Quantitative polymerase chain reaction in food microbiology

Since its first application in food microbiology in the late ‘90s, quantitative PCR (qPCR) has attracted the interest of researchers, working mainly in the field of food safety, but lately also of microbiologists studying spoilage and fermentation processes. In addition to the advantages that conventional PCR offers in microbiological testing, i.e. specificity, reduced time of analysis and detection of viable but not culturable cells, qPCR allows quantification of target populations. This aspect is particularly relevant for foodborne pathogens, for which specific microbiological criteria exist, but also for spoilage and technological important microorganisms, in order to follow their population kinetics in foods. Although advancements in food microbiology have been made from its application, qPCR has not yet been utilized to its full potentials: the quantification step is only rarely carried out and qPCR is often use as an alternative of conventional PCR. In this chapter we will critically describe the application of qPCR in food microbiology based on the available literature, taking into account the specific problems and giving some possible solutions.