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1.
Lantern fish of the species Lampanyctodes hectoris were shown to contain phospholipids (10 g kg?1) and non-phosphorylated lipids (140 g kg?1). The phospholipid fraction consisted of phosphatidyl choline (47% of total phospholipids), phosphatidyl ethanolamine (42%), phosphatidyl serine (3%), phosphatidyl inositol (1%), sphingomyelin (4%), lyso-phosphatidyl choline (1%) and cardiolipins (2%). Lantern fish (L hectoris) meals normally contain unacceptably high lipid contents (150 g kg?1 and over); this characteristic was found not to be due to a high phospholipid level in the lantern fish. The major fatty acid of the phospholipids was C22:6n-3 (25% total fatty acids) followed by C16:0 (18%), C18:ln-9 (16%) and C20:5n-3 (8%). This distribution was different from that of the non-phosphorylated lipids where the major fatty acid was C16:0 (21%) followed by C18:ln-9 (19%), C20:5n-3 (11%), C20:l (7%) and C22:6n-3 (7%). The lantern fish press oil and residual meal lipids had fatty acid distributions similar to those of the non-phosphorylated lipids.  相似文献   

2.
Food Science and Biotechnology - Since octopuses are similar in appearance and can be processed into various forms, seafood fraud has been reported. In this study, we developed the PCR assay to...  相似文献   

3.
The composition of hake flesh and hake liver phospholipids was determined by an hydrolytic procedure and by chromatography on silicic acid. The hydrolytic procedure involved determination of lecithin-choline, sphingornyelin-choline, lyso lecithin-choline, ethanolamine, serine, myo-inositol and the average equivalent weight of the liberated fatty acids. The composition of the flesh and liver phospholipids was very similar, the latter contained more sphingomyelins and cardiolipins at the expense of phosphatidyl choline. Phospholipid fatty acids had a markedly higher equivalent weight and unsaturation than the corresponding non-phosphorylated lipid fatty acids. The cephalin fractions contained more long chain polyunsaturated fatty acids, more stearic acid and less palmitic acid than the phosphatidyl choline fractions. Sphingomyelins were particularly rich in lignoceric and nervonic acid.  相似文献   

4.
Octopus muscle was pressurized at 200, 300 and 400 MPa for 15 min at 7 °C and 40 °C; treatments at 400 MPa continuously for 15 min and in three 5 min pulses at 7 °C and 40 °C were also carried out. Total viable counts of Enterobacteriaceae, Staphylococcus aureus and lactic bacteria, shear strength and autolytic activities were studied. High-pressure treatments reduced colony-forming units (cfu) for all groups tested, especially when applied in pulses at 40 °C, and caused a change of the predominant flora. Autolytic activity clearly decreased when pressure was over 200 MPa. When muscle is pressurized, shear strength increases although it is higher at lower pressures (200 MPa) than at higher pressure (400 MPa). When pressure was applied, morphological and ultrastructural changes were observed, mainly in the variation of fibrillar compacting, destruction of the sarcomere pattern, ultrastructural alteration of the myofibrils and gradual disappearance of the cell nucleus. The connective tissue was virtually unaffected by pressure despite the temperature applied.  相似文献   

5.
Squid (Loligo vulgaris) was found to contain 25 g kg?1 lipids of which approximately 75% were phospholipids. The phospholipids were shown to consist of phosphatidylcholine (56% of total phospholipids), phosphatidylethanolamine (29%), phosphatidylserine (2%), phosphatidylinositol (2%). sphingomyelin (5%), lyso-phosphatidylcholine(3%) and the unusual lipid ceramide aminoethylphosphonic acid (3%). The major saturated fatty acid in both phospholipids and non-phosphorylated lipid was C16:0 (26% and 21%, respectively, of total fatty acids), while the major unsaturated fatty acid in both lipid fractions was C22:6n-3 (34% and 23%, respectively) followed by C20:5n-3 (14% in both lipids).  相似文献   

6.
A comparison has been made between phospholipids extracted from a marine crab and from a fresh water crab. Marine crab (body and viscera) contained a phospholipid fraction which liberated 2-aminoethylphos-phonic acid upon hydrolysis, while this substance was absent from the fresh water crab. Marine crab phospholipids had a higher content of phosphatidyl choline (57%), a higher content of phosphatidyl serine (5%) but a lower content of phosphatidyl ethanolamine (22%) than phospholipids from the fresh water crab (respective values: 52, 2 and 27%). Marine crab phospholipids and non-phosphorylated lipids were richer in C20 plus C22 fatty acids but poorer in C18: 2 acid, than were the corresponding lipids from the fresh water crab.  相似文献   

