The PULSIFIER®:: A new instrument for preparing food suspensions for microbiological analysis

We evaluated a new sample processor, the PULSIFIER(R) for preparing food suspensions for microbiological analysis. In a comparative study on 96 samples of representative foods, Total Aerobic Counts (TACs) from "pulsified" samples equaled or exceeded those from a Stomacher(R) 400 at levels up to 10(7) CFU/g, ranging up to 2 x higher at low count levels. Except for already comminuted products, pulsified suspensions always contained much less food debris. For example, for 8 replicate samples of celery and carrot average TACs of pulsified samples were higher (1.3 x and 2.5 x, respectively) although pulsified suspensions were clear while stomachered suspensions contained enough debris to interfere with pipetting. The superior quality of microbial suspensions from the Pulsifier has implications for general analysis as well as techniques such as PCR and ATP bioluminescence, which are easily perturbed by tissue extracts.