Safe and save water part 2 – The case on Listeria
Due to climate change and subsequent water scarcity, it is important to efficiently use available freshwater. In
the Netherlands, wash water from vegetable processing is often only used once, after which it is disposed of. The
main reason is that this water may contain pathogens that may lead to recontamination of the product when the
water is reused. This research project focuses on developing new possibilities to (re)use fresh water in vegetable
processing more efficiently and the possible effects and solutions concerning food safety. Treating the water
with disinfection technologies aims to reduce the number of pathogens, allowing one to reuse the water and
results in a lower probability of recontamination of subsequent product batches. The development of
disinfection technologies applicable for the Dutch market, where the use of chemical agents is currently not
allowed, helps vegetable processors to make their companies more sustainable for water and energy use and
increase their international competitive position in which the use of chemical disinfection technologies is
Given an imminent need for sustainable fresh food production, possibilities are being sought to reuse raw materials and water. Within the fresh produce sector, water is needed at several places, e.g., to wash or transport fresh (cut) produce. Treating the water makes it possible to reduce the refreshment rate or reuse water, thereby contributing to water and energy reduction. However, these innovations cannot be at the expense of food safety. The presence of bacterial pathogens in the water can lead to high costs for the producer in connection with recalls and potential public health concerns for consumers.
The goal of the project is to investigate and develop possibilities for reducing freshwater consumption during processing to contribute to a more sustainable fresh food supply chain and ensure safe products are brought to the market. This aligns directly with the MMIP goal to build knowledge development during food processing to increase sustainability in the chain with innovation focusing on, i.a., water reduction without compromising safety.
The project provides the opportunity for knowledge development in the vegetable chain during processing, with a focus on increased sustainability through possible water reduction without losing product quality and safety.
The project’s aim is innovative with its approach to investigate combined disinfection water technologies (such as ultraviolet plus ozone, silver/copper, and chloride) that would otherwise not be implemented in the Dutch vegetable sector. Also, research on, e.g., the effect of the technologies on Listeria monocytogenes, is innovative and practical, given the overwhelming need to combat this Gram-positive pathogen in the sector.
The choice to investigate disinfection technologies (such as ultraviolet plus ozone, silver/copper, and chloride) in a bypass is an innovative application in the food sector. Previous PPP projects have looked at disinfecting water directly in the wash tank with chemicals or disinfecting water with a partial bypass system for one single technology (during fresh-cut vegetable processing). The use of these combined technologies has seldom been investigated in practice, although theory suggests that a further bacterial reduction could be possible. The results are applicable for processors and can bring sustainable food production a step further from theory to practice.
The general research approach is focused on research and development on the reduction of Listeria monocytogenes in the disinfected water used during vegetable processing. When selecting water disinfection technologies, attention is to the microbial log reduction so that potential reuse of water or alternative water sources does not compromise food safety.
The 3-year project is framed in three work packages (WPs). An overview of the intended results of the project in terms of milestones and deliverables and their status (as of January 2022) can be found below per WP.