Suitability of total nitrogen as a predictor of protein content in stream periphyton

2017 ◽  
Vol 36 (3) ◽  
pp. 533-541 ◽  
Author(s):  
Catharina Rose Grubaugh ◽  
John D. Wehr
Keyword(s):  
Protein Content ◽  
Total Nitrogen ◽  
Stream Periphyton

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.

scholarly journals ASSESSMENT OF BARLEY VARIETIES, CULTIVATED IN TATARSTAN, ON CROP PRODUCTIVITY AND GRAIN QUALITY

2018 ◽  
Vol 13 (1) ◽  
pp. 16-20
Author(s):  
Ирина Ганиева ◽  
Irina Ganieva ◽  
Василий Блохин ◽  
Vasiliy Blokhin ◽  
Денис Дюрбин ◽  
...  
Keyword(s):  
Nitrogen Content ◽  
Protein Content ◽  
Total Nitrogen ◽  
Grain Quality ◽  
Weather Conditions ◽  
Crop Productivity ◽  
Hydrothermal Coefficient ◽  
Average Productivity ◽  
Grain Productivity ◽  
Maximum Content

The estimation of Raushan variety of barley and the new Kamazhevsky variety, which was regionalized in Tatarstan in 2017, is given. The experiment revealed the influence of weather conditions and varieties during the years of research (2015-2017), on the formation of grain productivity, the content of total nitrogen in the aboveground mass of plants, the accumulation of protein in grain and gross harvest of protein per hectare. It is noted that the productivity for different years are different, the highest yields of grain of Raushan and Kamashevsky varieties were obtained in 2017 - 4.62 and 5.21 tons per hectare, respectively, when the hydrothermal coefficient was 1.3 units. In comparison with 2015 the productivity of Raushan variety was higher to 1.89 tons per hectare and to 1.69 tons per hectare in 2016. The same pattern was also found in Kamashevsky variety, 1.64 and 1.52 tons per hectare, respectively. The average productivity of Raushan variety for 3 years was 3.43 tons per hectare, less to 0.73 tons per hectare than Kamashevsky. The highest nitrogen content (close to the optimum 4.7-5.1%) in the aboveground mass was found in 2016 in plants of Raushan variety of 4.3%, Kamashevsky variety 4.0%, whereas in 2017 - 2.89% and 3.32%, respectively. The nitrogen content in dry years is higher in the aboveground mass of the Raushan variety, beginning with the tillering phase - 4.3%, Kamashevsky variety - 4.0%. It was revealed that the maximum content of protein in grain grade Kamashevsky accumulate in arid 2015-2016 years - 13.84%, more by 0.95% than the Raushan variety. In 2017 the protein content in the grain was formed at the same level Raushan 11.77%, Kamashevsky 11.07%. Evaluation of varieties on the gross harvest of protein per hectare, shows that the Kamashevsky variety forms on average 5.37 tons per hectare of protein over 3 years, more than Raushan grade by 1.08 tons per hectare.

scholarly journals DIETARY IMPACTS ON EARLY RUMEN MICROBIOTA DEVELOPMENT IN CALVES

2020 ◽  
Vol 21 (1) ◽  
pp. 241-246
Author(s):  
O. I. Shkromada ◽  
L. G. Ulko ◽  
Ya. S. Udovenko
Keyword(s):  
Protein Content ◽  
Total Nitrogen ◽  
Nitrogen Concentration ◽  
Food Additives ◽  
Bacterial Count ◽  
Quantitative Composition ◽  
Paramecium Caudatum ◽  
Rumen Microorganisms ◽  
Number Of Microorganisms ◽  
Experimental Group

