Purpose: This study aims to understand the risks posed by an OESCO Brush Washer, then to identify mitigating strategies to combat these risks and offer operators best management practices moving forward.
Methods: Environmental samples measuring coliforms were taken during the 2014 and 2015 growing seasons on four parts of the brush washer- the input and output chutes, the brushes and the drain area. The data were analyzed for seasonal trends and for areas with the highest potential for cross contamination to produce. These trends were then used to pose target cleaning strategies.
Results: Two season average of coliform count on the brush rollers was 5 log CFU/ml. Exact values were observed to vary based on last operation and operator. Over the summer 2015 season, coliform counts ranged from 0 to 4.5 log CFU/ml, evidence of operator inconsistencies when resetting machine for next use. The range on the brushes was the widest of all of the areas tested; hence it will be specifically targeted in the sanitation plan. Purging the machine for 5 minutes after use was shown to yield an average reduction of 1 Log CFU/ml on the brushes, indicating that a targeted cleaning plan can reduce the dramatic range of remaining bacteria.
Significance: Identifying best management practices for postharvest farm equipment can help with extension programming to reduce risks on-farm. These data suggest that farm owners and operators using this brush washer may want to modify their best management practices, SOPs, end-of-season decommissioning plans and employee training to account for this large variability.