Temperature_Control_in_Seafood

CONTENTS 1. INTRODUCTION 2. TEMPERATURE CONTROL IN PROCESSING OF FROZEN COOKED AND CLEANED SHRIMP PRODUCTS. 3. MANAGEMENT IN MONITORING AND VERIFICATION OF TEMPERATURE CONTROL IN RELATION WITH FOOD SAFETY PROCEDURES IN FROZEN COOKED AND CLEANED SHRIMP PROCESSING. 4. CRITICAL ANALYSIS IN CASE OF AN INCIDENT WITH FAILURE OF TEMPERATURE CONTROLLING IN FROZEN COOKED AND CLEANED SHRIMP PROCESSING. 5. RECOMMENDATION. 6. CONCLUSION 7. REFERENCES INTRODUCTION All fish and shell fish deemed fit for human consumption should always handle properly with particular attention should pay on time and temperature control. The storage of food is important to ensure adequate provision throughout the year. Correct storage of food is fundamental to the hygienic and profitable operation of any food business .Failure to ensure satisfactory conditions of temperature, humidity stock rotation and the integrity of packaging can result in problems of unfit or spoiled food. Spoilage occurs due to three main causes , bacterial , enzymatic , and biochemical .Fresh shrimps constitute a highly perishable food commodity and spoil very fast if adequate precautions are not taken while fishing and further processing .Being the most perishable human foods , shrimps and other fishes start spoiling the moment they are taken out of water and die . Temperature being a very important factor accelerates the process of spoilage. The best to prevent spoilage is by means of refrigeration technique. The simplest method is addition of ice .So all these points leads to the point temperature control. Heat and cold Heat is a form of energy, its use causes chemical bonds to bend, extends and contract, and sometimes so much that they shake themselves apart or collide in unpredictable ways. Cooling, by contrast causes the slowing down in chemical movements and therefore of chemical reactions .Cooling below freezing results in usable form; ice is water interacting with other molecules of water. In this form, the water molecules are denied to the molecules that make up cells and that rely on water for their activity. Cooling and heating food [or bacteria] is demanding on time since the crucial factor is the heating and cooling of water. All living things are between 50% to 80% of water and water demands 4.2 kJ of energy to raise 1 kg through 1 degree Celsius. Cooling food demands that this energy be lost and hence the difficulty of bringing food through the 5•cto 63•c,danger zone., in which the majority of pathogens survive and especially that middle range of 20•c to 50•c to accelerate the process in either direction by creating a bigger difference between the surrounding temperature and the temperature of food, thus creating a steeper temperature gradient and consequently steeper energy gradient . The maintenance of the desired temperature is how long the gradient is applied, so the effectiveness of heating or cooling is equally dependent on the time of cooking and cooling. Cooking causes the de- naturation [disruption] of proteins. That is it disrupted the movement of charged molecules and atoms in and out of cell. Similarly, if the cell is frozen, the water in the cell may crystallize as ice expanding and forming sharp edged crystals that may physically puncture the cell membrane, though freezing does not destroy all micro- organisms and is not effective at reducing micro organisms to safe level. So this disruption of the shape is called denaturing of proteins .Denaturizing of many proteins starts at around +63•c, but some proteins will survive as high as +80•c.Effective cooking drastically reduce the number of living microbes present , removing not only the pathogens but also the harmless commensal organisms . TEMPERATURE CONTROL IN PROCESSING OF FROZEN COOKED AND CLEANED SHRIMP PRODUCTS. Shrimps for frozen product originate from a wide variety of sources as varied as deep cold seas shallow tropical inshore waters and rivers through to aquaculture in tropical and semi tropical regions. The methods of catching, or harvesting and processing are as equally varied. In northern regions caught by freezer vessels, cooked, individually quick-frozen and packed on board in their marketing form. More often however, they will be raw IQF on board for further processing at on-Plants, or even landed chilled on ice. Shrimps of these species are invariably pre-cooked at onshore plants through in-line integrated process lines, followed by mechanical peeling, cooking, freezing ,Glazing and packing. A much larger product line is produced in tropical and sub-tropical countries wild caught and cultivated species: whole, headless (head off), peeled, peeled and defined and/or cooked products presented in different marketing forms (easy-peel, tail-on, tail-off butterfly ,stretched, sushi shrimp). This wide range of products is prepared in shrimp processing plants that may small and use manual techniques or large dimensions fully mechanized equipments. Cooked shrimp products are generally peeled after cooking. Warm water shrimps may also be subject to further benefit processes such as marinating and crumb coatings. Since some raw shrimp products, as well as cooked ones, may be consumed without further processing safety considerations are paramount. The processes described above are captured on the flow chart, but it must be appreciated that because the diverse nature of production methods individual HACCP/DAP plans must be devised for product. Shrimps should be inspected upon receipt to ensure that they are well iced or deep-frozen and properly documented to ensure product tracing. Shrimps should be stored in suitable facilities and allocated use-by times for processing to ensure quality parameters are met in products. A sensory evaluation should be performed on incoming lots to ensure that the product is of acceptable Quality and not decomposed. It is necessary to wash fresh shrimps after receiving in adequate equipment with a series of low velocity sprays with chilled clean water. Commercial preservation techniques in shrimp industry Preservation is the treatment of food to prevent or delay spoilage and inhibit growth of pathogenic organisms, which would render the food unfit .the usual preservation technique involves 1. The use of low temperatures or high temperatures [chilling, Cooking, freezing.] 2. Moisture control [control water content when freezing and cooking ] 3. Use of chemicals [salting] 4. Controlled atmosphere or restriction of oxygen.