Isolation, fractionation, and enrichment of casein fractions: conventional, emerging and lab techniques

Demand for casein-based products in nutraceutical applications, nutritional products, dairy products, and pharmaceutical and healthcare products has increased due to important technofunctional properties of caseins and their nutritional value. Casein fractions and their relative content in milk can impact milk processing and product value; thus, methods for separation of such fractions from milk and to understand their physicochemical and technofunctional properties are crucial. Since the beginning of 1950s, several methods have been developed for the isolation and enrichment of casein and its fractions, especially β-casein. These include, but are not limited to, bulky and long-term laboratory chemical methods, methods that rely on selective solubility and precipitation, membrane filtration, electrophoresis, and chromatography. However, separation techniques are mostly applied to a small-scale separation process. In this chapter, the most common methods to isolate casein and/or casein fractions, from milk, will be discussed and compared, highlighting the main limitations for potential upscaling.