Abstract
An Adiabatic Expansion Sterilizer in a moment is developed by using combination works between a taper steel valve and link-motion mechanism, which is able to run over 380000 MPa/s of decompression velocity at 200MPa. Mechanism of present high pressure sterilization on Bacillus stearothermophilus IFO 12550 spore was physical destruction of the spore coat by adiabatic expansion of water permeated through the spore coat under pressure. Water volume permeated through the spore coat under pressure is rate-determining on spore disintegration, which was influenced by temperature. Sterilization was promoted over 75°C. The spore of B. stearothermophilus IFO 12550 was almost ruptured at 100MPa. D value under 200MPa is 17min at 75°C, 11min at 85°C and 6min at 95°C, respectively, when B. stearothermophilus spore IFO 12550 (D100°C values=3000min) are compressed for 20min. Spore coats are broken to brittle fracture exactly when balk strain velocity of water exceeds in 42.4/s/sec (at decompression of 200MPa).
