The Effect of Combined Treatment with Carbonation, Heating, and Monoglycerol Fatty Acid Esters on the Inactivation and Growth Inhibition of Geobacillus stearothermophilus Spores

Abstract

The effect of carbonation with heating (CH) on the number of viable Geobacillus stearothermophilus spores was investigated in the presence of monoglycerol-caprate (MC₁₀) or -laurate (MC₁₂). CH was performed at 90 and 100°C, 5 MPa, for 30 or 60 min. Spore counts were reduced by 1.4 log CFU/ml after CH at 90°C for 60 min in the presence of MC₁₀. On the other hand, after CH at 100°C for 60 min, spore counts decreased by 3 – 4 log CFU/mL or remained low after 7 days of storage. CH decreased the optical density of a spore suspension at 650 nm more than heat treatment alone, indicating that spore germination triggered by CH could be involved in the drastic decrease in spore count caused by CH in the presence of MC₁₀ or MC₁₂.