Sterilization of flexible pouch by high frequency electromagnetic induction, using cooked chick and chick meal

Abstract

The effect of high frequency electromagnetic induction (EMI) in combination with various pre-heating conditions on sterilization of multilayer flexible pouches was studied. All samples of cooked chick and cooked chick meal pouches were sterilized using EMI which discharges square-wave pulses with variable voltage of 1-20 kV/cm and with different frequencies of 2-4, 4-6, 6-8 and 8-10 GHz in step one. The effect of high frequency electromagnetic induction on Clostridium and Bacillus is not adequate because spores of these bacteria are practically resistant to electrical field. So pouches were put in water bath chamber with different pre-heating conditions (80°C for 5 min; 80°C for 10 min; 80°C for 15 min; 85°C for 5 min; 85°C for 10 min; 85°C for 15 min) combined with 8-10 GHz. If cells are cultivated at higher temperature, this increasing tendency can permanently keep the fluid of cell membrane viscous before electromagnetic field; thus, EMI efficiency is increased. The populations of mesophile microorganisms depended on culture or type of treatment and chick. The death ratio of mesophile microorganisms increases in chick by 14200% more than in chick meal, but in every condition, growth of thermopile microorganism has not been reported. However, the chances of passive mesophile microorganisms in various thermal processing without EMI and preheating was evaluated in chick meal as 190500,106700 percent more than that of the chick type while the chance of positive thermopile microorganism growth in various thermal processing without EMI and preheating decreases in chick meal by 76.22% more than that of chick. Key words: High frequency electromagnetic fields, electromagnetic induction, flexible packaging, mesophile bacteria, thermopile bacteria, thermal processing, cooked chick, cooked chick meal.