The effect of simazine and cytokinins on potato tuber protein, nitrogen content and yield1,2

1974 ◽  
Vol 17 (3) ◽  
pp. 327-332 ◽  
Author(s):  
J. T. Vigue ◽  
P. H. Li
Keyword(s):  
Potato Tuber ◽  
Nitrogen Content ◽  
Protein Nitrogen ◽  
Tuber Protein

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.

Variation of Total Nitrogen, Non-protein Nitrogen Content, and Types of Alkaloids at Different Stages of Development inErythrina americanaSeeds†

1996 ◽  
Vol 44 (10) ◽  
pp. 2987-2991 ◽  
Author(s):  
R. García-Mateos ◽  
B. Lucas ◽  
M. Zendejas ◽  
M. Soto-Hernández ◽  
M. Martínez ◽  
...  
Keyword(s):  
Nitrogen Content ◽  
Total Nitrogen ◽  
Stages Of Development ◽  
Protein Nitrogen

scholarly journals Heat-induced conformational changes of patatin, the major potato tuber protein

1998 ◽  
Vol 252 (1) ◽  
pp. 66-72 ◽  
Author(s):  
Andre M. Pots ◽  
Harmen H. J. de Jongh ◽  
Harry Gruppen ◽  
Rob J. Hamer ◽  
Alphons G. J. Voragen
Keyword(s):  
Potato Tuber ◽  
Conformational Changes ◽  
Tuber Protein

Biochemical changes in progressive muscular dystrophy. VII. Studies on the biosynthesis of protein and RNA in various cellular fractions of the muscle of normal and dystrophic mice

1968 ◽  
Vol 46 (1) ◽  
pp. 35-41 ◽  
Author(s):  
Uma Srivastava
Keyword(s):  
Nitrogen Content ◽  
Microsomal Protein ◽  
Dystrophic Muscle ◽  
Protein Nitrogen ◽  
Progressive Muscular Dystrophy ◽  
Rna Content ◽  
Disease Protein ◽  
Dystrophic Mice ◽  
Muscle Homogenate

Protein nitrogen content, RNA concentration, and in vivo incorporation of L-[U-14C]leucine into protein and of [2-14C]uridine into RNA of homogenate and various fractions of muscle of normal and dystrophic mice were measured at various stages of the disease. Protein nitrogen content was always lower in dystrophic than in normal muscle, and this became more pronounced with the progress of the disease. Most of the decrease was due to loss of proteins from the myofibrils. RNA content increased in the homogenate, nuclei–myofibrils, supernatant, and microsomes of dystrophic muscle. In the mitochondria of dystrophic muscle, no change was noted compared to controls. The ratio of RNA content to protein in the homogenate, nuclei–myofibrils, supernatant, and microsomes was also greater in dystrophic muscle. It was not changed in dystrophic muscle mitochondria. Incorporation of L-[U-14C]leucine into proteins of dystrophic muscle homogenate and various fractions also increased to variable degrees over that in the controls. It was further observed that mitochondrial and microsomal protein incorporate L-[U-14C]leucine in dystrophic muscle at an increased rate but the disappearance of 14C was even greater, compared to controls.In vivo incorporation of [2-14C]uridine into RNA of dystrophic muscle increased at 30 days', remained the same at 60 days', and declined at 90 days' duration of the disease. Similar results were also obtained in the nuclei–myofibrillar fraction of dystrophic muscle. In all other fractions an increase was noted in incorporation in dystrophic muscle. The incorporation of [2-14C]uridine into RNA in supernatant and microsomes was higher in dystrophic muscle but the disappearance of 14C was greater, compared to controls. It is quite evident in the microsomal fraction at 90 days, where no change in the incorporation is noted in normal and dystrophic animals.

scholarly journals Possibility of Limiting Mineral Fertilization in Potato Cultivation by Using Bio-fertilizer and Its Influence on Protein Content in Potato Tubers

Agriculture ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 442
Author(s):  
Dorota Wichrowska ◽  
Małgorzata Szczepanek
Keyword(s):  
Amino Acids ◽  
Potato Tuber ◽  
Farmyard Manure ◽  
Fertilization Rate ◽  
Organic Fertilizers ◽  
Mineral Fertilizers ◽  
Catch Crop ◽  
Potato Tubers ◽  
Mineral Fertilization ◽  
Tuber Protein

