Process for the production of powdered protein materials from animal raw material

A process for the production of protein containing products from bone containing animal raw material, comprising:

• (a) grinding the bone containing animal raw material,
• (b) heat treating the ground animal raw material at a temperature above 100.degree. C. in order to obtain a mixture consisting of solids in a fluid phase,
• (c) mechanically separating said mixture in order to produce a fluid phase and a moist protein-containing bone/meal fraction,
• (d) drying the moist bone/meal fraction,
• (e) separating the dried meal fraction into a first protein product containing bone pieces and a second powdered protein product,
• (f) separating said fluid phase into a sludge, an aqueous protein phase and a fat containing phase,
• (g) returning the the sludge to step (b) or step (c),
• (h) passing the fat containing phase on to a fat purification apparatus,
• (i) concentrating the aqueous protein phase obtained by step (f) by removal of water by vaporization,
• (j) separating the concentrate in order to obtain a second sludge, a second fat containing phase and a purified concentrated protein phase,
• (k) returning the second sludge to step (b) or step (c),
• (l) passing the second fat containing phase on to the fat purification apparatus, and
• (m) spray-drying the concentrated protein phase separately in order to produce a third powdered protein product.