THE ESTIMATION OF FREE AMINO ACIDS USING A MICRODIFFUSION TECHNIQUE

1952 ◽  
Vol 30 (7) ◽  
pp. 522-528 ◽  
Author(s):  
W. B. McConnell
Keyword(s):  
Carbon Dioxide ◽  
Amino Acids ◽  
Free Amino Acids ◽  
Free Amino ◽  
The Other ◽  
Routine Analysis ◽  
Average Deviation ◽  
Substantial Saving ◽  
Ionic Concentrations ◽  
The Mean

The carbon dioxide evolved when α-amino acids were heated for one hour at 85 °C. with ninhydrin was determined in a partially evacuated microdiffusion cell. Distillation of solvent from one chamber to the other was minimized by keeping the ionic concentrations of the reaction mixture and absorbing mixture approximately equal. The method was useful for samples of amino acids which liberated from 0.06 to 0.3 mgm. of carbon dioxide. The average deviation from the mean was somewhat less than 1% for samples liberating 0.2 mgm. of carbon dioxide. Use of the method for routine analysis of enzymatic digests resulted in substantial saving of time and material.

scholarly journals Evaluating the Authenticity of the Raw-Milk Cheese Fontina (PDO) with Respect to Similar Cheeses

Foods ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 350
Author(s):  
Luisa Pellegrino ◽  
Johannes A. Hogenboom ◽  
Veronica Rosi ◽  
Paolo D’Incecco
Keyword(s):  
Amino Acids ◽  
Free Amino Acids ◽  
Free Amino ◽  
Raw Milk ◽  
Manufacturing Processes ◽  
Food Authenticity ◽  
Promising Tool ◽  
Production Area ◽  
The Mean ◽  
Raw Milk Cheese

The implementation of quality assurance schemes for the assessment of PDO food authenticity is an issue involving manufacturers, traders, retailers and consumers. In this respect, reliable analytical methods are needed to integrate paper-trailing information. The feasibility of distinguishing the Italian Fontina PDO cheese from the generic Fontal cheese was preliminarily evaluated on a set of commercial samples by measuring selected parameters (pH, alkaline phosphatase activity, content of copper, volatiles, extent of proteolysis) related to the different manufacturing processes. The relative profile of free amino acids proved to be a promising tool. A new set of 41 samples of Fontina PDO cheese was collected at representative dairies within the recognized production area and analyzed for free amino acids. A chemometric model of Fontina PDO cheese was built based on the mean content and standard deviation of 15 free amino acids. On this basis, all of the PDO samples were correctly identified, whereas all of the Fontal cheeses were recognized as different cheeses.

Free Amino Acids in Plasma and Urine by the Gasometric Ninhydrin-Carbon Dioxide Method

1963 ◽  
pp. 1-13 ◽  
Author(s):  
ELIZABETH G. FRAME ◽  
NEIL Y. CHIAMORI ◽  
PAULINE HALD ◽  
ETHEL CONGER
Keyword(s):  
Carbon Dioxide ◽  
Amino Acids ◽  
Free Amino Acids ◽  
Free Amino

scholarly journals Influence of the Breed of Sheep on the Characteristics of Zamorano Cheese

Dairy ◽  
2021 ◽  
Vol 2 (2) ◽  
pp. 242-255
Author(s):  
Domingo Fernández ◽  
Patricia Combarros-Fuertes ◽  
Erica Renes ◽  
Daniel Abarquero ◽  
José María Fresno ◽  
...  
Keyword(s):  
Amino Acids ◽  
Fatty Acids ◽  
Free Fatty Acids ◽  
Free Amino Acids ◽  
Free Amino ◽  
The Other ◽  
Hydrophobic Peptides ◽  
Protected Designation Of Origin ◽  
Acidity Index ◽  
Ewe's Milk

