Survival of Neosartorya fischeri and Talaromyces flavus ascospores in fruit powders

Recovery of ascospores of Neosartorya fischeri and Talaromyces flavus in apple, blueberry, grape, pineapple and strawberry powders ( a _w 0·23) stored at 25°C for up to 30 months as a function of heat activation treatments (none, 75°C for 15 or 30 min) was determined. Both moulds retained high viability. Ascospores of N. fischeri remained activated by the drying treatment used to prepare inoculum, and when stored in the fruit powders did not require heat activation. Conversely, T. flavus ascospores similarly prepared and stored required heat activation to recover maximal cfu/g.