special newsletter: hygiene, cleaning and sanitation
Independent approvals offer confirmation diagnostics work as planned – Neogen
It was the first time an ATP sanitation verification system was submitted for approval.
It follows a study by NSF International that showed it exceeded the performance of competitive system, said the company.
Adenosine triphosphate (ATP) sanitation monitoring systems are used to assess the effectiveness of sanitation programs. It goes beyond “visibly clean” by detecting actual protein residue.
Planning ATP testing
Gerry Broski, senior director of food safety marketing, said the process for ATP testing is simple, but there is an element of planning as to where and when to test.
“ATP test site selection can be automated and randomized so that test sites are automatically triggered by RFID tags and randomized so that the same site is not repeatedly sampled, potentially masking a problem area elsewhere,” he told FoodQualityNews.
“For the testing process itself, it is recommended that a 4” x 4” square surface is sampled using a sampler and then placed in a cartridge to react with an indicator.
“The cartridge is then placed in a compact hand-held instrument and a reading is displayed indicating relative cleanliness. The user then makes the determination if the surface needs to be re-cleaned and re-tested.
“Total time for testing is under five minutes. While the results are more or less immediate, all tests are recorded and then downloaded into a master data-manager for analysis and review.”
Broski said ATP is an organic chemical residue left behind by living or once-living cells, which would cover all foods or residues associated with foods.
“Sanitizers and proper sanitation procedures should eliminate ATP from environmental surfaces. If ATP is still present after sanitation, then the sanitation procedure was not effective and must be repeated and the surface re-tested,” he said.
“If ATP is detected post-cleaning, then the corrective action would be to re-clean the production line and re-test to ensure that the line has been properly cleaned.
“ATP testing can be incorporated into Sanitary Standard Operating Procedures (SSOP’s), as a verification step with results recorded for audit or training purposes.”
17 month approval process
The approval process began in 2015 with the submittal of a validation outline to the AOAC and has two main parts: Method Developer Studies and the Independent Laboratory Study.
Method Developer Studies include pure analyte LOD, matrix and microbial LOD, inhibition, lot-to-lot consistency and stability, instrument variation and robustness testing. The Independent Laboratory Study includes pure analyte and matrix LOD testing.
ATP testing systems can be used on most environmental and food-contact surfaces subject to sanitation. They are not good for porous surfaces and cannot be used directly on food products.
In the case of sanitary belting, porosity increases with wear, so an ATP test can be used to determine when to replace belting if it can no longer be sanitized.
The AccuPoint Advanced test system uses an ATP‐induced bioluminescence reaction to determine the cleanliness of test samples.
ATP is a chemical compound found in all living cells, including bacteria, yeast and mold and food debris. Bioluminescence is a chemical reaction that produces light.
ATP bioluminescence occurs when ATP from a sample comes into contact with luciferase, an enzyme found in fireflies, and luciferin, a substrate. The amount of light emitted is proportional to the amount of ATP detected in a sample.
Demand and difference from APC
There are several factors driving the increased interest and demand for ATP systems, said Broski.
“First, there is FSMA, and the preventive controls requirement which places a greater emphasis on prevention as opposed to reaction in risk mitigation,” he said.
“Proper sanitation is critical to food safety and ATP systems can be used as sanitation verification tools preventing the risk of unsanitary conditions. ATP systems also retain records of testing so that proof of sanitation and cleanliness are documented.
“Second, in this area of prevention, perhaps the most important aspect of using an ATP system is that it reinforces positive behaviour and is a process verification. ATP systems detect improper or incomplete sanitation events, and can uncover “hot spots” where extra effort may be needed for proper sanitation.
“Third, the ATP detection systems have become more sophisticated, and have become a process management tool through the use of software which uses random or static test sites to generate an overall picture of the sanitation status of a production line, a production area, a plant or even an enterprise-wide view of company performance.”
Broski said the difference between a system which measures ATP and an aerobic plate count (APC) or total plate count is the ATP system will provide faster results (five minutes to results), versus at least 24 hours for a total plate count.
“An ATP testing system will detect things like yeast, mould, and soil which an APC will not. Predominantly, a processor who is cleaning a production line is on a schedule and cannot wait for APC results,” he said.
“The SSOP process is to clean the line, verify that the cleaning is effective and begin production. You can only rely on APC if your process allows for a protracted time to result.
“Many times processors will hold product for before shipping and can wait for APC results. It is worthwhile noting that APC can be complimentary to ATP, allergen, and pathogen testing. All of these tests provide a piece of the environmental monitoring picture.”