This work aimed to study the effects of using ewe’s milk from Churra, Assaf, or both breeds on the physicochemical and sensory characteristics of Zamorano cheese at the end of ripening. Zamorano cheese is a hard variety with protected designation of origin (PDO) produced in the province of Zamora (Spain) with raw or pasteurized ewe’s milk. Five batches of Zamorano cheese were produced with pasteurized ewe’s milk. One batch was elaborated using milk from the Churra breed, the other using milk from the Assaf breed, and the remaining three employed milk mixtures of Churra and Assaf breeds in the proportions 75:25, 50:50 and, 25:75, respectively. Cheeses made with a higher proportion of Churra milk showed a predominance of hydrophilic peptides, while hydrophobic peptides predominated in cheeses with a greater percentage of milk from the Assaf breed. The largest content of most free amino acids was found in cheeses produced with the highest percentage of Churra milk. These cheeses presented the highest values for fat acidity index and free fatty acids content and showed greater elasticity and adhesiveness, as well as lower granularity and hardness. In the sensory evaluation, aftertaste and persistence were higher in these cheeses, being scored with the best overall values.

scholarly journals Irradiation of mixed ices as a laboratory cometary model

2008 ◽  
Vol 4 (S251) ◽  
pp. 447-448
Author(s):  
Maria Colin-Garcia ◽  
Alicia Negrón-Mendoza ◽  
Sergio Ramos-Bernal ◽  
Elizabeth Chacon
Keyword(s):  
Carbon Dioxide ◽  
Amino Acids ◽  
Ionizing Radiation ◽  
Carboxylic Acids ◽  
Free Amino Acids ◽  
Free Amino ◽  
Organic Molecules ◽  
Cometary Nuclei ◽  
Icy Bodies

AbstractIcy bodies in space are being irradiated continuously by ionizing radiation. Therefore, the transformation of organic molecules trapped in extraterrestrial ices might have been possible. This work studied a bulk irradiation of a mixture of some constituents of cometary nuclei. The results show that the formation of different compounds, among them ammonia, carbon dioxide, amines, ureas, free amino acids, and oligomeric material, yields carboxylic acids, amino acids, and purines upon hydrolysis.

scholarly journals Characteristics of Free Amino Acids (the Quality Chemical Components of Tea) under Spatial Heterogeneity of Different Nitrogen Forms in Tea (Camellia sinensis) Plants

Molecules ◽  
2019 ◽  
Vol 24 (3) ◽  
pp. 415 ◽  
Author(s):  
Li Ruan ◽  
Kang Wei ◽  
Liyuan Wang ◽  
Hao Cheng ◽  
Liyun Wu ◽  
...  
Keyword(s):  
Amino Acids ◽  
Spatial Heterogeneity ◽  
Root Length ◽  
Free Amino Acids ◽  
Free Amino ◽  
High Performance ◽  
The Other ◽  
Chemical Components ◽  
Split Root System ◽  
Analysis System

Nitrogen (N) forms are closely related to tea quality, however, little is known about the characteristics of quality chemical components in tea under the spatial heterogeneity of different N forms. In this study, a split-root system, high performance liquid chromatography (HPLC), and root analysis system (WinRHIZO) were used to investigate free amino acids (FAAs) and root length of tea plants under the spatial heterogeneity of different N forms. Uniform. (U.) ammonium (NH4+) (both compartments had NH4+), U. nitrate (NO3−) (both compartments had NO3−), Split. (Sp.) NH4+ (one of the compartments had NH4+), and Sp. NO3− (the other compartment had NO3−) were performed. The ranking of total FAAs in leaves were as follows: U. NH4+ > Sp. NH4+/Sp. NO3− > U. NO3−. The FAA characteristics of Sp. NH4+/Sp. NO3− were more similar to those of U. NO3−. The contents of the important FAAs (aspartic acid, glutamic acid, and theanine) that determine the quality of tea, increased significantly in U. NH4+. The total root length in U. NH4+ was higher than that in the other treatments. More serious root browning was found in U. NO3−. In conclusion, NH4+ improved the accumulations of FAAs in tea leaves, which might be attributed to the root development.

