scholarly journals The Relationships between Somatic Cells and Isoleucine, Leucine and Tyrosine Content in Cow Milk

2019 ◽  
Vol 9 (2) ◽  
pp. 349 ◽  
Author(s):  
Federica Ianni ◽  
Paola Sechi ◽  
Alessandro La Mantia ◽  
Lucia Pucciarini ◽  
Emidio Camaioni ◽  
...  
Keyword(s):  
Amino Acids ◽  
Free Amino Acids ◽  
Free Amino ◽  
Somatic Cells ◽  
Reversed Phase ◽  
Cow Milk ◽  
Phase Method ◽  
Isoleucine Leucine ◽  
Milk Samples ◽  
Group I

The early diagnosis of cow subclinical mastitis represents a pivotal factor for a prompt and adequate animal treatment. Although several methods are available, the somatic cells count (SCC) still remains the elective test directly carried out on milk samples. In mastitis affected cows (even at subclinical stages), altered concentrations of specific metabolites, including free amino acids, is a well-known occurrence. In order to define the relationships between the variation of the unbound amino acids content with the SCC value, a direct ion-pairing reversed-phase method based on the use of the evaporative light-scattering detector (IP-RP-HPLC-ELSD) was applied to 65 cow milk samples. The statistical analysis of variance (ANOVA) was pursued in order to find a correlation between the SCC value and the concentration of isoleucine (Ile), leucine (Leu), valine (Val) and tyrosine (Tyr). Samples were divided in two groups according to their SCC value: Group I comprised all ones with SCC < 400,000 cells/mL; Group II encompassed those with a SCC > 400,000 cells/mL. Statistical analyses highlighted significant differences in the content of the branched-chain amino acids Ile and Leu, between the two groups (p < 0.02* and <0.005**, respectively). This study confirms that a dysmetabolism of certain free amino acids parallels elevated SCC values.

scholarly journals Whey Proteins Characterization, Free Amino Acids Profile and Antimicrobial Study of Some Dairy Drinks based on Milk Serum

2020 ◽  
Author(s):  
Doina Prodan ◽  
Miuța Filip ◽  
Mihaela Vlassa ◽  
Marioara Moldovan ◽  
Rahela Carpa ◽  
...  
Keyword(s):  
Amino Acids ◽  
Free Amino Acids ◽  
Free Amino ◽  
High Performance ◽  
Whey Proteins ◽  
Reversed Phase ◽  
Bacterial Strains ◽  
Isoleucine Leucine ◽  
Milk Serum ◽  
Rp Hplc

The aim of this study was characterization of some dairy drinks based on Milk Serum regarding major whey proteins (WP) and free amino acids (FAAs) using reversed phase high performance liquid chromatographic (RP-HPLC) methods. The studied WP, -lactalbumin (-La), bovine serum albumin (BSA), -lactoglobulin A (-Lg A) and -lactoglobulin B (-Lg B) were separated on Aeris XB-C18 column at 214 nm detection. The RP-HPLC method was validated by selectivity, linearity (R2 &ge;0.99), sensitivity (LOQ, 1.35&ndash;10.08 &micro;g mL&minus;1), accuracy (recovery 96.79-103.07%) and precision (% RSD &le; 4.13%). The total studied WP in studied dairy drinks varied between 1.42 and 3.047 g·L-1. The chromatographic profile of FAAs (aspartic acid, glutamic acid, serine, histidine, arginine, glycine, threonine, alanine, tyrosine, cysteine, tryptophan, methionine, valine, phenylalanine, isoleucine, leucine and lysine) was determined in lyophilized concentrate of Milk Serum by RP-HPLC using pre-column derivatization reaction with orthophthalaldehyde (OPA). The total studied FAAs in studied samples varied between 1.103 and 1.119 mg·g-1. Moreover, the Milk Serum showed bacteriostatic activity against two bacterial strains Escherichia coli and Staphylococcus aureus. The obtained results confirm that dairy drinks based on the Milk Serum constitutes a valuable sources of bioactive components with benefits for human healthy nutrition.

scholarly journals The Relationship between S. aureus and Branched-Chain Amino Acids Content in Composite Cow Milk

Animals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 981 ◽  
Author(s):  
L. Grispoldi ◽  
M. Karama ◽  
F. Ianni ◽  
A. La Mantia ◽  
L. Pucciarini ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid Content ◽  
Branched Chain Amino Acids ◽  
Cow Milk ◽  
Total Amino Acid ◽  
Phase Method ◽  
Microbiological Analysis ◽  
Isoleucine Leucine ◽  
Milk Samples ◽  
Branched Chain