The rumen is an important digestive organ in which fermentation processes take place. Improving the rumen development of growing cattle is one of the major tasks. The need for ruminants in amino acids is as great as in mono-gastric animals. The rumen microorganisms cannot synthesize microbial protein in sufficient quantity to cover the need of developmental growth. The experiments were conducted on calves from four to five months of age at the «Za myr» farm in Sumy district, Sumy region. The calves were divided into three experimental groups of 10 animals each. The first experimental group was fed powder not protected methionine at a dose of 10 grams per animal, the second group was fed granulated methionine at a dose of 10 grams per animal for a month. The results suggest that bacterial count increased by 84,3%; Paramecium caudatum by 29,4 %; Entodiniomorpha by 26,6 % in the first experimental group to the 30th day. In the second group the indicators also changed after a month of research. The bacterial count was 93,2 % higher; Paramecium caudatum by 42,5 %; Entodiniomorpha by 25,9 % compared to control. According to the results of the experiment, we can assumed that powder methionine as well as granular had a positive effect on the qualitative and quantitative composition of the rumen microflora. In the first experimental group content of total nitrogen was higher by 12,2 % and protein content by 19,6 % compared to controls. In the second experimental group, where calves were fed a granulated methionine, content of total nitrogen was higher by 15,6 % and protein content by 22,4 % compared to controls. The residual nitrogen concentration significantly decreased by 32,2 % in the first group of calves and by 29,9 % in the second. It was experimentally proved that the enriched of granulated and non-granulated methionine food additives helped to increase the number of microorganisms in the rumen and increase the concentration of nitrogen in the rumen.

Seasonal variations in the total nitrogen, non-protein nitrogen and urea nitrogen contents of Friesian and Jersey milk

1972 ◽  
Vol 39 (1) ◽  
pp. 27-33 ◽  
Author(s):  
A. K. R. McDowell
Keyword(s):  
Protein Content ◽  
Total Nitrogen ◽  
Milk Sample ◽  
Seasonal Variations ◽  
Protein Nitrogen ◽  
Average Value ◽  
Milk Samples ◽  
Analytical Result ◽  
True Protein ◽  
Nitrogen Contents

SummaryA large number of samples (433) from the milk of Friesian herds was taken during the period November 1968 – September 1969, and a smaller number (159) from Jersey herds during the dairy ‘season’ September 1969 – April 1970, and analysed for total nitrogen (TN) and for non-protein nitrogen (NPN). The Friesian milk sample varied in TN from 0·456 to 0·624% (average 0·531 ± 0·021%) and in NPN from 0·024 to 0·054% (average 0·035 ± 0·004%). The Jersey samples varied in TN from 0·467 to 0·718% (average 0·584 ± 0·036%) and in NPN from 0·022 to 0·051% (average 0·033 ± 0·006%).The average NPN value for all the milks was 0·034 ± 0·005%.There was a seasonal trend in NPN and TN for the Jersey and in TN but not in NPN for the Friesian milks. The proportion of NPN as a percentage of TN varied widely – for the Friesian samples from 4·9 to 10·2% (average 6·46%) and for the Jersey samples from 3·7 to 8·7% (average 5·74%).Urea N also was estimated in 125 of the Friesian and in all the Jersey milk samples. It varied from 0·012 to 0·029% (average 0·020 ± 0·004%) in the Friesian and from 0·009 to 0·031% (average 0·020 ± 0·004%) in the Jersey samples. For all the milks the urea N as a percentage of NPN varied from 33 to 79 (average 56·5%).It is suggested that values for ‘protein content’ of milk should refer only to ‘true’ protein ((TN – NPN) × 6·38) and that in the absence of an analytical result for NPN the use of an average value such as that above would be justified.

Analysis of protein content in cereals by total-nitrogen proton activation

1985 ◽  
Vol 91 (2) ◽  
pp. 389-393 ◽  
Author(s):  
B. Constantinescu ◽  
E. Ivanov ◽  
D. Plostinaru ◽  
A. Popa-Nemoiu ◽  
G. Pascovici
Keyword(s):  
Protein Content ◽  
Total Nitrogen ◽  
Proton Activation
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