18 resultados para CARBOXYLIC-ACIDS


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This is the Proposed Environmental Quality Standards (EQS) for Nonylphenol in Water produced by the Environment Agency in 1997. The report reviews the properties and uses of Nonylphenol, its fate, behaviour and reported concentrations in the environment, and critically assesses available data on its toxicity and bioaccumulation. The information is used to derive EQSs for the protection of fresh and saltwater life as well as for water abstracted to potable supply.Nonylphenol (NP) is used extensively in the production of other substances such as non-ionic ethoxylate surfactants. It is through the incomplete anaerobic biodegradation of these surfactants that most nonylphenol reaches the aquatic environment in effluents, e.g. from sewage treatment works and certain manufacturing operations. It was explicitly stated by the Environment Agency that the EQS was to be derived for NP and not Nonylphenol ethoxylates. However, since NP is unlikely to be present in the aquatic environment in the absence of other nonylphenol ethoxylate (NPE) degradation by-products, the toxicity, fate and behaviour of some of these (i.e. nonylphenol mono- and diethoxylates (NP1EO and NP2EO), mono- and di-nonylphenoxy carboxylic acids (NP1EC and NP2EC) have also been considered in this report. In the aquatic environment and during sewage treatment, NPEs are rapidly degraded to NP under aerobic conditions. NP may then be either fully mineralised or may be adsorbed to sediments. Since NP cannot be biodegraded under anaerobic conditions it can accumulate in sediments to high concentrations.

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The effect of certain chemical agents on dopa oxidation by phenolases has been examined. Sulphur containing amino carboxylic acids are inhibitory agents for dopa oxidation. Tyrosine, a substrate for the enzyme also acts as an inhibitor for dopa oxidation by the enzyme. The possible mode of action has been discussed. The function of diethyl dithiocarbamate in suppressing the display of enzyme activity has been detailed and its behaviour has been compared to the other chemical agents studied.

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Sediment samples (28) collected during the ORV Sagar Kanya cruise-29, were analysed for humic acid (HA) concentration from the North-Central Arabian Sea. Generally oceanic samples had more HA concentration than the continental shelf (< 200 m depth) samples. The photo-acoustic infrared spectra of shelf sediment HA indicated the presence of more C-H saturated aliphatic chains, while oceanic HA had few peaks for the above groups. Both the IR spectra indicated the absence of aromatic C = C, carbonyl, ketonic groups. Clayey-silt sediment generally had higher concentration of HA compared to sandy-silt type of sediment.

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The course of development of a few free amino acids under the influence of aureomycin in oil sardine (Sardinella lingiceps) held in ice storage was investigated. The levels of leucines and valine regularly increased in the control and aureomycin treated fush throughout the storage period. Alanines and threonine showed similar trend in both control and fish treated with 20ppm aureomycin. These amino acids however showed a gradual fall in fish treated at 5 ppm level. The changes in tyrosine+tryptophane were found to be irregular. Most of the amino acids studied indicated a remarkable change in trend by about the 16th day of ice storage in the case of fish treated with 50ppm aureimycin.

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A study was carried out to determine the effect of tocopherol acetate along with cod liver oil astaxanthin enriched Moina micrura (MC- control, Ml- tocopherol acetate enriched, M2-tocopherol acetate combined with cod liver oil (CLO) enriched and M3- tocopherol acetate combined with astaxanthin enriched) on growth, survival and fatty acid composition of M. rosenbergii (de Man) larvae (TC- unenriched Moina fed larvae, Tl- tocopherol acetate enriched Moina fed larvae, T2- tocopherol acetate + CLO enriched Moina fed larvae to T3 – tocopherol acetate+ astaxanthin enriched Moina fed larvae). Growth was expressed as the time taken in to the settlement of 95% post larvae. Maximum growth i.e., the lowest time taken to the 95% PL settlement (40 days) and the maximum survival percentage (61%) was observed in both T2 and T3 treatments fed with M2 and M3 Moina respectively. Minimum growth and survival was observed in unenriched Moina fed larvae (TC). In larval treatments T2, (larvae fed with (M2) vitamin E + CLO enriched Moina), showed a higher percentage of EPA, DHA and higher HUFA level than other treatments.

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The triglyceride fatty acid components from the heart lipid of Puntius sarana of different sizes have been characterized by thin-layer and gas liquid chromatography. Csub(10) to Csub(24) acids including both odd-numbered and branched chain acids were detected. The major constituents were ante-iso Csub(10), Csub(10), Csub(12:2), Csub(14), Csub(16), Csub(16:1),Csub(17), Csub(18) , Csub(18:1), Csub(18:2), Csub(18:3) and Csub(20:4) while twenty other acids were detected in lower proportion. The composition of these acids and their variation with size of fish have been investigated and discussed.

