scholarly journals The Chemical Composition of Wool II. Analysis of the Major Histological Components Produced by Ultrasonic Disintegration

1965 ◽  
Vol 18 (2) ◽  
pp. 353 ◽  
Author(s):  
JH Bradbury ◽  
GV Chapman ◽  
NLR King

Ultrasonic disruption of powdered Merino wool in formic acid and dichloroacetic acid causes some protein to be dissolved, but the amino acid content of the residual wool is unchanged by the treatment. Cortical cells and disrupted cortical cells are found to have the same composition as the parent fibre, which is to be expected because the latter consists of about 90 % cortical cells. However, the cuticle of Merino wool is different in composition from the parent fibre, being richer in cysteic acid, serine, proline, glycine, valine, and cystine, and poorer in aspartic acid, threonine, glutamic acid, methionine, isoleucine, leucine, tyrosine, phenylalanine, and arginine than the whole fibre. Thus the cuticle is considerably less polar than the fibre as a whole. With the exceptions detailed below, it is found that the first group of amino acids listed above are classified as non a.helix.forming and the second group as a�helix� forming by Blout (1962). The exceptions are isoleucine and threonine, whilst arginine and glycine are not classified. It is therefore postulated that the cuticle is amorphous because of its high content of non a�helix.forming amino acids. The cuticle of Lincoln wool shows similar differences to those already given for Merino cuticle but, in addition, contains less lysine and histidine than the whole fibre.

2012 ◽  
Vol 108 (S2) ◽  
pp. S298-S305 ◽  
Author(s):  
Shane M. Rutherfurd ◽  
Paul J. Moughan

Available amino acids are those absorbed from the gastrointestinal tract in a form suitable for body protein synthesis. True ileal digestible amino acids are determined based on the difference between dietary amino acid intake and unabsorbed dietary amino acids at the terminal ileum. The accuracy of ileal digestible amino acid estimates for predicting available amino acid content depends on several factors, including the accuracy of the amino acid analysis procedure. In heat processed foods, lysine can react with compounds to form nutritionally unavailable derivatives that are unstable during the hydrochloric acid hydrolysis step of amino acid analysis and can revert back to lysine causing an overestimate of available lysine. Recently, the true ileal digestible reactive (available) lysine assay based on guanidination has provided a means of accurately determining available lysine in processed foods. Methionine can be oxidised during processing to form methionine sulphoxide and methionine sulphone and cysteine oxidised to cysteic acid. Methionine sulphoxide, but not methionine sulphone or cysteic acid, is partially nutritionally available in some species of animal. Currently, methionine and cysteine are determined as methionine sulphone and cysteic acid respectively after quantitative oxidation prior to acid hydrolysis. Consequently, methionine and cysteine are overestimated if methionine sulphone or cysteic acid are present in the original material. Overall, given the problems associated with the analysis of some amino acids in processed foodstuffs, the available amino acid content may not always be accurately predicted by true ileal amino acid digestibility estimates. For such amino acids specific analytical strategies may be required.


2021 ◽  
Vol 19 (1) ◽  
pp. 35-43
Author(s):  
Awatsaya Chotekajorn ◽  
Takuyu Hashiguchi ◽  
Masatsugu Hashiguchi ◽  
Hidenori Tanaka ◽  
Ryo Akashi

