scholarly journals EFFECT OF FREEZING ON THE FREE AMINO ACIDS IN SOIL

1966 ◽  
Vol 46 (2) ◽  
pp. 115-120 ◽  
Author(s):  
K. C. Ivarson ◽  
F. J. Sowden

Five soils were subjected to temperatures of 1° and −14 °C for 3 weeks. Freezing caused a marked increase in the total amount of free amino acids extracted. The amounts of free amino acids released were greater in soils where decomposition of organic matter was more complete. While prolonged storage of soil at 1 °C had no measurable effect on the free amino acids released, storage over a long period at −14 °C decreased the free amino acid content. Equilibration of wetted soil at room temperature prior to storage at cold temperatures decreased the extractable free amino acids. The data support the contention that part of the effect of soil freezing on the acceleration of microbial activity is due to release of available energy sources.

1964 ◽  
Vol 10 (5) ◽  
pp. 623-631 ◽  
Author(s):  
C. Ramirez ◽  
J. J. Miller

During 6-day exposures of cells of Saccharomyces cerevisiae to acetate sporulation medium, the content of free amino acids declined to approximately one-third of that of vegetative cells, but proline was exceptional in that it increased conspicuously in amount. The content of combined amino acids also diminished to about one-third, ammonia was evolved, and amino acids (not including proline) passed out of the cells into the medium. When dihydroxyacetone replaced acetate in the sporulation medium, the results were similar except that the decline in content of free and combined amino acids was much greater, more ammonia was evolved, and only very small amounts of amino acids could be detected in the medium. Transfer of sporulated cells to growth medium led to an increase in the pool of free amino acids, except for proline, which declined in amount.In two other species of Saccharomyces the free proline content also increased on exposure to sporulation medium, but in Schizosaccharomyces pombe and Torulopsis famata no such increase was observed.


1973 ◽  
Vol 52 (3) ◽  
pp. 418-419 ◽  
Author(s):  
Pan H. Papanayotou ◽  
Joanna Dozi-Vassiliades ◽  
Anast. Kovatsis

By the use of thin layer chromatographic techniques and exchange column chromatography, 20 free amino acids were found in human saliva. No qualitative or semiquantitative differences in the amino acid content were observed among caries-susceptible and caries-resistant individuals 20 to 30 years old.


Foods ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1377
Author(s):  
Lucía Gómez-Limia ◽  
Roxana Cutillas ◽  
Javier Carballo ◽  
Inmaculada Franco ◽  
Sidonia Martínez

This study evaluated the effects of the canning process and different filling media on the free amino acid and biogenic amine contents of eels. The main free amino acids were histidine, taurine and arginine, which constituted 72% of the free amino acids in raw eels. All steps in the canning process significantly altered the free amino acid content of eels, relative to raw samples. The changes were influenced by the step, the composition of the frying or filling medium and the storage time. The biogenic amine contents were very low in all samples. Histamine was not detected in either raw eels or canned eels. The highest values were obtained for 2-phenylethylamine. The step of the canning process, the composition of the frying or filling medium and storage time also determined the changes in the biogenic amine contents. The biogenic amines indices were low, indicating the good quality of canned eels.


2009 ◽  
Vol 5 (2) ◽  
pp. 194-196 ◽  
Author(s):  
Stuart Warwick ◽  
Karim Vahed ◽  
David Raubenheimer ◽  
Stephen J Simpson

Nuptial gifts that are manufactured by the male are found in numerous insect species and some spiders, but there have been very few studies of the composition of such gifts. If, as has been proposed recently, nuptial gifts represent sensory traps, males will be selected to produce gifts that are attractive to females but such gifts will not necessarily provide the female with nutritional benefits (the ‘Candymaker’ hypothesis). We examined the free amino acid content of the spermatophylax of the cricket Gryllodes sigillatus (Orthoptera: Gryllidae) using high performance liquid chromatography (HPLC). The spermatophylax (dry weight) consisted of approximately 7 per cent free amino acids. The free amino acid composition was highly imbalanced, with a low proportion of essential amino acids (18.7%) and a high proportion of proline and glycine. The main free amino acids found in the spermatophylax appeared to act as phagostimulants: the duration of feeding on artificial gels by females was positively related to the free amino acid content of the gels. The results therefore suggest that males use free amino acids to ‘sweeten’ a relatively low-value food item. A possible function of glycine in inhibiting female movement is also proposed.


