EN
The aim of the study was to investigate the effect of acidification and heat on the survival of Clostridium spores in third category animal by-products. Poultry minced meat and minced fish waste, contaminated with Clostridium sporogenes IW 1306 spore suspension, were subjected to the combined action of formic acid and high temperature of different values. To assess the efficiency of examined hygienization method, the spore number in biomass samples after acidification and heat treatment was estimated. For this purpose a 10-fold dilution series in peptone water was prepared and heat-treated at 80°C for 10 min. After cooling-down, one milliliter of each dilution was pour-plated onto DRCM medium solidified with agar. Statistical analyses were performed using the Statistica software. The results of the microbiological analysis show that lowering the pH to about 4 results in increasing the sensitivity of Clostridium sporogenes spores to a high – but not exceeding 100°C – temperature. The fastest inactivation of spores occurred after heating the acidified biomass at a temperature of 90°C. In the case of meat the 48-hour exposure to formic acid allowed the thermal inactivation of the spores within 15 minutes. The investigated method of hygienization may guarantee not only the inhibition of spores germination, but also enables their total elimination, reducing the epidemiological risk related to animal by-products handling.