AbstractWild soybean (Glycine soja) is a valuable genetic resource for soybean improvement. Seed composition profiles provide beneficial information for the effective conservation and utilization of wild soybeans. Therefore, this study aimed to assess the variation in free amino acid abundance in the seeds of wild soybean germplasm collected in Japan. The free amino acid content in the seeds from 316 accessions of wild soybean ranged from 0.965 to 5.987 mg/g seed dry weight (DW), representing a 6.2-fold difference. Three amino acids had the highest coefficient of variation (CV): asparagine (1.15), histidine (0.95) and glutamine (0.94). Arginine (0.775 mg/g DW) was the predominant amino acid in wild soybean seeds, whereas the least abundant seed amino acid was glutamine (0.008 mg/g DW). A correlation network revealed significant positive relationships among most amino acids. Wild soybean seeds from different regions of origin had significantly different levels of several amino acids. In addition, a significant correlation between latitude and longitude of the collection sites and the total free amino acid content of seeds was observed. Our study reports diverse phenotypic data on the free amino acid content in seeds of wild soybean resources collected from throughout Japan. This information will be useful in conservation programmes for Japanese wild soybean and for the selection of accessions with favourable characteristics in future legume crop improvement efforts.


2018 ◽  
Vol 74 (10) ◽  
pp. 5971-2018 ◽  
Author(s):  
PRZEMYSŁAW KNYSZ ◽  
MICHAŁ GONDEK ◽  
RENATA PYZ-ŁUKASIK ◽  
MONIKA ZIOMEK ◽  
ŁUKASZ DROZD ◽  
...  

The aim of the study was to determine the variability in the chemical composition and nutritive value parameters of smoked and unsmoked short-ripened rennet cheeses and unsmoked long-ripened rennet cheeses produced by traditional methods. The raw material for the production of short-ripened cheeses was pasteurized cows’ milk obtained from a dairy, whereas the long-ripened cheeses were manufactured from raw cows’ milk obtained from the producer’s farm. All three varieties of cheese examined were produced with commercial dairy starter cultures. The material for the study was collected in winter, directly at the producers’ retail outlets in southern and eastern Poland. The basic chemical composition was determined according to the Polish Standards, whereas the amino acid profiles of proteins from the cheeses were determined by ion-exchange chromatography. The result analysis revealed significant differences between the different varieties of cheese in terms of their water content, ranging from 32.2% to 42.1%, as well as protein content, which varied from 25.6% to 31.6%. Fat levels ranged between 22.2% and 24%, whereas total ash content amounted to 5.1-5.8%. The significantly highest salt content was found in unsmoked short-ripened cheeses. In all three cheese varieties, the total exogenous amino acid content was comparable, ranging from 46.17 g to 47.36 g/100 g protein, and that of endogenous amino acids varied from 52 g to 53 g/100 g protein. The biological value of proteins was determined by calculating to the chemical score (CS), as described by Mitchell and Block, and the essential amino acid index (EAAI), as described by Oser. A comparison of the results with the standard chicken egg white proteins showed that the limiting amino acids for all varieties of cheese were methionine and cysteine. On the other hand, a comparison with the FAO/WHO-suggested pattern of amino acid requirements (1991) for all age groups over 1 year of age showed that the limiting amino acids were methionine and cysteine in smoked and unsmoked short-ripened cheeses, and treonine in long-ripened cheeses. Considering the chemical indices, such as CS and EAAI, it may be concluded that the traditional rennet cheeses produced in southern and eastern Poland have a favourable amino acid composition of proteins and a high nutritive value..


2017 ◽  
Vol 25 (2) ◽  
pp. 85-90 ◽  
Author(s):  
Anket Sharma ◽  
Vinod Kumar ◽  
Ashwani Kumar Thukral ◽  
Renu Bhardwaj

Abstract Pesticides are applied to protect crops from a variety of insect pests but their application cause toxicity to plants that results, among others, in reduction of protein as well as amino acid contents. The present study is aimed at observing the effect of seed pre-soaking with 24-epibrassinolide (EBL) on the protein and amino acid content in the leaves of Brassica juncea L. grown in soil that is amended with pesticide im-idacloprid (IMI). Soil amendment with IMI resulted in a decrease in the contents in leaves of total proteins and 21 amino acids studied. Seed soaking with 100 nM of EBL resulted in the recovery of total protein as well as amino acid contents in leaves, when compared with plants grown in only IMI amended soils.