The early diagnosis of mastitis is an essential factor for the prompt detection of the animal for further actions. In fact, if not culled, infected cows must be segregated from the milking herd and milked last, or milked with separate milking units. Besides microbiological analysis, the somatic cell count (SCC) commonly used as predictor of intramammary infection, frequently lead to a misclassification of milk samples. To overcome these limitations, more specific biomarkers are continuously evaluated. The total amino acid content increases significantly in mastitic milk compared to normal milk. S. aureus requires branched-chain amino acids (BCAAs—isoleucine, leucine, and valine) for protein synthesis, branched-chain fatty acids synthesis, and environmental adaptation by responding to their availability via transcriptional regulators. The increase of BCAAs in composite milk has been postulated to be linked to mammary infection by S. aureus. The aim of this work is to demonstrate, by a direct ion-pairing reversed-phase method, based on the use of the evaporative light-scattering detector (IP-RP-HPLC-ELSD), applied to 65 composite cow milk samples, a correlation between the concentration of isoleucine and leucine, and S. aureus load. The correlation coefficient, r, was found to be 0.102 for SCC (p = 0.096), 0.622 for isoleucine (p < 0.0001), 0.586 for leucine (p < 0.0001), 0.013 for valine (p = 0.381), and 0.07 for tyrosine (p = 0.034), standing for a positive correlation between S. aureus and isoleucine and leucine concentration. The link between the content of BCAAs, isoleucine and leucine, and udder infection by S. aureus demonstrated with our study has an important clinical value for the rapid diagnosis of S. aureus mastitis in cows.

scholarly journals Differentiation between Ripening Stages of Iberian Dry-Cured Ham According to the Free Amino Acids Content

Foods ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 82 ◽  
Author(s):  
Ángela Alcazar Rueda ◽  
José Marcos Jurado ◽  
Fernando de Pablos ◽  
Manuel León-Camacho
Keyword(s):  
Amino Acids ◽  
Gas Chromatography ◽  
Free Amino Acids ◽  
Free Amino ◽  
Internal Standard ◽  
Gas Chromatography Mass Spectrometry ◽  
Isoleucine Leucine ◽  
Linear Discriminant ◽  
Ripening Stages ◽  
Dry Cured Ham

In this paper, the differentiation of three ripening stages, postsalting, drying, and cellar, of Iberian dry-cured ham has been carried out according to their free amino acids contents. Eighteen L-amino acids, alanine, 2-aminobutanoic acid, aspartic acid, cysteine, glutamine, glycine, histidine, hydroxyproline, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tyrosine, and valine have been determined by gas chromatography with derivatization with N,O-bis(trimethylsilyl)-trifluoroacetamide. Gas chromatography–mass spectrometry was used to confirm the presence of the eighteen amino acids in the ham samples, and gas chromatography using a DB-17HT column and flame ionization detector was used for quantitative determination. Extraction with a mixture methanol-acetonitrile has been carried out, achieving recoveries in the range 52–164%. Methimazole was used as internal standard. Limits of detection ranged between 7.0 and 611.7 mg·kg−1. Free amino acids have been used as chemical descriptors to differentiate between the ripening stages. Principal component analysis and linear discriminant analysis have been used as chemometric techniques, achieving complete differentiation between the ripening stages. Alanine, tyrosine, glutamine, proline, 2-aminobutanoic acid, cysteine, and valine were the most differentiating amino acids.

The effect of starvation and low nitrogen intakes on the concentration of free amino acids in the blood plasma and on the nitrogen metabolism in sheep

1970 ◽  
Vol 21 (5) ◽  
pp. 723 ◽  
Author(s):  
J Leibholz
Keyword(s):  
Amino Acids ◽  
Free Amino Acids ◽  
Free Amino ◽  
Dry Matter ◽  
Control Diet ◽  
Amino Nitrogen ◽  
Essential Amino Acids ◽  
Isoleucine Leucine ◽  
Plasma Urea ◽  
Low Nitrogen

Crossbred wethers were given a control diet (8 g nitrogen, 730 g dry matter daily) or a low nitrogen diet (0.5 g nitrogen, 520 g dry matter daily) or starved, for a 12 or 20 day experimental period. The concentrations of free serine, glutamine, glycine, alanine, histidine, and arginine in the plasma of the starved sheep decreased significantly while the concentrations of lysine, 3-methylhistidine, and isoleucine increased significantly. The ratio of essential to non-essential amino acids increased from 0.35 to 0.56 in the starved sheep. In sheep on the low nitrogen diet, the ratio of essential to non-essential amino acids in the plasma decreased from 0.40 to 0.27, with significant increases in the concentrations of glutanlic acid, glutamine, glycine, isoleucine, leucine, and 3-methylhistidine. Starvation and the low nitrogen diet both resulted in a reduction of the plasma urea concentrations. Starvation and the low nitrogen diet resulted in a 20-50 % reduction in the flow of saliva and a 40-78% increase in the concentration of total nitrogen. This resulted in no significant change in the daily secretion of nitrogen in the saliva. The concentration of urea in the saliva was increased by 3-54%. The concentrations of individual free amino acids in saliva are reported. The nitrogen content of the rumen was reduced, and after 7 days of starvation or on the low nitrogen diet all rumen nitrogen could be attributed to ammonia and free �-amino nitrogen.