7.
Critical control points (CCPs) were identified in the risk assessment of octopus ( Octopus vulgaris ) processing and implemented in the hazard analysis critical control point (HACCP) plan. In the hazard analysis worksheet the different hazards were identified at each processing stage, whereas in the HACCP plan each CCP is identified and accompanied with the relevant significant hazard, critical limit, monitoring of the CCP and corrective actions. In this work comparison of ISO 22000 analysis with HACCP is carried out over octopus processing and packaging. ISO 22000 Analysis Worksheet was employed for determination of some prerequisite programmes (PrPs). Comparison between the two systems has been carried out using the hazard analysis worksheet. The PrPs are the main difference between the two systems. The incorporation of PrPs in the ISO 22000 made the system more flexible as a smaller number of CCPs was introduced.  相似文献   

8.
Failure mode and effect analysis (FMEA) model was applied in conjunction with cause-and-effect analysis for the risk assessment of octopus processing ( Octopus vulgaris ). Critical control points were identified and implemented in the cause-and-effect diagram (also known as Ishikawa, tree diagram and fishbone diagram). The main emphasis was put on the quantification of risk assessment by determining the risk priority numbers (RPN) per identified processing hazard. Chemically contaminated product, decomposed raw materials, scombrotoxin presence in the final product, incorrectly labelled product, storage in cans (foreign matter) and defective products, were identified as those with the highest RPN (378, 294, 280, 252, 245 and 144 respectively) and corrective actions were undertaken. Following the application of corrective actions, a second calculation of RPN values was carried out, leading to considerably lower values (below the upper acceptable limit of 130). It is concluded that the incorporation of FMEA analysis within the ISO2200 system of an octopus-processing industry is imperative.  相似文献   

9.
The progress of the oxidation of phospholipids and non-phosphorylated lipids in the manufacturing process of pilchard meal was examined. It was shown that pilchard phospholipids were oxidised to a certain extent in the laboratory drying process, but a severe destruction of phospholipid and non-phosphorylated lipid fatty acids took place on storage of the meal at room temperature. Phospholipid oxidation was determined by the drop in average unsaturation of the fatty acids and also by the drop in free amino-nitrogen. In addition, the composition of pilchard phospholipids was determined.  相似文献   

10.
The spoilage potential of fresh musky octopus ( Eledone moschata ) was determined by evaluating the changes in biochemical and physical properties, microbial growth and sensory quality of the mantle and tentacles, over a period of 18 days. Whole musky octopus, stored in melting ice from the time of harvest, had a storage life of 10 days. Early deterioration in the sensory quality resulted primarily from autolytic reactions. Pseudomonas spp. dominated the spoilage flora, reaching an average count of 108 CFU g−1 at the end of the trial. The bacterial metabolic end products (trimethylamine, total volatile bases) were not useful as objective indicators of freshness, and measurements of pH would only provide an indicator of decomposition. Changes in the dielectric properties of the mantle were reflective of quality deterioration, but could not yield precise information on the storage history of the cephalopod. The common sulphide producer, Shewanella putrefaciens , was not a major spoiler of ice-stored musky octopus.  相似文献   

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用玉米淀粉合成了一种带羧基的氧化淀粉,研究该合成氧化淀粉和玉米淀粉对Cr(VI)的吸收。玉米淀粉和氧化淀粉对Cr(VI)的吸收均受反应pH、温度、时间和吸收剂用量的影响。通过实验发现玉米淀粉对Cr(VI)的吸收各因素影响主次是pH>温度>吸收剂用量>时间;氧化淀粉对Cr(VI)的吸收各因素影响主次是pH>时间>温度>吸收剂。两者影响因素主次稍有不同,这可能是由羧基所造成的。实验结果表明氧化淀粉的吸收效果优于玉米淀粉。  相似文献   

