72 Chilled foods storage life and the length of time that elapses before freezing occurs. Chilled storage of lamb for one day at ooC prior to freezing can reduce the subsequent storage life by as much as 25% when compared to lamb which has undergone accelerated conditioning and 2 hours storage at 0C. - It has been shown that pork which had been held for seven days deteriorated at a faster rate during rage than carcasses chilled for one and 4s AgeI ing for periods greater than seven days was found by Zeigler" to produce meat with high peroxide and free fatty acid values when stored at.C or -29oC Although shorter ageing times appear to have a beneficial effect on storage life there is obviously a necessity for it to be coupled with accelerated conditioning to prevent any toughening effects. Whilst there has been significant research in such areas as these, little appears to be known about the relationship between the frozen storage life of meat as a raw material and the chilled life of the product in 3.3.2 Poultry After bleeding and death, poultry carcasses are scalded by immersing them in hot water for approximately three minutes. Scalding loosens the feathers so that they can be easily removed. Carcasses can either be soft scalded at 52-53oC or marketed in a chilled state it will be soft scalded and air or spray chilled 2 g hard scalded at 58C Hard scalding removes the cuticles on chicken skin, which gives an unattractive appearance after air chilling. Generally if the poultry is Spray washing is used at numerous points during processing to remove visual contamination. It also has some small role in reducing bacterial contamination The EU Poultry Meat Directive 0 requires poultry to be washed inside and out immediately prior to water chilling. The amount of water to be used (i.e. 1.5 litres for a carcass up to 2.5 kg)is defined in the directive. Water chillers are designed to operate in a counter-current manner to minimise cross-contamination. Th carcasses exit from the chillers at the point where the clean, chilled water enters the system. Again, the Directive defines a minimum water flow through the chiller, i.e. at least one litre per carcass for carcasses up to 2.5 kg in weight Chicken breast muscle ages ten times faster than beef (Table 3.4). He ence geing in poultry carcasses occurs during processing and is usually accomplished before they reach the chiller/freezer. Pool et al. have shown that there were no detectable flavour differences over an 18-month period between turkey that had been frozen immediately and turkey that had been held at +2C for 30 hours 3. 4 Conclusions Even with the best practice, the maximum shelf-life of chilled meat can be measured in weeks. Freezing will extend the storage life of meat to a number of years. If the frozen storage life is not exceeded, freezing and frozen storage ofstorage life and the length of time that elapses before freezing occurs. Chilled storage of lamb for one day at 0ºC prior to freezing can reduce the subsequent storage life by as much as 25% when compared to lamb which has undergone accelerated conditioning and 2 hours storage at 0ºC.12 It has been shown that pork which had been held for seven days deteriorated at a faster rate during storage than carcasses chilled for one and three days.48 Ageing for periods greater than seven days was found by Zeigler49 to produce meat with high peroxide and free fatty acid values when stored at
18ºC or
29ºC. Although shorter ageing times appear to have a beneficial effect on storage life there is obviously a necessity for it to be coupled with accelerated conditioning to prevent any toughening effects. Whilst there has been significant research in such areas as these, little appears to be known about the relationship between the frozen storage life of meat as a raw material and the chilled life of the product in which it is used. 3.3.2 Poultry After bleeding and death, poultry carcasses are scalded by immersing them in hot water for approximately three minutes. Scalding loosens the feathers so that they can be easily removed. Carcasses can either be soft scalded at 52–53ºC or hard scalded at 58ºC. Hard scalding removes the cuticles on chicken skin, which gives an unattractive appearance after air chilling. Generally if the poultry is marketed in a chilled state it will be soft scalded and air or spray chilled. Spray washing is used at numerous points during processing to remove visual contamination. It also has some small role in reducing bacterial contamination. The EU Poultry Meat Directive50 requires poultry to be washed inside and out immediately prior to water chilling. The amount of water to be used (i.e. 1.5 litres for a carcass up to 2.5 kg) is defined in the directive. Water chillers are designed to operate in a counter-current manner to minimise cross-contamination. The carcasses exit from the chillers at the point where the clean, chilled water enters the system. Again, the Directive defines a minimum water flow through the chiller, i.e. at least one litre per carcass for carcasses up to 2.5 kg in weight. Chicken breast muscle ages ten times faster than beef (Table 3.4). Hence, ageing in poultry carcasses occurs during processing and is usually accomplished before they reach the chiller/freezer. Pool et al.51 have shown that there were no detectable flavour differences over an 18-month period between turkey that had been frozen immediately and turkey that had been held at +2ºC for 30 hours. 3.4 Conclusions Even with the best practice, the maximum shelf-life of chilled meat can be measured in weeks. Freezing will extend the storage life of meat to a number of years. If the frozen storage life is not exceeded, freezing and frozen storage of 72 Chilled foods