36 resultados para Curing salts
Resumo:
This paper deals with the levels and distributions of nutrient salts in the United Arab Emirates waters. Water samples were collected bimonthly during 1994-1995 from the marine environment of the United Arab Emirates, which extends more than 800km along the Arabian Gulf and the Gulf of Oman. Concentrations of ammonium, nitrite, nitrate, phosphate, silicate, as well as total concentrations of total dissolved nitrogen, phosphorus, and silicon in the area were scattered in the ranges: (ND-6.32; mean: 0.84 µg-at N/l), ND-3.02; mean: 0.42 µg-at N/l), (ND-10.88; mean: 1.18 µg-at N/1), (ND-4.22; mean: 0.62 µg-at P/l), (1.14-28.80; mean: 6.52 µg-at Si/l), (1.52-39.58; mean: 12.28 µg-at N/l), (0.40-4.98; mean: 1.07 µg-at P/l), and (2.77-44.74; mean: 13.02 Si/l) respectively. Of inorganic nitrogen species, ammonium was the highest in the Arabian Gulf waters and nitrate was the highest at the Gulf of Oman. The dissolved inorganic nitrogen total species, phosphate and silicate amounted to 16.4, 47.6, 56.5% respectively, of the concentrations of nitrogen, phosphorus and silicon in the Arabian Gulf and 22.6, 64.4, 44.9% respectively, in the Gulf of Oman, indicating that more than 80% of nitrogen was present in organic forms. Distributions of nutrient in the two regions were higher in the summer season and lower in the winter season due to the oxidation of organic materials. Regional distributions revealed higher values for nitrite (1.3 times), nitrate (2.8 times), phosphate (2.2 times), total dissolved nitrogen (1.3 times), total dissolved phosphorus (1.6 times), and total dissolved silicon (1.3 times) in the Gulf of Oman compared to the Arabian Gulf, indicating more oligotrophic conditions at the Arabian Gulf Whereas no distinct patterns of distribution were observed in the Arabian Gulf waters, an increase in the seaward direction was measured at the Gulf of Oman. Vertical distributions indicated a general increase with depth in the two regions. The mean ratios for total concentrations of phosphorus, nitrogen, and silicon in the Arabian Gulf (1: 11.6: 12.6) and the Gulf of Oman (1: 10.1: 11.8) were lower than the Redfield ratio.
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In December 1956 the U. S. Geological Survey, in cooperation with the Florida Geological Survey and the Board of County Commissioners of Pinellas County, collected waterlevel and chloride content of water in 94 wells in Pinellas County. First sampled in 1947, resampling and reanalyzing the water from these wells was used to determine the change in the chloride content of the ground water from 1947 to 1956. The chloride content of ground water is generally a reliable indication of the contamination of ground water by sea water, as 90 percent of the dissolved solids of sea water are chloride salts. (PDF contains 15 pages.)
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The paper examines the pattern of utilization of freshwater fish species in Nigeria. It was observed that although fishermen have a preference for fresh fish sales only 30% of fresh fish captured actually get to the consumers. The rest are preserved by smoke curing (60-65%), salting and sundrying (less than 5%), deep frying and fermentation (about 1%). Constraints to fish utilization were identified which include poor infrastructure, losses of fish and fish products as a result of traditional post harvest technology and socio economic factors. The need for the development of appropriate research to solve the problems of traditional post harvest technology was emphasised
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This short paper records some measurements made on the Little Sea, a shallow, coastal, acidic lake on Studland Heath, Dorset. The lake, formed about 100 years ago by dunes cutting off a sea inlet, has not received any input of agricultural fertilizers or other waste products for at least the last 30 years. It is a Site of Special Scientific Interest (SSSI). Samples of surface water were taken from the northern and southern ends of the lake at 3-monthly intervals, from July 1995 to April 1996. The first samples in July 1995 were taken during a period of drought; rain, sometimes very heavy, came in late September. With the exception of silicate, potassium and phosphate, there were no large changes in plant nutrient concentrations during the year. The concentration of nitrate-nitrogen was very low (close to the limits of analytical detection), but total phosphorus at ca. 30 mu g per litre was similar to concentrations found in some of the Cumbrian eutrophic lakes. The large number of algal species at low cell/colony concentrations suggested that the lake is mesotrophic. Sodium, chloride and magnesium in the lake water were close to the same proportions as those found in sea water. Dry and wet deposition of sea-salts on the lake surface and its catchment area probably is the major source of sodium, magnesium and chloride ions in the lake, and also accounts for about half of the mean potassium and sulphate concentrations.
