scholarly journals Impact of Short-term Artificial Low Salinity Stress on the Flavor Quality of Scylla Paramamosain

2021 ◽  
Vol 36 (2) ◽  
pp. 179-195
Author(s):  
Tu Chunfei ◽  
Li Xing ◽  
Wang Huan ◽  
Chen Yuhao ◽  
Liang Guoling ◽  
...  

Scylla paramamosain is a kind of large euryhaline marine crab. As an important physicochemical parameter of seawater, salinity has a great impact on the survival, growth and quality of Scylla paramamosain. This research tested the content of non-volatile flavor substance, lactic acid and taurine on the 0, 1st, 3rd, 7th and 15th day in three salinity gradients (3, 13, 23) with HPLC (High-performance Liquid Chromatography) technology. Results have shown that in low salinity stress, the cumulative amount of free amino acids in muscle of Scylla paramamosain is more than that in hepatopancreas, while the cumulative amount of essential amino acids in hepatopancreas is more than that in muscle. In muscle, contents of three flavor amino acids are ranked as follows: sweet, bitter and delicious amino acid, and in hepatopancreas, it is bitter, sweet and delicious amino acid. The fluctuation rule of free amino acid, essential amino acid and lactic acid in Scylla paramamosain in the low salinity group is similar to that of other salinity control group, while the content of sweet amino acid, bitter amino acid, nucleotide, EUC, taurine is different from that of other salinity control groups.

Foods ◽  
2018 ◽  
Vol 7 (9) ◽  
pp. 132 ◽  
Author(s):  
Mehdi Triki ◽  
Ana Herrero ◽  
Francisco Jiménez-Colmenero ◽  
Claudia Ruiz-Capillas

This paper studies the changes that occur in free amino acid and biogenic amine contents of raw meats (beef, pork, lamb, chicken and turkey) during storage (2 °C, 10 days). The meat cuts samples were harvested from a retail outlet (without getting information on the animals involved) as the following: Beef leg (four muscles), pork leg (five muscles), lamb leg (seven muscles), turkey leg (four muscles), and chicken breast (one muscle). Meat composition varied according to meat types. In general, pH, microbiology counts, biogenic amine (BA), and free amino acid (FAA) contents were also affected by meat types and storage time (p < 0.05). Chicken and turkey presented the highest levels (p < 0.05) of FAAs. Total free amino acids (TFAA) were higher (p < 0.05) in white meats than in red ones. The behavior pattern, of the total free amino acids precursors (TFAAP) of Bas, was saw-toothed, mainly in chicken and turkey meat during storage, which limits their use as quality indexes. Spermidine and spermine contents were initially different among the meats. Putrescine was the most prevalent BA (p < 0.05) irrespective of species. In general, chicken and turkey contained the highest (p < 0.05) levels of BAs, and TFAAP of BAs. In terms of the biogenic amine index (BAI), the quality of chicken was the worst while beef meat was the only sample whose quality remained acceptable through the study. This BAI seems to be more suitable as a quality index for white meat freshness than for red meat, especially for beef.


Foods ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 66 ◽  
Author(s):  
Yiyong Chen ◽  
Lanting Zeng ◽  
Yinyin Liao ◽  
Jianlong Li ◽  
Bo Zhou ◽  
...  

Amino acids contribute to the nutritional value and quality of black tea. Fermentation is the most important stage of the black tea manufacturing process. In this study, we investigated protein degradation and proteinaceous amino acid metabolism associated with enzymatic reactions during fermentation in the black tea manufacturing process. The results showed that the concentrations of both protein and free amino acids decreased during fermentation. We also confirmed that proteins were broken down into free amino acids by artificially synthesized dipeptide benzyloxycarbonyl glutamyl-tyrosine (Z-Glu-Tyr). Metabolites of the amino acid metabolic pathway increased significantly during fermentation. Furthermore, we confirmed that free amino acids were degraded to volatile compounds in a tracer experiment with the isotope precursor. These results provide information that will help black tea manufacturers improve the quality of black tea.


2019 ◽  
Vol 48 (4) ◽  
pp. 989-1000
Author(s):  
Long Jiang ◽  
Haiyan Yu ◽  
Dianyuan Chen ◽  
Xiaoming Yu ◽  
Hui Xu ◽  
...  

