rizvi ◽  
R.V. Josephson
Keyword(s):  
Nitrogen Content ◽  
Cheese Whey ◽  
Nonprotein Nitrogen

scholarly journals Principal Aliphatic Secondary Amines of Burley Tobacco

1970 ◽  
Vol 5 (6) ◽  
Author(s):  
L. Bush
Keyword(s):  
Nitrogen Content ◽  
Plant Tissue ◽  
Steam Distillation ◽  
Secondary Amines ◽  
Basic Medium ◽  
Stem Tissue ◽  
Drying Process ◽  
Leaf Lamina ◽  
Burley Tobacco ◽  
Amine Content

AbstractQuantity and distribution of the principal aliphatic secondary amines - dimethylamine, methylethylamine, diethylamine, and methylpropylamine - varied within plant tissue and among Nicotiana spp. In Burley tobacco the stem tissue had the highest content of these amines and the leaf midrib the lowest. Leaf lamina, roots and seed were intermediate in amine content. Among Nicotiana spp. there was considerable difference in total amine content as well as among the ratios of the amine fractions measured. Amine content of tissue was positively correlated with nitrogen content of tissue and was altered by the drying process of tissue prior to analysis. The amines were not present as free amines or salts but were detected only following steam distillation from a basic medium

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