Effect of the quality of washing water on shelf-life and product safety of rinsed produce

The quality of washing water has a significant effect on the shelf-life and product safety of the rinsed produce. A recently conducted assessment shows how the biodegradable disinfectant Huwa-San TR-50 can clean the water system completely, removing biofilm, microbiological load, low oxygen levels, and post-harvest pathogens such as Erwinia, Sclerotinia, and Botrytis cinerea.

Biodegradable disinfectant© Roam Technology (main)
The assessment aimed to evaluate the hygiene challenges in a post-harvest washing system and the effectiveness of biodegradable disinfectant Huwa-San TR-50, developed by Roam Technology. Persistent biofilm formation, poor water quality, and the presence of pathogenic microorganisms were identified as key issues affecting product safety and shelf life. The performance of Huwa-San TR-50 was examined to determine its efficiency in reducing microbial load and maintaining a clean water system.

Filippos Potsios, Roam Technology, explains how upon arrival at the processing facility, the vegetables are washed to remove dirt. "The water system showed significant biofilm formation, which can harbour and protect various microorganisms. The washing water was of low quality, with a high microbiological load and low oxygen levels. Pathogens such as Escherichia coli and Salmonella were detected in the water, and common post-harvest pathogens in leafy vegetables—Erwinia, Sclerotinia, and Botrytis cinerea—were found on the fresh produce. These factors contributed to a reduced shelf life of the crops."

The chlorine dioxide (ClO₂) tablets, previously used for water disinfection, required a final rinse with potable water to remove residual chlorine before packaging, adding extra washing steps and thereby increasing operational costs. "Despite these efforts, the chlorine-based treatment proved ineffective in reducing the microbiological load of the water and in preventing biofilm formation within the system."

The solution turned out to be a switch from Chlorine tablets (ClO2) to Huwa-San TR-50. The chlorine dioxide tablets were replaced with Huwa-San TR-50, an advanced broad-spectrum disinfectant based on silver-stabilised hydrogen peroxide.

The water tanks were sprayed with a 6% Huwa-San TR-50 solution and left to dry completely before refilling. "No rinsing with fresh water was required, as Huwa-San leaves no toxic residues and breaks down into water and oxygen", Filippos explains.

Disinfection of the water system
A Clean-In-Place (CIP) disinfection cycle was performed using a 1% Huwa-San TR-50 solution for 30 minutes to effectively remove biofilm deposits and disinfect the entire water distribution system. A dosing pump continuously added 20 ppm of Huwa-San TR-50 into the main water tank to maintain system hygiene and prevent biofilm reformation. A second dosing pump added an additional 60 ppm directly into the pipeline before the water entered the post-harvest washing unit, ensuring a minimum concentration of 70 ppm in the washing water used for fresh produce.

Results
The results showed that implementing Huwa-San TR-50 delivered high-quality, oxygen-rich washing water with no chemical residues, odour, or aftertaste. "Because the product naturally decomposes into water and oxygen, no final rinse was required, which resulted in lower operational costs. Additionally, the water system remained free from biofilm, ensuring consistent hygiene and system efficiency", Filippos points out. "As a result, fresh produce stayed firmer and fresher for longer thanks to the elimination of pathogens, extending shelf life and increasing market value."