Milk contains many proteins that have health benefits. Common techniques used in the dairy industry to extract milk proteins include precipitation, membrane filtration, and chromatography. Precipitation involves adjusting factors like pH, salts, or temperature to make proteins insoluble and aggregate. Membrane filtration separates components based on size or hydrophobicity. Chromatography techniques like ion exchange and affinity chromatography isolate proteins based on their charge or affinity for specific chemical groups.