Free Amino Acids in Human Tonsillar Tissue

1975 ◽  
Vol 21 (3) ◽  
pp. 414-417 ◽  
Author(s):  
Yasuyuki Doi ◽  
Akikatsu Kataura
Keyword(s):  
Amino Acids ◽  
Glutamic Acid ◽  
Aspartic Acid ◽  
Butyric Acid ◽  
Free Amino Acids ◽  
Free Amino ◽  
Age Groups ◽  
Isoleucine Leucine ◽  
Amino Butyric Acid ◽  
Pathological Conditions

Abstract Free amino acids in the tonsils of 20 individuals were measured column chromatographically. Those always found in readily detectable amounts included O-phosphoserine, taurine, O-phosphoethanolamine, aspartic acid, hydroxyproline, threonine, serine, glutamic acid, proline, glycine, alanine, α-amino-n-butyric acid, valine, cystine, methionine, isoleucine, leucine, tyrosine, phenylalanine, ornithine, γ-amino-butyric acid, lysine, histidine, and arginine. Results were compared for three clinical pathological groups and for four age groups. Some abnormal values may result from the pathological conditions.

scholarly journals Possibilities for prediction of congenital fetal malformations and chromosomal abnormalities based on the determination of the levels of free amino acids and their nitrogen-containing derivatives in blood plasma of pregnant women

2020 ◽  
pp. 152-158
Author(s):  
L. N. Keda ◽  
A. V. Naumov ◽  
V. YU. Smirnov
Keyword(s):  
Amino Acids ◽  
Blood Plasma ◽  
Pregnant Women ◽  
Free Amino Acids ◽  
Free Amino ◽  
Chromosomal Abnormalities ◽  
Group I ◽  
Fetal Malformations ◽  
In Blood Plasma

Objective: to determine the possibilities for prediction and diagnosis of congenital fetal malformations and chromosomal abnormalities on the basis of the study of the levels of amino acids and their nitrogen-containing derivatives in blood plasma of pregnant women with pathological conditions requiring artificial termination of pregnancy. Material and methods. The content of free amino acids and their nitrogen-containing derivatives was studied in 104 pregnant women having congenital malformations and chromosomal abnormalities in their fetuses at 13-22 weeks` gestation (group I) and 25 women with physiological pregnancy (group II). The amino acid level was determined by the high-performance liquid chromatography method. Results. The levels of 14 out of the 26 studied amino acids in the blood plasma of the pregnant women of group I were statistically higher than those of the women in group II. ROC analysis was used to determine six amino acids (glycine, α-aminobutyric acid, hydroxylysine, glutamic acid, citrulline, serine) and their threshold values which with high accuracy (85.3 %) allow of predicting congenital fetal malformations and chromosomal abnormalities. A prognostic model making it possible to determine high probability of congenital fetal anomalies based on the determination of the concentration of 5-hydroxytryptophan, glycine, asparagine, and serine in blood plasma of pregnant women has been developed. Conclusion. The study of the levels of amino acids and their nitrogen-containing derivatives in plasma of pregnant women at 13-22 weeks` gestation can be used for prenatal diagnosis of congenital fetal malformations and chromosomal abnormalities, as well as used as an additional criterion for making the decision on the necessity for artificial termination of pregnancy upon fetal medical indications.

scholarly journals Reversed-Phase Liquid Chromatographic Profile of Free Amino Acids in Strawberry-tree (Arbutus unedo L.) Honey

2009 ◽  
Vol 92 (4) ◽  
pp. S1145-S1156 ◽  
Author(s):  
Nadia Spano ◽  
Irene Piras ◽  
Marco Ciulu ◽  
Ignazio Floris ◽  
Angelo Panzanelli ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Free Amino Acid ◽  
Free Amino Acids ◽  
Free Amino ◽  
Reversed Phase ◽  
Arbutus Unedo ◽  
Strawberry Tree ◽  
Phase Liquid ◽  
Liquid Chromatographic

