Bacteriological contamination levels in reception and storage equipments of milk in Milk Collection CenterS in the province of Valdivia

Abstract

In order to evaluate the bacteriological quality of the equipments used for milk transport, reception and storage, an investigation was conducted in three Milk Collecting Centers (MCC) located in the province of Valdivia between April and June of 2002. Mesophylic aerobic bacterial counts were taken from milk buckets, milk unloading tanks, milk filters, pump-hose and storage tanks by the standard plate count method. Bacterial count results showed statistical significant difference (p < 0,05) for milk unloading tanks of Santa Rosa and Paillaco, identical situation was found for the milk filter of these two MCC; for the storage tank differences were found in the three MCC. The bacterial counts were compared with international hygienic standards; all MCC had bacterial counts indicative of unsatisfactory hygiene for milk buckets (more than 250.000 cfu/bucket) and for milk unloading tanks (more than 25 cfu/cm²). Only the storage tank of one of the MCC ( Santa Rosa) complied with standars (lower than 5 cfu/cm²). The bacterial analysis of water, revealed that only one MCC (Pichirropulli) has suitable (potable) water for cleaning and disinfecting routines. An evaluation instrument was applied to characterise these MCC; it was found that the MCC with the worst evaluation (Paillaco) also had the highests bacterial counts.