If fat is selectively removed from the animal carcass and carefully rendered, the result product can be simply filtered to remove particulate.
For more complex products with more rigorous quality specifications, the complete processing train of caustic refining, bleaching, hydrogenation, blending and deodorization is used.
Animal fats recovered from fatty tissues by cooking processes known as rendering. The two predominant rendering processes are wet and dry rendering.
In wet rendering, the fatty tissue is heated under steam pressure, thus rupturing the cells and liberating the fat. The lard produced by this method of rendering is known as ‘prime steam lard’. In addition to lard, tallow and whale oil also usually steam rendered. The wet process is preferred for edible animal fats.
In dry rendering, the fatty tissue is heated in jacketed drums with agitation until the fats is released. Presently, centrifuges are used to separates the fat from water and protein. The dry rendering process is preferred for inedible products.
Animal fats processing