Solutions to brush sanitation tailored to the producer’s appetite for capital investment and labor intensity

Produce brushes are important tools for washing and polishing a variety of produce. Despite their utility, they are difficult to effectively clean and sanitize. Pathogens that are not removed through sanitation may increase in number and cross-contaminate fruit subsequently processed on that equipment. Clearly, effective methods for sanitation are needed. However, sanitation is resource intensive. The goal of our project is to help the industry best allocate their resources. Produce brushes will deteriorate over time with repeated use – like a toothbrush kept too long before replacement. Deteriorated produce brushes are more difficult to clean. But there is a lack of evidence on when produce brushes should be replaced. Our research aims to fill that gap by quantifying the impact of brush deterioration on wax and Listeria retention. We will investigate how well different bristle types resist deterioration. And we will define the critical parameters for steam treatments. Finally, we will test some of our findings in commercial settings. This project will provide industry with tools to assess tradeoffs in brush replacement and sanitation, improving their hygienic status and enhancing control over pathogen cross-contamination.

Wear-and-tear accumulates on brushes over time and decreases their hygienic status. The brush filaments bend and splay which impacts their performance and the ability of sanitation staff to effectively clean and sanitize the brush bed. Insufficient brush sanitation may lead to cross-contamination of pathogens such as Listeria. Apple facilities vary widely in their frequency for brush replacement. Some facilities replace brushes every 6 months while others may go 6 years before replacing brushes, based on a variety of factors including production volume and use intensity as well as tolerance for brush bristle deterioration. Wax brushes are typically replaced more frequently, are difficult to clean due to wax accumulation, and represent important sites for potential pathogen harborage. Yet, the impact of brush deterioration on the hygienic status of these tools has not been investigated. As a consequence, individual producers are left to evaluate these variables and decide when to purchase replacement brushes. These decisions are at the intersection of several factors: food safety and hygienic design, quality of wax application, cost of purchasing replacement equipment parts, and in some facilities, downtime to complete the replacement. To help facilities determine a course of action that minimizes microbial risk while limiting excessive costs of equipment replacement, we propose investigating the effect of brush deterioration on sanitation outcomes. We will specifically evaluate wax brushes (horsehair, horsehair-PSE blends, waxright) and wash brushes (PSE, nylon) made from different bristle fibers to provide evidence for supporting stakeholder decisions around the tradeoffs in brush bristle selection. We will also test the use of steam treatments applied in-place and out-of-place on wax removal and Listeria inactivation and trial proposed interventions in a collaborating facility. Results from these objectives will provide much needed evidence to the industry so that facilities can make informed decisions on the hygienic design and sanitation strategy for their brush beds. The findings can provide information on potential sanitation steps facilities can undertake to prevent potential cross-contamination. Our goal is to highlight the tradeoffs among different approaches to hygiene control and define concrete criteria for effective management.

Objective 1: Identify the impact of brush tuft deterioration on pathogen retention. 

Objective 2: Define deterioration markers for replacing brushes to mitigate pathogen retention. 

Objective 3: Trial steam to clean and sanitize brushes of varying deterioration states. 

Objective 4: Trial protocols with collaborating apple processors and evaluate microbial outcomes.

This project is ongoing. A final report will be provided when the project is finished.