Frozen meat causes a number of problems with regard to transporting, storage, quality maintenance and processing. The most promising method of thawing frozen meat is the use of saturated steam in a vacuum.
Compared to air treatment, the thawing duration is reduced by 30-50%. Vacuum massage defrosters also require less space than other conventional industrial installations. As result of the vacuum, contamination with bacteria is also avoided. Movement of the product during the thawing process ensures equal warming, which also improves the quality and prevents too intensive warming.
The main advantage of the present method is the reduction of losses. These do not exceed 1% and in certain cases even an increase in mass can occur. The most effective method is achieved in connection with simultaneous massaging and thawing. At present vacuum massage defrosters are supplied by CFS, Lutetia, Henneken and Meat Master among others.
CFS ScanMidi uses an enclosed steam process in which meat, poultry and prawns are thawed out evenly from -18°C to +2°C without loss of weight and in 50% less time than with traditional methods. Specialists at CFS point out that the products do not only thaw out more quickly, but can also be massaged and marinated, which is of particularly advantage in the case of poultry pieces.
The controlled steam temperature in the tumbler does not exceed 30°C. With this PLC controlled method improved quality, increased profitability and a greater throughput are achieved. A cover with a diameter of 90cm gives improved access to the installation. The installation is also better to operate and saves energy,
The CFS ScanMidi defroster thaws meat from -18°C to +1°C in 6-8 hours. As there is no loss of meat juices the yield increases by 3-10%. Through being in a vacuum with low pressure steam the meat protein does not coagulate.
In the case of the patented defrosting system by Lutetia the frozen blocks of meat are thawed in a vacuum massager with steam from -25°C to +3 to +4°C in two processes. Gradual warming of the products takes place through steam injection in a controlled vacuum. Breaking down of the blocks and maintenance of a uniform temperature are assured. An automatic control assures the internal temperature in the drum, the pressure, the quantity of steam, the speed of rotation, the time cycle of the drum and the vacuum in the drum. On reaching the set product temperature the massager switches off.
The advantages of the installation consist in the preservation of the quality of fresh meat and a 5-7% greater yield with a treatment duration of 4-12 hours. The installation requires less production space, with an area of only 8.5 m2 sufficing to thawing 3.5 tonnes of raw material. The combined defrosting and massage installation also ensures improved hygiene.
Henneken builds combined installations for large and small enterprises with a drum volume of 650-12,000l for ham, poultry, seafood, meat with or without bones. The drums have guides for moving the product laterally and longitudinally and guarantee a uniform temperature distribution. A Siemens microprocessor makes up to 99 programmes possible. The drum speeds can be changed from 0.5 - 12 revolutions per minute.
Russian research and development institutions have developed an installation for combining the thawing, salting and cutting of meat in a vacuum. Control examinations of the treated products show improved water uptake by the meat proteins and improved water binding in the muscle tissue, which prevent the loss of meat juices.
The developed system comprises three parts: a vacuum mixer, a steam generator and a vacuum system. For intensive steam production in a vacuum superheated steam is used and a stable warming process with improved energy use is achieved. The vacuum mixer is designed as a cylinder with internal fittings for mixing the product and for special differentiated supply of the heat carrier. Salting can take place with brine or pulverised salt. The vacuum can be regulated between 1.3 and 2.9kPa and is produced by a water ring vacuum pump.
Through the variable use of the steam and vacuum system the installation is suitable for various product treatments, e.g. vacuum cooking, cooling, dewatering, massaging and salting. Source: Meat TechnologyAuthor: ast / Editor fleischnet