Resource and Environmental Monitoring

There are 3 key areas to monitor within processing and storage facilities in order to avoid microbial contamination of fresh produce products.

Air Quality

The air inside a processing plant can be a vehicle for contamination of fresh produce by mould, yeast, dust, or pathogens if not properly controlled. Where fresh and fresh-cut fruits and vegetables are exposed to open air, we recommend that air quality be monitored to ensure that it is of suitable quality.

We also recommend that fresh-cut processors consider the following to maintain appropriate air quality:

• Using positive, negative, and ambient air pressure differentials to direct potential airborne contaminants away from microbially sensitive areas. For example, negative air pressures in raw product areas, microbiology laboratories, and restrooms may help to keep air from those areas from flowing into the processing areas. Similarly, positive air pressure can be maintained in areas such as the processing and packaging area.

• If air filtering equipment is used in a fresh-cut processing facility, filters should be performing at manufacturer specified levels of performance

• Filtering compressed air (such as oxygen (O2), nitrogen (N2), and carbon dioxide (CO2) used in modified atmospheric packaging) when such air contacts fresh produce using a 0.3-micron filter (with an efficiency of approximately 75%)

Water Supply

Water can be a carrier of microorganisms including pathogens. Adequate quality water is critical in a fresh-cut processing facility because of the absence of a step lethal to pathogens (kill step) in processing the product as well as the presence of factors such as the high degree of product handling, the damage to fresh produce product during cutting, shredding, etc., and the potential for temperature abuse in processing and storage. We recommend that the water supply in a food processing plant be sufficient for the operations intended and be derived from an adequate source. We recommend that water for operations in the processing facility, such as cleaning and sanitising the facility and equipment as well as preparing the product for processing, processing the product, and manufacturing ice, be of adequate quality.

Where water does not become a component of the fresh-cut produce, we recommend that water be safe and sanitary, at suitable temperatures, and under pressure as needed for all uses. For water that is used in a manner such that the water may become a component of the fresh-cut produce (such as when water contacts components, fresh-cut produce, or any contact surface), we recommend that water complies with applicable industry requirements.

We recommend the following practices regarding the water used in a processing facility:

• Complying with applicable Federal, State, and local requirements for water that contacts fresh-cut produce or food-contact surfaces, including water used to make ice
  We recommend that processors protect sources of water and ice from contamination and that ice be manufactured, transported, and stored under sanitary conditions

• Testing well water, if used, at the site of the well and at the point in the plant most distant from the well on a regular basis to ensure compliance with Federal, State, and local requirements

• Maintaining and inspecting on a routine basis any water charcoal filtering system to prevent it from becoming a source of microbial or physical contamination of water

• Reviewing on a periodic basis water systems to ensure that no cross-connections exist between systems carrying water that is of adequate quality and systems carrying water that is not

• Ensuring that the volume, temperature, and pressure of water is adequate for all operational and clean up demands

Environmental Monitoring

We recommend an environmental monitoring program designed to detect areas of pathogen harborage and to verify the effectiveness of cleaning and sanitising programs in preventing cross-contamination. We recommend the following practices:

• Performing environmental sampling on both food contact and non-food contact surfaces (e.g., drains)

• Determining the appropriate target pathogen, test locations, and frequency of sampling
  We recommend that the appropriate target pathogen be the most resistant microorganism of public health significance that is likely to occur in fresh-cut produce.

• Focusing environmental monitoring on an indicator organism, such as Listeria spp., which indicates microbial contamination but is nonpathogenic and more easily detectable than a target pathogen, such as L. monocytogenes

• Establishing a plan for action in the event that a microbiological test indicates the presence of a target pathogen or indicator organism

• Documenting corrective actions and follow-up for all positive microbial test results

• Installing an Environmental Sensor for storage spaces much like PostHarvest’s own Environmental Sensor, in order to track the environmental levels in the atmosphere surrounding fresh produce supplies