scholarly journals Foliar Urea Application in the Fall Affects Both Nitrogen and Carbon Storage in Young `Concord' Grapevines Grown under a Wide Range of Nitrogen Supply

2004 ◽  
Vol 129 (5) ◽  
pp. 653-659 ◽  
Author(s):  
Guohai Xia ◽  
Lailiang Cheng

One-year-old `Concord' grapevines (Vitis labruscana Bailey) were fertigated with 0, 5, 10, 15, or 20 mm N in a modified Hoagland's solution for 8 weeks during summer. Half of the vines fertigated at each N concentration were sprayed with 3% foliar urea twice in late September while the rest served as controls. Four vines from each treatment combination were destructively sampled during dormancy to determine the levels and forms of N and carbohydrates. Nitrogen fertigation during the summer did not significantly alter vine N concentration whereas foliar urea application in the fall significantly increased vine N concentration. In response to foliar urea application, concentrations of both free amino acid-N and protein-N increased, but the ratio of protein-N to free amino acid-N decreased. Arginine was the most abundant amino acid in free amino acids and proteins, and its concentration was linearly correlated with vine N concentration. Concentrations of total nonstructural carbohydrates (TNC) decreased slightly in response to N supply from fertigation. Foliar urea application in the fall significantly decreased TNC concentration at each N fertigation level. Starch, glucose, and fructose decreased in response to foliar urea applications, but sucrose concentration remained unaffected. Approximately 60% of the carbon decrease in TNC caused by foliar urea application was recovered in proteins and free amino acids. We conclude that free amino acids account for a larger proportion of the N in vines sprayed with foliar urea compared with the unsprayed vines, but proteins remain as the main form of N storage. In response to foliar urea application, part of the carbon from TNC is incorporated into proteins and free amino acids, leading to a decrease in the carbon stored in TNC and an increase in the carbon stored in proteins and free amino acids.

HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 827E-828
Author(s):  
Guohai Xia* ◽  
Lailiang Cheng

One-year-old `Concord' vines were fertigated with 0, 5, 10, 15, or 20 mm N in a modified Hoagland's solution for 8 weeks during summer. Half of the vines fertigated at each N concentration were sprayed with 3% foliar urea twice in late September while the rest served as controls. Four vines from each treatment combination were destructively sampled during dormancy to determine the levels and forms of N and carbohydrates. Nitrogen fertigation during the summer only slightly increased vine N concentration whereas foliar urea application in the fall significantly increased vine N concentration. In response to foliar urea application, concentrations of both free amino acid-N and protein-N increased, but the ratio of protein N to amino acid N decreased. Arginine was the most abundant amino acid in free amino acids and proteins, and its concentration was linearly correlated with vine N concentration. Concentrations of total non-structural carbohydrates (TNC) decreased slightly in response to N supply from fertigation. Foliar urea application in the fall significantly decreased TNC concentration at each N fertigation level. Starch, glucose and fructose decreased in response to foliar urea applications, but sucrose concentration remained unaffected. Approximately 60% of the carbon decrease in TNC caused by foliar urea application was recovered in proteins and free amino acids. We conclude that free amino acids account for a larger proportion of the N in vines sprayed with foliar urea, but proteins remain as the main form of N storage. In response to foliar urea application, part of the carbon from TNC is incorporated into proteins and free amino acids, leading to a decrease in the carbon stored in TNC and an increase in the carbon stored in proteins and free amino acids.


1980 ◽  
Vol 239 (6) ◽  
pp. G493-G496 ◽  
Author(s):  
E. J. Feldman ◽  
M. I. Grossman

Using intragastric titration in dogs with gastric fistulas, dose-response studies were carried out with liver extract and with a mixture of amino acids that matched the free amino acids found in liver extract. All solutions were adjusted to pH 7.0 and osmolality to 290 mosmol x kg-1. Doses are expressed as the sum of the concentrations of all free amino acids. At each dose studied (free amino acid concentration: 2.8, 5.6, 11, 23, and 45 mM), acid secretion in response to the free amino acid mixture was not significantly different from that of liver extract. The peak response to both liver extract and the free amino acid mixture occurred with the 23-mM dose and represented about 60% of the maximal response to histamine. The serum concentrations of gastrin after liver extract and the amino acid mixture were not significantly different. It is concluded that in dogs with gastric fistula, gastric acid secretion and release of gastrin were not significantly different in response to liver extract and to a mixture of amino acids that simulated the free amino acid content of liver extract.