Free amino acids in muscle: effect of muscle fiber population and denervation

1990 ◽  
Vol 258 (3) ◽  
pp. E485-E491 ◽  
Author(s):  
J. Turinsky ◽  
C. L. Long
Keyword(s):  
Amino Acids ◽  
Muscle Fiber ◽  
Soleus Muscle ◽  
Free Amino Acids ◽  
Free Amino ◽  
The Other ◽  
Independent Effect ◽  
Slow Twitch Muscle ◽  
Intracellular Concentrations ◽  
Fast Twitch

One hindlimb of each rat was denervated by sectioning the sciatic nerve. Three days later, soleus, plantaris, and gastrocnemius muscles of the sham hindlimb and the contralateral denervated hindlimb were excised and analyzed for intracellular concentrations of 23 free amino acids and the dipeptides carnosine and anserine. Compared with the sham soleus (slow-twitch) muscle, the sham plantaris and gastrocnemius (fast-twitch) muscles showed 57-81% lower concentrations of histidine, glutamine, glutamate, aspartate, and serine and also 32-78% lower levels of taurine, citrulline, phosphoserine, and ornithine. On the other hand the fast-twitch muscles exhibited 31% higher concentrations of free glycine and alanine and 113-127% higher levels of carnosine and anserine than the soleus muscle. The denervation caused greater changes in soleus muscle than in the other two muscles. The denervation-induced changes in soleus muscle included 38-87% increases in concentrations of free valine, leucine, isoleucine, and glutamate associated with 21-56% decreases in the levels of glutamine, glycine, aspartate, serine, alanine, and citrulline. It is concluded that both muscle fiber population and muscle denervation have an independent effect on the intracellular concentrations of free amino acids in muscles.

Hydrolysis of fat and protein in small cheeses made under aseptic conditions

1969 ◽  
Vol 36 (1) ◽  
pp. 65-76 ◽  
Author(s):  
B. Reiter ◽  
Y. Sorokin ◽  
A. Pickering ◽  
A. J. Hall
Keyword(s):  
Amino Acids ◽  
Lactic Acid ◽  
Free Amino Acids ◽  
Free Amino ◽  
Ph Value ◽  
Low Ph ◽  
The Other ◽  
Feeding Regime ◽  
Aseptic Conditions ◽  
Hydrolysis Of

SummaryAseptically drawn milk was made into small cheeses (100 g) under aseptic conditions. The influence of the cow's feeding régime on the composition of the cheese fat, and the hydrolysis of the cheese fat and protein by bacterial and native milk enzymes, was studied.In the absence of a strongly lipolytic bacterial cheese flora, the free fatty acid (FFA) content of cheese appeared to depend on several variables:1. The initial FFA content of the milk varied according to the mode of milking (the lowest was obtained by cannulation of the udder) and the feeding régime of the cow. When one of a pair of monozygotic twin cows was maintained on pasture and the other on winter feed (hay and concentrates), the cheese made from the milk of the latter contained less FFA than did that from the former.2. The major changes in the composition of the milk fat of the cows on winter regime were an increase of myristic and palmitic acids from 8 to 11% and 21 to 28%, respectively, and a decrease in stearic and oleic acid from 11 to 7·5% and 38 to 28%; minor changes in the other fatty acids were also observed.3. The milk lipase in raw milk cheese liberated substantially more FFA than did the weakly lipolytic lactic acid streptococci. Milk lipase was active at the low pH value of cheese, but was inactivated when the milk was pasteurized at 63°C for 30 min.4. Although rennet did not produce any amino acids in the mature cheeses it hydrolysed some of the cheese protein to nitrogen soluble in water (WS), trichloroacetic acid (TCA-S) or phosphotungstic acid (PTA-S). Some of the WS-N appeared to be utilized by the lactic acid streptococci. The native milk protease resisted the heat treatment used and liberated amino acids at the low pH value of cheese, but its contribution to the proteolysis was relatively less important than the contribution of the milk lipase to the fat breakdown in cheese.5. The free amino acids of the milk, which appeared in the whey, were not recovered in the cheese. The cheese made from unheated milk with δ-gluconic acid lactone contained low amounts of free amino acids apparently due to the action of milk protease. The proteolytic activity of the lactic acid bacteria increased the amino acid content appreciably.

