Abstract: The present invention relates a process for the production of liquid and powdered bifidogenic infant and dietetic foods that are reduced in their antigenicity. The process, according to the invention, is characterized by the cleavage, but not removal, of sialic acid from milk protein and/or milk protein degradation products, via acid hydrolysis, in order to achieve a bifidogenic product. Thus, it is possible to produce bifidogenic infant foods, particularly suitable for infants, premature and undersized babies, and those parties who cannot tolerate usual milk products. In addition, the process can be used to produce dietetic food, particularly for persons suffering from intestinal allergies, other allergic diseases and failure of the liver and kidney.