Effects of calcium propionate and water activity on growth and aflatoxins production by aspergillus parasiticus

Efficacy of calcium propionate at two different doses (0.5% and 1%) against growth and aflatoxins production by aspergillus parasiticus (prr-2747) was investigated in vitro on czapek yeast extract agar at different levels of water activity (aw) in the range of 0.996-0.94aw. a. parasiticus spores germinated on all calcium propionate and aw treatments,however,1% calcium propionate at 0.94 aw delayed the germination process up to 9 days. mycelial growth rate was also found slower (0.57mm day-1) at 1% calcium propionate and 0.94aw. aflatoxins (b1,b2,g1 and g2) were also produced minimally (44.45,2.72,21.39 and 2.06 ng g-1 of media,respectively) at the aforementioned dosage of calcium propionate and water activity. it was concluded from the results that addition of calcium propionate and a,amelioration can prove effective tools for suppressing the germination,growth rate and aflatoxins production by a. parasiticus in different substrates. copyright 2010 zoological society of pakistan.