ABSTRACT
INTRODUCTION Fungi play an important role as spoilage or toxigenic microorganisms mainly for plantderived foods. It is estimated that about 25% of the annual production of plants for human and animal nutrition is spoiled due to the growth of fungi (Smith et al., 1994). Besides their spoiling activity many of the food-relevant fungi are able to produce mycotoxins (Samson et al., 2004), secondary metabolites with a variety of toxic activities. About 300 different mycotoxins are known; however, only a few play a role for human health, as they can occur in measurable amounts in food and feed. Table 1 shows the most important mycotoxins occurring in food and the main producing fungi. For all of these fungi molecular detection systems have been described. Most molecular detection systems developed for food-relevant fungi are targeted against important mycotoxin-producing fungi and only a few have been described for spoilage fungi. The fungal contamination of a food sample is usually assessed by classical mycological means, such as the plate count technique (Samson et al., 2004). This technique has the great advantage that the spectrum of fungal species and their numbers present in a food sample can be determined. This method is very important for analysing the ecological change of fungal communities during production, storage or ripening of a food product. A prerequisite for this type of analysis, however, is trained personnel with taxonomical skills.