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(Sardinella) are available all year round in Sierra Leone. The best time to use them for baiting herrings is during the dry season when they are fattest and feeding well. The most common method of processing herring locally is hot smoking to give either soft, moist and cooked product or a dry, brittle product with very low moisture content. The author describes a curing method intended to add variety to the types of products that can be obtained from local herring. It is only mildly preservative, the product cannot be kept more than 24 hours without refrigeration. Particular attention is paid to the source and quality of the raw material used, and the processing method is detailed with attention to washing, splitting, brining, smoking, and the application of the Torry fish smoking kiln to the process.
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Two large hydrologic issues face the Kings Basin, severe and chronic overdraft of about 0.16M ac-ft annually, and flood risks along the Kings River and the downstream San Joaquin River. Since 1983, these floods have caused over $1B in damage in today’s dollars. Capturing flood flows of sufficient volume could help address these two pressing issues which are relevant to many regions of the Central Valley and will only be exacerbated with climate change. However, the Kings River has high variability associated with flow magnitudes which suggests that standard engineering approaches and acquisition of sufficient acreage through purchase and easements to capture and recharge flood waters would not be cost effective. An alternative approach investigated in this study, termed On-Farm Flood Flow Capture, involved leveraging large areas of private farmland to capture flood flows for both direct and in lieu recharge. This study investigated the technical and logistical feasibility of best management practices (BMPs) associated with On-Farm Flood Flow Capture. The investigation was conducted near Helm, CA, about 20 miles west of Fresno, CA. The experimental design identified a coordinated plan to determine infiltration rates for different soil series and different crops; develop a water budget for water applied throughout the program and estimate direct and in lieu recharge; provide a preliminary assessment of potential water quality impacts; assess logistical issues associated with implementation; and provide an economic summary of the program. At check locations, we measured average infiltration rates of 4.2 in/d for all fields and noted that infiltration rates decreased asymptotically over time to about 2 – 2.5 in/d. Rates did not differ significantly between the different crops and soils tested, but were found to be about an order of magnitude higher in one field. At a 2.5 in/d infiltration rate, 100 acres are required to infiltrate 10 CFS of captured flood flows. Water quality of applied flood flows from the Kings River had concentrations of COC (constituents of concern; i.e. nitrate, electrical conductivity or EC, phosphate, ammonium, total dissolved solids or TDS) one order of magnitude or more lower than for pumped groundwater at Terranova Ranch and similarly for a broader survey of regional groundwater. Applied flood flows flushed the root zone and upper vadose zone of nitrate and salts, leading to much lower EC and nitrate concentrations to a depth of 8 feet when compared to fields in which more limited flood flows were applied or for which drip irrigation with groundwater was the sole water source. In demonstrating this technology on the farm, approximately 3,100 ac-ft was diverted, primarily from April through mid-July, with about 70% towards in lieu and 30% towards direct recharge. Substantial flood flow volumes were applied to alfalfa, wine grapes and pistachio fields. A subset of those fields, primarily wine grapes and pistachios, were used primarily to demonstrate direct recharge. For those fields about 50 – 75% of water applied was calculated going to direct recharge. Data from the check studies suggests more flood flows could have been applied and infiltrated, effectively driving up the amount of water towards direct recharge. Costs to capture flood flows for in lieu and direct recharge for this project were low compared to recharge costs for other nearby systems and in comparison to irrigating with groundwater. Moreover, the potentially high flood capture capacity of this project suggests significant flood avoidance costs savings to downstream communities along the Kings and San Joaquin Rivers. Our analyses for Terranova Ranch suggest that allocating 25% or more flood flow water towards in lieu recharge and the rest toward direct recharge will result in an economically sustainable recharge approach paid through savings from reduced groundwater pumping. Two important issues need further consideration. First, these practices are likely to leach legacy salts and nitrates from the unsaturated zone into groundwater. We develop a conceptual model of EC movement through the unsaturated zone and estimated through mass balance calculations that approximately 10 kilograms per square meter of salts will be flushed into the groundwater through displacing 12 cubic meters per square meter of unsaturated zone pore water. This flux would increase groundwater salinity but an equivalent amount of water added subsequently is predicted as needed to return to current groundwater salinity levels. All subsequent flood flow capture and recharge is expected to further decrease groundwater salinity levels. Second, the project identified important farm-scale logistical issues including irrigator training; developing cropping plans to integrate farming and recharge activities; upgrading conveyance; and quantifying results. Regional logistical issues also exist related to conveyance, integration with agricultural management, economics, required acreage and Operation and Maintenance (O&M).
