Inoculation

Challenge studies determine the survival of inoculated pathogenic or spoilage organisms in food products.  These analyses are also used to define the effectiveness of an anti-microbial agent or process. The information produced from a challenge study can be instrumental in the development, formulation or packaging of a food product.

At DonLevy Laboratories, challenge studies are custom designed to a client’s specifications and objectives. A detailed study design and proposal are generated prior to initiation of a challenge study. The design process involves detailed discussions with our client and an evaluation of the objective of a given study.

The organisms to be inoculated are cultivated by traditional cultural techniques and then harvested and prepared as an inoculum. The quantity and level of the inoculum to be used in a study is clearly defined in the design process.

Packaged food products are aseptically opened and the inoculum introduced. The packages are re-sealed and stored under specified conditions. The microbiological analysis for the inoculated organisms involves cultural enumeration at established time intervals. The tests to be performed and the time intervals are defined in the design of the study. Many challenge studies also involve concurrent shelf life analyses.