Composition of free amino acid in waxy maize DH lines was analysed and the nutritional quality of waxy maize germplasm resources was evaluated by o-phthaladehyde (OPA) pre-column derivatization reversed-phase high performance liquid chromatography (HPLC). Results obtained showed that there were at least 14 kinds of free amino acids, DH57 line had the highest (25.185 mg/g), and DH21 line had the lowest (6.203 mg/g) and the average was 12.226 mg/g. The contents of essential amino acids varied from 2.59 to 14.09 mg/g, accounting for 29.55 - 75.64% of the total free amino acids. The quality of free amino acids was evaluated by comprehensive indices with principal component analysis and the first top three DH lines were DH57, DH59 and DH55. The contents of free amino acids in 60 waxy maize DH lines had obvious genetic diversity. As to the free amino acid content, the amino acids quality of DH57, DH59 and DH55 were the best, while DH21 was the worst. Results provide a theoretical guidance for the cultivation of new varieties of waxy maize with good quality.


2021 ◽  
Vol 12 ◽  
Author(s):  
Junwen Wang ◽  
Jing Zhang ◽  
Jing Li ◽  
Mohammed Mujitaba Dawuda ◽  
Basharat Ali ◽  
...  

5-Aminolevulinic acid (ALA) plays an important role in plant growth and development. It can also be used to enhance crop resistance to environmental stresses and improve the color and internal quality of fruits. However, there are limited reports regarding the effects of ALA on tomato fruit color and its regulatory mechanisms. Therefore, in this study, the effects of exogenous ALA on the quality and coloration of tomato fruits were examined. Tomato (Solanum lycopersicum “Yuanwei No. 1”) fruit surfaces were treated with different concentrations of ALA (0, 100, and 200 mg⋅L–1) on the 24th day after fruit setting (mature green fruit stage), and the content of soluble sugar, titratable acid, soluble protein, vitamin C, and total free amino acids, as well as 11 kinds of free amino acid components, intermediates of lycopene synthetic and metabolic pathways, and ALA metabolic pathway derivatives were determined during fruit ripening. The relative expression levels of genes involved in lycopene synthesis and metabolism and those involved in ALA metabolism were also analyzed. The results indicated that exogenous ALA (200 mg⋅L–1) increased the contents of soluble sugars, soluble proteins, total free amino acids, and vitamin C as well as 11 kinds of amino acid components in tomato fruits and reduced the content of titratable acids, thus improving the quality of tomato fruits harvested 4 days earlier than those of the control plants. In addition, exogenous ALA markedly improved carotenoid biosynthesis by upregulating the gene expression levels of geranylgeranyl diphosphate synthase, phytoene synthase 1, phytoene desaturase, and lycopene β-cyclase. Furthermore, exogenous ALA inhibited chlorophyll synthesis by downregulating the genes expression levels of Mg-chelatase and protochlorophyllide oxidoreductase. These findings suggest that supplementation with 200 mg⋅L–1 ALA not only enhances the nutritional quality and color of the fruit but also promotes early fruit maturation in tomato.


2017 ◽  
Vol 1 (1) ◽  
pp. 27-35
Author(s):  
Antonija Trontel ◽  
Anita Slavica ◽  
Mario Novak ◽  
Nuša Jelovac ◽  
Srđan Novak ◽  
...  

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.


1966 ◽  
Vol 44 (11) ◽  
pp. 1447-1459 ◽  
Author(s):  
James E. Stewart ◽  
J. R. Dingle ◽  
P. H. Odense

Electrophoretic and sedimentation analyses were made on the plasma and serum of the hemolymph of the lobster Homarus americanus, and on purified hemocyanin and fibrinogen prepared from these. Amino acid analyses of these two proteins and the plasma, and of the free amino acids of the plasma were also determined. Fibrinogen maintained its function and character upon isolation. It was completely and selectively removed from the plasma by stirring with small amounts of oleic acid. The pH of the hemolymph was 7.6; this was a stable characteristic. The lactic acid in the hemolymph of lobsters held unfed in a disturbing environment at first increased fivefold and then returned to normal; the carbohydrate level remained unchanged.