1972 ◽  
Vol 70 (2) ◽  
pp. 409-416 ◽  
Author(s):  
S. Jaszczak ◽  
E. S. E. Hafez

ABSTRACT Free amino acid content was measured in the uterine fluid and blood serum in the following groups of rabbits 168 h post copulation: intact; intact progesterone-treated; ovariectomized progesterone-treated; ovariectomized progesterone-oestradiol-treated; and ovariectomized without hormonal treatment. At implantation, concentration of the majority of amino acid in uterine fluid exceeded greatly that of blood serum; the difference in concentration being maximal for glycine, taurine, alanine, glutamic acid, aspartic acid, serine and threonine. Glutamine-asparagine and arginine were found in comparable quantities or were even higher in blood serum. Glycine, alanine, taurine, glutamic acid, serine and glutamine-asparagine were found in highest concentration in the uterine fluid. The level of ammonia in uterine fluid was also relatively high. Exogenous progesterone and oestradiol caused significant changes in the concentration of some amino acid. The concentration of glycine, taurine, alanine, serine, glutamic acid, aspartic acid, threonine, ½ cystine and histidine seems to be especially hormonally dependent. The results are discussed in relation to hormonal activity of corpora lutea during early pregnancy, physiological significance of free amino acids in uterine fluid and nourishment of an early embryo.


1968 ◽  
Vol 46 (3) ◽  
pp. 217-223 ◽  
Author(s):  
R. M. Behki ◽  
S. M. Lesley

The concentration of each free amino acid present in hypocotyl tissue of sunflower seedlings was determined during the period following both sterile wounding and inoculation with either tumorigenic (strain 1025) or non-tumorigenic (strain IIBNV6) Agrobacterium tumefaciens. The concentration of the total free amino acids of hypocotyl tissue reached a maximum 68 hours after infection with strain 1025 and this level was 50% greater than that found in plants treated with strain IIBNV6. The total content of free basic amino acids increased to a peak value at 20 hours after infection by strain 1025 and this represented 1.4 to 3 times the level found in strain IIBNV6 inoculated seedlings at 20 hours.The amount of free proline decreased with time and it was essentially absent 164 hours after infection with strain 1025. At 2 months the concentration of free proline in the tumor tissue was greatly increased with 75% of the total free amino acids accounted for as proline.The free amino acid content of strain 1025 growing in either the presence or absence of an extract from wounded seedlings was measured and the results indicated no significant relationship between the plant and bacterial systems with regard to their free amino acid pools.


1956 ◽  
Vol 9 (3) ◽  
pp. 400 ◽  
Author(s):  
RH Hackman

Blood from the larval, prepupal, and early pupal stages of Calliphora augttr' (F.) contains the same 18 free amino acids. In addition, hydroxyproline is present in larval and prepupal blood. The quantitative differenccs in the concent,ratiolls of these amino acids arc reported. Larval blood has the highest free amino acid content (6'6 mgjml) followcd by early pupal blood (4'6 mgjml) and prepnpal blood (3'3 mgjml). As the larva matures to the prepupa, the greatest decreases occm in the concentrations in the blood of alanine, glutamic acid, glutamine, glycine, proline, and tyrosine. The metabolic significance of these changes are discussed.


2018 ◽  
Vol 17 (2) ◽  
pp. 188-194
Author(s):  
Zhao Bing ◽  
Li Su ◽  
Zhou Hui-min ◽  
Zhang Shun-liang ◽  
Wang Hui ◽  
...  

