Decapterus Maruadsi Research Articles

Purification of an iron-binding peptide from scad (Decapterus maruadsi) processing by-products and its effects on iron absorption by Caco-2 cells.

This work was aimed at producing peptides containing iron-binding capabilities from scad (Decapterus maruadsi) processing by-product with alcalase hydrolysis. The chelating peptides were purified by ultrafiltration, immobilized-metal affinity chromatography, gel filtration chromatography, and reversed-phase high-performance liquid chromatography. A novel iron-binding peptide was purified with 1,386.63Da molecular weight and amino acid sequence of QKGTYDDYVEGL. The peptide binds to iron mainly through carboxyl and hydroxyl oxygen bonds. The iron-binding peptide can significantly promote the absorption of inorganic iron in Caco-2 cells. These results have contributed to development of the peptide from scad processing by-products hydrolyzate in iron supplementations. PRACTICAL APPLICATIONS: Iron deficiency is one of the most common and widespread nutritional disorders in the world. Iron-peptide chelates may be suitable for iron-fortification. Our study shows that a peptide purified from scad processing by-product has iron-chelating activity, and significantly increases iron absorption by Caco-2 cells. Hence, this peptide has potential application as a novel carrier for enhancing iron absorption.

Effect of pH shifting on conformation and gelation properties of myosin from skeletal muscle of blue round scads(Decapterus maruadsi)

To clarify the gel formation mechanism of isolated proteins recovered from blue round scads by isoelectric solubilization/precipitation, the physiochemical, conformational and gelation properties of the major protein myosin treated by acidic-(AM) or alkaline-(KM) pH-shifting were investigated and compared with native myosin (NM). The solubility in all myosin samples dropped significantly at 40 °C, with remarkable increases of particle size, turbidity and surface hydrophobicity. Among the samples, AM exhibited the lowest solubility and highest turbidity than NM and KM as the temperature was higher than 40 °C, indicating that AM is easily to be denatured and aggregated. Circular dichroism (CD) analysis showed that both acidic and alkaline pH treatments led to conformational changes of myosin, together with α-helix content variations. When pH was readjusted to neutral, KM recovered its structure similar to NM, while AM failed to refold to its native state. NM exhibited the highest storage modulus (G′) at 90 °C, while AM revealed the lowest G′ value. Furthermore, AM did not change obviously during heating, especially at the gelling temperature range (60–90 °C). These results strongly suggested that acidic treatment led to an irreversible conformational change in myosin, consequently induced a fierce denaturation and aggregation at the initial stage of heating, and eventually led to a complete loss of gel-forming ability. Alkaline pH-shifting, on the other hand is thus more feasible for protein recovery from blue round scads.

Comparison of the Changes in Fatty Acids and Triacylglycerols between <i>Decapterus maruadsi</i> and <i>Trichiurus lepturus</i> during Salt-dried Process

In order to reveal changes in fatty acids and triglycerides during the pickling process of white-fleshed and dark-fleshed fish with high-fat, to compare the changes of triacylglycerols (TAGs) and fatty acids (FAs) in round scad (Decapterus maruadsi, dark-fleshed) and hairtail (Trichiurus lepturus, white-fleshed) during salt-dried processing, ESI-MS/MS and GC-MS techniques were used to quantify. Lipid oxidation was evaluated via peroxide values (POVs), and thiobarbituric reactive substances (TBARS). A total of 31 and 27 FAs, 45 and 44 TAGs were quantified in round scad and hairtail, respectively. DHA (C22:6n3), palmitic acid (C16:0), stearic acid (C18:0), and oleic acid (C18:1n9) were the main FAs in round scad. POO (16:0/18:1/18:1), PPO (16:0/16:0/18:1), POD (16:0/18:1/22:6), and PPaO (16:0/16:1/18:1) were dominant TAGs in both species. Salt-dried processing significantly affected (p < 0.001) 7/5 FAs and 24/29 TAGs in round scad/hairtail. MUFAs changed significantly (p < 0.05) in dark-fleshed round scad; only SFAs and PUFAs changed in white-fleshed hairtail. Both species exhibited near-identical TAG compositions with different variation trends. More significant changes were observed in FAs at the half-dried stages and in TAGs (p < 0.05) at the salted stage. This coincided with the changing stages of POV and TBARS values that also increased significantly (p < 0.05) at the salted stages but peaked at the half-dried stages of both species.

