scholarly journals Applying gas chromatography to monitor extracellular free amino acids content in cultivation medium during lactic acid fermentation

2017 ◽  
Vol 1 (1) ◽  
pp. 27-35
Author(s):  
Antonija Trontel ◽  
Anita Slavica ◽  
Mario Novak ◽  
Nuša Jelovac ◽  
Srđan Novak ◽  
...  
Keyword(s):  
Amino Acids ◽  
Lactic Acid ◽  
Amino Acid ◽  
Free Amino Acid ◽  
Free Amino Acids ◽  
Free Amino ◽  
Lactic Acid Fermentation ◽  
Acid Fermentation ◽  
Demineralized Water ◽  
Mrs Medium

Abstract The aim of this work was the adaptation of a Gas Chromatographic-Flame Ionization Detector (GC-FID) method for detection and quantification of extracellular free amino acids in demineralized water, De Mann Rogosa Sharpe (MRS) medium and corn grits (CG) withdrawn during lactic acid fermentation. In order to analyze free amino acids by the GC-FID method it was necessary to convert free amino acids to volatile compounds. This was accomplished by derivatization of free amino acids with ethylchlor formate in aqueous medium followed by extraction of volatile free amino acid esters with chloroform. It was proven that the combination of derivatization and extraction procedure with developed GC-FID method gave accurate, reproducible and sensitive analytical results. Quantification of 15 (Ala, Gly, Val, Leu, Ile, Phe, Tyr, Trp, Asn, Met, Pro, Lys, His, Asp and Glu) out of 20 ethoxycarbonyl-ethyl esters of free amino acids in demineralized water and MRS medium was achieved by established methods. In corn grits medium all of the above mentioned 15 amino acids, except His, were quantified with this GC-FID method. The established method was efficiently verified in monitoring of extracellular free amino acid concentration during lactic acid production with Lactobacillus rhamnosus DSM 20021T in MRS medium and Lactobacillus amylovorus DSM 20531T in corn grits medium.

Changes in the free amino acids and the biogenic amine contents during lactic acid fermentation of different lupin species

2016 ◽  
Vol 51 (9) ◽  
pp. 2049-2056 ◽  
Author(s):  
Elena Bartkiene ◽  
Vadims Bartkevics ◽  
Janis Rusko ◽  
Vytaute Starkute ◽  
Daiva Zadeike ◽  
...  
Keyword(s):  
Amino Acids ◽  
Lactic Acid ◽  
Biogenic Amine ◽  
Free Amino Acids ◽  
Free Amino ◽  
Lactic Acid Fermentation ◽  
Acid Fermentation

Liver extract and its free amino acids equally stimulate gastric acid secretion

1980 ◽  
Vol 239 (6) ◽  
pp. G493-G496 ◽  
Author(s):  
E. J. Feldman ◽  
M. I. Grossman
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Acid Secretion ◽  
Gastric Acid Secretion ◽  
Free Amino Acid ◽  
Free Amino Acids ◽  
Free Amino ◽  
Liver Extract ◽  
Amino Acid Mixture ◽  
Acid Mixture

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.

scholarly journals Changes in flavor compounds of Aloididae aloidi during enzymatic hydrolysis

2021 ◽  
Vol 233 ◽  
pp. 02040
Author(s):  
Xuting Bai ◽  
Tao Li ◽  
Honglei Zhao ◽  
Xuepeng Li ◽  
Wenhui Zhu ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Enzymatic Hydrolysis ◽  
Free Amino Acid ◽  
Free Amino Acids ◽  
Free Amino ◽  
Flavor Compounds ◽  
Peptide Analysis ◽  
Soluble Peptide ◽  
Maximum Value

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.

scholarly journals Effect of Different Edaphic Crop Conditions on the Free Amino Acid Profile of PH-16 Dry Cacao Beans

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 ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Glutamic Acid ◽  
Free Amino Acid ◽  
Free Amino Acids ◽  
Free Amino ◽  
Principal Component ◽  
Amino Acid Profile ◽  
Gamma Aminobutyric Acid ◽  
Significant Difference

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.

Free Amino Acid and Haemolymph Concentration Changes in Sphaeroma Rugicauda (Isopoda) During Adaptation to a Dilute Salinity

1969 ◽  
Vol 50 (2) ◽  
pp. 319-326
Author(s):  
R. R. HARRIS
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Free Amino Acid ◽  
Free Amino Acids ◽  
Free Amino ◽  
Sea Water ◽  
Protein Nitrogen ◽  
Body Sodium ◽  
Concentration Changes ◽  
Total Body

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.

scholarly journals The Effect of Mineral Nutrition on the Content of Free Amino Acids and Amides in Tomato Plants I A Comparison of the Effects of Deficiencies of Copper, Zinc, Manganese, Iron, and Molybdenum

1956 ◽  
Vol 9 (4) ◽  
pp. 539 ◽  
Author(s):  
JV Possingham
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Free Amino Acid ◽  
Mineral Nutrition ◽  
Free Amino Acids ◽  
Free Amino ◽  
Quantitative Estimation ◽  
Acid Fraction ◽  
Tomato Plants ◽  
Copper Zinc

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.

scholarly journals Free Amino Acids in Peanuts as Affected by Seed Size and Storage Time1

1981 ◽  
Vol 8 (2) ◽  
pp. 113-116 ◽  
Author(s):  
Harold E. Pattee ◽  
Clyde T. Young ◽  
Francis G. Giesbrecht
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Free Amino Acid ◽  
Seed Size ◽  
Free Amino Acids ◽  
Free Amino ◽  
Storage Conditions ◽  
Commercial Source ◽  
And Storage

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.

EFFECT OF CORTISOL TREATMENT ON FREE AMINO ACID LEVELS IN RATS

1973 ◽  
Vol 59 (1) ◽  
pp. 57-63 ◽  
Author(s):  
W. DE LOECKER ◽  
M. L. STAS
Keyword(s):  
Skeletal Muscle ◽  
Amino Acids ◽  
Amino Acid ◽  
Free Amino Acid ◽  
Protein Turnover ◽  
Free Amino Acids ◽  
Free Amino ◽  
Experimental Period ◽  
Amino Acid Levels ◽  
Amino Acid Concentrations

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.

Changes in tissue nitrogen and phosphorus and foliar free amino acids in autumn olive, black locust, American sycamore, and honey locust during autumn

1993 ◽  
Vol 23 (4) ◽  
pp. 665-672 ◽  
Author(s):  
Christoph S. Vogel ◽  
Jeffrey O. Dawson
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Free Amino Acid ◽  
Free Amino Acids ◽  
Free Amino ◽  
Black Locust ◽  
Autumn Olive ◽  
Honey Locust ◽  
Amino Acid Contents ◽  
Tissue Nitrogen

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.

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