Control of coliform on warabi [Pteridium aquilinum] by heat-treatment with calcined calcium

Viable cell number (106) of Escherichia coli O 157 type CR-3 and CE-273 inoculated to wild plant Warabi was decreased by addition of 0.2% calcium preparation which was made from oyster shells with ohmic heating. However, E. coli O 157 inoculated was able to grow when the calcium preparation-treated Warabi was transfered to the lactose-broth liquid medium. With 0.2% calcium preparation E. coli O 157 in Warabi was sterilized by heat-treatment at 60-70°C for 10min, but without calcium preparation it was not sterilized completely. Application of heat-treatment at 60-70°C with calcium preparetion seemed to be a useful technique for control coliform groups on wild plant Warabi.