The memory improving effects of round scad (Decapterus maruadsi) hydrolysates on sleep deprivation-induced memory deficits in rats via antioxidant and neurotrophic pathways.

Sleep deprivation negatively influences memory formation and consolidation, which leads to memory impairment associated with oxidative stress and neurotrophic pathways. In this study, a sleep-deprived rat model was used to evaluate the protective effects of round scad hydrolysates (RSH, 333 and 666 mg per kg bw) on memory impairment and the underlying mechanisms. The result of the Morris water maze test revealed that RSH significantly reversed the cognition deficits induced by sleep deprivation. Moreover, RSH supplementation alleviated oxidative stress by increasing the activities of glutathione peroxidase and superoxide dismutase and the ratio of glutathione/oxidized glutathione in the brain. Furthermore, RSH significantly up-regulated the expression of antioxidant defense-related proteins, including nuclear factor E2-related factor 2 (Nrf2) and its downstream heme oxygenase-1 (HO-1), as well as the phosphorylation of Akt in rats. Moreover, RSH improved the expression of brain-derived neurotrophic factor (BDNF), the phosphorylation of cAMP response element-binding (CREB) and tropomyosin-related kinase B (TrkB) in vivo, indicating that RSH can also promote the expression of proteins related to the neurotrophic pathway. Additionally, UPLC-qTOF-MS/MS was further used to identify the peptides in RSH. The results indicated that RSH mainly consists of low molecular weight peptides with hydrophobic, aromatic and positively charged amino acids in sequence. Taken together, these findings demonstrate that RSH exerts memory-improving actions by regulating the antioxidant and neurotrophic pathways, and RSH can be a potential functional ingredient for the prevention and protection of cognitive deficits.

Changes of endogenous enzymes and physiochemical indicators in the process of dry-salted Decapterus maruadsi

ABSTRACTIn order to evaluate the relationship between of endogenous enzymes and physiochemical indicators during the processing of dry-salted Decapterus maruadsi produced by the traditional method. The evolution of the endogenous enzymes (cathepsin B, cathepsin L, cathepsin H, acid lipase, neutral lipase, and phospholipase) and physical and chemical parameters (moisture content, salt content and pH) of dry-salted Decapterus maruadsi during processing were investigated. Principal component analysis and Pearson correlation coefficient analysis were used to explore the main factors influencing the endogenous enzyme activity and the interactions between endogenous enzymes. The following results were observed during the processing of dry-salted Decapterus maruadsi: the salt content could stimulate cathepsin (L and B) activity and inhibit lipase activity; a lower moisture content could inhibit lipase activity, while the inhibitory effect on cathepsin was inconspicuous; pH had a minor influence on the endogenous enzyme activities; cathepsin B and L could partially inhibit lipase activity.

Isolation and characterization of 49 polymorphic microsatellite loci for Decapterus maruadsi using SLAF-seq, and cross-amplification to related species

