Purpose: The purpose of this study was to develop and assess the performance of a device for the rapid detection of spoilage Alicyclobacillusmicroorganisms in the juice and beverage industries.
Methods: Experiments were performed to select the optimal growth medium and indicator chemistries for the most rapid detection of Alicyclobacillus microorganisms. Inclusivity studies used a panel of the target organisms at levels of <100 CFU/ml. The detection time in the test instrument and growth of low inoculum levels of organisms in food matrices were examined. A confirmatory test for guaiacol producing Alicyclobacillus was performed using the contents from a vial with positive growth.
Results: The inclusivity test panel consisted of eight Alicyclobacillus organisms. The instrument detection times were as low as 12.2 hours for 12 CFU/ml of A. acidoterrestris ATCC 49025. In juice, the detection time was 10.9 hours for an inoculum level of 8 CFU/ml of Alicyclobacillus spore suspension in lemonade pre-incubated for 24 hours. The majority of the other target organisms containing < 100 CFU/ml detected in < 48 hours. The food matrices tested did not interfere with the vial test.
Significance: The new test Alicyclobacillus vial provides a system for the rapid detection of spoilage Alicyclobacillus microorganisms in many beverage products in < 48 hours compared to the standard incubation time of 5 days for agar plates.