324 Meat refrigeration Table 16.3 Examples of commercial ham cooling in the UK Cooling method 动品 Total Final rature° In metal mould in chill oom17to6°C,0.2ms In bag in chill room -3°Cto-10°0.3ms In bag water shower then chill room at-1°then 3°Cto5°C In bag in ambient 13.5 15°Cto7°C Source: James, 1990c later study cooling times were still as long as 16h but final temperatur.e as 21h, and final temperatures high: 15-20C(Table 16.3, Table 16.4). In the were no higher than 8C (Table 16.6) A similar picture is seen in data on the cooling of cooked pork with final mperatures as high as 12C and cooling times of up to 20h(Table 16.4) Corresponding figures for the cooling of cooked beef were 15C and 22h (Table 16.4). Data obtained from numerous sources within the UK cater- ing industry by Mottishaw(1986)indicate that the cooling procedures for bulk-cooked meats could also vary considerably(Table 16.6). For example, some meat products are said to be cooled to 1C in 2h, whereas at the other extreme, products may take 72h to cool to 4 C. Commonly, a 4.5kg product ill take 12h to cool below 5C and larger products could take longer. In ddition, there is often a delay before chilling begins, this may vary from 10 min up to 6h 16.1.3 Experimental studies The most relevant cooling data for cooling of cooked meat from laboratory investigations are shown in Table 16.7. A simple process for estimating the immersion cooling time of beef roasts has been produced by Nolan (1986). Generally, the results show that immersion cooling is almost twice as fast as air cooling at the same temperature. Vacuum cooling was an order of magnitude faster than immersion cooling but the weight loss was substantially (over twice) higher. Using a less severe vacuum treatment or a combination of the different methods is likely to provide an optim solution The James and Bailey(1982) study showed that in ham cooling, a 0. 75h initial cooling period in ambient air reduced the initial load on the refrig- eration by a factor of almost 2. If the ham was placed straight into air atas 21 h, and final temperatures high: 15–20 °C (Table 16.3,Table 16.4). In the later study cooling times were still as long as 16 h but final temperatures were no higher than 8 °C (Table 16.6). A similar picture is seen in data on the cooling of cooked pork with final temperatures as high as 12 °C and cooling times of up to 20 h (Table 16.4). Corresponding figures for the cooling of cooked beef were 15 °C and 22 h (Table 16.4). Data obtained from numerous sources within the UK cater￾ing industry by Mottishaw (1986) indicate that the cooling procedures for bulk-cooked meats could also vary considerably (Table 16.6). For example, some meat products are said to be cooled to 1 °C in 2 h, whereas at the other extreme, products may take 72 h to cool to 4 °C. Commonly, a 4.5 kg product will take 12 h to cool below 5 °C and larger products could take longer. In addition, there is often a delay before chilling begins, this may vary from 10 min up to 6 h. 16.1.3 Experimental studies The most relevant cooling data for cooling of cooked meat from laboratory investigations are shown in Table 16.7. A simple process for estimating the immersion cooling time of beef roasts has been produced by Nolan (1986). Generally, the results show that immersion cooling is almost twice as fast as air cooling at the same temperature.Vacuum cooling was an order of magnitude faster than immersion cooling but the weight loss was substantially (over twice) higher. Using a less severe vacuum treatment or a combination of the different methods is likely to provide an optimum solution. The James and Bailey (1982) study showed that in ham cooling, a 0.75 h initial cooling period in ambient air reduced the initial load on the refrig￾eration by a factor of almost 2. If the ham was placed straight into air at 324 Meat refrigeration Table 16.3 Examples of commercial ham cooling in the UK Cooling method Weight Height Cooling Total Final (kg) of joint time to (h) temperature (°C) (cm) 20 °C (h) In metal mould in chill 6.4 19 12 1.4 15 room 17 °C to 6 °C, 0.2 ms-1 In bag in chill room 7.3 18 9.3 21 2 -3 °C to -10 °C, 0.3 ms-1 In bag water shower then 6.8 18 6.6 14 5 chill room at -1 °C then 3 °C to 5 °C In bag in ambient 6.8 20 – 13.5 24 15 °C to 7 °C Source: James, 1990c