The firm will be using GreenLight instrumentation from MOCON to test extended shelf-life (ESL) milk.
MOCON claims GreenLight can provide results at low bacterial loads in less than 24 hours without in-carton pre-incubation – meaning it does not need enrichment which saves time and money.
This compares to 48 to 72 hours required by traditional, agar-based, standard plate count methods used by Arla before.
Milk spoilage testing capability
GreenLight will be part of a system for detecting, identifying and tracking potential sources of spoilage.
Uses of the instrument will likely expand to include in-process monitoring, said MOCON.
“The best way to identify how spoilage is caused is to first screen samples to isolate potential problems, followed by identification of specific organisms. There is also potential for tracking these problem organisms to the source using methods such as environmental swabs,” said Alan Traylor, business manager, microbial detection at MOCON.
“MOCON has no knowledge regarding Arla’s future plans, but we can say that our GreenLight technology offers bacterial load testing capability for a variety of dairy products including raw and ultra-high temperature (UHT) milk and high-value powders.
“Although we are unable to discuss evaluation specifics, we can say that GreenLight has consistently outperformed competitors in an array of customer evaluations.”
How does it work?
In the test the milk sample is poured into a bar-coded APCheck vial, which has a built-in oxygen sensor. Samples can be measured directly or with nutrient media added and no serial dilutions are needed.
MOCON said GreenLight tests use a larger sample volume than other methods which increases sensitivity and the chance of detecting very small bacterial loads in final packaged products.
When the automated GreenLight 930-15 is used, the vials can be batch loaded onto the 24-position carousel, or individually during the unit’s “continuous” mode.
As bacteria in the test sample multiply and respire, they consume oxygen. This change is used to detect presence of growth organisms.
At certain levels, the bacterial load, calculated in the PC and stored on a database, can be enumerated.
“We spent a significant amount of time evaluating new bacterial testing technologies and selected GreenLight due to its performance capabilities and affordability. Arla and MOCON are collaborating to customize GreenLight assays to meet desired objectives,” said Rowena Marshall, quality senior technical manager at Arla.
MOCON said this ‘customization’ involves balancing time to result and sensitivity.
The GreenLight technology was developed by MOCON’s partner, Luxcel Biosciences.
Luxcel creates assays that can be used with GreenLight to serve the market for dairy products.
These include detection of bacteria that survive pasteurization and that grow in cold temperatures.