EXPERIMENTAL EVALUATION OF A NEW THERMAL PROCESS FOR MICROORGANISMS INACTIVATION

摘要

A new thermal process for the inactivation of microorganisms in beverages hasrnbeen studied and is presented in this paper. The treatment, not yet studied in thernscientific literature, mainly consists of a thermal shock characterized by temperaturernincreases up to 30℃/s, with final temperatures up to 65℃. This study presentsrnthe first experimental results obtained by the application of the new thermalrntreatment, with different combinations of the process parameters (rate of temperaturernrise, final temperature and holding time), on separate suspensions ofrnPseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, Listeria innocuarnand Candida albicans. The required rapid temperature increase has been performedrnby means of a properly designed test bench. The treatment proved to berneffective against all the microorganisms tested, obtaining a load reduction greaterrnthan 5 Log units. Compared with the commonly employed thermal treatments forrnmicroorganisms inactivation, this new process is characterized by a very interestingrncombination of a short duration (few seconds) and a low final temperature,rnwhich makes it particularly attractive for the application in the beverage industry.