Processing Of Chilled Foods

Chilled-food processing lines are designed to produce quality finished products as well as to control the presence and growth of microorganisms in finished products. A particular production method may be used in concert with another to produce a product of superior organoleptic and microbiological quality. The following procedures are common throughout the industry in the production of chilled foods.

Controlled Product Handling During Processing

Product handling during all phases of chilled-food production is crucial from a microbiological safety and quality standpoint. A typical processing diagram for chilled foods indicating separation of production zones can be found in Figure 6.

Separate zones for raw receiving, preprocess preparation, product assembly and cooking, pasteurization, chilling, and packaging are usually identified and maintained in chilled-food operations (2). Physical separation of different production zones is necessary to prevent cross-contamination between raw and cooked or processed product. Other aspects of hygienic process design, such as clean rooms and air handling systems, may be incorporated into chilled-food processing to reduce the risk of microbial contamination. For example, clean rooms may be maintained in the assembly and packaging of already-processed constituents, and air handling systems may be used to filter particles 0.5 ¡xm or smaller from product assembly areas to minimize postprocess microbial contamination. A rigorous cleaning protocol for machines and the factory environment is also to be included as part of a good manufacturing practice for the manufacture of chilled-food products (3).


Pasteurization involves heating food products to eliminate specific types of microorganisms. Chilled products can be pasteurized before packaging and clean-filled (hot fill hold) or filled and pasteurized in-pack (IPP). Cooking processes may be considered as part of the pasteurization process, but care must be taken to prevent contamination during latter processing steps. For chilled products having an expected shelf life of 10 to 14 days, a minimal heat process to eliminate infectious pathogens is recommended, especially if the product is ready to eat. An example of a typical process for these product types is 70°C per 2-min hold, which will eliminate 106 Listeria monocytogenes per gram of product. Chilled products having an expected shelf life of more than two weeks generally require a more severe process to eliminate spore-forming psychrotrophic pathogens. Typical processing conditions for these extended shelf-life products are at least 90°C per 10-min hold to eliminate 10® nonproteolytic, psychrotrophic Clostridium botulinum per gram of product.

Pasteurization processes are defined in terms of P-value, which is the time a product is held at a certain processing temperature (typical value for nonproteolytic C. botulinum would be written as P90»c = 10). Conventional

Figure 5. Actual and predicted market for chilled foods in Japan, 1992-2001.

Homemade Pet Food Secrets

Homemade Pet Food Secrets

It is a well known fact that homemade food is always a healthier option for pets when compared to the market packed food. The increasing hazards to the health of the pets have made pet owners stick to containment of commercial pet food. The basic fundamentals of health for human beings are applicable for pets also.

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