34 resultados para glutathione peroxide

em Aquatic Commons


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The first aim of this research was to identify fatty acids, amino acids composition of Thunnus tonggol roe and their changes during cold storage (-18'C). The second aim was to determine the changes of moisture, protein, fat and ash contents of the roe during one year cold storage (-18'C). 60 samples of longtail tuna (Thunnus tonggol) ovaries were randomly collected form Bandar-e-Abbas landings. The samples were frozen at-30'C and kept in cold store at -18'C for one year. According to a time table, the samples were examined for identification of fatty acids, amino acids, moisture, protein, fat, ash, peroxide and T.V.N. and their changes were evaluated during this time. The results showed that 26 fatty acids were identified. The unsaturated fatty acids (UFA) and saturated fatty acids (SFA) were 62.33 and 37.6%, respectively, in fresh roe. So that, DHA (C22:6) and oleic acid (C18:1) had high amounts (24.79 and 21.88%) among the UFA and palmitic acid (C16:0) was the most content (22.75%) among the SFA. The PUFA/SFA was 0.91. Also, 17 amino acids were identified that essential amino acids (EAA) and nonessential amino acids (NE) were 10478 and 7562 mg/100g, respectively, and E/NE was 1.38. Among the EAA and NE, lysine (2110mg/100g) and aspartic acid (1924 mg/100g) were the most contents. Also, results showed that moisture, ash, protein and fat contents were 72.74, 1.8, 19.88 and 4.53%, respectively, in fresh roe. The effects of freezing and cold storage on the roes showed that UFA and SFA contents have reached to 49.83 and 48.07%, respectively, at the end of cold storage. It indicated that these compounds change to each other during frozen storage. Also, n-3 and n-6 series of fatty acids were 32.75 and 1.61% in fresh roe. But their contents decreased to 22.96 and 1.25% at the end of period. Among the fatty acids, 22:6 and C16:0 had the most changes. The changes of fatty acids were significantly at 95% level except for C15:1, C18:3(n-3) and C20:4(n-6). All of the amino acids decreased in frozen storage and their changes were significantly (P<0.05). EAA was 7818 mg/100g and E/NE was 1.27 at the end of storage period. Among the amino acids, leucine and lysine had the most changes. Moisture, ash, protein and fat contents were 70.13, 1.82, 19.4 and 6.51%, respectively, at the end of storage period. The peroxide value and T.V.N. increased during storage. So that, their contents have reached to 5.86 mg/kg and 26.37 mg/100 g, respectively, at the end of frozen storage. The best shelf life of Thunnus tonggol roe was 6 or 7 months, because of lipid oxidation and increasing of peroxide.

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During a two years research hydrogen peroxide efficacy evaluated for Persian sturgeon, Chinese carps and common carp eggs. These series of the experiments conducted in various conditions different concentration of hydrogen peroxide include 250, 500, 750, 1,000 1,500 2,000 3,000 and 9,000 PPM used as ten and fifteen minutes baths, compared with Malachite green and natural control . In the next phase effect of Levaemisole hydrochloride as an immunostimulator which applied as 5 mg/I in twenty minutes baths from day sixth after hatch evaluated by daily mortality rate and leukocytes counts. The results shown that according fertilization percent and temperature condition hydrogen peroxide at 1,000 and 1,500 PPM concentrations is a effective antifungal agent during incubation periods of Persian sturgeon and even sometimes increasing hatching rates significantly comparing with natural controls and Malachite green. In Chinese carps although hydrogen peroxide controls water molds but it is not recommended in high temperatures because it make shortened incubation time and mold infections will decrease. Also the results shown 750 PPM concentration of hydrogen peroxide in common carp eggs controls water moulds infections and increase hatching rate significantly comparing with Malachite green and natural control. Daily mortality rates accessing of Persian sturgeon fries show that 20 minutes baths of 5mg/1 levamisole hydrochloride decreases daily mortality rate during yolk sac absorption. Nitrogenous compounds: nitrate and ammonium differ significantly between treated tanks with control. Blood leucocytes concentrations as an immune index was different significantly in treated fishes by levamisole hydrochloride comparing with controls. In Chinese carps because yolks sac absorption time is short there is not necessary to use the levamisole hydrochloride. Although treated larvae were more active than controls. As a result our suggestions is to use hydrogen peroxide in Persian sturgeon and common carp artificial propagation and also suggest the use levamisole hydrochloride for Persian sturgeon beside management method in stress and pollution condition