[during thawing, processing and packing] 5. Smoking [for smoked items only]. These techniques described in shrimp production method of cooked shrimp product. Equipments and machinery The equipments and machineries used for the temperature control purpose are thawing device [defrosting chamber], cooker, blast chiller, counter flow chiller, freezer, glazer and glaze hardening, automatic packing systems, cold stores, and refrigerated distribution vehicles. Thawing chamber The raw frozen shrimps are generally in block form having -18 to -22•c.Such block shrimps are thawed under controlled atmospheric conditions by using special advanced equipments. After defrosting the product temperature do not exceed +5 •c, helps to keep the product under safety. Cooker Cookers should be designed to provide constant and adequate supply of heat so that all crustaceans could be given the same time/temperature exposure during the cooking operation. The cooking process is one of the very important steps in cooked shrimp production. Cooking can be defined as means boiling of crustaceans in potable water, clean seawater or brine or heating in steam for a period sufficient for the thermal centre to reach a temperature adequate to coagulate the protein. The equipments are of three different types, that is either steam cooking or water cooking or a combined form, in which steam provide heat energy and water becomes the cooking media. The cookers in present shrimp industry are of advanced types. So minute temperature fluctuations are maintained immediately to proven the core temperature of the product after cooking should always be effected above +75•c. Blast chiller Blast chiller is a cabin with chiller facilities to give a continuous chilling effect to the semi-processed products on emergencies or to keep the raw material during work in process stage. The blast chiller must need a temperature monitoring display system, it should be monitor frequently and noted in the log for traceability .The iced raw material also kept in this cabin as a measure for food safety. Counter flow chiller This is a continuous chilling system placed in the processing line to reduce the product temperature from the high cooked stage to a sudden cooling stage. For effecting cooling, the product should pass through the chilled water for seconds. This gives cold shock effect on the spores to prevent the future germination. Chilling should take place as rapidly as possible to prevent microbiological growth and deterioration. Freezer Freezing systems are of different types, fluidized – bed – freezer, air blast freezer, plate freezer, cryogenic freezer, Pello freeze system. These modern freezing equipments are works on the principle of quick freezing. The quick freezing and slow freezing methods have direct impact on the product quality. A. Fluidized bed freezer – vegetables and peas are moved along a tunnel on perforated tray, through a blast of very cold air. This freezer generates a cushion of airflow forced up from below. Therefore, each piece is individually quick-frozen. The process takes three to eight minutes. B. Air blast freezer – they are the commonest method of freezing and include static tunnels in which trolleys of boxed products such as beef, and cakes, fishes, fillets, steaks, shrimps whole etc. In air blast freezers solid continuous belt freezer also used widely for shrimp production, are called spiral freezer. Air circulates around the food at temperatures of -30•c to -40•c. The freezing time depends on the dimension of the food. C. Plate freezer- method of freezing is used for food packed in flat cartons. The common items used for this type of freezing are meals and shrimp blocks, squid whole blocks, cuttle fish blocks, octopus in blocks etc. in this type the product is placed between narrow shelves in which the very cold refrigerant passes or circulates , so ensuring freezing . It takes about two to three hours. D. Cryogenic freezer- the food is sprayed or dipped in to cold refrigerant such as liquid nitrogen, it is a very quick technique and although capital cost relatively very low. High refrigerant costs restrict its use to high cost, small products such as raspberries and prawns. E. Pello freeze system – it is an interesting development in freezing technology, which involves liquids and semi solids in pellet form. Cream, orange juice, egg and soup have all been frozen commercially by this method. Glazer and glaze hardener Glazing is applied to frozen shrimps to protect against dehydration and maintain quality during storage and distribution. Ice block frozen shrimps is the simplest form of glazing, followed by dipping and draining frozen shrimps in chilled potable water. A more sophisticated process is to pass frozen size graded shrimps under cold-water sprays on vibratory belts such that the shrimps pass at a steady rate to receive an even and calculable glaze cover. Ideally, glazed shrimps should receive a secondary re-freezing prior to packing, but if not, they should be packaged as quickly as possible and moved to cold storage. If this is not achieved, the shrimps may freeze together and ‘spot weld’ or clump as the glaze hardens. There are Codex methods for the determination of glaze. Automatic packing systems They are the advanced multi head weighing equipments used to pack quickly without any delay. This system enables to control the temperature and time as far as possible. Cold stores Insulated facility having blowers with freezing equipments operating temperature of -25•c to -30•c.Frozen products should be stored at frozen temperature in a clean, sound and hygienic environment. The facility should be capable of maintaining the temperature of the shrimp at or below minus 18oCwith minimal temperature fluctuations (+ or -3oC).the storage area should be equipped with a calibrated indicating thermometer. Fitting of a recording thermometer is strongly recommended. A systematic stock rotation plan should be developed and maintained. Products should be properly protected from dehydration, dirt and other forms of contamination. All frozen products should be stored in the cold store to allow proper air circulation. Refrigerated distribution vehicles Vehicles used for the distribution of frozen perishable food items always be an insulate and refrigerated. Insulation of the roof and floor is as important as the walls. Properly located thermometers are very important. A sensor fitted in the returned airflow system will record the maximum temperature, and the minimum temperature can be recorded near the outlet of the evaporators. These vehicles are designed for frozen or chilled products only. Vehicles should be pre cooled prior to the loading. Loading must be carried out as quickly as possible to avoid unacceptable temperature rises. The temperature of food should be checked on arrival. Food requiring refrigerated storage should be rejected if above 8 •c and food rejected if above -12•c. Deliveries must be placed in refrigerated storage as quickly as possible to avoid temperature exceeding the rejection stage .The quick frozen food to be delivered below -15•c.