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A survey of the quality of salt cured fish in Kanyakumari District, Madras State was done during the years 1963 and 1964 to obtain necessary basic information to formulate quality standards for these products which are gaining importance in the export trade. 155 trade samples of sun-dried, dry-salted, wet-cured and pit-cured fishery products were examined for their chemical quality and organoleptic characteristics. 26.5% of the sun-dried products, 25% of the wet cured fish, 55.21% of the dried salted products and none of the pit cured samples were found to be good in quality. The sun dried products were generally found to have heavy admixture of sand and were inadequately dried. The chief defects in the salt cured fish products were found to be the use of spoiled fish, imperfect cleaning and washing, use of impure salt, inadequate salting, curing and drying, and unhygienic conditions in all stages. Quality standards must be formulated for each variety of salt cured fish product and adequate measures taken to rectify the defects and enforce the quality standards.
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Even though smoke curing is a very elegant method of preserving fish, the resultant products have only a very restricted shelf-life, unless stored under refrigerated conditions. The main source of spoilage is the early setting in of a vigorous growth of moulds. This problem is of a serious nature even in temperate climatic conditions. In full and universal recognition of the gravity of the problem, the FAO conference on herring technology held in September 1950 at Bergen in Norway has recommended the problem of "means of prevention of mould growth in smoked products" for future research study. This note records an interesting observation made at this Laboratory on the inhibitory action of sodium chloride on the development of mould in smoked fishery products.
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The 66 kilo-Dalton (k-Da) protein split off from the cross linked myosin heavy chain (CMHC) formed due to the setting of Alaska pollack surimi, frozen-storage of Pacific cod flesh, and vinegar-curing of Pacific mackerel mince was identified as a light meromyosin (LMM). Puncture and stress-relaxation tests showed that the actomyosin subunits (AMS) of Alaska pollack surimi, upon setting at 30°C, transformed into gel, although the elasticity of this gel was very low when compared to the gels from surimi or actomyosin (AM). Electrophoretic studies showed that the band due to LMM in the gel from AMS gradually disappeared with the progress of setting but higher molecular weight polymer did not form. The intensity of the bands due to other myosin sub-fragments decreased a little. The findings suggest that at setting temperature, LMM of MHC molecule leads to an unfolding resulting in an intramolecular aggregation through non-covalent interactions, and thus plays a significant role in the crosslinking of MHC.
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A quality of survey was conducted at the fish curing yards in a northwest coast and the southern coast in Sri Lanka. A total of 40 samples different varieties of fishes were collected from the market and jaadi curing yards and all were evaluated for the quality, fungal and insect infestation. Samples were analyzed for proximate composition chemical, microbiological and sensory quality. Thirty percent of the total analyzed samples of fish were found to be unfit for consumption. Samples collected from Negombo were found to the infected with maggots. Only 42% samples had dry matter above 50%. All the samples showed a protein content above 20%. The highest protein content was 27.92% in hurulla. Over 90% of the samples had TVN at acceptable quality limits (>40). The TBC for 33% of the samples were in the range 104-105/g range, while 48% were in the range of 107-108/g due to contamination of maggots and fungi. The Survey showed jaadi had a high level of protein in its composition. But defects of curing process such on imperfect cleaning inadequate salting resulted in low (Chemical and microbiological) quality of the product.