14.
Qualitative and quantitative analysis of the polar ttpids in water-melon (Citrullus vulgaris) and squash, melon (Citrullus vulgaris variety fistulosus) is reported under the present study. Eight classes of polar ttpids, i.e. lysophosphatidylcholine, lysophosphatidylethanolamine, phosphatidylinositol, phosphatidyiethanolamine, phosphatidylglycerol, monogalactosyldiglyceride and phosphatidic acid have been identified. In both the species, phosphatidylcholine and phosphatidyl inositol formed the major portion of the ttpids. The squash-melon was found to contain a higher proportion of monogalactosyldiglycerides and phosphatidyl ethanolamine than water melon. Only a few fatty adds (palmitic, stearic, oleic and linoleic) were present in a measurable amount in the seed oils of these species with linoleic as the major and stearic as the minor one. There was great variation in the fatty add composition in different classes of polar lipids. The two species seem to be closely related to each other regarding their lipid make-up. They differ only in the fatty acid composition and the relative proportions of various classes of polar lipids.  相似文献   

15.
The stimulation of microbial U(VI) reduction is currently being investigated as a means to reduce uranium's mobility in groundwater, but little is known about the concentration at which U(VI) might inhibit microbial activity, or the effect of U(VI) on bacterial community structure. We investigated these questions with an ethanol-fed U(VI)- and sulfate-reducing enrichment developed from sediment from the site of an ongoing field biostimulation experiment at Area 3 of the Oak Ridge Field Research Center (FRC). Sets of triplicate enrichments were spiked with increasing concentrations of U(VI) (from 49 microm to 9.2 mM). As the U(VI) concentration increased to 224 microM, the culture's production of acetate from ethanol slowed, and at or above 1.6 mM U(VI) little acetate was produced over the time frame of the experiment. An uncoupling inhibition model was applied to the data, and the inhibition coefficient for U(VI), Ku, was found to be approximately 100 microM U(VI), or 24 mg/L, indicating the inhibitory effect is relevant at highly contaminated sites. Microbial community structure at the conclusion of the experiment was analyzed with terminal restriction fragment length polymorphism (T-RFLP) analysis. T-RFs associated with Desulfovibrio-like organisms decreased in relative abundance with increasing U(VI) concentration, whereas Clostridia-like T-RFs increased.  相似文献   

16.
Sulfonamide antimicrobials are used in both human therapy and animal husbandry. Sulfonamides are not readily biodegradable and have been detected in surface water and in secondary wastewater effluents. The chemical oxidation of sulfonamides by an environmentally friendly oxidant, ferrate(VI) (Fe(VI)O4(2-), Fe(VI)), was conducted. The sulfonamides used in the oxidation studies were sulfisoxazole, sulfamethazine, sulfamethizole, sulfadimethoxine, and sulfamethoxazole. Kinetics of the reactions were determined as a function of pH (7.0-9.7) and temperature (15-45 degrees C) by a stopped-flow technique. The rate law for the oxidation of sulfonamides by Fe(VI) is first-order with respect to each reactant. The observed second-order rate constants decreased nonlinearly with an increase in pH and are possibly related to the protonation of Fe(VI) (HFeO4- <==> H+ + FeO4(2-); pK(a,HFeO4) = 7.23) and sulfonamides (SH <==> H+ + S-; pK(a,SH) = 5.0-7.4). The activation parameters of the reactions vary with pH due to temperature dependence on the protonation of Fe(VI) and sulfonamides. These results were used to obtain enthalpy of dissociation of sulfonamides. Stoichiometry and products of sulfamethoxazole (SMX) reactions with Fe(VI) were studied in detail using various analytical techniques to evaluate the effect of the oxidation process on the fate of sulfonamides in water. At a stoichiometric ratio of 4:1 (Fe(VI): SMX), complete removal of SMX was achieved. Analyses of oxidation products of the reaction as well as kinetic measurements of substructural models of SMX suggest that the attack of Fe(VI) occurs at the isoxazole moiety as well as at the aniline moiety with minimal preference. The results of the studies reported suggest that Fe(VI) has the potential to serve as a chemical oxidant for removing sulfonamides and converting them to relatively less toxic byproducts in water.  相似文献   