Potato protein is a valuable source of essential plant-derived amino acids, the composition of which is similar to that of chicken egg protein considering the amino acid reference. Many factors used in potato cultivation can modify its composition. The use of bio-fertilizers in potato growing offers a possibility of a better use of minerals from soil and organic sources and reducing the need for mineral fertilizers by activating minerals present in soil. The effect can be to improve not only the potato tuber yield but also the nutritional value. The aim of this study has been to determine the hanges in the content of crude protein and the composition of amino acids in potato tubers, depending on the application of the bio-fertilizer (UGmax), organic fertilizers (pea as a catch crop, straw, and farmyard manure (FYM)) as well as mineral fertilization (100% and 50% of the reference rate). The application of bio-fertilizer significantly increased the content of essential and non-essential amino acids in potato tuber protein. With the half-decreased mineral fertilization rate, bio-fertilizer most effectively increased the content of tyrosine, methionine, asparagine in potato tuber protein in the treatments with FYM or with a catch crop as well as without organic fertilization.

scholarly journals Protein fractions of oats and possibilities of oat utilisation for patients with coeliac disease

2011 ◽  
Vol 22 (No. 4) ◽  
pp. 151-162 ◽  
Author(s):  
I. Capouchová ◽  
J. Petr ◽  
H. Tlaskalová-Hogenová ◽  
I. Michalík ◽  
O. Faměra ◽  
...  
Keyword(s):  
Coeliac Disease ◽  
Nitrogen Content ◽  
Protein Complex ◽  
Total Protein ◽  
Electrophoretic Analysis ◽  
Gluten Free Diet ◽  
Protein Fractions ◽  
Gluten Free ◽  
Protein Nitrogen ◽  
Average Percentage

The applicability was evaluated of 16 different oats species and varieties of different provenance in the coeliac diet in view of the composition of the protein complex and immunological testing during two-year experiments (2001 and 2002). Determination was carried out of total nitrogen content (average of evaluated oats collection in 2001 was 2.21%, in 2002 2.78%), protein nitrogen content (average 2001 1.94%, 2002 2.28%), and crude protein (N × 6.25) content (average 2001 13.80%, 2002 17.37%). The proportions of different protein fractions play a decisive role for the aims of this study because, based on the existing knowledge, coeliacally active protein components are present particularly in the prolamin fraction. The percentage of prolamins (determined by discontinual fractionation after Osborne) in the author’s evaluated collection of oats species and varieties under the conditions of Central Bohemia reached on average 17.68% of the total protein in 2001, and 15.36% in 2002. The average percentage of albumins and globulins of the total protein reached 36.97% in 2001 and 41.04% in 2002, the average percentage of glutelins of the total proteins was 37.61% in 2001 and 34.10% in 2002, and residual was on average 7.55% in 2001 and 8.70% in 2002, respectively, of the total protein. Electrophoretic analysis of reserve (gluten) proteins (SDS-PAGE ISTA) showed in the oats collection evaluated the percentage of LMW + prolamins in the range 56–77% of the total reserve proteins in 2001, and 52–73% in 2002. The results of A-PAGE electrophoretic analysis of prolamin proteins confirmed the presence of α-prolamins, that ranged in the total content of prolamins from 50 to 88% in 2001, and from 77 to 100% in 2002, while β- + γ-prolamins ranged in 2001 from 11 to 49%, and in 2002 from 0 to 22%. These values do not give serious guarantees for the possible utilisation of oats in the gluten-free diet. The results of the immunological evaluation of the amount of prolamins in oats grains using ELISA showed great differences between different varieties and the experimental years. In 2001, 7 oats samples out of 13 evaluated, and in 2002 10 samples out of 12 evaluated were below the limit for the gluten-free diet (10 mg prolamins (gliadins)/100 g of sample dry matter), but the other varieties exceeded the limit, particularly in 2001, very significantly. The results obtained in the evaluated collection of species and varieties of oats revealed a great variability in the structure of the protein complex and in the immunological testing. In addition a significant effect of the year on the results of all analyses was evident. Based on our results, the use of oats in the diet for coeliac disease can be very risky for these reasons.  

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