Milk powder, also known as powdered milk or dry milk, is made by evaporating the water content from regular liquid milk. The primary ingredient in milk powder is cow’s milk, but it can also be made from the milk of other animals such as goats or sheep. It is important to note that milk powder can come in different variations, such as whole milk powder, skim milk powder, or fortified milk powder, which may have additional ingredients added to enhance nutritional value or prolong shelf life. Because of this, it’s crucial to analyze the product to help ensure quality and that the finished product contains exactly what the package says it should contain.
How is Dry Milk Made?
The milk used for making milk powder undergoes a process to remove the water content, resulting in a dry and powdered form. The milk is first pasteurized to eliminate any harmful bacteria and to ensure its safety. It is then subjected to evaporation, which involves heating it under reduced pressure. This process helps remove the water content from the milk. The concentrated milk is then passed through a spray dryer where the milk is atomized into small droplets and sprayed into a hot air chamber. The hot air quickly evaporates the remaining moisture, leaving behind fine milk particles consisting of solid components of the milk, including milk proteins, lactose (milk sugar), milk fat, and various vitamins and minerals.
After the milk particles are dried, they are cooled down and then packaged into airtight containers to maintain their quality and prevent moisture absorption. The resulting milk powder can be reconstituted by adding water, making it a convenient and long-lasting alternative to liquid milk.
How Manufacturers Can Confirm the Quality of their Dry Milk Products
A variety of analytical techniques are used in the food industry to determine the nutritional value of milk-based powders (e.g., infant formula), which consist of milk powder with added nutrients. Examples of nutrients found in these “fortified” milk powders include proteins, fats, carbohydrates, vitamins, and minerals.
Energy-dispersive X-ray fluorescence (EDXRF) is used near the production line to control the elemental content of milk-based powders.
EDXRF is a spectroscopic technique used for elemental analysis of various materials. EDXRF works by bombarding a sample with high-energy X-rays, which causes the atoms within the sample to emit characteristic fluorescent X-rays. These emitted X-rays are then measured and analyzed to determine the elemental composition of the sample.
In an EDXRF setup, the X-rays are generated by an X-ray tube, typically using a metal target material such as rhodium or silver. The X-rays pass through a collimator and interact with the sample, causing the emission of fluorescent X-rays. These X-rays are then detected using an energy-dispersive detector, which measures the energy and intensity of the emitted X-rays.
The energy of the emitted X-rays is specific to each element, allowing for the identification and quantification of elements present in the sample. The intensity of the X-rays is proportional to the concentration of the corresponding element in the sample, enabling quantitative analysis.
In EDXRF analysis, the characteristic X-rays of different elements present in a reading are separated into a complete fluorescence energy spectrum. EDXRF technology is engineered to simultaneously process whole groups of elements for qualitative or quantitative analysis and can be used in portable and laboratory-based formats. As a result, EDXRF can accommodate samples of almost any shape and size.
EDXRF is a versatile technique widely used in various fields such as environmental analysis, archaeology, geology, pharmaceuticals, forensics, and materials science. It offers several advantages, including non-destructive analysis, high sensitivity, wide elemental range, and the ability to analyze solids, liquids, and powders.
Analyzing Dry Milk with EDXRF Spectrometry
An EDXRF spectrometer is a convenient and cost-effective analysis tool for delivering major, minor and trace element quantification from F (C*) to Am for a wide range of samples with minimal sample preparation.
We conducted an analysis of nutrients in milk-based powders by EDXRF, especially monitoring the elements Sodium (Na), Magnesium (Mg), Phosphorus (P), Chlorine (Cl), Potassium (K), Calcium (Ca), Manganese (Mn), Iron (Fe), Copper (Cu), and Zinc (Zn) to determine the nutritional value of milk-based powders.
We concluded that using a specific EDXRF Spectrometer, when equipped with a graphene detector window, is an excellent tool for monitoring the elemental composition of milk-based powders.
You can read the application note Analysis of nutrients in milk-based powders by EDXRF for specific details, including instrumentation used, sample preparation, measurement conditions, calibration and validation methods, as well as analysis spectra and charts.
Additional Resources
- Application Note: Analysis of nutrients in milk-based powders by EDXRF
- EDXRF spectrometer features, instruments, applications, and resources
