What it does
Caseins emulsify extremely well and are heat stable, which is why they survive processes that destroy other proteins. Whey proteins denature and gel on heating, which is the opposite behaviour and useful for different reasons. Both bind water and both contribute a clean dairy flavour and a white colour.
Where it works
Processed and analogue cheese, where casein is the structure. Emulsified meat products, for fat stabilisation. Dairy drinks and desserts, for body. Anywhere a neutral protein with reliable emulsification is wanted.
Where it does not
It is a declared allergen and excludes a product from vegan and most plant based positioning. Whey will aggregate and give a grainy texture if heated at the wrong pH. Cost is also volatile, tracking the dairy commodity market rather than the ingredient market.
What it interacts with
Calcium and pH, decisively for casein. Heat, decisively for whey. Emulsifying salts, which exist to disperse casein.