Decapterus maruadsi is a commercially important species in China, but has been heavily exploited in some areas. There is a growing need to develop microsatellites promoting its genetic research for the adequate management of this fishery resources. The recently developed specific-locus amplified fragment sequencing (SLAF-seq) is an efficient and high-resolution method for genome-wide microsatellite markers discovery. In this study, 28 905 microsatellites (mono- to hexa-nucleotide repeats) were identified using SLAF-seq technology, of which di-nucleotide was the most frequent (13 590, 47.02%), followed by mono-nucleotide (8 138, 28.15%), tri-nucleotide (5 727, 19.81%), tetra-nucleotide (1 104, 3.82%), pentanucleotide (234, 0.81%), and hexa-nucleotide (112, 0.39%). One hundred and thirty-two microsatellite loci (di- and tri-nucleotide) were randomly selected for amplification and polymorphism, of which 49 were highly polymorphic and well-resolved. The average number of alleles per locus was 13.63, ranging from 4 to 25, and allele sizes varied between 110 bp and 309 bp. The observed heterozygosity ( Ho ) and expected heterozygosity ( He ) ranged from 0.233 to 1.000 and from 0.374 to 0.959, with mean values of 0.738 and 0.836, respectively. The polymorphism information content (PIC) ranged from 0.341 to 0.941 (mean=0.806). However, 12 loci deviated from Hardy-Weinberg equilibrium. Furthermore, transferability tests were also successful in validating the utility of the developed markers in five phylogenetically related species of family Carangidae. A total of 48 microsatellite markers were successfully cross-amplified in Decapterus macarellus, Decapterus macrosoma, Decapterus kurroides, Trachurus japonicus, and Selaroides leptolepis. The present microsatellites provided the first known set of microsatellite DNA markers for D. maruadsi, D. macarellus, D. kurroides, and D. macrosoma, and would be useful for further population genetic and molecular phylogeny studies as well as help with the fisheries management formulation and implementation of the understudied species.

Interannual to decadal variability in the catches of small pelagic fishes from China Seas and its responses to climatic regime shifts

Small pelagic fishes such as sardine and anchovy play an important role in marine ecosystem and are affected largely by environmental changes because of their character as r-strategists and their low trophic levels. Small pelagic fishes are crucial targets of Chinese fisheries, accounting for 26% of the total catch in 2014. Their catches show an increasing trend since the 1950s. However, there is still little information on small pelagic species inhabiting Chinese waters. Catch trends and impacts of climatic regime shifts for six typical commercially important small pelagic species, chub mackerel (Scomber japonicus), Japanese scad (Decapterus maruadsi), Pacific herring (Clupea pallasi), Japanese anchovy (Engraulis japonicus), Japanese sardine (Sardinops melanostictus) and horse mackerel (Trachurus japonicus), are analyzed using Chinese Fishery Statistics, FAO data, climatic indices and sea surface temperature (SST) data. The aim is to explore the interannual to decadal variability of their catches in China Seas and their responses to climatic regime shifts. Decadal variability is evident in the catches of the six small pelagic fishes with different variation patterns between warm- and cold-water species. Step changes in catches of the six species were observed in 1976/77, 1986/87, 1995/96, 2001/02 and 2005/06, while regime shifts in climatic/SST indices occurred around 1976/77, the late 1980s and the mid-1990s. This indicates that decadal variations in small pelagic fishes respond strongly to the climatic regime shifts, and the different response patterns of warm- and cold-water species reflect their different life strategies. Marine thermal variation patterns during the period 1981–2000 were well explained by different phase changes in the SSTs between summer and winter and were consistent with the step change in the catches of small pelagic fishes. The double-integration hypothesis, which indicates that cumulative integrations of atmospheric forcing can generate marine population responses, is useful both to understand the process from climate forcing to fish and the controlling mechanism of climate variability on small pelagic fishes in China Seas.

Activities of Endogenous Lipase and Lipolysis Oxidation of Low-Salt Lactic Acid-Fermented Fish (&lt;i&gt;Decapterus maruadsi&lt;/i&gt;)