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The preventive effect of fumarate, maleate, tartrate and oxalate on the denaturation of frozen rohu actomyosin at -20°C in 0.7 M KCl for 7 weeks was examined using an in vitro test model. The rate of denaturation was followed by estimating percentage salt extractability, Ca²+ ATP-ase activity and the clearing response test. Fumarate, maleate and tartrate showed cryoprotective effect for higher concentration of pre-rigor rohu actomyosin of 10 mg/ml and 20 mg/ml. At actomyosin concentration of 6 mg/ml, maleate and tartrate showed some preventive effect whereas fumarate enhanced denaturation. Oxalate showed poor cryoprotective action. Post-rigor rohu actomyosin was preserved frozen without denaturation to a greater extent than pre-rigor actomyosin.

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Lipid hydrolysis and the nature of fatty acids lost as a result of lipid hydrolysis in milk fish (Chanos chanos) during frozen storage at -20°C is discussed in this paper. There was a preferential loss of saturated acids during the first three weeks of storage. This was followed by loss of polyunsaturated acids during the next seven weeks. Sharp decrease in the levels of monounsaturated acids was observed from the 10th week of frozen storage. These observations are due to the preferential hydrolysis of phospholipids with relatively high proportion of saturated acids during the first three weeks, followed by the hydrolysis of phospholipids with high proportions of polyunsaturated fatty acids from the 3rd to the 10th week, and finally, predominant hydrolysis of neutral lipids from the 10th week onwards. Storage of fish in the ice prior to freezing was found to accelerate lipid hydrolysis, especially that of neutral lipids, during frozen storage.

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The purpose of this study, Evaluation the effect of Rosmarinus officinalis and Thymus vulgaris extracts on the stability of poly unsaturated fatty acids in frozen Silver carp minced. Treatments include: Treatment 1 - Control: frozen meat packaged in conventional Treatment 2: Frozen Silver carp minced+Thyme 300 mg/kg in normal packaging Treatment 3: Frozen Silver carp minced+Rosemary 200 mg/kg in normal packaging Treatment 4: Frozen Silver carp minced+Rosemary compound (100 mg/kg) and Thyme (100 mg/kg) in normal packaging After rapid freezing of samples in the spiral freezer by individual quick freezing method, to maintain the cold temperature (-18) °C were transferred. Sampling and measurements to determine the fatty acid profile of the zero phase beginning in the first month and then every ten days, and 15 days in the second month of the third month after the monthly test. Identifying, defining and measuring the fatty acid profile by gas chromatography was performed. In this study, levels of both saturated and unsaturated fatty acids in three experimental and one control were identified as follows: A: saturated fatty acids: Meristic C14: 0/Palmitic C16: 0/Hepta decaenoic C17: 0/Stearic C18: 0/Arashidic C20: 0/B:Mono unsaturated fatty acids: palmitoleic C16: 1-W7/Oleic C18: 1-W9/Gadoleic C20: 1-W9 C:Poly unsaturated fatty acids: Linoleic C18: 2-W6/α-Linolenic C18: 3-W3 D:High unsaturated fatty acids: Arachidonic C20: 4-W6 Eicosapentaenoic acid C20: 5-EPA/W3 Docosahexaenoic C22: 6-DHA/W3 Results of this study was to determine, Thyme and rosemary extracts containing silver carp minced stored in freezing conditions, Stability of different types of fatty acids, monounsaturated fatty acids, poly-unsaturated fatty acids, omega-3 and omega-6 fatty acids are. So that none of the fatty acids measured were not significant 100% increase or decrease, While changes in the fatty acid oxidation during storage time is minimized. The results obtained from the fatty acid profiles and indicators of their and statistical tests show that treatment with rosemary extract More stable during storage (-18) ° C In comparison with the control and other treatments are shown; And at relatively low compared to other treatments and control samples oleic acid and linoleic acid, palmitic more. According to studies,in Silver carp minced that containing rosemary extract, end of the storage period of six months. Were usable, so even rosemary extract the shelf-life examples to increase more than six months.

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The present study aims to find the effect of freezing Time on the quality of Cobia (Rastrelliger kanagurta) and Indian Squid in commercial scale during freezing and subsequent frozen storage (−18◦C). Total time for freezing was significantly different (P<0.05) between the Cobia and Indian squid samples. The difference in the freezing time could be attributed to the varied quality of the 2 samples. Upon freezing, the moisture content decreased in Indian Squide samples compared to Cobia freezer where protein content decreased in both the samples. Upon freezing and during frozen storage, lipid oxidation products (peroxide value, and free fatty acid value) and volatile bases (total volatile base nitrogen) showed an increasing trend in both the samples with values slightly higher in Indian squid samples compared to cobia frozen samples. The total plate counts showed a significantly (P<0.05) decreasing trend in both the samples. K value did not show any significant (P<0.05) difference between the samples whereas the histamine formation was significantly (P<0.05) increased in Indian squid frozen samples compared to cobia samples. The taste and overall acceptability was significantly different (P<0.05) in cobia samples compared to Indian squid frozen samples on 5th month. Both samples were in acceptable condition up to 5 month but the Cobia frozen samples quality was slightly better than the air blast frozen samples.

