Chemistry of non-enzymic browning. II. Reactions between Amino Acids, Organic Acids, and sugars in freeze-dried Apricots and Peaches

1957 ◽  
Vol 10 (2) ◽  
pp. 182 ◽  
Author(s):  
EFLJ Anet ◽  
TM Reynolds

The water-soluble constituents of apricot and peach purees were examined qualitatively and quantitatively before and after storage for 4 to 16 months at 25 �C and 70 per cent. R.H. All samples contained all the amino acids, organic acids, sugars, and polyols previously detected (Reynolds 1967 ; Anet and Reynolds 1955a, 1966b ; Ash and Reynolds 1955a, 1955b) in the two species of fruit. The stored samples also contained the following compounds : eleven 1-(N-amino acid)-1-deoxyfructoses, traces of two 2-(N-amino acid)-2-deoxyglucoses, nine by-products of unknown constitution formed from the reaction between glucose and aspartic acid and glucose and asparagine, three compounds formed from ammonia and glucose, two series of sucrose, glucose, and fructose mono-esters of malic acid, traces of a sorbitol mono-ester of malic acid, and some sugar mono-esters of citric acid.�The free amino acid or organic acid lost was equal, on a molar basis, to the amino acid-deoxyfructoses (and related compounds) and sugar esters formed. After allowing for these derivatives as much as 7 per cent. of the total sugar (calculated as hexoses) originally present could not be accounted for.

1958 ◽  
Vol 11 (4) ◽  
pp. 575 ◽  
Author(s):  
DL Ingles ◽  
TM Reynolds

1-(N-Amino acid)-1-deoxyfructoses have been determined by elution chromatography on columns of a buffered cation exchange resin following the method described by Moore and Stein (1954a) for the determination of amino acids. This method has been used to determine the free amino acids and ammonia in freeze-dried apricots before and after storage for 12 months at 25 �C and 70 per cent. R.H., as well as to determine the 1-(N-amino acid)-1-deoxyfructoses and related compounds formed (Anet and Reynolds 1957) during storage. The total free amino acid decreased by 61 per cent. and the ammonia by 9 per cent., the changes in individual amino acids ranging from 22 to 81 per cent. The amino acid-deoxyfructoses and related compounds accounted for 90 per cent. of the free amino acid lost, the actual discrepancy being 1.2 mM/100 g dry weight of fruit.


Nature ◽  
1956 ◽  
Vol 177 (4519) ◽  
pp. 1082-1083 ◽  
Author(s):  
E. F. L. J. ANET ◽  
T. M. REYNOLDS

2014 ◽  
Vol 57 (1) ◽  
pp. 149-155 ◽  
Author(s):  
Jerzy W. Poskuta ◽  
Eugeniusz Parys ◽  
Elżbieta Romanowska ◽  
Halina Gajdzis-Gujdan ◽  
Barbara Wróblewska

Roots of whole 3 week-old seedlings of maize were exposed for 24 h to a solution of PbCl<sub>2</sub>. The concentrations of Pb were: 0, 200, 400, 800, 1200, 2400 mg dm<sup>-3</sup>. The amount of Pb taken up by roots was independent of the concentration of this element in the medium. The Pb taken up by shoots increased linearly with increasing treatment concentration. Pb caused: concentration-dependent inhibition of photosynthesis (PS), transpiration (T), <sup>14</sup>CO<sub>2</sub> uptake and incorporation of label into photosynthetic products. The largest limitation by Pb of the flow of photoassimilated carbon occurred into starch and sugar phosphates. Among the water-soluble photoassimilates, the largest limitation of carbon flow occurred into organic acids and sugars and the smallest into amino acids.


2021 ◽  
Vol 6 (1) ◽  
pp. 10-22
Author(s):  
N. Yu. Mezenova ◽  
S. V. Agafonova ◽  
O. Ya. Mezenova ◽  
L. S. Baidalinova ◽  
T. Grimm

Highly mineralized collagen-containing beef raw materials (tibia, fibula and costal bones) are a source of valuable protein nutraceuticals. They include high molecular weight proteins, oligopeptides and amino acids, which anabolic and physiological potential is used insufficiently. Protein nutraceuticals were obtained by high-temperature hydrolysis of beef raw materials in combination with enzymolysis by proteolytic enzyme preparations Alcalase 2,5 L, Protamex, Protosubtilin G3x. The water-soluble fraction of hydrolysates was studied after its separation and freeze-drying on the content of nitrogenous compounds, fats, minerals, formol-titrated nitrogen, fractional molecular composition. The mathematical dependencies of accumulation of low molecular weight products of protein hydrolysis on enzymolysis duration and doses of different enzyme preparations were obtained. The rational technological scheme of complex processing of beef raw materials with production of protein, fat and mineral-protein additives was proposed. The protein weight fraction in the freeze-dried protein hydrolysates was 69.5–89.6%. All studied protein additives contained peptides with a molecular weight of not more than 100 kDa. The content of low-molecular weight oligopeptides with a molecular weight of less than 10 kDa in the protein additives obtained by enzymatic thermal hydrolysis was more than 90%. The amino acid composition of protein additives produced by different hydrolytic methods was analyzed. Sensory and functional-technological properties of freeze-dried protein compositions were studied. The amino acid potential, high assimilability and physiological activity of protein nutraceuticals from collagen-containing beef raw materials were established. It is recommended to use them in the composition of specialized biologically active additives (BAAs) to food of the osteotropic direction in recipes of specialized and personalized products as a source of amino acids and active peptides.