17.
The bacterial strain F6 was isolated from a biological aerated filter that is used for purifying recirculating water in a marine aquaculture system and was identified as Marinobacter sp. based on the analysis of its 16S rRNA gene sequence. Strain F6 showed efficient aerobic denitrifying ability. One hundred percent of nitrates and 73.10% of nitrites were removed, and the total nitrogen (TN) removal rates reached 50.08% and 33.03% under a high nitrate and nitrite concentration in the medium, respectively. N(2)O and (15)N(2), as revealed by GC-MS and GC-IRMS, were the products of aerobic denitrification. Factors affecting the growth and aerobic denitrifying performance of strain F6 were investigated. The results showed that the optimum aerobic denitrification conditions for strain F6 were the presence of sodium succinate as a carbon source, a C/N ratio of 15, salinity ranging from 32-35?g/L of NaCl, incubation temperature of 30°C, an initial pH of 7.5, and rotation speed of 150?rpm [dissolved oxygen (DO) 6.75?mg/L]. In addition, strain F6 was confirmed to be a heterotrophic nitrifier through its NO(2)(-) generation and 25.96% TN removal when NH(4)(+) was used as the sole N source. Therefore, strain F6, the first reported member of genus Marinobacter with aerobic heterotrophic nitrifying-denitrifying ability, is an excellent candidate for facilitating simultaneous nitrification and denitrification (SND) in industry and aquaculture wastewater.  相似文献   

18.
In situ microbial reduction of soluble U(VI) to sparingly soluble U(IV) was evaluated at the site of the former S-3 Ponds in Area 3 of the U.S. Department of Energy Natural and Accelerated Bioremediation Research Field Research Center, Oak Ridge, TN. After establishing conditions favorable for bioremediation (Wu, et al. Environ. Sci. Technol. 2006, 40, 3988-3995), intermittent additions of ethanol were initiated within the conditioned inner loop of a nested well recirculation system. These additions initially stimulated denitrification of matrix-entrapped nitrate, but after 2 months, aqueous U levels fell from 5 to approximately 1 microM and sulfate reduction ensued. Continued additions sustained U(VI) reduction over 13 months. X-ray near-edge absorption spectroscopy (XANES) confirmed U(VI) reduction to U(IV) within the inner loop wells, with up to 51%, 35%, and 28% solid-phase U(IV) in sediment samples from the injection well, a monitoring well, and the extraction well, respectively. Microbial analyses confirmed the presence of denitrifying, sulfate-reducing, and iron-reducing bacteria in groundwater and sediments. System pH was generally maintained at less than 6.2 with low bicarbonate level (0.75-1.5 mM) and residual sulfate to suppress methanogenesis and minimize uranium mobilization. The bioavailability of sorbed U(VI) was manipulated by addition of low-level carbonate (< 5 mM) followed by ethanol (1-1.5 mM). Addition of low levels of carbonate increased the concentration of aqueous U, indicating an increased rate of U desorption due to formation of uranyl carbonate complexes. Upon ethanol addition, aqueous U(VI) levels fell, indicating that the rate of microbial reduction exceeded the rate of desorption. Sulfate levels simultaneously decreased, with a corresponding increase in sulfide. When ethanol addition ended but carbonate addition continued, soluble U levels increased, indicating faster desorption than reduction. When bicarbonate addition stopped, aqueous U levels decreased, indicating adsorption to sediments. Changes in the sequence of carbonate and ethanol addition confirmed that carbonate-controlled desorption increased bioavailability of U(VI) for reduction.  相似文献   

19.
Time-resolved laser-induced fluorescence spectroscopy (TRLFS) and imaging spectromicroscopy (TRLFISM) were used to examine the chemical speciation of uranyl in contaminated subsurface sediments from the U.S. Department of Energy (U.S. DOE) Hanford Site, Washington. Spectroscopic measurements for contaminant U(VI) were compared to those from a natural, uranyl-bearing calcite (NUC) that had been found via X-ray absorption spectroscopy (XAS) to include uranyl in the same coordination environment as calcium. Spectral deconvolution of TRLFS measurements on the NUC revealed the unexpected presence of two distinct chemical environments consistent with published spectra of U(VI)-substituted synthetic calcite and aragonite. Apparently, some U(VI) substitution sites in calcite distorted to exhibit a local, more energetically favorable aragonite structure. TRLFS measurements of the Hanford sediments NP4-1 and NP1-6 were similar to the NUC in terms of peak positions and intensity, despite a small CaCO3 content (1.0 to 3.2 mass %). Spectral deconvolution of the sediments revealed the presence of U(VI) in calcite and aragonite structural environments. A third, unidentified U(VI) species was also present in the NP1-6 sediment. TRLFISM measurements at multiple locations in the different sediments displayed only minor variation, indicating a uniform speciation pattern. Collectively, the measurements implied that waste U(VI), long-resident beneath the sampled disposal pond (32 y), had coprecipitated within carbonates. These findings have major implications for the solubility and fate of contaminant U(VI).  相似文献   

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