scholarly journals Analysis of the basic components and free amino acid composition of pineapple fruit vinegar

2020 ◽  
Vol 185 ◽  
pp. 04047
Author(s):  
Xiao-fang Wang ◽  
Yuhao Hu ◽  
Ji-Hua Li ◽  
Li Zhang ◽  
Xiao Gong ◽  
...  
Keyword(s):  
Amino Acids ◽  
Acetic Acid ◽  
Amino Acid ◽  
Free Amino Acids ◽  
Free Amino ◽  
Acetobacter Aceti ◽  
Acid Fermentation ◽  
Acetic Acid Fermentation ◽  
Acetic Fermentation ◽  
Pineapple Fruit

Acetic acid fermentation is an essential step in producing high-quality vinegar. In this study, the alcoholic medium was used as a seed broth for acetic fermentation using Acetobacter aceti as the inoculum for approximately 7 days at 32℃ to obtain 45.87g/L acetic acid. During the Acetic acid fermentation stage, the content of the total polyphenols decreased first and then increased. Based on amino acid analyzer analysis, pineapple vinegar contains 18 kinds of free amino acids. And the contents of sweet and umami free amino acids are the main free amino acids, followed by bitter amino acids.

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of extracellular free amino acids in demineralized water, De Mann Rogosa Sharpe (MRS) medium and corn grits (CG) withdrawn during lactic acid fermentation.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.

Biochemische Aspekte des Aminosäuren-Stoffwechsels bei Psoriasis vulgaris / Biochemical Aspects of Amino Acid Metabolism in Psoriasis vulgaris

1973 ◽  
Vol 28 (7-8) ◽  
pp. 449-451 ◽  
Author(s):  
G. Peter ◽  
H. Angst ◽  
U. Koch
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Free Amino Acids ◽  
Free Amino ◽  
Amino Acid Metabolism ◽  
Acid Metabolism ◽  
Psoriasis Vulgaris ◽  
Normal Subjects ◽  
Pathological Process

Free and protein-bound amino acids in serum and scales were investigated. In serum the bound amino acids of psoriatics are significantly higher with exception of Pro, Met, Tyr and Phe in contrast to normal subjects. For free amino acids the differences between normal subjects and psoriatics found in serum and scales are not significant. Results are discussed in relation to the single amino acids and the biochemical correlations are outlined which takes the pathological process as a basis.

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.

Effect of Amino Acid Imbalance on Plasma and Tissue Free Amino Acids in the Rat

1968 ◽  
Vol 96 (3) ◽  
pp. 303-318 ◽  
Author(s):  
P. M.-B. Leung ◽  
Q. R. Rogers ◽  
A. E. Harper
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Free Amino Acids ◽  
Free Amino ◽  
Amino Acid Imbalance

Free amino acids in extracts of cultured skin fibroblasts from patients with various amino acid metabolic disorders

2008 ◽  
Vol 7 (5) ◽  
pp. 421-425 ◽  
Author(s):  
Vivian E. Shih ◽  
Roseann Mandell ◽  
Harvey L. Levy ◽  
John W. Littlefield
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Free Amino Acids ◽  
Free Amino ◽  
Metabolic Disorders ◽  
Skin Fibroblasts ◽  
Cultured Skin

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.

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