Most forms of bacteria prefer moderate to warm conditions. Not so with psychotropic microorganisms. They like colder temperatures, around 40 degrees (F), if not chillier.

Because of this, they are often found developing in, of all places, cooler display cases in supermarkets. 

“Sometimes these organisms, which are different forms of bacteria and fungi, are brought into the display case when food is shipped,” says Mike Perazzo with Kaivac, manufacturers of cleaning systems designed specifically for use in grocery and convenience stores.

"Other times they develop as food deteriorates in the [refrigerated] display case.”

According to the Valencian Institute of Microbiology, a private reference laboratory, “psychotropic microorganisms are the main microorganisms involved in the deterioration of refrigerated foods.”

If food containing psychotropic bacteria is purchased and later consumed, it can prove health-risking. 

For supermarket professionals, these microorganisms can develop on display cases and shelves, destroying hundreds of thousands of dollars' worth of food products each year, seriously cutting into profit margins.

The food products most likely to become contaminated with psychotropic microorganisms are the following:

  • Products of animal origin, primarily raw or cooked meats
  • Fresh or cooked seafood
  • Fruits and raw vegetables
  • Dairy products, especially milk, as well as cheese and butter
  • Ready-to-eat and grab-and-go foods.

Making matters worse, as these microorganisms grow, biofilms can develop on shelving. Biofilms are sheltered bacterial communities that are exceedingly difficult to remove.

To detect psychotropic microorganisms, display cases must be swabbed, with the swabs sent to a laboratory for testing. Results can take hours or a few days.

“Testing is usually not practical or possible in most grocery or convenience store settings,” says Perazzo.

“The best option is effective cleaning of cooler displays. This helps remove [psychotropic] microorganisms from display cases and prevents the growth of future microorganisms.’

To clean display cases, Perazzo recommends cooler display case cleaning systems that can be used by in-house staff.

These system apply cleaning solution to shelves, fans, condenser coils, and refrigeration components. 

Areas are then pressure rinsed, removing psychotropic microorganisms and other pathogens, which are then vacuumed up by the machine.

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