By: Russell Owings
BioSafe Systems, LLC
Food safety regulations are becoming more prominent as the government implements changes to the Food Safety Modernization Act regarding growing, processing and shipping of food supplies. Antimicrobial interventions in process waters and facility sanitation are key components of this initiative. Good management practices help ensure that both processing facilities and our fruits, vegetables and meats are free of pathogens that could cause illness or premature decay of product. In order for sanitizers and detergents to be effective they must be dosed at specific rates and titrated to assure the desired chemical concentration is achieved. Low levels can allow unsafe organisms to thrive while high levels are unnecessarily expensive and can alter product quality. There are several different measurement tools on the market today for testing and titrating chemicals and it is important to find the one that is most effective for your operation.
Test strips provide a quick and inexpensive “indicator” of chemical presence in a solution. The color of the strip will change based on the level of active chemical present in the solution and the resulting color is compared to a chart indicating a parts per million range (ppm). Test strip results should not be considered a titration as they do not provide a precise ppm. Results are subjective based on the person conducting the test and his or her matching the test strip to the color chart. Test strips do have a place in food processing as they are often used as a “quick- check” to assure a sanitizer has been applied. Results are manually logged.
Drop Count Titration Kits
Drop count titration kits provide another option for measuring chemical levels. The process includes collecting a sample of solution and adding a measured amount of reagent chemical. The person conducting the test would use a dropper bottle to add a titrant chemical (often referred to as “Indicator Solution”) one drop at a time until the sample changes color. To calculate the ppm, users multiply the number of drops of titrant added by a number provided in the test kit manual. Drop Count titrations are time consuming and subjective. The size of the titrant drop will vary depending on the angle the dropper bottle is held which can affect the end result. If the indicator solution amounts are off by even one drop the titration is flawed. Some Quality Assurance Managers (QA) and USDA inspectors may not allow drop titration kits to be used inside the plant due to risk of contamination from the titrant chemical. Additionally, if the glass vile were to be dropped into the product it would not be picked up by a metal detector. A water sample may need to be taken to a QA office or other office not in the processing facility to conduct the titration. Results are manually logged.
Test Strip and Drop Count Titration Drawbacks
Both test strips and drop titrations are subject to human error and require manual logging of the results. Test strips provide a quick indicator but not precise ppm concentrations. Drop count titrations are time consuming and results can vary greatly from test to test.
A New Era of Testing: The EMD Reader
With the increased risk associated with food safety failures and potential litigation, the industry needs to move away from subjective testing procedures. An EMD Reader is a highly sensitive reflectometry instrument that combines the speed and convenience of test strips with precise accuracy. The all-in-one system generates on-the-spot results which are shown on an LCD display. Results may be manually logged or downloaded to a PC to create printable reports.
The scanner eliminates the subjective reading of a test strip, removing problems arising from issues with interpreting the color results of either test method. The EMD scanner has a built-in procedure to calibrate the unit to ensure accurate test results. The scanner can store up to 50 individual solution tests and the results can also be converted into spreadsheets for report writing and analysis.