Know Your EMP Risks in Fruit & Vegetable Processing
Food safety risks in fruit and vegetable processing environments can come from many different sources. Agricultural items are inherently dirty products, which can introduce risk- including microbial pathogens- to a facility from the outside environment. If your Environmental Monitoring Program (EMP) and sanitation programs are not sufficient to control these risks, these products could be potentially cross contaminating other products that are subsequently processed in the facility. It is therefore imperative that we think about risks from both our incoming products and our processes when designing environmental monitoring programs.
Key Organisms of Concern in Produce
When performing a risk assessment for produce processing, it is important that we consider all potential foodborne pathogens that may be present. This includes:
- Salmonella
- Escherichia coli O157:H7
- STEC (EHEC)
- Listeria monocytogenes
- Cyclospora
- Hepatitis A and other viruses
We should also keep in mind that spoilage organisms can be just as detrimental in terms of ensuring appropriate shelf life and customer satisfaction. Spoilage organisms can include not only bacteria commonly found in soil and water, such as Pseudomonas and Bacillus, but also yeasts and molds. A robust risk assessment should consider control of these organisms and not just potential pathogens.
Pathogen vs. Indicator Testing
When designing your environmental monitoring program, it is important to consider what you are testing for and how you are going to use that information.
Pathogen testing targets the specific organisms listed above and would typically be most helpful in Zone 1 (high-risk areas) but carries risks such as product holds or recalls in the event of a positive result.
Indicator testing monitors a broader range of organisms than just pathogens. A positive result would indicate that conditions are permissive for pathogen growth, providing valuable data on microbial trends and potential risk areas without immediate recall concerns. Common indicator testing might be aerobic plate count (total bacterial counts), generic E. coli and/or coliform, Enterobacteriaceae (EB), and Listeria spp. testing.
The Agricultural Side: Challenges from Incoming Products and the Environment
The produce industry specifically is a very dynamic industry with constant change, and unfortunately that means your food safety and your food risks can change as well. It may be hard to predict when and how risks are going to change, but it is important to recognize the potential and modulate your EMP program in response to changes throughout the year in order to manage food safety risk.
Agricultural variables influence food safety risks in several ways:
Variable supply chain
- Frequent supplier changes, seasonal geographic shifts, field rotations, and soil management shifts introduce diverse microbial risks that require EMP adjustments throughout the year.
Seasonal quality issues
- Temperature fluctuations (e.g., heatwaves or cold snaps) and precipitation patterns impact microflora, affecting the contaminants that enter your facility.
Adjacent land use
- Nearby land changes (e.g., introduction of cattle or poultry farms) can increase contamination risks, requiring proactive EMP updates.
Animal intrusion
- Migratory bird patterns or animal movement across fields can inadvertently introduce pathogens to your supply.
Lack of a Kill-Step
- Without a definitive kill-step during processing, risk management must rely heavily on environmental controls, sanitation, and proactive testing.
Short shelf life
- Product shelf life in and of itself is not necessarily a food safety risk, but since many produce commodities have short shelf lives, decisions around safety and contamination management must be made quickly and efficiently.
The Facility Side: Unique Challenges within the Fruit and Vegetable Processing Environment
Produce processing facilities have some unique challenges in comparison to general food facilities. The unique shapes and characteristics of the product demand the use of a variety of specialized equipment and controls. The environment is also often very wet and contains dirty materials such as the fruit/vegetable product itself, soil, and water coming in on the product and/or used as a means of processing. These environmental conditions, like agricultural conditions, can be seasonal, requiring adaptation and reevaluation over time.
Key Risk Areas
- Drains, wash flumes, belts, peelers/grinders: These areas are prone to harbor sticky residues and soil-borne organisms like Listeria.
- Hygenic zones and facility design: Keeping raw and finished products separated, along with controlled employee movement, minimizes cross-contamination. Monitoring these areas to recognize risk and identify when risk is elevated is a key consideration in an EMP.
- Hollow equipment: Can provide an opportunity for bacterial harborage, as bacteria can get into cracks and crevices. As the equipment then vibrates during production in a wet environment, it may aerosolize the organisms into zone 1 and the rest of the facility.
Cooling, Condensation, and Airflow
- Cooling tunnels, forced air systems, blanchers, ice machines, and other processing means create temperature gradients that encourage condensation, providing an environment for microbial growth.
- Temperature gradients, particularly with freezers, IQF tunnels and frozen processing, can also pull the air from areas of higher temperature to lower temperature, effectively pulling airborne risks towards the freezers and potentially food contact surfaces.
- Air circulation can unintentionally spread contaminants, especially if HVAC units or fans draw from contaminated zones.
Temperature and Moisture Management
- Seasonal temperature and humidity shifts may allow for moisture buildup (e.g., ice in cold storage areas), increasing the potential for Listeria growth even at low temperatures.
Managing Your Risk
As you are evaluating risk, whether it comes from the facility or the products themselves, the primary concern is to design a food safety program that minimizes these risks and uncertainties. Due in part to the variability in fruit and vegetables and the inherent risks from agricultural products, the potential food safety risk is high if sanitation, good manufacturing, and other programs are not well managed.
Microbial testing provides the opportunity to verify your that the systems you have in place are effective, that you are monitoring the correct activities, and cumulatively the data obtained from testing can provide some insights and identify trends that can be used for risk prevention and management.
As you build your program, it is important to consider all these risks and unique challenges when determining what should be monitored, and the tools necessary to find, track, and reduce risk.
Questions on how this information is applicable to your food process or results?