There is increasing demand for low-salt meat products that retain traditional flavors. In this study, dry-salted fish (Decapterus maruadsi) were processed by 2 methods to obtain traditional salted fish (HS) and low-salt lactic acid-fermented fish (LAF). The relationship between lipolysis and lipid oxidation was investigated by evaluating changes in endogenous lipase (lipolytic enzymes; lipoxygenase, LOX), free fatty acid composition, thiobarbituric acid reactive substances (TBARS), and peroxide value (POV) during processing. Lipolytic enzyme activity showed a decreasing trend, in general. LOX activity initially increased and eventually decreased. Phospholipase, acid lipase, and neutral lipase activity was 0.33, 0.17, 0.57 (in HS) and 0.39, 0.25, 0.67 (in LAF) times in the final product than the activity levels observed in fresh fish. A principal component analysis indicated that phospholipase and neutral lipase play major roles in promoting lipid hydrolysis (in HS and LAF), the correlation between lipolytic activity and lipid oxidation in HS is greater than the correlation in LAF, and the contribution of LOX to lipid oxidation was minor in salted fish.

Assessing Target Strength, Abundance, and Biomass for Three Commercial Pelagic Fish Species along the East Coast of Peninsular Malaysia Using a Split-Beam Echo Sounder

ABSTRACT Hashim, M.; Aziz, M.F.H.A.; Hassan, R.B., and Hossain, M.S., 2017. Assessing target strength, abundance, and biomass for three commercial pelagic fish species along the east coast of Peninsular Malaysia using a split-beam echo sounder. Decapterus maruadsi (round scad), Megalaspis cordyla (torpedo scad), and Selar boops (oxeye scad) are commercially important small pelagic fish species of Malaysia. Despite their commercial and ecological value, little is known about their target strength (TS), spatial and vertical distributions, and biomass estimates. A split-beam acoustic survey was performed in the east coast of Peninsular Malaysia (ECPM) in March–June 2009. The calibrated echo sounder allowed determination of TS, estimation of fish density (spatial distribution) and biomass, and produced density maps along depth gradients (vertical distribution). The TS–length relationships indicated that the logarithmic TS was proportional to the squared length. Additional water parameters that included salini...

Niche and interspecific association of the dominant fish in the south coastal waters of Wenzhou, China

The studies about the niche and interspecific association in China were mainly focused on the plants, birds and marine animals, and seldom on fish. Based on the fishery resources survey in spring (May) and autumn (September) in 2015, the associations among major fish species in south coastal waters of Wenzhou were investigated. The methods including niche breadth, niche overlap, variance ratio (VR), Χ2-test, association coefficient (AC), percentage of co-occurrence (PC) and point correlation coefficients (Ф) were used. The results showed that 47 fish species were identified, including 9 orders, 27 families and 41 genera. Four species were dominant species and 9 were important species, which together accounted for 17%. The niche breadth cluster analysis demonstrated two clearly identifiable ecological niches. The first one referred to wide niche that included Harpodon nehereus, Collichthys lucidus, Engraulis japonicas, Pampus echinogaster, Argyrosomus argentatus, Polynemus sextarius, Decapterus maruadsi and Trichiurus haumela, and the second one was narrow niche that included Muraenesox cinereus, Amblychaeturichthys hexanema, Cunoglossus robustus, Pseudosciaena polyactis and Ilisha elongate. The niche overlap value of the main fish was 0-0.90, indicating that there was difference in the resource utilization among the species. The ecological niche widths of C. robustus and M. cinereus were narrow, and the overlap values were high. This indicated that there was competition between these two species. The VR analysis revealed significant positive correlation among the main fish species. In view of the advantages of Ф value, which could reduce the impact of the analysis results of Χ2-test, AC and PC to the interspecific association, the Ф value method was selected in this study, and the association of 63 couples were positive. Both the interspecific association and ecological niche had different degrees of correlation with the stability of community structure and community succession.

