Optimized cleaning of conveyor belts using plasma-processed water assisted by optical detection of food residues

Abstract

As food of animal and plant origin is prone to microbial spoilage, its production must be monitored and conducted safely to avoid consumer hazards. At the same time, environmental and sustainability aspects are becoming increasingly important. In this study, washing of food conveyor belts at ambient temperature was performed with plasma-processed water (PPW) and an optical detector to monitor the cleaning success. The microbial plate counts could be reduced with pressurized water, foam and PPW by >3 log10 CFU/cm2, similar to the standard industrial washing with amine-based disinfectant (Neoseptal®, Dr. Weigert, Germany). However, PPW degrades to naturally occurring substances, and the inactivation time was reduced from 15 to 1 min. The optical detector could mostly distinguish between uncleaned and cleaned belts. The fast, precise and easy applicable measurement could be integrated into the production line for automated monitoring, which could result in cleaning cycles based on demand. Industrial relevance: An on-demand cleaning process with less need for chemicals would save time and money plus protect the environment. Plasma-processed water is as effective as a chemical disinfectant combined with a reduced decontamination time (from 15 to 1 min) and free of complex chemical compounds. The optical detector can be used inline, fast and easy for automated hygiene monitoring in the food production.