ASSESSMENT OF THE HYGIENIC CHARACTERISTICS OF A PROCESS FOR THE DISTRIBUTION OF PROCESSED MEATS, AND OF STORAGE-CONDITIONS AT RETAIL OUTLETS

The temperature histories of boxes of fresh sausages and wiener sausag es were collected from three consignments in each of nine loads carrie d in each of two refrigerated trucks that distributed the products to retail outlets. Each temperature history was integrated with respect t o models describing the dependencies on temperature of the growths of Escherichia coli, Listeria monocytogenes and leuconostocs. A storage e fficiency factor was calculated for each history from the calculated p roliferation of leuconostocs. Both types of product in truck A cooled towards the truck air temperature of -3.5 degrees C during transportat ion periods of up to about 36 h. Temperatures of all product remained too low for the growth of E. coli. All growth of L. monocytogenes was calculated to be <1 generation, except when transportation was precede d by assembly of a consignment on the day before dispatch. Most storag e efficiency values for fresh sausages and wiener sausages were >40% a nd 13%, respectively, with the highest values being obtained for the l ongest histories. The temperatures of fresh sausages in truck B genera lly rose towards the truck air temperature of 2 degrees C. The tempera tures of wiener sausages generally fell or remained unaltered. However , control over product temperatures was lost with three consignments i n which temperatures rose to >7 degrees C. Proliferations of E. coli < 1 generation, and of L. monocytogenes >1 generation were calculated fo r some temperature histories. Most storage efficiency values for fresh and wiener sausages were <40% and <13%, respectively. The process of transportation in truck B would be hygienically inadequate if transit times were extended beyond one working day. Thirty-seven of the temper ature records included post-delivery periods that were of sufficient d uration for the conditions experienced by products at 25 retail outlet s to be identified. The temperature histories from five outlets were c haracterized by average temperatures >4 degrees C, storage efficiencie s <16%, E. coli proliferations >1 generation and/or L. monocytogenes p roliferations averaging >1 generation/day. Poor control of product tem peratures at those outlets was variously due to mismanagement of loadi ng product from transport to storage, high temperatures of delivered p roduct, or high operating temperatures of storage chillers. The temper ature histories from 18 outlets were characterized by average temperat ures between 1.3 and 3.5 degrees C, storage efficiencies between 19 an d 35%, little (less than or equal to 0.2 generation) or no E. coli pro liferation and proliferation of L. monocytogenes averaging <1 generati on/day. Superior control over product temperatures occurred at only tw o outlets, where average temperatures were about 0 degrees C, storage efficiencies about 50% and proliferation of L. monocytogenes averaged <0.1 generation/day.