Free amino acids of sex organs of the mouse: regulation by androgen

1975 ◽  
Vol 228 (4) ◽  
pp. 1231-1235 ◽  
Author(s):  
CD Kochakian
Keyword(s):  
Amino Acids ◽  
Seminal Vesicle ◽  
Free Amino Acids ◽  
Free Amino ◽  
Testosterone Propionate ◽  
The Other ◽  
Aminobutyric Acid ◽  
Cysteic Acid ◽  
High Concentration ◽  
Vesicle Fluid

Male mice were castrated at 2 mo and a pellet of testosterone propionate was implanted subcutaneously 2 wk later. Mice were killed after 11 days and tissue extracts were analyzed. All the common 20 amino acids were present in widely varying concentrations. Castration uniformly increased the concentration of all free amino acids of the seminal vesicle, excepy proline, cystine/2, and tryptophan; androgen restored values to normal. These changes were not entirely due to changes in quantity of seminal vesicle fluid. Concentrations of amino acids of the prostate were not significantly changed by castration or testosteronepropionate. Fifteen other ninhydrin-postive compounds were detected. Hypotaruine, taurine alpha-aminobutyric acid, and cysteic acid in seminal vesicles were greatly decreased and several other compounds were slightly decreased by castration and restored tp normal by testosterone propionate. In the prostate, hypotaurine, alpha-aminobutyric acid, cysteic/cysteinessulfinic acids, glycerophosphoethaniomine, cystathionine, and phosphoethanolamine were decreased and alpha-amino-n-butyric acid was increased by castration and restored to normal by testosterone propionate. Concentrations of taurine and 5 other compounds were not affected. Epidiymis and testis also contained appreciable pools of amino acids and the other compounds. Amino acids concentrations were lower in cauda than in caput epididymis; in the testis values were intermidate, with much higher concentrations of glutamic and aspartic acids. Taurine concentrations were twice as great in cauda as in caput epidiymis; concentrations of hypotaurine and the other sulfur-containing compounds were similar in both parts of the epidiymis. The most striking result in the testis was the high concentration of reduced glutathione.

THE METABOLISM OF VALERATE-3-C14 AND -5-C14 BY WHEAT STEM RUST UREDOSPORES

1964 ◽  
Vol 42 (3) ◽  
pp. 327-332 ◽  
Author(s):  
H. Reisener ◽  
A. J. Finlayson ◽  
W. B. McConnell
Keyword(s):  
Carbon Dioxide ◽  
Amino Acids ◽  
Glutamic Acid ◽  
Stem Rust ◽  
Phosphate Buffer ◽  
Free Amino Acids ◽  
Free Amino ◽  
Methyl Groups ◽  
Wheat Stem Rust ◽  
Carbon 14

Uredospores of wheat stem rust took up about 90% of the carbon-14 present either as valerate-3-C14 or as valerate-5-C14 in M/30 phosphate buffer pH 6.2 in 3 hours. The initial valerate concentration was 0.017 mM and spores were supplied at the rate of 250 mg/30 ml of buffer. Carbon 3 of the valerate was largely respired as carbon dioxide but carbon 5 was extensively incorporated into spore components. Free amino acids contained about 40% of the radioactivity in the spores labelled with valerate-5-C14 and glutamic acid was highly labelled. Carbon 1 contained 8.1% and carbon 5, 3.8% of the carbon-14 in this glutamic acid and thus internal carbons contained 88%. The results with valerate-3-C14 and with valerate-5-C14 compare well with those of experiments done earlier with propionate-1-C14 and propionate-3-C14 respectively. It is concluded that propionate is formed from carbons 3, 4, and 5 of valerate, and thus that carbon 3 is converted to carbon dioxide, and carbons 4 and 5 to the carboxyl and methyl groups respectively of acetate.

Sign in / Sign up

Export Citation Format

Share Document