Categories: Food Safety, Microbial Testing Tuesday, December 20, 2011
In recent years, advancements in wash water sanitation have created questions as well as answers. New developments have occurred both in the field and in research findings, leaving some companies to wonder how to decide which technology is best for them. I’ve increasingly fielded questions from buying companies as they consider rewriting product specifications to require use of one sanitizer over another. I’ve also received several calls from producers wanting to understand how to determine if they should change their systems. My purpose in this post is to highlight a few of the factors each company should consider in evaluating their wash water system.
The first step in evaluating any wash water scheme is to test the products in your system and validate what works in your specific operation. Validation is an extremely important concept. Past measures have often revolved around adding a sanitizer to water and then measuring the level of sanitizer at some time interval that meets a specific HACCP requirement. But, indirect measures of sanitizer (such as oxidation reduction potential) while convenient and continuous do not accurately reflect actual sanitizer levels, especially when organic loads accumulate during the production run.
In today’s world we must understand how effective a particular wash water system is in controlling the bacteria that could accumulate in wash water over a wide variety of treatment conditions and time. In evaluating whether new technologies will work for a specific operation, it’s crucial to conduct experiments on each possible technology. An operation must validate that the practices used for wash water sanitation actually achieve microbial control or reduce the risk of cross-contamination under the conditions typically encountered in their production environment. A generalized or “one size fits all” approach is simply not appropriate or effective.
From a buyer perspective, the key issue is not so much which program is being used, but rather if the system used by the suppler is validated. Can a supplier show the data that validates its treatments are working? And, can the supplier provide verification data demonstrating adherence to its wash water sanitation program?
Before employing or requiring any wash water sanitizer, it is important to fully understand how or if its use will improve product safety and wash water quality, change the microbial ecology of the finished product, impact the operational aspects of the process and affect quality of the finished product.
Thus, in evaluating the efficacy of a new wash water sanitizer from a scientific perspective, several questions should be addressed. First, consider how effective the product is in controlling or killing suspended microorganisms (primarily bacteria and viruses) in the wash water and how its effectiveness could be impacted by organic load, material surface, pH, dwell time, or temperature. Then look at how the new sanitizer compares to other established wash water sanitizers and how the effective level can be monitored. Consider what the mode of action for the sanitizer is. What are the chemical, physical and biological interactions? Can they be reversed? What are the consequences of concentration? Under what conditions is equilibrium achieved or lost? Lastly, is the product labeled as a processing aid or a disinfectant, sanitizer, pesticide, etc? Has the product been approved by FDA and/or EPA? Are the ingredients GRAS?
As far as microbial ecology goes, consider that all microorganisms might not be equally susceptible to the sanitizer. Look at how continued use of the sanitizer could result in the evolution of resistant microorganisms. In looking at operational impact, see if the sanitizer is effective under normal processing conditions. Take into consideration the practical logistical aspects as well. For example, how is the sanitizer mixed and delivered to the wash system? What are the training requirements? How versatile is the new sanitizer? What is the environmental impact of sanitizer use? Will the sanitizer impact waste water removal? Is the sanitizer compatible with the construction of your equipment?
Lastly, consider the finished product quality taking into account the impact on shelf life and if the postharvest physiology of the finished product changed. These are just a few of the many questions involved in truly analyzing a wash water system. For more details and a comprehensive list of the questions to consider, stay tuned for my Wash Water Paper being produced in 2012.
Remember, food safety is not passive, food safety is personal. Each company must accept the responsibility to experiment and validate different technologies with its specific system. This is an area of developing technology and I look forward to sharing new development and information with you in future posts. Please contact me at AskDrBob@pma.com with any comments or questions. Your feedback is always valuable.