Real-Time Quantitative PCR as a Tool for Monitoring Microbiological Quality of Food

Microbiological parameters of food provide quality information regarding the processing, storage, and distribution conditions, shelf life, as well as whether the food poses a health risk to the population. In this context, the concern with food safety is a competitive advantage, as the pressure of consumers, who are increasingly interested and concerned about what they are consuming, directs the trade to reach the quality of products and services offered. With regard to microbiological analyses, researchers have been developing sensitive techniques to produce rapid results, since traditional methods of microbiological culture are time-consuming and very laborious. Thus, the real-time quantitative PCR technique (qPCR) offers the possibility of quantifying the total bacterial DNA in a food sample without the need of the microbial growth step. That is, the result can be expressed on the same day, and it is possible to perform a simultaneous quantification of more than one pathogen in a single assay. Therefore, it can be a useful tool for monitoring microbiological quality in food industries. In this chapter, we will present the advantages and disadvantages of this methodology for food microbiology emphasizing the challenge of differentiating viable cells from nonviable cells.