2020 ◽  
Vol 22 (9) ◽  
pp. 657-662 ◽  
Author(s):  
Mustafa Celik ◽  
Alper Şen ◽  
İsmail Koyuncu ◽  
Ataman Gönel

Aim and Objective:: To determine the mechanisms present in the etiopathogenesis of nasal polyposis. It is not clear whether amino acids contribute in a causal way to the development of the disease. Therefore, the aim of this study was to determine the plasma-free amino acid profile in patients with nasal polyposis and to compare the results with a healthy control group. Materials and Methods:: This was a prospective controlled study that took place in the Otolaryngology Department at the Harran University Faculty of Medicine between April 2017 and April 2018. Plasmafree amino acid profile levels were studied in serum samples taken from a patient group and a healthy control group. Patients who were diagnosed with bilateral diffuse nasal polyposis and were scheduled for surgical interventions were included in this study. Individuals whose age, gender, and body mass index values were compatible with that of the patient group and who did not have any health problems were included in the control group. All the participants whose levels of plasma-free amino acid were thought to be affected by one or more of the following factors were excluded from the study: smoking and alcohol use, allergic rhinitis presence, the presence of acute or chronic sinusitis, a history of endoscopic sinus surgery, unilateral nasal masses, a history of chronic drug use, systemic or topical steroid use in the last three months for any reason, and liver, kidney, hematological, cardiovascular, metabolic, neurological, or psychiatric disorders or malignancies. Results: In patients with nasal polyposis, 3-methyl histidine (3-MHIS: nasal polyposis group (ng) = 3.22 (1.92 – 6.07); control group (cg) = 1.21 (0.77 – 1.68); p = 0.001); arginine (arg: ng = 98.95 (70.81 – 117.75); cg = 75.10 (54.49 – 79.88); p = 0.005); asparagine (asn: ng = 79.84 (57.50 – 101.44); cg = 60.66 (46.39 – 74.62); p = 0.021); citrulline (cit: ng = 51.83 (43.81 – 59.78); cg = 38.33 (27.81 – 53.73); p = 0.038); cystine (cys: ng = 4.29 (2.43 – 6.66); cg = 2.41 (1.51 – 4.16); p = 0.019); glutamic acid (glu: ng = 234.86 (128.75 – 286.66); cg = 152.37 (122.51 – 188.34); p = 0.045); histidine (his: ng = 94.19 (79.34 – 113.99); cg = 74.80 (62.76 – 98.91); p = 0.018); lysine (lys: ng = 297.22 (206.55 – 371.25); cg = 179.50 (151.58 – 238.02); p = 0.001); ornithine (ng = 160.62 (128.36 – 189.32); cg = 115.91 (97.03 – 159.91); p = 0.019); serine (ser: ng = 195.15 (151.58 – 253.07); cg = 83.07 (67.44 – 92.44); p = 0.001); taurine (tau: ng = 74.69 (47.00 – 112.13); cg = 53.14 (33.57 – 67.31); p = 0.006); tryptophan (trp: ng = 52.31 (33.81 – 80.11); cg = 34.44 (25.94 – 43.07); p = 0.005), homocitrulline (ng = 1.75 (1.27 – 2.59); cg = 0.00 (0.00 – 0.53); p = 0.001); norvaline (ng = 6.90 (5.61 – 9.18); cg = 4.93 (3.74 – 7.13); p = 0.021); argininosuccinic acid (ng = 14.33 (10.06 – 25.65); cg = 12.22 (5.77 – 16.87) p = 0.046); and plasma concentrations were significantly higher than in the healthy control group (p <0.05). However, the gamma-aminobutyric acid (gaba: ng = 0.16 (0.10 – 0.24); cg = 0.21 (0.19 – 0.29); p = 0.010) plasma concentration was significantly lower in the nasal polyposis group than in the healthy control group. Conclusion: In this study, plasma levels of 15 free amino acids were significantly higher in the nasal polyposis group than in the healthy control group. A plasma level of 1 free amino acid was found to be significantly lower in the nasal polyposis group compared to the healthy control group. Therefore, it is important to determine the possibility of using the information obtained to prevent the recurrence of the condition and to develop effective treatment strategies. This study may be a milestone for studies of this subject. However, this study needs to be confirmed by further studies conducted in a larger series.


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.


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