Preservative and Temperature Effect on Growth of Three Varieties of the Heat‐Resistant Mold, Neosartorya fischeri, as Measured by an Impedimetric Method

The combined effects of inoculum amount, temperature, pH, and food preservatives on growth of three varieties of heat‐resistant mold Neosartorya fischeri cultured on a fruit juice‐like medium was investigated. JV. fischeri var. glabra growth occurred at 100 mg sodium benzoate/L at pH 3.5, a level that completely inhibited outgrowth of the other varieties. All were similarly affected by sulfur dioxide; completely inhibited by 300 mg/L at pH 3.5. The inhibitory effect of preservatives was strongly affected by pH, inoculum amount, and temperature. Growth was significantly delayed when temperature was decreased from 32 to 25 to 18°C or pH from 4.5 to 3.5. This is the first report on the use of impedance microbiology to study the effects of environmental factors on molds.