Growth and mortality of exploited fishes in China's coastal seas and their uses for yield-per-recruit analyses

Given the scarcity of information suitable for other forms of fish stock assessments, the growth, and mortality of 10 important marine exploited fishes in China's coastal seas were estimated, based on published length‐frequency data and the ELEFAN approach and software. The resulting parameters, complemented with growth curves from FishBase were then used for yield‐per‐recruit analyses. These 10 species were both traditional commercial species (Trichiurus lepturus, Larimichthys polyactis, Scomber japonicus) and less commercial interest species (Coilia nasus, Engraulis japonicus, Decapterus maruadsi, Psenopsis anomala, Coilia mystus, Setipinna tenuifilis, Harpadon nehereus). The yield‐per‐recruit analyses indicated that the fishing mortality experienced by these 10 fish species was very high, especially in view of the extremely small cod‐end mesh sizes deployed by Chinese trawlers, of about 10 mm or less (vs. 25 mm as minimum legal size). More precisely, all 10 species suffered from growth overfishing, which was very pronounced in large species. Indeed, enlarging cod‐end mesh size, by increasing mean sizes at first capture, would increase yield‐per‐recruit for all 10 fish species by a factor of up to 2.5. Obviously, such increases in mesh size would have to be in tandem with other management measures designed to ensure the sustainability of China's marine fisheries resources.

BIOLOGICAL CHARACTERISTICS OF ROUND SCAD DECAPTERUS MARUADSI (TEMMINCK &amp; SCHLEGEL, 1843) IN THE TONKIN GULF

Biological characteristics of the round scad Decapterus maruadsi (Temminck &amp; Schlegel, 1843) were analyzed using data collected by Vietnam - China Corporation Survey Project for the Marine Fisheries Resources Assessment in the Common Fishing Zone in the Gulf of Tonkin. Biological samples were monthly and randomly collected from the catches of trawl fisheries in Cat Ba island (Hai Phong) and Lach Hoi, Lach Bang (Thanh Hoa province). There were a total of 7,614 individuals of round scad collected in the period from 2012 - 2013. The result showed that the fork length of fish varied in range of 45 - 262 mm with the mean length from 166 - 167 mm. The Von Bertalanffy growth function of round scad was expressed as . Round scad spawned once a year with the spawning season extending from January to April and reaching a peak in March. The estimated length at first maturity (Lm50) was 160.96 mm for female and 161.37 mm for male.

Optimization of Hydrolysis Conditions for the Production of Iron-Binding Peptides from Scad (&lt;i&gt;Decapterus maruadsi&lt;/i&gt;) Processing Byproducts

The scad (Decapterus maruadsi) processing byproduct (SPB) was hydrolyzed by four commercial enzymes, namely, trypsin, flavourzyme, protamex and alcalase, for preparing high Iron-Binding Capacity (IBC) hydrolysate. Alcalase was the best choice for obtaining high IBC hydrolysate from SPB. Response surface methodology using a central-composite design was employed to optimize the enzymatic hydrolysis conditions with alcalase to obtain a maximum hydrolysate yield from the SPB with high iron-binding capacity. The best alcalase hydrolysis conditions were as following: Hydrolysis temperature of 46°C, enzyme substrate ratio of 6040 U/g-protein and hydrolysis time of 66 min, respectively. Under these optimal hydrolysis conditions, the predicted iron-binding capacity was 317.2 µg g-1, which was consistent with the average of three replicates of 296.2 µg g-1 obtained in the validation experiments. The IBC of hydrolysate did not displayed linear relationship with antioxidative ability or the Degree of Hydrolysis (DH). Results indicated that the alcalase hydrolysate from scad processing byproduct can be developed into iron supplant ingredients in functional foods.

Ceratothoa carinata (Isopoda: Cymothoidae) from Japanese scad Decapterus maruadsi in coastal waters of the western North Pacific off central-western Japan

Ceratothoa carinata (Isopoda: Cymothoidae) from Japanese scad Decapterus maruadsi in coastal waters of the western North Pacific off central-western Japan

Growth , Mortality and Relative Yield per Recruit of Japanese Scad Decapterus Maruadsi ( Temminck and Schlegel , 1842 ) in the Gulf of Suez , Red Sea , Egypt

Growth , Mortality and Relative Yield per Recruit of Japanese Scad Decapterus Maruadsi ( Temminck and Schlegel , 1842 ) in the Gulf of Suez , Red Sea , Egypt