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Ozone due to having low half-life and devoid of environmental harmful effects is recognized as one of the most effective disinfectant and fungicide in aquaculture. The objective of this study is to consider the effects of periodicay ozonation, hydrogen peroxide treatment, and physical treatment capability in hatching rate enhancement. Three concentrations of 0.05, 0.1 and 0.15 ppm ozone (10 min) and peroxide hydrogen with dose of 500 and 1000 ppm in two procedures accompanied with physical treatment and without physical treatment were examined on hatching rate. In the first year, Egg ozonation (0.1 ppm) with physical treatment have been resulted the greatest hatching rate (81.4%). In the second year, egg treatment with 1000 ppm hydrogen peroxide with physical treatment have been showed the greatest hatching rate (78%). Average hatching rate for the blank control treatment (without disinfectin and physical treatment) was 32.7%. From the economic viewpoint, 0.05 ppm ozone with physical treatment, due to considerable minimizing at consumption energy and ozonation system retention costs, indicated as the best treatment than other ozone treatments for fungal control. Very low correlation (r=-0.14) have been observed between hatchery water temperature and fungal infection percentage in control treatment.

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There are various tools for monitoring the concentration of pollutants on aquatic ecosystems. Today these studies are based on biological monitoring and biomarkers. The aim of this study was to measure the concentration of the acetylcholinesterase (AChE), glutathione S-transferase and catalase as biomarkers of heavy metal contamination in pearl oyster Pinctada radiata and their mechanism in aquatic ecosystems. Heavy metals lead, cadmium and nickel were measured in soft tissue and studied stations in four seasons. Samples were collected seasonally in Lavan stations, Hendurabi and Nakhilo (in the northern Persian Gulf) from spring 2013 to winter of that year by scuba diving. Pearl oysters are divided according to their shells size; shells separated from soft tissues and were transferred to the laboratory for analysis of heavy metals and enzymes. Moopam standard method for were used for measuring the concentration of heavy metals and for analyzing tissue concentrations of glutathione S-transferase in Clam the method recommended by Habig et al in 1974 were used. For measuring acetylcholinesterase Ellman method were used. Catalase contamination in pearl oyster in the supernatant obtained from the study based on the method homogeate soft tissue of mussels (Abei, 1974) was evaluated. The results showed that the concentration of lead has significant difference in sediments station, the concentration of lead in Lavan is significantly higher than the other two stations, This could be due to the movement of tanker, boats and floating refueling and with a considerable amount of wastewater containing oil and Petroleum into the water, and also due to precipitation and industrial discharges the lead in the region is increasing, land-disposed sewage sludge, has large concentrations of lead. Compare the results of this study with standards related and other similar studies at the regional and international level showed that pollutant concentration of heavy metals in all cases significantly less than all the standards and guide values associated. And also compared to other world research results have been far less than others, Being Less of the conclusion given in this research according that nickel is one of the indicators of oil pollution in the study area and emissions have been relatively low of oil. The concentration of acetylcholinesterase at several stations, in large and small sizes and in the seasons had no significant difference. Variations of catalase, and glutathione S-transferase were almost similar to each other and parameters, station and seasons were significantly different in the concentrations of these enzymes. The effects and interaction between various parameters indicate that following parameters has impact on the concentration of catalase and glutathione S-transferase. Stations; Seasonal changes in antioxidant enzymes related to (assuming a constant in salinity and oxygen) to age, reproductive cycle, availability of food and water temperature. With increasing temperature at warm season, antioxidant enzymes were increase, with increasing temperature and abundance of food in the environment the amount of antioxidant enzymes may increase. The presence of the enzyme concentration may indicate that the higher levels of the enzyme to eliminate ROS activities to be any healthier situation. At the time of gonads maturation and spawning season catalase activity increases. This study also indicates that catalase was significantly higher in the warm season. Due to low pollutants of heavy metals in the study area, a lower level of contaminants were observed in shellfish tissue incidents of international standards and strong correlation between the amount of heavy metal contamination in pearl oyster tissue and enzymes was not observed. Therefore, we can say that the pearl oyster remains in a healthy condition and the amount of enzyme is normal.

