US: Del Monte Salmonella outbreak to expand
Food Safety & Environmental Health Blog
Cantaloupes are again the vehicle for Salmonella. Such instances should be closely investigated to determine the root cause. Typical contamination sources in growing cantaloupes would include irrigation, run off, human waste, animal intrusion and infected workers.
The problem of contamination and potential growth of bacteria on melons is a difficult one. Normally, with a product that can both harbor and grow bacteria we would require that the items containing it be kept under temperature control; the FDA retail food code does require cut melons to be held at 41 degrees until service, for example.
Prior to cutting (processing), there are no current regulations for limiting growth of bacteria on melons. There are no requirements for shipping or storage temperatures for whole intact melon. Food safety efforts with melons, and most raw agricultural products is primarily a matter of contamination control. Melons may or may not be washed in the packinghouse to remove contamination before shipping to retailers. Again, no mandatory provisions exist for any type of post-harvest treatment with melons. Thus, the final processing of the product is the final opportunity for prevention and also the step with the highest risks.
The challenges for the fresh produce industry are in identifying the risks in the growing, harvesting, packing and shipping of these items, and then taking a combination of preventive measures that reduces those risks to the next user to some measurable level. The new research pointed out in Bill Marler's blog found below, is useful, but the industry response will take some time, given the nature of the industry and what it has traditionally seen as risk.
Farmers know that wild animals are a major concern in melon operations; they consume and destroy a significant amount of crops. Deer, pigs, raccoons, as well as birds are attracted to these growing and harvesting areas. While growers may not have absolute control over access to the growing areas, harvesting methods must account for contamination found. Operations under third party standards are required to monitor for these hazards and not harvest areas with obvious signs of animal intrusion. That procedure if rigorously done limits the wide scale fecal contamination problem but does not eliminate it. Handling thereafter must be sanitary. Packers that do not wash melons can do little to remove contamination. Buyers drive this model, and many will accept raw agricultural products that have not had a washing step, leaving the consumer hard pressed to defend themselves.
However, washing in a large packinghouse is itself hazardous. During washing, if antimicrobial quality of wash water is not maintained, water becomes a vehicle to further spread contamination between lots. Diligent control of wash water quality is often a critical control in a food safety program for this reason.
We may not be able to eliminate the pathogens in melons at any one stage of the production system, thus calling for a coordinated effort between growers, handlers, shippers and end users. We need to strengthen the weak links in this chain to the extent we can, and combine that effort with effective microbiological testing, recall procedures and oversight.
The regulation of the supply chain for agricultural products in general is very weak at present, but we expect this situation to change soon. Efforts to properly guide the fresh produce industry and enforce necessary public health controls will improve as the new federal policies and procedures come into effect. An expansion of the regulatory controls and industry led efforts will eventually reduce the risk of contamination in raw agricultural products overall, but don't expect immediate resolution of the fundamental problems of melons, and perhaps, other high risk produce items.