Application of electro-activated potassium acetate and potassium citrate solutions combined with moderate heat treatment on the inactivation of Clostridium sporogenes PA 3679 spores

Abstract

Combined effects of moderate temperatures and the electro-activated aqueous solutions of potassium acetate and potassium citrate on the inactivation of C. sporogenes PA 3679 spores (D121°C = 1.18 min) were studied. Four types of solutions (potassium acetate with/without KCl and potassium citrate with/without KCl) were activated at 400 mA for 60 min. The oxidation reduction potential (ORP) and pH values ranged from + 417.50 to + 1043.33 mV and 3.18 to 3.47, respectively. The combination of these solutions with a moderate heat treatment (95 °C, 105 °C, and 115 °C) for different time (5, 10, 20, and 30 min) was sufficient to reach a 100% of spore destruction (inactivation) in a medium with an initial contamination level comprised between 7.0 and 7.8 log CFU/mL. The sporicidal effect of solutions was also present even if activated solutions were applied alone against spores without being combined with heat treatment. Spore morphology was determined under transmission electron microscopy and showed that there were important damages, such as rupture of spores and release of spore components in all of the treated spores. Thus, the sporicidal effect detected was the result of inactivation mechanisms of electro-activated solutions on spores. In almost all of observed micrographs, there were coreless spores, deformed spores, or debris of spores. The current investigation can be used for achieving further studies in order to better understand the mechanisms of inactivation of C. sporogenes spores by electro-activated solutions. This research article aims to study the combined effect of electro-activated potassium acetate and citrate solutions and moderate heat treatment on the viability of Clostridium sporogenes in model solutions as a non-pathogenic surrogate of Clostridium botulinum. The objective was to use hurdle technology to produce nutritious, minimally processed foods while ensuring food safety. Moreover, this approach allowed for a reduced level of sodium in canned foods since the solutions were sodium-free.