Influence of potassium sorbate and sodium benzoate on Gamma-irradiated conidia of aspergillus ochraceus, penicillium chrysogenum and fusarium moniliforme

Experiments were conducted to determine if two preservatives potassium sorbate and sodium benzoate had a synergistic effect with gamma irradiation on inactivation of conidia of A. ochraceus, P.chrysogenum and F.moniliforme. A second objective was to determine if gamma-irradiated conidia had increased sensitivity to preservatives in a recovery media. As the concentrations of the two preservatives increased from 0.05 to 0.50%, the rate of inactivation of mould increased. Aspergillus ochraceus was noticed to be very sensitive to gamma irradiation (D10= 0.13 KGy). whereas Penicillium chrysogenum was the most radioresistant (D10=1.60 KGy). as compared to fusarium moniliforme (D10 =1.23 KGy). Potassium sorbate was observed to cause an increase in the rate of gamma irradiation of A.ochraceus (D10 = 0.11 KGy at 0.05%), P. chrysogenum (D10 = 0.63 KGy AT 0.05%) and F. moniliforme (D10 = 0.63 KGy at 0.05%) and F.moniliforme ( D10 = 0.63 kGy at O.02%). Also, sodium benzoate caused a decrease in D10 values of gamma irradiated conidia of A. ochraceus (D10 =0.11 KGy at 0.1%), P.chrysogenum (D10=0.058 KGy at 0.06%) and F. moniliforme ( D10=0.06 KGy at 0.04%). Therefore, the use of preservatives and radiation induced a synergistic effect of the inactivation of mould under investigation and this synergistic effect was proportional to the irradiation dose.3 tab