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Ciguatoxins (CTX) are polyether neurotoxins that target voltage-gated sodium channels and are responsible for ciguatera, the most common fish-borne food poisoning in humans. This study characterizes the global transcriptional response of mouse liver to a symptomatic dose (0.26 ng/g) of the highly potent Pacific ciguatoxin-1 (P-CTX-1). At 1 h post-exposure 2.4% of features on a 44K whole genome array were differentially expressed (p ≤ 0.0001), increasing to 5.2% at 4 h and decreasing to 1.4% by 24 h post-CTX exposure. Data were filtered (|fold change| ≥ 1.5 and p ≤ 0.0001 in at least one time point) and a trend set of 1550 genes were used for further analysis. Early gene expression was likely influenced prominently by an acute 4°C decline in core body temperature by 1 h, which resolved by 8 h following exposure. An initial downregulation of 32 different solute carriers, many involved in sodium transport, was observed. Differential gene expression in pathways involving eicosanoid biosynthesis and cholesterol homeostasis was also noted. Cytochrome P450s (Cyps) were of particular interest due to their role in xenobiotic metabolism. Twenty-seven genes, mostly members of Cyp2 and Cyp4 families, showed significant changes in expression. Many Cyps underwent an initial downregulation at 1 h but were quickly and strongly upregulated at 4 and 24 h post-exposure. In addition to Cyps, increases in several glutathione S-transferases were observed, an indication that both phase I and phase II metabolic reactions are involved in the hepatic response to CTX in mice.

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The studies provided data on the spoilage pattern of Otolithus argenteus during low temperature preservation. Changes in the total volatile bases, hypoxanthine, tyrosine, salt soluble nitrogen, non-protein nitrogen, pH, peroxide value, free fatty acids and thiobarbituric acid number along with organoleptic score have been reported. Organoleptically, fish stored at +20 degree C remained in acceptable condition upto 12 days while for those stored at 0 degree C in ice upto 19 days. Of the various indices tested Hypoxanthine, salt soluble nitrogen and total volatile bases nitrogen, in the order of merit can be used as freshness tests for refrigerated fish.

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Fresh Bombay ducks and Bombay ducks dried (a) without any pre-treatment or (b) after brining with NaCl solutions of 15% and 7.5% concentrations for 18 hours were analyzed for moisture, ash, minerals, vitamins, fat, free fatty acids, peroxide value, thiobarbituric acid value, total protein, total amino nitrogen, soluble proteins and trimethylamine contents. All the dried samples were stored in (a) tightly closed tin containers or (b) polythene bags and analyzed for the above mentioned constituents every 1½ months. It was observed that brining did not exercise any marked influence on keeping properties. Organoleptic observations showed that fish stored in tin containers kept better and longer than those stored in polythene bags.

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This paper reports on the relationship between the seasonal variations in the oil content of the Indian oil sardines (Sardinella longiceps) and their frozen storage life at -l8°C and on the use of various chemicals and coating materials to extent their storage life. It is observed that there is an inverse relationship between the oil content and the frozen storage life- oil content varying from 10.33 to 42.43% (MFB) and storage life from 2 to 5 months. Extension of storage life is achieved by dipping in hydroquinone solution prior to freezing or by coating with agar after freezing. Data on changes in peroxide value, free fatty acids, moisture, drip and organoleptic characteristics during frozen storage are presented.

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Proximate composition and nutritional characteristics of the two fermented fish products Hentak and Ngari of Manipur (India) were evaluated. Percentage of moisture, protein, lipid and ash contents in Hentak and Ngari were respectively: 36.30 versus 36.03; 33.33 versus 38.38; 13.60 versus 13.34 and 11.43 versus 5.49. Digestibility values in feeding trials in laboratory rats for 28 days were 82.37% for Hentak 89.46% for Ngari and that of Casein was 92.69%. The biological value, food conversion ratio and protein efficiency ratio (PER) of Hentak were 96.94, 4.83 and 1.8 respectively and that of Ngari were 97.83, 3.17 and 1.8 respectively. The α amino nitrogen of Hentak and Ngari in Pepsin + Trypsin phase were 28.40 and 28.92 respectively. The TBA number, peroxide value and TVBN were within the acceptable limits.