Abstract The typical profile of the free amino acids contained in strawberry-tree (Arbutus unedo L.) honey is reported for the first time. An optimized reversed-phase liquid chromatographic (RP-LC) method with phenyl isothiocyanate precolumn derivatization was used. Fourteen free amino acids were identified and quantified in 16 analytical samples. Proline (65.63) was found to be the most abundant free amino acid, followed by glutamic acid (6.49), arginine (5.21), alanine (5.17), and phenylalanine (4.97). The total free amino acid content of strawberry-tree honey (average value, 436 mg/kg) was found to be low in comparison to amounts cited in the literature concerning unifloral honeys. The analytical method was optimized and fully validated in terms of detection and quantitation limits, precision (by testing repeatability and reproducibility), linearity, and bias (by means of recovery tests). The acceptability of the validation protocol results was verified using Horwitz's mathematical model and AOAC guidelines.

scholarly journals Dynamic and migration characteristics of soil free amino acids during the whole growth period of rice after application of milk vetch

2021 ◽  
Author(s):  
Jing Yang ◽  
Yi Lin ◽  
Christopher Rensing ◽  
Liming Zhang ◽  
Biqing Zhou ◽  
...  
Keyword(s):  
Amino Acids ◽  
Free Amino Acids ◽  
Free Amino ◽  
Bacterial Biomass ◽  
Growth Period ◽  
Inhibitory Effect ◽  
Growth Stages ◽  
Isoleucine Leucine ◽  
Total Contribution ◽  
And Migration

Abstract. Free amino acids (FAAs) in soil play an important role in the soil nitrogen cycle and plant nutrition. However, the attributing factors and migration characteristics of free amino acid pools in paddy soils after green manure application during the entire growth period of rice have not been elucidated. In this study, a single application of chemical fertilizer (CK) was used as a control under equal nitrogen, phosphorus and potassium conditions, and different application rates of milk vetch (15 000 kghm−2(CL), 30 000 kghm−2(CM) and 45 000 kg hm−2(CH)) were selected to investigate the dynamic of FAAs concentration and composition in paddy soil. Soil FAAs concentration at different growth stages under the same fertilization treatments was highest at the seedling stage and lowest at the tillering stage. The concentration of threonine, alanine, valine, isoleucine, leucine, phenylalanine was most abundant under different fertilization treatments during the growth period, accounting for 59.42 %–76.46 % of the respective FAAs pool. The application of milk vetch was shown to increase the soil FAAs concentration, especially glutamic acid, which increased by 368.17 %–680.78 %, but excessive application had an inhibitory effect. Soil pH, organic matter, protease, bacterial biomass and community were critical factors affecting the concentration of soil FAAs. Bacteroidetes, Firmicutes and Nitrospirae significantly affected the dynamics of FAAs in bacterial communities, and their total contribution rate was 56.89 %. FAAs displayed significant vertical profile characteristics, and the mobility of serine, glycine and proline was high. Conclusively, the application of milk vetch was able to significantly change the concentration and composition of soil FAAs, which may affect the capture of N by plants.

scholarly journals Evaluation of the Content of Free Amino Acids in Tobacco by a New Liquid Chromatography-Tandem Mass Spectrometry Technique

2015 ◽  
Vol 26 (7) ◽  
Author(s):  
Serban C. Moldoveanu ◽  
Jeff Zhu ◽  
Wayne A. Scott
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Free Amino Acids ◽  
Free Amino ◽  
Amino Acid Level ◽  
Reversed Phase ◽  
Tandem Mass ◽  
Reliable Technique ◽  
The Usa ◽  
Amino Acid Precursors

SummaryThe present study describes a reliable technique for the analysis of free amino acids in tobacco leaf. The levels of amino acids in tobacco are important since they are related to both tobacco quality and the potential generation in cigarette smoke of toxicants having amino acid precursors. Other techniques used in the past for amino acid analysis have various shortcomings that were avoided in the present method. The new method uses HPLC separation and a tandem mass spectrometer for detection with no derivatization step as sample preparation. The separation has been obtained using ion pair HPLC on a reversed phase column that offers excellent chromatographic resolution. The MS/MS detection procedure offers very good sensitivity and positive identification of the analytes. The procedure was fully validated and can be used for the analysis of 24 amino acids. It was applied for the quantitation of amino acids from 16 types of tobacco including flue-cured and Burley, some domestic and some not grown in the USA, two types of Oriental tobacco, and from tobacco of a 3R4F Kentucky reference and a common commercial cigarette. It was shown that the analysis provides useful information regarding the amino acid level variation between tobacco types, between tobacco stalk positions, and between the growing locations of different tobaccos. [Beitr. Tabakforsch. Int. 26 (2015) 334-343]

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