Growth , Mortality and Relative Yield per Recruit of Japanese Scad Decapterus Maruadsi ( Temminck and Schlegel , 1842 ) in the Gulf of Suez , Red Sea , Egypt

Growth , Mortality and Relative Yield per Recruit of Japanese Scad Decapterus Maruadsi ( Temminck and Schlegel , 1842 ) in the Gulf of Suez , Red Sea , Egypt

続・"アオアジ"のエ : その正体

続・"アオアジ"のエ : その正体

Preparation of Antioxidant Hydrolysates from Round Scad (&lt;i&gt;Decapterus maruadsi&lt;/i&gt;) Protein by Composite Enzymatic Hydrolysis

Round scad (Decapterus maruadsi) was hydrolyzed by composite enzymatic hydrolysis to obtain the hydrolysates possessing high antioxidant activity. The optimum conditions of antioxidant hydrolysates preparation by composite enzymatic hydrolysis were investigated. The results demonstrated that superior antioxidant activities (low IC50 values of radical scavenging activity and high reducing power) were obtained at an enzyme (a mixture of neutral protease and trypsin, 1:1 w/w) to substrate ratio of 0.3%, an incubation time of 5 h and an incubation temperature of 50 °C. Under the conditions, the recovery ratio of protein was 75.24% and the degree of hydrolysis was 25.86%

Emulsifying Properties of Cross-Linking Between Proteins Extracted from Cold/Hot Pressed Peanut Meal and Hydrolysed Fish (Decapterus Maruadsi) Proteins

The peanut proteins were extracted from cold pressed and hot pressed peanut meal in this work. Emulsifying properties of cross-linking between cold pressed peanut/hot pressed peanut and fish (Decapterus maruadsi) protein hydrolysates catalyzed by transglutaminase were investigated. Electrophoresis indicated that cross-linked proteins were formed in all the transglutaminase-treated samples, and the susceptibility of cold pressed peanut or hot pressed peanut subunits to transglutaminase was enhanced by addition of the (Decapterus maruadsi) protein hydrolysates. For the cross-linked cold pressed peanut-(Decapterus maruadsi) protein hydrolysates and hot pressed peanut-(Decapterus maruadsi) protein hydrolysates protein conjugates, the surface area mean diameter d32, volume mean diameter d43, creaming index, and instability decreased after TGase treatment. Besides, the addition of (Decapterus maruadsi) protein hydrolysates could remedy the disadvantage of essential amino acids (e.g., Thr, Met, and Lys) deficiency in cold pressed or hot pressed peanut. For cold pressed peanut or hot pressed peanut, transglutaminase treatment had no effect on the emulsifying activity but the emulsion stability was improved.

Histamine-producing bacteria in blue scad (Decapterus maruadsi) and their abilities to produce histamine and other biogenic amines

Using decarboxylation medium and 16S rDNA sequence analysis, histamine-producing bacteria (HPB) in blue scad (Decapterus maruadsi) were isolated and identified, and the histamine-producing abilities of the isolated HPB were determined. Nine mesophilic strains (H1-H9) isolated from the muscle of blue scad were identified as the genera of HPB, including Arthrobacter bergeri (H1), Pseudomonas sp. (H2, H5 and H6), Psychrobacter sp. (H3), Shewanella baltica (H4 and H7), and Aeromonas salmonicida (H8 and H9), respectively. Results showed that most of the HPB strains were weak on histamine formation (13.0-20.4 mg/l), except for the H8 strain with the ability of producing 115 mg of histamine/l in trypticase soy broth containing 1.0 % L-histidine. As the strongest HPB in blue scad, bacterial strain H8 also presented a strong ability to produce other biogenic amines, such as putrescine, cadaverine, spermidine, spermine, tyramine and tryptamine. Therefore, the H8 strain identified as the genus of A. salmonicida was the dominant mesophilic HPB strain for producing histamine and other biogenic amines in blue scad at room temperature.