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Shark livers are considered as an important raw material providing a quality fish oil. It has been reported to aid white — blood-cell production and act as an active ingredient in hemorrhoid treatments. It is also reported that liver oil as a good supplement of vitamin A and poly-unsaturated fatty acids which are important to the development of brain cells in human. Freshness of livers is very important to extract better quality oil. In Sri Lanka, the annual shark production amounts to 8000t, however the quality of livers collected from landing sites has not being measured yet. Present study was conducted to evaluate the quality of silky (Charcarninus fakiformis) shark livers available in Negombo and Beruwala landing sites in the West Coast of Sri Lanka and also to study the relationship between organoleptic and bio-chemical correlation on freshness of shark livers. Liver samples which were collected from landing sites in the West coast of Sri Lanka, were evaluated for external and internal colour, texture and odour. Total volatile nitrogen (TVN), pH value, free fatty acid (FFA%) and peroxide (PV) values of livers were also determined to assess quality. According to the organoleptic scoring system 4.3% of liver samples were categorized as best in quality while 30.4%, 56.5% and 8.7% rated as good, medium and poor in quality respectively at the Negombo and Beruwala landing sites. Bio-chemical analysis showed that the better quality livers had the highest score for sensory evaluation and low values for TVN, FFA and peroxide value while low quality livers gave low score for sensory evaluation and high TVN, FFA, peroxide values. Correlation coefficient of organoleptic scores against total volatile nitrogen value, pH value, free fatty acid % and peroxide value of shark livers were determined by statistical analysis. Organoleptic score of shark livers was found to be highly.

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The overall quality of five SIS products was found in good condition up to 2 months storage on the basis of organoleptic, biochemical and bacteriological characteristics and all the products was excellent in sealed packed condition up to 45 days of storage. However, quality of the products stored in open air atmospheric temperature was found excellent for first 15 days. In an average the initial moisture content was in the range of 13.5 to 15.0% with highest moisture content in puti and lowest in chapila. At the end of the 60 days the moisture content reached to the range of 18.5 to 19.0% which was more or less near the recommended limit of 16% for dried fishery products. The moisture content beyond the recommended limit as the storage period increased further and at the end of 90 days the moisture content increased to the range of 22.9 to 24% when organoleptically the product quality became very poor. The changes in the value of total volatile base nitrogen (TVB-N), peroxide value (PO), moisture and aerobic plate count (APC) of solar tunnel dried products in sealed polythene packages were investigated during 60 days of storage. There was little or no differences in TVB-N, PO and bacterial load of each species packed under various polythene density. The initial TVB-N values were in the range of 10.30 to 12.40 mg/100g of the samples. TVB-N value increased slowly up to the end of the storage period and was to in the range of 46.20 to 57.00 mg/1 00 g of sample. Initially the peroxide values (P.O.) were in the range of 6.54 to 8.40 m.eq./kg oil of the samples. During 60 days of storage, P.O. values increased slowly and at the end of the storage period these values reached to the range of 22.00 to 25.30meq./kg of sample. The initial APC was in the range 5.3xl04-7.3x104 CFU/g. The bacterial load increased slowly and at the end of the 60 days storage period reached to the range 6.6x106 - 8.6x107 CFT/g.

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Fish kamaboko with spinach was prepared by mixing fish kamaboko with spinach prepared with different combinations of ordinary starch (OS) and modified starch (MS), viz., 40:60, 50:50, 60:40, 100%) MS and 100% OS. The products were frozen at -40°C and stored at -20°C, and subjected to biochemical (peroxide value, total titratable acidity, pH and moisture) organoleptic (appearance, taste and colour), microbiological (total plate count) and physical (folding and expressible water) tests at monthly intervals. Among the different combinations tried, it was observed that fish kamaboko with spinach prepared with 50:50 and 60:40 combinations of OS and MS could be stored for six months at-20°C.

