Membrane separation and recombination method for core nutritional ingredients of infant milk product and application of membrane separation and recombination method

The invention relates to the technical field of food, and provides a membrane separation and recombination method for core nutritional ingredients of infant milk products and application of the membrane separation and recombination method. The method comprises the following steps: taking more than one of single cream, casein trapped fluid, whey protein concentrated solution, demineralized whey protein concentrated solution, lactose concentrated solution and demineralized lactose concentrated solution as main raw materials to form the core nutritional ingredient; the raw material preparation method comprises the following steps: degreasing raw milk to obtain skim milk and single cream; performing multi-stage microfiltration on the skimmed milk to obtain whey protein permeate and casein trapped fluid; performing multistage ultrafiltration on the whey protein permeate to obtain a lactose permeate and a whey protein trapped fluid, and concentrating the whey protein trapped fluid to obtain a whey protein concentra