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When it comes to the effective and efficient use of testing instruments to support the production of dairy products, calibration is key.
While the testing equipment is vital for ensuring the proper quality and composition of ingredients and finished products, it is crucial for processors to support ongoing instrument calibration to maintain productive operations and prevent potential financial and product losses.
"Calibration is a fundamental requirement for even the most advanced instruments and software," explains Jackie Trudell, senior global market manager for dairy and liquids at PerkinElmer. "Regular and precise calibration of an analyzer is essential to sustain its ability to consistently deliver accurate and reliable results."
The significance of calibration in the production of dairy products cannot be overstated. It serves as the linchpin that upholds product quality, customer satisfaction, and operational efficiency. Therefore, it remains a fundamental necessity for processors in ensuring that their products consistently meet the necessary standards and consumer expectations while safeguarding their reputation and success in the market.
The importance of accuracy in measuring the composition of raw milk at intake, for instance, extends beyond quality control; it also holds significant implications for the relationship between processors and farmers.
Processors rely on precise measurements of key milk components such as fat, protein, moisture, carbohydrates, solids, and lactose when determining payment amounts to farmers. This practice ensures that farmers are compensated fairly based on the quality and composition of the milk they provide.
Ultimately, the commitment to accuracy helps maintain the stability and sustainability of the dairy supply chain, benefiting both processors and farmers alike. For processors, precision in measuring elements is critical if they are to meet the necessary product parameters.
In addition, exactness in calculating elements is critical for meeting contractual requirements, minimizing waste, and maximizing profits.
Potential product waste is a major concern during the production of varieties of milk. Procedures typically include the removal of all fat from raw milk before adding back an amount of fat to reach the desired product fat content.
“To confirm that their process is correct and finished products meet the necessary standards, processors will test products to verify the proximate values, including fat, protein, lactose, total solids, and solids that are not fat,” Trudell explains.“If a milk item is being analyzed for fat content and the predicted result is 2 percent, it should be near 2 percent fat when using reference methods. If the sample contained 3 percent fat, there would be an additional 1 percent in the product which could have been used for manufacturing other products.”
Such imprecisions also can lead to regulatory issues, especially during the production of butter that should typically contain at least 80 percent, depending on the country of production.
“If the instrument is not accurately quantifying fat content because it was not calibrated and it is reading 80 percent fat, but the amount is actually 78 percent, the organization can get into a lot of trouble because they are now selling something that isn’t butter,” Trudell says. “On the flip side, if the instrument is showing 80 percent but it is really 82, percent, they are giving away 2 percent of the fat that they could be using elsewhere. It can impact margins long term if the readings are inaccurate.”
Operators can determine the need for calibration by routinely running standards, or test samples with known results, through the inspection instruments and carefully analyzing the obtained data.
“Over time there will be a drift and that is a trigger for performing a calibration and adjusting the instrument back to where it should be,” says Sofia Karlberg, global product manager at PerkinElmer. The LactoScope™FT-A is PerkinElmer’s most versatile mid-infrared analyzer that can accurately test a wide range of dairy products, including milks, creams, whey, concentrates, ice-creams, and yogurt mixes in 30 seconds.
The need to calibrate testing instruments will be commensurate with the volume of samples tested. A heavily used instrument analyzing hundreds of samples per day may need recalibration every four weeks. A lightly used device may stay stable for 12 weeks or longer.
“Running large amounts of samples will cause the equipment to drift faster and differences in the results will occur faster,” Karlberg says. “Then, there is a need to calibrate the instrument more often to bring it back to the true reading.”
The type of product under production also can influence calibration frequency. Since products with particles, such as sugar, will accelerate equipment wear, processors that produce such sugar-laden products as chocolate milk and yogurt varieties with fruit will likely need to calibrate instruments more often than those exclusively handling raw milk.
The largest processors will typically experience the most severe consequences from utilizing analyzers that offer less accurate results. Such companies may stand to lose massive amounts of product, money, and prestige if performance is off even slightly. Processors that produce millions of pounds of butter annually, for instance, will generate substantial waste if finished products contained 81 percent fat instead of the requisite 80 percent.
This need for precision is making the effective leveraging of reference samples increasingly important as well. While processors can create their own samples to use as references, purchasing samples from external providers typically guarantees an accurate composition.
Reference samples are available for each product type, such as raw milk, processed milk, cream, and whey, and the amount sought by processors will typically vary in accordance with the number of different products that their plants develop. Producers of milk alone may routinely utilize up to a half-dozen reference sample types to match the different fat levels in the items.
To accurately calibrate the testing devices, it is essential that users receive the necessary training from experts, many of whom are associated with instrument manufacturers and reference sample providers. A crucial element is learning how to handle and maintain the test samples.
“It is not difficult to run the samples, which almost anyone can do,”Karlberg says. “It is more of how to treat and properly store the samples.”
Samples are available in fresh and frozen states and must be kept in an appropriate refrigerator or freezer to remain effective. Prior to use, samples should be warmed in a water bath of about 104 degrees Fahrenheit (40 degrees Celsius) and undergo mixing or turning to ensure the composition is homogeneous.
When assessing testing equipment accuracy, processors might run five samples through the instruments before and following calibration adjustments. “There will be differences between the sample test results and the actual composition of the product if the calibration has not been done correctly,” Karlberg says.
Device calibration can take two or more hours, with times lengthier for facilities that produce a wider range of dairy products. It is important that the workers closely follow the instrument manufacturer’s specifications to achieve precise readings and that the calibration takes place under suitable plant conditions, which includes proper temperatures.
Technology suppliers can support calibration initiates by providing software that enables instrument administrators to easily adjust the equipment settings by leveraging the results of the reference sample analyses. “After running the reference samples, users can enter the lab results into the software and it will calculate the recommended adjustment to the instrument,” Karlberg states. “The Results Plus software that we use in conjunction with the LactoScope FT-A is designed to guide the user to make a correct adjustment to the instrument. This can also be done remotely by using a cloud solution like our NetPlus™software.”
While most operators use internal resources to calibrate equipment, companies also can delegate the procedure to third parties. Such outsourcing can relieve processors of the time and expense of having in-house workers perform the measures in lieu of focusing on other matters. It is important, however, that the outside organization has the appropriate accreditations and certifications for rendering the services.
Whether done internally or with a third party, the calibration process can be expensive, particularly because it can cost hundreds of dollars to purchase the samples. Companies often have a subscription for reference standards with many receiving samples every two months.
“Processors with sophisticated laboratories can develop their own reference methods and standards,” Karlberg says. “But when you buy the samples externally, you know that the results they come with are accurate. In most cases, it is better to source them externally.”
Nevertheless, there are instances in which operators may need to create their own samples, particularly when vendors lack the references to support products with proprietary recipes and uncommon compositions.
For the most effective calibration, dairy producers should analyze and adjust devices at scheduled intervals. Tagging devices with an approved identification mark following calibration can confirm that the procedure was accomplished.
“It is important that processors take ongoing steps to ensure that their instruments remain top of the line and calibration is a very important part of that,” Trudell states. “Similar to the need for ongoing automobile maintenance, routine upkeep of the testing analyzers is crucial to keep them running smoothly.”