Most of the dialogue with produce growers, packers, and distributors revolves around the risk ethylene and fungus present to their product. With good reason, these two indoor air quality issues are well known to cause expensive consequences. However, the less well known threat that comes from Bacteria may well be the biggest problem they have. Strains such as Escherichia Coli (E.Coli), are abundantly present in manure used in the fields to fertilize developing food crops. It has been conclusively demonstrated that the pathogenic bacteria present in the manure spreads to the fruit through the air. If this is true, then there is likelihood of the same happening in a cold storage environment. One infected fruit could lead to many infected fruits. This can have horrific effects later in the supply chain. Staying with the E.Coli example, it causes symptoms such as diarrhea, anemia, and even kidney failure. Furthermore, outbreaks receive eager press coverage. Airocide NASA PCO technology has the ability to minimize this risk, and protect brands from unexpected and catastrophic circumstances downstream.
The foundation of this problem is presented in Airborne Transport of Foodborne Pathogens from Bovine Manure to Vegetable Surfaces (DeNiro et al). The work was published through the Environmental Sciences department at the Ohio State University in 2013. It is no surprise that produce consumption has risen dramatically over the last twenty years. The perceived health benefits, and nutritional content are the drivers. However, due to the way produce is marketed it remains relatively uncommon for it to be properly washed prior to consumption. Keywords like “fresh” and the general trust society has in consumer goods make food borne illness an afterthought. The result is that twenty percent of all food borne illness outbreaks in the United States from 1990 to 2004 came from produce products. Furthermore, it is estimated that seventeen percent of the entire US population contracts a food borne illness every year from produce consumption. DeNiro et al. recognizes lettuce, spinach, other leafy greens, and tomatoes as the primary vectors of food borne illness. E.Coli and Salmonella javiana (S.Javiana) are the primary pathogens. E.Coli is most commonly associated with leafy greens, and S.Javiana with tomatoes.
Produce products are commonly fertilized with manure from dairy cows. And, this is becoming increasingly common as organic products gain marketshare on grocery shelves. Cows shed very large lodes of pathogenic bacteria in their waste. When the waste is untreated, the pathogenic bacteria are transferred to fields where produce is in production. The bacteria are very persistent, and have been demonstrated viable for as long as 154 days after the manure was applied. This extends the timeline in which produce products can be infected to the entire growing cycle. E.Coli has even proven resistant to low temperatures and acidic soil conditions. Bacteria are transferred to produce surfaces by aerosol, which occurs when droplets dry quickly and become solid particles referred to as bioaerosols. Once the bacteria is established on the surface of the produce product, it becomes embedded in the stomata which are tiny pores used in respiration. This makes invalidation during standard post harvest washing nearly impossible.
Once produce products are harvested they are sent to packing houses to be sorted and distributed to the end user. During this process it will spend anywhere from 12 hours to two weeks in cold storage. If any of the fruit is infected with bacteria, it can spread in cold storage by the same mechanism. DeNiro et al. established the correlation between residual humidity and viability. Cold storage rooms are maintained at RH levels of 50% to 100% making aerosolization more likely. This converts non infected produce into substrates for future bacterial colonization. Quality Assurance and quarantine procedures are rarely advanced enough to monitor bacterial content in incoming produce, which increases the risk of introducing pathogenic bacteria into storage environments.
If the future destination of the stored produce is a food processing facility, then the end user usually has a chlorine wash procedure or irradiation process for bacterial invalidation. However, if the recipient of the produce is selling it, as is, to the general public, pathogenic bacteria can very easily cause illness due to improper washing. Airocide can significantly lower the probability of the spread of pathogenic bacteria in a cold storage environment, and reduce the risk of human infection.