Nazanin Zand
The effect of high frequency electromagnetic field, and combination of it with various condition of pre-heating (80- 85 oc ) for sterilization of different mushroom meals has been studied. All samples of mushroom meal were filled in pouches (retort multilayer films). EMI treatment which discharges square-wave pulses with variable voltage 1-20 kV/cm ,and different frequency(2-3GHz ,3-4 GHz ,4-5GHz, 5-6 GHz ) have been done in step one . The effect of high frequency electromagnetic on clostridium and bacillus is not adequate because spore of these bacteria are practically resistant in electric fields, so pouches have been put in water bath chamber ,and different condition of pre heating (80oc 5min;80oc 10min;80oc 15min;85oc 5min;85oc 10min;85oc 15min) have been done ,so the effect of each thermal processing combined with best result of electromagnetic field for these meals which belonged to 5-6 GHz. If cells are cultivated at higher temperature, this increasing tendency which can permanently keep fluidity viscosity of the cell membrane before electromagnetic field thus EMI efficiency was increased. The populations of mesophile microorganisms depended on type of treatment, type of mushroom meal ,and type of culture ,so the death ratio of mesophile microorganisms increased in mushroom meal ( without spice) 14466 percent more than mushroom meal(with spice), but in every conditions of this process growth of thermophile microorganism has not been reported. However, the chances of passive mesophile microorganisms in various EMI treatment without preheating was evaluated in mushroom meal(with spice) as 180133 percent more than mushroom meal( without spice )while the chance of positive thermophile microorganism growth in various EMI treatment without preheating decreased in mushroom meal(with spice) by 73.33 percent more than mushroom meal(without spice) .