The objective of this study was to investigate the effect of protein oxidation on microbial, free amino acids (FAAs) and biogenic amines (BAs) in Chinese dry sausage during processing. Three different batches of Chinese dry sausages were examined: control batch, pro-oxidation batch and anti-oxidation batch. The experimental results revealed that anti-oxidation batch showed the lowest degree of protein oxidation compared with control batch, while the results of the pro-oxidation batch were just opposite. With the increasing protein oxidation, estimated by protein carbonyls and sulfhydryls, microbial content and free amino acid content increased, while BA content decreased. The protein carbonyls were positively correlated with total FAAs (P < 0.01) and total BA content (P < 0.05), while sulfhydryls content was negatively correlated with total FAA content (P < 0.01), total viable counts (P < 0.01), and total BA content (P < 0.01). In conclusion, reduced protein oxidation contributes to improved quality of Chinese dry sausage. This research provided a new strategy to improve the quality of meat product manufacture.


1975 ◽  
Vol 53 (22) ◽  
pp. 2639-2649 ◽  
Author(s):  
John P. Cherry ◽  
Clyde T. Young ◽  
Larry R. Beuchat

Protein and amino acid composition of peanuts (Arachis hypogaea L.) inoculated with Aspergillus parasiticus Speare were compared with those of non-infected seeds during an 18-day test period to determine metabolic changes within this interrelationship. The levels of buffer-soluble proteins of infected peanuts decreased rapidly to quantities much lower than those of non-infected seeds shortly after inoculation. Simultaneously, the levels of insoluble proteins increased to quantities greater than those contained in soluble fractions. Gel electrophoresis of soluble extracts from inoculated peanuts showed that proteins were hydrolyzed to many small-molecular-weight components, which eventually disappeared as fungal growth progressed. A corresponding increase in quantity of most free amino acids was observed shortly after inoculation of the peanuts. Major changes in free amino acid content coincided with substantial alterations of proteins in both soluble and insoluble fractions. These data suggested that inoculation of peanuts with A. parasiticus initiated a sequence of events whereby proteins were hydrolyzed first to small polypeptides and (or) insoluble components, then to free amino acids. After extended periods of infection, levels of free amino acids varied from day to day, suggesting that differential utilization of these components by the fungus was occurring. Quantities of total amino acids in whole seeds and soluble and insoluble fractions were different for non-inoculated and inoculated peanuts. Distinct differences were especially notable among samples of these three fractions of inoculated seeds. Differences in total amino acid contents apparently reflect qualitative and quantitative changes in proteins and (or) polypeptides present in various fractions examined during the infection period.


Author(s):  
KANCHAN RAWAT RANA ◽  
NIRMALA CHONGTHAM ◽  
MADHO SINGH BISHT ◽  
AJAY PATIAL ◽  
SAVITA VERMA ATTRI

Objective: This study was conducted to assess the amino acid profiles of edible shoots of five species of bamboos growing in various geographical regions of India. Methods: Qualitative and quantitative estimation of free amino acids was done by Reverse Phase-Ultra High Performance Liquid Chromatography (RP-UHPLC). Separation of amino acids was carried out using Zorbax eclipse plus C18 Reverse Phase (1.8 μm), 50 mm × 2.1 mm column on quaternary UHPLC system using modified gradient elution. Derivatization was done by using auto-sampler Agilent’s 1290 infinity. Data assortment and processing were accomplished by using Open Lab Chromatography Data System EZchrome edition, version A.04.06 (Agilent technologies, USA). Results: In the study, 19 free amino acids were identified, eight essential, five conditionally essential, and six non-essential amino acids (EAA). The principal amino acids were tyrosine (29.41–74.64 μg/mg d.w.) and asparagine (12.81–111.04 μg/mg d.w.). The amount of EAAs ranged from 0.46 to 21.11 μg/mg d.w. For the 1st time, taurine and ornithine are reported in bamboo shoots. The analysis exhibited significant variation (p<0.05) in free amino acids content among the five studied species. Of the five species, Phyllostachys mannii was best compared to the other species in amino acid content. Conclusion: Results showed superior amino acid composition of bamboo shoots that can be utilized to improve nutritional value of functional foods. Amino acids have various health and therapeutic properties can contribute to the basis for further expansion of these bamboos and imminent potential in applications of food and pharmaceuticals.


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