Author(s):  
Valerie Vranová ◽  
Hana Kaňová ◽  
Klement Rejšek ◽  
Pavel Formánek

The aim of this mini-review was to identify the dominant carbohydrates, organic acids and amino ­acids in water-soluble root exudates of plants which represent dominant compounds there. The study is focused on plants of C4-type of metabolism taking into account available literature. From group of carbohydrates, those dominant are represented glucose, fructose, arabinose and sucrose. Between dominant amino acids occurring in root exudates of C4-metabolism plants are alanine, se­rine, arginine, glutamine, glutamic and aspartic acid, glycine, proline, cystine, lysine and g-aminobutyric acid. Citric, malic, tartaric, succinic, trans-aconitic represent the dominant organic acids. This knowledge may be useful for planning analyses of these compounds in root exudates of C4plants. Except for this preparation of synthetic root exudates to simulate rhizosphere of C4plants may be performed based on these results.


Pharmaceutics ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 941
Author(s):  
Melvin Wostry ◽  
Hanna Plappert ◽  
Holger Grohganz

Freeze-drying was evaluated as a production technique for co-amorphous systems of a poorly water-soluble drug. Naproxen was freeze-dried together with arginine and lysine as co-former. To increase the solubility of naproxen in the starting solution, the applicability of five surfactants was investigated, namely sodium dodecyl sulfate, pluronic F-127, polyoxyethylene (40) stearate, tween 20 and TPGS 1000. The influence of the surfactant type, surfactant concentration and total solid content to be freeze-dried on the solid state of the sample was investigated. X-ray powder diffraction and differential scanning calorimetry showed that the majority of systems formed co-amorphous one-phase systems. However, at higher surfactant concentrations, and depending on the surfactant type, surfactant reflections were observed in the XRPD analysis upon production. Crystallization of both naproxen and amino acid occurred from some combinations under storage. In conclusion, freeze-drying was shown to be a feasible technique for the production of a selection of co-amorphous drug–amino acid formulations.


1962 ◽  
Vol 40 (1) ◽  
pp. 459-469 ◽  
Author(s):  
P. H. Jellinck ◽  
Louise Irwin

Aerobic incubation of estrone-16-C14with peroxidase in the presence of serum albumin and other proteins resulted in the formation of water-soluble, ether-insoluble metabolites in high percentage yields. Similar products were formed when protein was replaced by cysteine or tryptophan but none of the other amino acids tested had any effect. The evidence points to an initial generation of hydrogen peroxide from these nitrogenous compounds by the enzyme acting as an aerobic oxidase, and the subsequent peroxidation of estrone to highly reactive products. These then combine with the protein or amino acid or else undergo alternative reactions. A strong chemical bond is formed with albumin and attempts to release the estrone metabolites from it were unsuccessful. Uterine homogenates from estrogen-treated rats showing high DPNH oxidase activity contained no "peroxidase" as measured by the formation of water-soluble products from estrone in the presence of protein.


1957 ◽  
Vol 35 (1) ◽  
pp. 1005-1016 ◽  
Author(s):  
J. B. Derrick ◽  
Audrey P. Hanley

Observations have been made on the specific free amino acids (chromatographic analysis) and other nitrogenous constituents in the serum and urine of normal and arthritic men under controlled dietary conditions, before and after a glycine load and adrenocorticotropin administered separately and together.Differences in the metabolism of amino acids between normal individuals and arthritics, particularly of alanine, proline, glutamic acid, taurine, and possibly tyrosine (and/or tryptophan) and cystine, were apparent. The differences were largely confined to the non-essential amino acids. Concomitant increases seen in the serum levels and in the excretion of several amino acids, in response to a load of a single amino acid, indicate that the increases in excretion are more than a matter of competition for reabsorption in the kidney. A prerenal phenomenon appears to be involved, possibly interconversion of amino acids. This concept is supported by the evidence that the increases in the serum levels were restricted to the non-essential amino acids.


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