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The shelf-life of standardized horse mackerel fish balls was assessed by biochemical, microbiological, organoleptic and other spoilage changes at 0-2°C. There was decrease in pH value, moisture and the organoleptic scores. Expressible water percentage, TMA-N, TVB-N and peroxide value showed increasing trends. Total plate count also increased gradually during storage. Water separation in the treated sample was observed after 12 days and slimy consistency was noticed in the control sample on the 24th day. Based on these observations, it can be concluded that fish balls can be stored at 0-2°C for 20 days.

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The study was conducted on the present status of HACCP based quality management system of golda, Macrobrachium rosenbergii farms in Fulpur region of Mymensingh. Information was collected on general condition of farms, culture systems and post-harvest quality management. In almost all farms, there is no or inadequate infrastructure facilities such as, road access, electric supply, telecommunications, ice, feed storage facility, vehicle for golda transportation, washing and toilet facilities. The problems associated with sanitation and hygiene was: widespread use of cow dung, poultry manure and construction of open toilet within the vicinity of prawn culture pond. Different grades of commercially available and locally prepared feeds were used for golda culture in the pond. Golda post-larvae (PL) of 40-50 days old were stocked with carp species. The price of golda PL ranged from Tk. 1.00 to Tk. 1.25/piece. The pond size varied from 50 decimal (0.2 ha) to 2.5 acre (1.0 ha) with an average depth of 2-2.5 m. The culture period of golda varied from April-May to November-December and survival rate ranged between 75 and 80%. Production of golda varied from 250-500 kg/acre (625-1,250 kg/ha). Harvested golda were transported to city market within 4 h. Two size grading were generally followed during pricing, e.g. Tk. 500 to 550/kg for >100 g size and Tk. 300/kg for <100 g size. The cost-benefit ratio was found to remain around 1:1.25 depending on availability of PL. Water quality parameters such as, water temperature, pH, dissolved oxygen, total alkalinity and chlorophyll a in five golda farms in Fulpur region were monitored. Water temperature ranged from 29°C to 33°C, dissolved oxygen from 2.28 to 4.13 mg/l, pH between 6.65 and 7.94, alkalinity from 44 to 70 mg/l and chlorophyll a concentration from 61.88 to 102.34 µg/l in the five investigated ponds. The Aerobic Plate Count (APC) of the water sample was within the range of 2.0x10^6 - 2.96x10^7 CFU/ml and of soil samples within the range of 6.9x10^6 - 7.73x10^6 CFU/g. Streptococcus sp., Bacillus sp., Escherichia coli, Staphylococcus sp., Pseudomonas sp. and Salmonella sp. were isolated from pond water and sediment. Different feed samples used for golda was analyzed for proximate composition. Moisture content ranged around 14.14-21.22%, crude protein 20.55-44.1%, lipid 4.67-12.54% and ash 9.7-27.69%. The TVB-N values and peroxide values of feeds used as starter, grower and fish meal were found within the acceptable ranges and samples were free from pathogenic organisms. A training was organized for the golda farmers on HACCP, water quality and post-harvest quality management of prawn.

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Aspartate aminotransferase (E.C. 2.6.1.1.) from the skeletal muscle of fresh water fish Cirrhina mrigala has been purified 40 fold by ammonium sulphate fractionation, adsorption on alumina Csub(8) gel and chromatography using DEAE-cellulose column and the properties of the purified enzyme studied. The pH optimum of the enzyme is 7.8. The Km value of aspartic acid and 2-oxoglutaric acid are found to be 2.8 x 10sub(-3) M and 1.0 x 10sub(-4) M respectively. The activity of enzyme is inhibited by p-chloromercurybenzoate, hydroxylamine hydrochloride and sodium cyanide. The inhibition by pchloromercurybenzoate is reversed by reduced glutathione, B-mercaptoethanol and cysteine. Dicarboxylic acids such as maleic acid, malic acid and succinic acid inhibit the enzyme activity. The enzyme is not activated by any of the metal ions tested and heavy metal ions such as mercury and silver strongly inhibit the enzyme activity.