Artificial Organic Load for Produce Safety Research: The Need for Standardized Method

摘要

The Produce Rule has generated interest in produce safety. Ensuring proper control of the water quality used throughout a production chain is a critical step in ensuring food safety. Properly validated food safety processing controls are needed for effective food saftey management for produce processing water, such as the use of sanitizer in washing systems to avoid possible pathogenic cross-contamination. While previous work has been conducted to assess the influence of sanitizer in the presence of organic matter, there are a wide spectrum of approaches to mimic vegetative organic matter, as well as various methods to analytically characterize the presence of organic load and its effects on sanitizer efficacy. In order to provide better technical support to the produce industry about effective antimicrobial solutions available that work in the presence of organic matter, there is a need for a standard artificial organic load replication method. This review examines the physiochemical properties used to analyze organic load on bench top settings such as turbidity, chemical oxygen demand (COD), biochemical oxygen demand (BOD), total dissolved solids (TDS), oxidation-reduction potential (ORP) and UV254 in efforts to make a comparison between quantitative tools used for measuring organic load and how these compare to measurements seen in onfarm processing conditions. It also looks at procedures used to replicate the organic load and how these affect the physiochemical properties of the water in sanitizer efficacy trials, which has become an important issue in light of the Food Safety Modernization Act (FSMA) regulation where farmers are required to test their agricultural water for the presence of Escherichia coli. Current research approaches that include vegetative material to mimic the organic load found in production water are done artificially using a variety of methods, which makes it challenging to make efficacy comparisons among existing work, and there is minimal published work that utilized production process water conditions. The most common methods of generating artificial organic load utilize fresh produce processed via two different routes: processing with blenders or paddle mixers. While there are various methods currently being used in bench top settings to quantify artificial wash water quality, not all are representative of measures seen on–farm, therefore presenting a challenge to assessing sanitizers most effective in real-world application. Based on published work, COD and TDS provide a more effective indicator to quantify water quality because their respective values provide a linear relationship with the amount of produce that is washed. Understanding the physicochemical properties of agricultural wash water and how they affect the efficacy of sanitizers, would enable the industry to develop a standardized method for organic load replication for the screening of commercially available sanitizers.