What is a Special Project? These are special testing projects that are not typically covered by laboratory testing when you run into a question that you really can’t answer, says Centrella. Special projects can be used for:
- Development, validation or implementation of a new testing method;
- Comparing performance of a new testing platform against a standard;
- Validation of pathogen control, for instance, to check effectiveness of CCPs;
- Shelf-life investigation;
- Verification of effectiveness of antimicrobials; and
- Determination of whether a product requires refrigeration.
With method validation, the situation can be that you work with PCR for Salmonella, and there are certain number of matrices approved, but you want to take advantage of that method and extend the matrix. So special projects can help you answer if that method would be suitable for your product.
Another category of special projects is pathogen control. In this situation, you can see if you have a process or an ingredient that’s in your product, or simulate that intervention in a lab setting (either heat or cool step or a treatment like a wash) to check for pathogen growth. In this case, the target matrix is inoculated with high level of analyte, and the aim is to show large log reduction, or even complete elimination, once the matrix is treated with the intervention.
Shelf-life studies is another example of special projects. In this case, we simulate retail storage of the product to determine expected shelf life or determine typical storage conditions. Here, assay are prepared to assess threats to product shelf-life, microbial, chemical or nutritional in nature. Such threats could be build-up of lactic acid due to bacterial activity, or might be gas-producing microorganisms, or chemical targets that cause rancidity in oils. Often these include an organoleptic compound which could change how a product looks, or if it has an odor. It’s important to remember that often the souring of the product due to lactic acid, gas bubbles or off odors will present themselves before microbial counts become obvious.
Shelf life testing is conducted at predetermined intervals, and depending on need, we can stagger these intervals, for instance, we can do more frequent testing during the anticipated end of shelf life. The final shelf life is defined by the last acceptable result.
Antimicrobial effectiveness is another example of special projects, and these involve products that already have an antimicrobial ingredient. In these situations, we inoculate target microorganism into the product and use assay to determine log reduction, or prevention of outgrowth. Antimicrobial effectiveness studies often include aspects of shelf life studies, where product is typically held at a given time-temp combination. These studies may use specific references such as using USP <51>, or reference could include specific microorganisms, and criteria to determine effectiveness (such as log reduction).
Another example is determination of if a product requires refrigeration. For this, we first start with the food product itself, which has a specific combination of pH and water activity to prevent growth of groups of pathogens. Once we have this information, we don’t have to look at broad range of organisms, but can look at specific organisms. The remaining potential threats become challenge organisms for the study. We store the product at room temperature and test for these challenge organisms.