Extraction Of Lactoferrin By Membrane Technology

Lactoferrin has some applications in the food industry and in the medical domain, but thechnologies used to extract lactoferrin have still disadvantages (high cost, great volume of effluents, etc.), which restrain the use of lactoferrin for high added value product. This study aimed at exploiting a new process using membrane technology to extract lactoferrin from skim milk. The extraction of lactofferin was realized by concentration of casein micelles with crossflow microfiltration (0.1μm) and liberation of lactoferrin from micelles by physicochemical modifications. The optimum parameters to extract the lactoferrin were first defined and optimized at a laboratory scale:for a high content of caseins (78 g.kg^-1), an ionic strength higher than 200 mmol.L^-1 and a pH adjustement to 6.4 are sufficient to release all the lactoferrin linked to casein micelles. Our results obtained from 3 industrial trials showed the feasibility of extracting lactoferrin by membrane technologies. A process was finally proposed with the following steps: Concentration of lactoferrin by a factor of 3 according to casein micelles concentration; Elimination of other whey proteins by diafiltration with ultrafiltrate; liberation of lactoferrin according to NaCl addition (300 mmol.L^-1) and pH adjustement (6.4) in the PPCN solution; Recovery of lactoferrin in the final product by ultrafiltration and diafiltrafion with osmosis water. The process resulted in a lactoferrin fraction with 36% purity (based on protein content) and a yield of 58%. Moreover, it could be advantageously combined to cheese manufacture. What's more, this process is generally less expensive, less polluting and simpler than traditional technologies.