Author(s):  
Lata . ◽  
Narender Singh Atri

Objective: In this paper amino acid profile of Lentinus sajor-caju (Fr.) Fr., a basidiomycetous mushroom has been investigated.Methods: During the evaluation 15 amino acids (lysine, aspartic acid, serine, threonine, glutamic acid, cysteine, glycine, alanine, valine, methionine, isoleucine, leucine, tyrosine, phenylalanine and histidine) were determined from the dried sample of Lentinus sajor-caju by following the standard technique of biochemistry using ion-exchange chromatography.Results: The total amino acid content has been evaluated at 18.82 g/100g. Amongst the evaluated amino acids, exogenous amino acid lysine (6.66 g/100g) is preponderantly present in comparison to all other amino acids. The essential amino acid (EAA) index (44.64%) and biological value (BV=36.93%) has also been determined for the examined sample.Conclusion: Lentinus sajor-caju (Fr.) Fr. is a potential source of quality protein with a substantial proportion of exogenous and endogenous amino acids.


1980 ◽  
Vol 35 (11-12) ◽  
pp. 1094-1095
Author(s):  
Rüdiger Riehl

Abstract The oocytes of the marine goby Pomatoschistus minutus were analyzed for their amino acid content. Most of the amino acids exist as protein, only a little part is free or peptide-bound. Among the protein-bound amino acids, high levels of glutamic acid, proline, alanine, aspartic acid, valine and leucine were detected. These represent more than 60% of the protein amino acids. Among the free acids, glutamic acid, serine and alanine, are dominant. There are no certain proofs of the occurrence of peptide pools in the oocytes of Pomatoschistus minutus.


1956 ◽  
Vol 104 (2) ◽  
pp. 183-191 ◽  
Author(s):  
Kenneth E. Lentz ◽  
Leonard T. Skeggs ◽  
Kenneth R. Woods ◽  
Joseph R. Kahn ◽  
Norman P. Shumway

Preparations of hypertensin II, obtained from the treatment of hypertensin I by the action of the hypertensin converting enzyme of plasma and purified by countercurrent distribution, were quantitatively analyzed for their amino acid content. Chromatography on ion exchange columns showed the presence of equimolar amounts of aspartic acid, proline, valine, isoleucine, tyrosine, phenylalanine, histidine, and arginine. Hypertensin I was found to contain one mole of leucine and one mole of histidine in addition to the amino acids of hypertensin II. These two amino acids were isolated from the conversion products of hypertensin I and identified as the peptide histidylleucine. Carboxypeptidase digestion of hypertensin I showed the carboxyl terminal sequence of amino acids to be residue-phenylalanyl-histidylleucine. Similar studies of hypertensin II demonstrated residue-phenylalanine. It was concluded that the conversion of hypertensin I by the plasma hypertensin converting enzyme involved hydrolysis of the phenylalanyl-histidine bond to form hypertensin II and histidylleucine. The further removal by carboxypeptidase of phenylalanine from hypertensin II destroyed all of the vasoconstrictor activity.


Author(s):  
Radha Palaniswamy ◽  
Dhanyasri Selvaraj ◽  
Sandhiya Renganathan

Objective: To determine the protein quality, especially the amino acid content of 8 tropical fruits both raw and boiled samples. Eight different tropical fruits were used in the study (Apricot, Jamun, Dragonfruit, Pomegranate, Mangustan, Litchi, Jackfruit, and Kiwi.Methods: Ninhydrin method was used for the estimation of the concentration of amino acids present in the above fruits. Raw and boiled fruits were used for the study.Results: Both raw and boiled forms which showed thats Jamun and Mangustan contained highest concentration amino acids whereas apricot shows the lowest concentration of amino acids except in Jamun which showed higher values in the raw fruit whereas in others the boiled samples showed higher values.Conclusion: It was evident that tropical fruits have a good balance of the essential amino acids (both raw and boiled fomr) which provide significant sources of protein in our diet.


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.


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