2021 ◽  
Vol 233 ◽  
pp. 02040
Author(s):  
Xuting Bai ◽  
Tao Li ◽  
Honglei Zhao ◽  
Xuepeng Li ◽  
Wenhui Zhu ◽  
...  

Protamex was selected to prepare the hydrolysate. E-tongue, free amino acid combined with soluble peptide analysis were used to detect the flavor changes of Aloididae aloidi during enzymolysis. Degree of proteolysis increased with the prolongation of enzymolysis time, and reached the maximum value at 8 hours. The content of soluble peptide of hydrolysate increased firstly and then decreased in the later process. The E-tongue could effectively distinguish the taste difference of hydrolysates at different enzymolysis time, and the hydrolysate presented strong bitterness and astringency during the whole enzymolysis. The total amount of free amino acids in the hydrolysate increased gradually, and some sweet, umami and bitter amino acids increased in varying degrees during the process of enzymolysis.


Agronomy ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1637
Author(s):  
Quintino Reis de Araujo ◽  
Guilherme Amorim Homem de Abreu Loureiro ◽  
Cid Edson Mendonça Póvoas ◽  
Douglas Steinmacher ◽  
Stephane Sacramento de Almeida ◽  
...  

Free amino acids in cacao beans are important precursors to the aroma and flavor of chocolate. In this research, we used inferential and explanatory statistical techniques to verify the effect of different edaphic crop conditions on the free amino acid profile of PH-16 dry cacao beans. The decreasing order of free amino acids in PH-16 dry cacao beans is leucine, phenylalanine, glutamic acid, alanine, asparagine, tyrosine, gamma-aminobutyric acid, valine, isoleucine, glutamine, lysine, aspartic acid, serine, tryptophan, threonine, glycine. With the exception of lysine, no other free amino acid showed a significant difference between means of different edaphic conditions under the ANOVA F-test. The hydrophobic free amino acids provided the largest contribution to the explained variance with 58.01% of the first dimension of the principal component analysis. Glutamic acid stands out in the second dimension with 13.09%. Due to the stability of the biochemical profile of free amino acids in this clonal variety, it is recommended that cacao producers consider the genotype as the primary source of variation in the quality of cacao beans and ultimately the chocolate to be produced.


1969 ◽  
Vol 50 (2) ◽  
pp. 319-326
Author(s):  
R. R. HARRIS

1. Non-protein and protein nitrogen fractions of the isopod Sphaeroma rugicauda were measured in animals adapted to 100 and 2% sea water. 2. The non-protein nitrogen component was reduced in animals acclimatized to the lower salinity. 3. Free amino acids accounted for 88 and 74% respectively of the non-protein nitrogen in the two salinities. 4. In 2% sea water taurine, proline, glycine, alanine and glutamic acid showed the greatest decreases in concentration compared to the levels measured in animals adapted to 100% sea water. 5. The decrease in total free amino acids of animals acclimatized to 100% sea water and transferred to 2% sea water was measured. 6. The total free amino acid concentration is reduced to the 2% sea water level within 12 hr. after transfer. 7. Free amino acid, haemolymph sodium and total body sodium levels after transfer to 2% sea water were compared. 8. The asymmetry between the fall in haemolymph sodium concentration and the decrease in total body sodium under these conditions is thought to be due to a water shift from the haemolymph into the tissues. 9. It is suggested that the osmotic pressure of the cells falls at a slower rate than that of the haemolymph.


1956 ◽  
Vol 9 (4) ◽  
pp. 539 ◽  
Author(s):  
JV Possingham

The lovel and the qllHnj~itat,jve compositien of the free amino acid fraction of tomato plants grown in full nutrient and in cultures doficiollt ill zinc, copper, nlallganeso, iron. and molybdenum have beon cletormiuecl. 'I'he methods used in the investigation inelude the quantitative estimation of amino aeids by a technique involving paper chromatogl'l1phy, and the cultm'o of tomato plants in highly purified n utriollt solutions.


