Evaluación del agua electrolizada en la limpieza y desinfección de acero inoxidable como superficie modelo en el procesamiento de productos lácteos

Stainless steel is one of the most used materials in processing equipment for food industry. Different protocols for the cleaning and disinfection have been developed to guarantee the safety of processed food. Chemical agents (strong alkalis and acids) and sodium hypochlorite are able to remove food waste and microorganisms; nowadays these are being replaced by less dangerous agents. A new system is electrolyzed water (EW) that has demonstrated activity against pathogen and spoilage microorganisms, besides, it eliminates effectively the organic matter on surfaces. The objective of this study was to evaluate a cleaning and disinfection process with alkaline and neutral EW respectively on stainless steel as a model for processing equipment of dairy products. Stainless steel type 304-2B plates were used with and without surface modification. These plates were preconditioned with raw milk, followed by inoculations with a mixture of three microorganisms of approximately 106 UFC/cm2 each one (Enterococcus faecalis, Pseudomonas aeruginosa and Micrococccus luteus). An experimental design was carried out to evaluate the efficiency of the cleaning process, using three concentrations of alkaline EW, three temperatures and three contact times. After each treatment, disinfection with neutral EW was done. The response variable was the microbial population, determined by the Miles-Misra technique. Statistical analysis showed that time, concentration, modification and the interactions timesuperficial modification and temperature-surface modification had statistical significance (p <0.05). A reduction of about 4 log in microbial population was observed. Two sources of neutral EW were compared; a commercial trademark and other one produced by CIDETEQ, and the results showed that there is a similar behavior for both of them regarding disinfection. For the cleaning and disinfection processes of the plates with surface modification, a lower contact time was required, because the surface does not provide a physical protection to contaminants. This innovative system for cleaning-disinfection, using EW is a more ecological alternative and with a lower consumption of water than using actual agents, therefore, its use has a promising future in food industry.