The 3M Microbial Luminescence System (MLS) UHT Beverage Screen Kit is a rapid test for Ultra High Temperature (UHT) and Extended Shelf Life (ESL) beverages.
The test expands use of the system from UHT dairy products to a variety of UHT and ESL beverages such as fruit juices, caffeinated drinks, coconut waters, smoothies, dairy, dairy substitutes, and dairy/juice mixtures.
It provides a rapid method for quality release testing, reducing the time-to-result by two to three days or more.
ATP detection
Using bioluminescence technology, the system detects ATP (adenosine triphosphate), an energy molecule present in all living organisms. This technology allows faster time-to-result than traditional pH measurement or agar plate tests, and can more reliably detect microorganisms.
Eric Amann, 3M Food Safety global marketing manager, said it measures quality by looking at the ATP that comes from microorganisms, including ATP from bacteria, yeasts and molds.
“Yeasts and molds are important, common spoilage organisms in UHT juices and other beverages,” he told us.
“Thermophilic spores are also important microorganisms to detect since they could survive the UHT thermal treatment and continue growing in the beverage, impacting its quality.
“Because ATP is present in all living cells - yeasts, molds, all types of bacteria - it can be used as a universal marker for biological contamination across all microorganisms. You can be confident that you’re not missing critical organisms and don’t have to test with several different types of agar plates to make sure you are detecting everything.”
The 3M MLS is able to detect light and display a numeric value called Relative Light Units (RLU). When the system is first installed these numeric values are used to establish a threshold or a limit to qualitatively determine if a sample is contaminated or not.
Then the software associated to the system will display a color-coded result to let the user know whether a sample has passed or failed the commercial sterility test.
Following a two to three day sample pre-incubation time, the technology provides a result in less than 30 minutes, eliminating the need for further plating and incubating of agar dishes.
Faster product release
This time-to-result enables beverage producers to release product quicker, reduce inventory and storage space as well as increase their flexibility and lab productivity, said the firm.
UHT and ESL beverages and their processing techniques are becoming more sophisticated and diverse. Yet the historical test methods continue to lag behind and are time-consuming and limiting, said Amann.
“The beverage processing method just uses different techniques to reduce the bacterial content in the beverage. What matters is which ingredients are in the beverage and how they influence the recovery and growth of microorganisms,” he said.
“We take this into account by testing a wide variety of UHT and ESL beverages available in the market and using a wide, relevant variety of spoilage organisms in our testing process.”
Amann said the processes for developing a test kit for beverages versus food are quite similar with a wide variety of beverage types procured and tested.
“One difference with UHT and ESL beverages is that a two-five day pre-incubation of the sample container is needed before the test is run,” he said.
“With food methods, we collect a portion of the food and provide nutrients through broth or agar plates to promote growth so microbial contamination can be demonstrated.
“With UHT and ESL beverages, if a microorganism is present, the beverage itself will provide the nutritional requirements for the microorganisms to grow during the incubation period.
“Incubation takes place in the original closed container (e.g. juice bottle), which provides the closest scenario to real shipping and storage conditions that can allow microbial growth to occur during the shelf life cycle of the product.”
3M MLS customers using the Dairy UHT kit have the option to upgrade to the Beverage UHT kit, which is easier to use with less vials and improved shelf life.
Current customers do not need to change equipment, with a software upgrade the only thing required.
3M said it will continue to make the Dairy UHT kit available along with support to any customer that does not wish to upgrade.