In the past few decades, the majority of foodborne outbreaks have been associated with contaminated fruits and vegetables. The last 7 years prior to 2018 saw more than 20 outbreaks coming from produce in North America alone. Some of the pathogens involved are Salmonella spp., Escherichia coli O157:H7, Listeria monocytogenes, hepatitis A, etc. Myriad produce types, such as cantaloupes, romaine lettuce, cucumbers, and even frozen produce, are responsible for these outbreaks.[1] This year, the United States experienced a massive foodborne outbreak of E. coli O157:H7 in romaine lettuce. Although the recall is pretty much over, consumers, farmers, and retailers face a lot of repercussions. As of May 30, 2018, more than 150 individuals have become ill, and several have died. In addition, farmers have experienced extreme crop loss, retail sales have plummeted, and restaurants are changing suppliers and finding substitutes for romaine lettuce, which stops or slows down the supply chain flow.[2]
Water Alone Is NOT Enough
In light of all these outbreaks, washing and rinsing the produce with water alone are not sufficient to eliminate pathogens.[1] The solution to this issue is the use of disinfectants and sanitizers. Disinfectants and sanitizers are two different types of chemicals used in ensuring food safety. A sanitizer is used to reduce the number of bacteria on a surface to an acceptable level, whereas a disinfectant can eliminate a wider range of microorganisms.[3] One cleaning agent cannot be effective against all pathogens, so it is important to know about multiple cleaning agents and how they work.
Factors Affecting Efficacy
Before discussing specific sanitizers and disinfectants, it is important to note that several different environmental factors can play into an antimicrobial’s efficacy:
• Potable Water: It is critical for the water to be potable and not contain any debris, odor, or microorganisms.
• Low Total Dissolved Solids (TDS): TDS are mineral deposits in water that can encourage the survival of pathogenic bacteria or bind to the bactericidal ingredients of a sanitizer. Because of this, it is better to use soft water instead of hard water. The presence of soil hinders the ability of a sanitizer to do its job, so getting rid of as much soil as possible is necessary for sanitation.
• Water Temperature: It is essential to maintain proper water temperature, because sanitizers typically do not work as well if the water is too cold. If the water is too hot, the sanitizer can vaporize and release toxic gas into the environment. Water temperature must also be considered in maintaining the quality of the produce. Different types of produce have different tolerance levels for water temperature.
• Water pH: Testing the water for pH is critical because sanitizers have different optimal pH values.
• Contact Time: In addition to temperature and pH, it is important to consider the contact time, because if a sanitizer or disinfectant is not applied long enough, sanitation will be insufficient. If a sanitizer is applied too long, it will be harder to clean off, may cause an off taste, and can cause a chemical hazard.
• Produce Surface Texture: Since sanitizers and disinfectants are usually applied to the surface, it is important to consider the surface texture. For example, a fruit with a lot of bruises or punctures will be much more difficult to clean than a fruit that is very smooth.
There are many other factors to consider, but these are the six most basic factors. Considering all these factors will help determine the right sanitizer or disinfectant to use on which fruit or vegetable and to kill a target pathogen.[4]