A process comprises concentrating a whey composition to at least about 75 weight % solids in one or more evaporators connected in series to form a concentrated whey composition, wherein at least one of the evaporators comprises an evaporator configured to agitate the whey composition within the at least one evaporator, crystallizing at least a portion of the lactose in the concentrated whey composition in a crystallization cascade comprising one or more crystallizing stages to form an at least partially-crystallized whey composition and drying the at least partially-crystallized whey composition to form a dried whey product.

The invention relates to the technical field of collagen food. The pure collagen milk powder is prepared by concentrating and drying pure collagen milk, and the pure collagen milk is composed of the following raw materials in parts by weight: 10-80 parts of a pure collagen solution, 0.1-1 part of an emulsion stabilizer, 0.25-5 parts of white granulated sugar, 0.15-3 parts of salt, 0.01-0.5 part of a food flavor, and 20-90 parts of drinking water, wherein the pure collagen solution is a pure collagen solution containing small molecule short-chain peptides.