210 Meat refrigeration Table 10.2 General levels of microbiological contamination reported on meat carcasses throughout the world Type of ry APC*K Reference (logo org 19-3.7 Ingram and Roberts(1976) Ingram and roberts (1976) New zealand Ingram and Roberts (1976) New Zealand Norway 1.3-3.9 chanson et aL. (1983) Roberts et al. (1984) 4-3.8 Hudson et al. (198 New zealand 04-3.3 Bell et al.(1993) australia Anon(1997) Canad 1.5-3.2 Gill et al.(1998b) Hinton et al.(1998) Lamb/ New Zealand Newton et al.(1978 Prieto et al. (1991) New Zealand 2.3-4.1 Bell et al. (1993) New Zealand Biss and Hathaway(1995) australia 2.5-3.3 Ingram and Roberts(1976) Hanson et al.(1983) 16-3.8 Christensen and Sorensen(1991) 4.3-5.0 Barbuti et aL. (1992) 4 Values are not directly comparable since different sampling techniques and incubation temperatures have been used The initial level of bacterial contamination will of course affect the storage life. Over 40 years ago Ayres(1955), in his comprehensive review of microbiological contamination in slaughtering, concluded that an aerobic population of 4.0-5.0logio cfucm- and an anaerobic population of between 3.7 and 4.7" would be reasonable for wholesale cuts of meat Surveys from the mid-1970s have shown that in general levels of between 1 and logo cfug- can be expected on red meat carcasses(Table 10.2) Specific surfaces of the carcass can have very high levels of initial con- tamination Beef subcutaneous fat has been shown to have a high initial microbial load and a capacity to support extensive bacterial growth(Lasta et aL., 1995). Initial values of total viable counts increase from an initial value of 5.4 to 10.0logo cfucm" after 11 days in a moist environment at 5C (Fig. 10.2). No noticeable deterioration in appearance of the sample was found after 14 days which was worrying. This type of material is often incor orated in manufactured products or could provide a cross contamination source The above results were obtained on the surface of samples stored in air nearly saturated with water vapour. There is much industrial belief that the surface of meat carcasses must be allowed to dry or storage life will be com-The initial level of bacterial contamination will of course affect the storage life. Over 40 years ago Ayres (1955), in his comprehensive review of microbiological contamination in slaughtering, concluded that an aerobic population of 4.0–5.0 log10 cfucm-2 and an anaerobic population of between 3.7 and 4.7 log10 cfug-1 would be reasonable for wholesale cuts of meat. Surveys from the mid-1970s have shown that in general levels of between 1 and 4 log10 cfu g-1 can be expected on red meat carcasses (Table 10.2). Specific surfaces of the carcass can have very high levels of initial con￾tamination. Beef subcutaneous fat has been shown to have a high initial microbial load and a capacity to support extensive bacterial growth (Lasta et al., 1995). Initial values of total viable counts increase from an initial value of 5.4 to 10.0 log10 cfu cm-2 after 11 days in a moist environment at 5°C (Fig. 10.2). No noticeable deterioration in appearance of the sample was found after 14 days which was worrying.This type of material is often incor￾porated in manufactured products or could provide a cross contamination source. The above results were obtained on the surface of samples stored in air nearly saturated with water vapour. There is much industrial belief that the surface of meat carcasses must be allowed to dry or storage life will be com- 210 Meat refrigeration Table 10.2 General levels of microbiological contamination reported on meat carcasses throughout the world Type of Country APC* Reference meat (log10 organism) Beef UK 1.9–3.7 Ingram and Roberts (1976) Sweden 2.2–3.4 Ingram and Roberts (1976) New Zealand 1.3–4.3 Ingram and Roberts (1976) New Zealand 1.4–2.2 Newton et al. (1978) Norway 1.3–3.9 Johanson et al. (1983) EU 2.3–3.9 Roberts et al. (1984) UK 3.4–3.8 Hudson et al. (1987) New Zealand 0.4–3.3 Bell et al. (1993) Australia 3.2 Anon (1997) Canada 1.5–3.2 Gill et al. (1998b) UK 2.45–4.29 Hinton et al. (1998) Lamb/ New Zealand 2.5–2.9 Newton et al. (1978) sheep Spain 4.96 Prieto et al. (1991) New Zealand 2.3–4.1 Bell et al. (1993) New Zealand 3.9–4.6 Biss and Hathaway (1995) Australia 3.9 Anon (1997) Pig UK 2.5–3.3 Ingram and Roberts (1976) Norway 2.6–3.9 Johanson et al. (1983) Denmark 1.6–3.8 Christensen and Sørensen (1991) Italy 4.3–5.0 Barbuti et al. (1992) * Values are not directly comparable since different sampling techniques and incubation temperatures have been used