1981 ◽  
Vol 8 (2) ◽  
pp. 113-116 ◽  
Author(s):  
Harold E. Pattee ◽  
Clyde T. Young ◽  
Francis G. Giesbrecht

Abstract Peanuts from a commercial source were segregated into specific seed sizes and placed in storage conditions approximating commercial conditions to determine the amino acid changes taking place during storage within various size seeds. Concentrations of the isolated free amino acid fractions significantly decreased with seed size except for phenylalanine which significantly increased with seed size. Significant changes also occurred in the free amino acid fractions across storage periods up to nine months in duration. These results are the first to document a change in amino acids during the storage of peanuts.


1973 ◽  
Vol 59 (1) ◽  
pp. 57-63 ◽  
Author(s):  
W. DE LOECKER ◽  
M. L. STAS

SUMMARY Changes in the concentrations of free amino acids in intracellular fluids and blood plasma were measured in rats treated with cortisol. Increasing age raised the concentrations of free amino acids in plasma, while in liver, with the exception of glycine and alanine, decreased concentrations were observed. Cortisol treatment reduced free amino acid levels in plasma and liver which suggested a progressive catabolism of body proteins and increased protein synthesis in the liver. In skeletal muscle of control rats the free amino acid concentrations increased during the experimental period. Cortisol increased the concentration of certain amino acids and decreased that of others due to an increased protein turnover in muscle.


1993 ◽  
Vol 23 (4) ◽  
pp. 665-672 ◽  
Author(s):  
Christoph S. Vogel ◽  
Jeffrey O. Dawson

Changes in tissue nitrogen, phosphorus, and foliar free amino acids of four temperate woody deciduous plants (autumn olive (Elaeagnusumbellata Thunb.), black locust (Robiniapseudoacacia L.), American sycamore (Platanusoccidentalis L.), and honey locust (Gleditsiatriacanthos L.)) were determined during the autumns of 1987 and 1988 on two physically and nutritionally distinct sites in central Illinois, United States. The dinitrogen-fixing species, actinorhizal autumn olive (Frankia nodulated) and leguminous black locust (Rhizobium nodulated), resorbed a greater proportion of phosphorus than nitrogen from leaves prior to autumnal leaf abscission in comparison with the nonfixing American sycamore and honey locust. The net autumnal changes in nitrogen or phosphorus of each species did not differ with site in most cases. Free amino acid contents of leaves tended to decline as leaves senesced during the drier autumn of 1987; however, during the autumn of 1988 foliar free amino acid contents tended to increase as the season progressed, with abscised leaves having the greatest contents. Root bark seemed to be a major sink for phosphorus during autumn in the dinitrogen-fixing species, while all of the species investigated showed significant autumnal increases in twig-bark concentrations of nitrogen.


2021 ◽  
Vol 33 (12) ◽  
pp. 2989-2992
Author(s):  
Borche Makarijoski ◽  
Gordana Dimitrovska ◽  
Vesna K. Hristova ◽  
Elena Joshevska ◽  
Mahmoud A. Abdelaziz Mahmoud ◽  
...  

The present work is focussed to determine the Macedonian white brined cheese’s free amino acid profile. Four variants of the Macedonian white brined cheese to analyze and determine free amino acid concentration; cheese samples define the Macedonian white brined cheese as a typical cheese. All free amino acids were specified, except the amino acid tyrosine. The detected amino acids in the tested cheese variants were present in different but approximate parameter values. The estimated essential free amino acids, the concentration of lysine was found highest in all examined samples with values from 26.40 ± 0.02 mg% to 28.20 ± 0.04 mg% and the concentration of threonine was the lowest from 3.19 ± 0.02 mg% to 3.32 ± 0.02 mg%). In the detected unessential free amino acids, the concentration of aspartic amino acid was highest in all the samples with values from 11.02 ± 0.05 mg% to 11.32 ± 0.03 mg% and the concentration of proline was at the lowest level from 4.16 ± 0.06 mg% to 4.22 ± 0.04 mg%.


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