AMP is a powerful DNA technique that provides a detailed profile of the microorganisms present in a product, without the need to culture. The technique has been used to support investigations into the safe shelf-lives of products.
Culture-based methodology for microbiological food safety relies on monitoring the presence or behaviour of pathogenic microorganisms. One way of achieving this is through challenge testing, where a product is deliberately inoculated with a pathogen and the levels of that pathogen are monitored over shelf-life.
Many intrinsic factors can affect the pathogen, such as pH, water activity or preservatives. One factor that can have an impact, but has been poorly studied, is the natural microflora. AMP offers a way to monitor the changes in microflora over the shelf-life of a product in much more detail, allowing flora that are inhibitory to pathogens to be accurately identified.
Once done, this data can be used to support future investigations, or to screen products to select those most likely to inhibit the growth of contaminating pathogens. Campden BRI uses this technique and aims to start a project to build core data on inhibitory flora, against which future products can be assessed.
AMP is also a useful tool for monitoring hygiene as it describes the microflora of any sample from which DNA can be extracted. Swabs can be analysed to examine the microbial populations of various areas of a factory, for example, to compare a high-care area with the associated ingredient-assembly area. If these areas are separated correctly, a clear difference in population can be expected. If there is still significant communication, the similarities can be used to determine the route through which that communication occurs.
Dr Greg Jones is a microbiologist at Campden BRI