Abstract: To study the germicidal effects of ohmic heating on Alicyclobacillus acidoterrestris, the microbe was killed by self-made ohmic heating installation, and the survival curves of different voltages, heating time, pH values and volumes were compared and analyzed. The germicidal effects of ohmic heating on the microbe observed by environmental scanning electron microscope (ESEM) with conductometer and ultraviolet spectrophotometer to detect the leakage of the microbial intracellular contents. The results demonstrated that ohmic heating can destroy the Alicyclobacillus acidoterrestris efficiently. The germicidal effects on Alicyclobacillus acidoterrestris increase with voltage and volume increase, and also increase with pH value decrease. ESEM photographs of treated Alicyclobacillus acidoterrestris showed that crushed and destroyed microbe cells result from the ohmic heating, where as the increase of the electrical conductivity and the OD value indicate the leakage of the intracellular contents. Results showed that the mechanism of ohmic heating on Alicyclobacillus acidoterrestris cells is the electro-punctureda ction.

Key words: Ohmic heating, Alicyclobacillus acidoterrestris, germicidal, electro-punctured