Airborne Microorganisms in a Pork Processing Establishment

Airborne microorganisms were enumerated in the various processing rooms of a commercial pork slaughter and further processing plant, every other month for a year. The room where sausage emulsions were prepared had higher airborne aerobic bacteria and yeast-mold counts than the other rooms sampled. The mean log aerobic bacteria counts per 0.028 m³ across months were 1.83, 1.83, 1.82, 1.71, 1.93, 2.48, 2.08, 1.62, and 0.95 for the evisceration, offal, carcass cooler, carcass breaking, curing cellar, sausage emulsion preparation, sausage stuffing, sausage packaging, and sliced meat packaging rooms, respectively. The mean log yeast-mold counts per 0.028 m³ for the same rooms were 0.90. 0.88, 0.32, 1.06, 1.11, 1.25, 1.03, 1.01, and 0.97, respectively. Coliform counts did not exceed 5 per 0.028 m³ in any of the samplings and usually were totally absent from the sampled air except in the sausage stuffing and the offal rooms. The mean log aerobic counts per 0.028 m³ for all sampling locations combined were 1.86, 1.78, 1.78, 1.14, 1.84, and 1.93 for February, April, June, August, October, and December, respectively. The lowest count was during the August sampling, and may represent more outside air being introduced into the plant. The mean log yeast-mold counts per 0.028 m³ for the same months were 0.84, 0.53, 1.12, 0.91, 1.04, and 1.03, respectively. The mean temperatures (°C) of the processing rooms referred to above, across months, were 19.5 ± 3.3; 19.4 ± 4.1; 2.4 ± 1.4; 11.0 ± 2.5; 7.0 ± 1.2; 10.0 ± 2.1; 9.3 ± 1.8; 9.6 ± 1.1; and 10.6 ± 0.8, respectively. Different (P<0.05) temperatures within processing rooms among months were noted for the carcass cooler, curing cellar, sausage stuffing, sausage packaging, and sliced meat packaging rooms. These data provide baseline data for the airborne microorganisms in the various rooms in a pork processing establishment.