Every day, food processors must make the high-risk decision to begin production, and one key factor in that determination is the effectiveness of the most recent cleaning and sanitation of their manufacturing environment. These judgment calls usually need to be made quickly and under tight schedules. Therefore, it’s critical to have a hygiene monitoring and testing program that can be relied on to efficiently provide both accurate and precise results. While no sampling method is capable of recovering 100 percent of the contaminants and organisms present, food processors and industry professionals still need to be as confident as possible before they begin production that the surfaces they are working on are sufficiently clean in order to comply with QA criteria and reduce the risk of potential food contamination.
While QA compliance may seem like enough of a motivator, the risk factors go beyond mere failure to comply. Improper cleaning can result in cross-contamination with spoilage or pathogenic organisms that may impact product quality or safety, respectively, sometimes even resulting in product recalls and unwanted media attention. After factoring in potential financial toll and regulatory agency involvement, it becomes clear just how important ensuring the cleanliness of surfaces and equipment should be to an organization.
Distinguishing Cleaning from Sanitizing
One of the first things a food manufacturing plant operator can do is to take a step back in understanding the difference between cleaning and sanitizing; they are not one and the same, though many assume this to be the case. Cleaning involves the removal of food residue and other types of soils from surfaces. By contrast, sanitizing refers to reducing the number of microorganisms to safe levels. The sanitation typically occurs through heat or chemical processes.
Verification: Its Importance and Forms
A critical next step in assessing whether a surface or piece of equipment is clean is comprehending that cleaning is not just a process food safety professionals will complete prior to sanitation, but a process that will be verified before sanitizing takes place. Verification of the efficacy of cleaning is possible with the use of methods such as visual inspection, microbial enumeration, and adenosine triphosphate (ATP) detection. Rigorous industry standards dictate that individuals responsible for this process establish a quantifiable baseline reference, then verify that cleaning has been performed at or exceeding this threshold. In a food manufacturing plant, for example, this process usually involves identifying several test points based on surface and product type, hygiene zone, and risk level that must be verified before production can begin.
Visual inspection allows for the overall assessment of surfaces and equipment, and its definition can be taken at face value: It means visually inspecting a piece of equipment or surface for cleanliness. Although the method is still used for many reasons, it is limited in that it is subjective, and most importantly, even if a surface appears clean it does not mean that it is. Therefore, visual inspection should be documented and utilized as a supplement to other methods in the verification process.
Microbial enumeration is a tool to verify cleaning and sanitation that involves estimation of microbial loads through direct counting of colonies in a microbiological medium, and includes indicator organisms in addition to pathogens. While microbial enumeration has an exclusive emphasis on direct estimation of microbial loads on surfaces, its main limitation is the amount of time taken to obtain results (24-48 hours).
ATP measurement is the most common rapid verification approach used by many facilities. Measuring the levels of ATP on surfaces or in closed systems via rinse water sampling allows for assessing the sanitary conditions after cleaning, and has become an indispensable method over the last several years. ATP is present in all living cells, making it the ideal molecule to test for to verify that no organic material remains on a cleaned surface. Most ATP systems are simple to use and provide an indirect estimation of microbial contamination and residual organic matter that may still be present. Instruments used for the detection of ATP—or luminometers—can be photodiode or silicon-based, among other emerging technologies, and establish a correlation between light emitted from a bioluminescent reaction proportional to the amount of ATP present.