Mold Content of Commercial Popcorn†

Abstract

Internal mold infection levels for microwave yellow popcorn, nonmicrowave white popcorn, nonmicrowave yellow popcorn and specialty popcorn were determined by direct plating of kernels on Dichloran–rose benga–chloramphenicol agar (DRBC), Dichloran–18% glycerol agar (DG-18), Aspergillus flavus/parasiticus agar (AFPA) and Czapek's iprodione agar (CZID). The total percentage of mold-infected kernels was low in microwave yellow popcorn (5.9%) and nonmicrowave yellow popcorn (7.3%), but somewhat higher in specialty popcorn (13.6%) and nonmicrowave white popcorn (15.1%). Of the molds found, Fusarium species predominated in the microwave yellow popcorn (54.2%) and nonmicrowave white popcorn (66.2%), whereas Aspergillus species predominated in the nonmicrowave yellow popcorn (43.8%) and specialty popcorn (52.9%). Of the Fusarium species isolated, F. moniliforme was the predominant species in all types of popcorn including microwave yellow (70.4%), nonmicrowave white (70.4%), nonmicrowave yellow (72.3%) and specialty popcorn (85.7%). Other Fusarium species found were F. proliferatum, F. semitectum, F. subglutinans, F. anthophilum, and F. graminearum. The presence of the Aspergillus flavus-parasiticus group was negligible in the popcorn samples evaluated. No significant differences were found among media in enumerating total mold infection levels. DG-18 was found to be effective in enumerating Aspergillus species, but ineffective in enumerating Fusarium species from popcorn. No significant differences were found among other media in enumerating Aspergillus and Fusarium species.