Canned meat provides high-quality, protein-rich food that is stable at ambient temperatures .
Canned meat products include whole muscles, meat stews, luncheon meat, sausages, sauces with meat pieces, and paste products.
Meat Canning is a great method to preserve and extend shelf life and is essentially includes three main operations: can filling, exhaustion, and heat treatment.
Products are prepared by hermetically sealing (preventing the escape or entry of air) the product in a container (usually tin coated steel cans) and thermally processed to destroy spoilage microorganisms. Canned meat products also called thermally processed products may be grouped into two categories: sterilized products and pasteurized products. Sterilized products must be heated to reach an internal temperature of at least 101 °C (heating temperature of 121 °C) and are shelf-stable. In commercially sterile canned meat products, all viable microorganisms including spores be either destroyed or rendered dormant. Canned products are processed in retort cooker that operates under 12–15 psi pressure. Recently metal cans have been replaced by retort pouches i.e., laminated multi-layer, flexible pouches which can withstand high temperature and pressure processing. These laminated pouches act as barrier to gases and moisture. Foil-laminated retort pouches costs less and are lighter in weight enabling easy distribution and marketing with faster processing time.
CHARACTERISTICS OF HEAT-TREATED PRESERVED MEAT AND MEAT PRODUCTS
The prolonged shelf-life of heat-treated meat and meat products is achieved through reducing growth of, or inactivating, micro-organisms by a thermal process. The principal steps of the heat preservation method are to:
1. place the product in a container (can, glass jar, pouches of synthetic material or laminate with aluminium) which is hermetically sealed after filling and which is impermeable to any external substances; and
2. submit the hermetically sealed product to thermal treatment with a defined temperature and time combination.
The thermal death time for spores of Clostridium botulinum at 121°C is 2.45 minutes or in other words, an F-value of 2.45 is needed to inactivate all these spores in the product at 121°C. Spores of other micro-organisms are more or less heat resistant. Vegetative cells of micro-organisms are generally destroyed at temperatures of less than 100°C and therefore play no role in the F-value calculations.
The definition of the F-value at 121°C is as follows:
F = 1: lethal effect at 121°C on micro-organisms after 1 minute
F = 2(3, 4, etc.): lethal effect at 121°C on micro-organisms after 2(3, 4, etc.) minutes. In below tables some examples are given for F-values obtained at different time/temperature combinations:
F-values corresponding to various temperatures
|F = 0.003
|F = 0.008
|F = 0.025
|F = 0.079
|F = 0.251
|F = 1.0
|F = 2.51
|F = 7.94
F-values in relation to temperature and time
|In order to reach F = 1, the following time-temperature combinations are required:
|110°C during 12.5 minutes
|116°C during 3 minutes
|121°C during 1 minute
|130°C during 0.13 minutes
|In order to reach F = 4, the following parameters are required:
|110°C during 50 minutes
|116°C during 12 minutes
|121°C during 4 minutes
|130°C during 0.5 minutes
|In order to reach F = 0.6, the following parameters are required:
|110°C during 7.5 minutes
|116°C during 2 minutes
|121°C during 0.6 minutes
|130°C during 0.08 minutes