Separation of lactoperoxidase, secretory component and lactoferrin from milk or whey with a cation exchange resin

A process for separating lactoperoxidase, secretory component and lactoferrin from milk or whey using a single cation exchange resin which binds lactoperoxidase, secretory component and lactoferrin, said process comprising:

• a. contacting the milk or whey with said cation exchange resin for about 15 minutes to about 15 hours thereby causing any lactoperoxidase, secretory component or lactoferrin contained therein to become adsorbed to said cation exchange resin;
• b. washing said cation exchange resin with an aqueous solution having an ionic strength of less than about 0.2 and a pH of about 5 or lower, then sequentially;
• c. first eluting said lactoperoxidase by contacting the cation exchange resin with an aqueous solution having an ionic strength of from about 0.2 to about 0.5 and a pH of 5 or lower thereby forming an eluate containing lactoperoxidase;
• d. second eluting said secretory component by contacting the cation exchange resin with an aqueous solution having an ionic strength of from about 0.1 to about 0.5 and a pH higher than 5 thereby forming an eluate containing secretory component;
• and
• e. third eluting said lactoferrin by contacting the cation exchange resin with an aqueous solution having an ionic strength higher than about 0.5 and a pH higher than 5 thereby forming an eluate containing lactoferrin;
• wherein the lactoperoxidase, secretory component and lactoferrin obtained in steps (c), (d) and (e) each have a purity of about 80% or greater.