This blog post starts a new series on sample preparation and analysis of milk and dairy products.
In this first blog post, we present a simpler solvent extraction method for dairy that saves significant sample preparation time, solvent, and time. Sample extraction for dairy products is challenging as they consist of complex matrices and, typically, pretreatment steps are necessary to denature casein—a phosphoprotein—to expose the fat to extraction solvent. Other dairy samples, such as cheese, require several pretreatment steps before extraction. The manual extraction process requires 2 to 3 h and more than 100 mL of solvent per sample (AOAC Official Method 933.05).
Standard fat extraction methods, (e.g., Roese-Gottlieb, Gerber, Babcock, and Mojonnier) do provide satisfactory results but are time consuming and labor intensive.
Here we present Application Note 364, Rapid Determination of Total Fat from Dairy Products, (downloadable PDF) describing the extraction of fat in whipping cream, cream cheese, non-fat milk, sour cream, and coffee creamer in 25 min compared to 2 to 3 hours for the other techniques!
Like what you are learning?
The instrument used in the application note is an accelerated solvent extractor (Thermo Scientific Dionex ASE Accelerated Solvent Extractor) designed for the extraction of solid and semisolid sample matrices using common solvents at elevated temperatures and pressures.
Here is a short video of about 4 min on this system.
Let us know if this blog post was helpful to you. Also, don’t forget to mention other applications you are interested in. We look forward to hearing from you!