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Chemical ecology is the science of study and analysis of natural chemical products in result of biochemical processes in organisms and their reactions to variations of ecological and environmental parameters. In marine chemical ecology the existence of natural products in aquatic organisms and their ecological roles in marine animals and their reactions to environmental parameters variations will be studied. Among them, fatty acids are the most various and abundant ones in natural products which had been extracted from many marine organisms such as mollusks and algae. In this study selected animals were the dominant species of mollusks in intertidal zone of chabahar bay including gastropods, bivalves and polyplacophora classes. Nerita textilis and Turbo coronatus species are among gastropoda, Saccostrea cucullata is from bivalve, and Chiton lamyi is from polyplacophora. After seasonal sampling, separation and identification of natural products of these species, fatty acids had been isolated and identified by GC mass chromatography and their seasonal variations had been identified. In addition environmental factors of the location including pH, salinity temperature, dissolved oxygen, chlorophyll a and nutrients were measured monthly. Then the effect of seasonal variations of environmental factors on fatty acids had been studied by applying statistical analysis. GC/MS resulted thirteen fatty acids, which the most importants were myristic, stearic, oleic, palmitoleic, arachidonic and eicosapentaenoic acids. In majority of species palmitic acid was most abundant than the others and saturatedes had the most percentage levels than unsaturated ones. Although seasonal variations of identified fatty acids was not similar in species, but the majority of unsaturated ones had their maximum during winter, while saturated acids reached their maximum in summer. Statistical Analysis showed the strong correlations between Environmental factors and some fatty acids and temperature, nitrate, silicate and pH had strong correlations in all species. The species was studied from the point of lipid content and the results showed a good quality of lipid content in the selected species in the intertidal zone of Chabahar bay.

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The main aim of this research was to identify fatty acids composition of Caspian sea of White fish Rutilus frisi kutum tissue and their changes during one year cold storage (-18Ċ).The secondary aim was to determine the changes of moisture, ash, protein, fat, and to investigate the effects of storage time on peroxide, TBAi, FFA, and extractability of myofibrillar proteins of the fish tissue during one year cold storage (-18 Ċ). 10 samples of (Rutilus frisi kutum) were randomly collected from Anzali landings. The samples were frozen at -30 Ċ and kept in cold storage at -18Ċ for one year. According to time table, the samples were examined. The results showed that 27 fatty acids were identified. The unsaturated fatty acids (UFA) and saturated fatty acids (SFA) were 74/09 and 21/63 %, respectively, in fresh tissue. So that DHA (C22:6) oleic acid (C18:1c) had high amounts (15/07 ,20/57 ) among the UFA and palmitic acid (C16:0) was the most (13/09 %) among the SFA. The effects of freezing and cold storage on fish tissue showed that UFA and SFA contents have reached to 58/79 and 22/17 %, respectively, at the end of cold storage. It indicated that these compound change to each other during frozen storage. Also ω-3 and ω-6 series of fatty acids was 24/22 and 15/56% in fresh tissue, but their contents decreased to 8/68 and 5/11% at the end of period. Among the fatty acids C22:6, C18:1c and C16:0 had the most changes. The changes of fatty acids were significantly at 95% level expected for C18:0. Results showed that moisture, ash, protein, and fat contents were 75/9±0/03, 1/28±0/012, 21/8±0/2, and 4/1±0/01 % respectively, in fresh tissue. The moisture, ash, protein, and fat contents were 72/3±0/04, 1/83±0/05, 1/91±0/01 and 19/9±0/01 % respectively, at the end of storage period. Lipid damage was measured on the basis of free fatty acids (FFA), peroxide value (PV), and Thiobarbituric acid index (TBA-i). PV, TBARS and FFA concentration of frozen Caspian Sea white fish stored at -18 Ċ the temporal variation of these three variables were statistically significant (p<0.001). Results of White fish myofibrillar proteins showed aggregation of bound reduced for stored at 12 months. SDS-PAGE analysis revealed that, the intensity of the myosin heavy chain and actin bound was reduced with increasing storage time. SDS-PAGE patterns showed that myosin heavy chain was much more susceptible to hydrolysis than actin. Key words: Rutilus frisi kutum, frozen storage, ω-3, ω-6, protein myofibrillar