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A comparative study was carried out between the two biggest creeks along the Arabian Gulf coast of the United Arab Emirates to evaluate impacts of sewage and industrial effluents on their hydrochemical characteristics. Surface and bottom water samples were collected from Abu Dhabi and Dubai creeks during the period from October 1994 to September 1995. The hydrochemical parameters studied were: temperature (21.10-34.00°C), salinity (37.37-47.09%), transparency (0.50-10.0 m), pH (7.97-8.83), dissolved oxygen (1.78-13.93 mg/l) and nutrients ammonia (ND- 13.12,ug-at N/1), nitrite (ND-6.66 ,ug-at N/1), nitrate (ND- 41.18 ,ug-at N/1), phosphate (ND- 13.06 ,ug-at P/1), silicate (0.68-32.50 ,ug-at Si/1), total phosphorus (0.26- 21.48 ,ug-at P/1), and total silicon (0.95- 40.32 ,ug-at Si/1). The present study indicates clearly that seawater of Abu-Dhabi Creek was warmer (28.l2°C) than Dubai (27.56°C) resulting in a higher rate of evaporation. Owing to more evaporation, salinity levels showed higher levels at Abu Dhabi (43.33%) compared to Dubai (39.03%) seawater. The study also revealed higher secchi disc readings at Abu Dhabi Creek (4.68 m) as compared to Dubai Creek (2.60 m) suggesting more transparency at Abu Dhabi Creek. Whereas, seawater of Dubai exhibited higher levels of pH (1.03 times), and dissolved oxygen (1.05 times) than Abu Dhabi seawater due to an increase in productivity. Meantime, seawater of Dubai showed higher tendency to accumulate ammonia (8.22 times), nitrite (10.93 times), nitrate (5.85 times), phosphate (10.64 times), silicate (1.60 times), total phosphorus (3.19 times), and total silicon (1.54 times) compared to Abu Dhabi seawater due to the enrichment of seawater at Dubai with domestic sewage waters which has distinctly elevated the levels of the nutrient salts particularly in inner-most parts of the creek leading to eutrophication signs. The changes occurred in the receiving creek water of Dubai as a result of waste-water disposal that have also reflected on the atomic ratios of nit: Effect of pollution rogen: phosphorus: silicon.
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This work deals with adsorption of salt and expulsion of moisture in Synagris japonicus, Sciaenids sp. and Lactarius lactarius during prolonged salting. The fish used in this study were procured fresh and handled immediately. They were gutted, gilled, cleaned well and salted. Results indicated that larger salt proportions and higher temperature of salting both accelerate the rates of absorption of salt and shedding of moisture by fish muscle during salt curing.
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While carp themselves may destroy carp eggs by sucking from outside the happa, destruction in the absence of carp also occurs. During observations of the effect of electrical field on developing carp eggs it was seen that the egg membrane ruptured prematurely under certain potential differences. In natural waters and mud potential differences occur in the presence of high concentrations of certain salts compared with the internal concentration. Temperature and pH fluctuations following strong sun or heavy rain accelerates the diffusion of ions along side water through the egg membrane. The egg cells expand rapidly and the embryos were rapidly dropped.
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The paper presents results of studies on the effect of seasonal variations in the fat content on the quality and shelf life of dry cured, pickle cured and smoke cured oil sardines. The merits and defects of each method of curing during different seasons are discussed.
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Results of chemical, bacteriological and organoleptic quality studies of cured fishery products of commerce collected from six major fish curing centres on the west coast of India are presented. 77.12% of the samples had moisture above 35%, 97.18% showed salt content below 25% and all samples had acid insoluble ash above 1.5%. 42.32% gave standard plate counts above 10,000 and 45.77% were contaminated with 'Red' halophiles. The major defects in curing were imperfect cleaning, inadequate salting and unhygienic conditions of processing.