Short communication: extraction of beta-casein from goat milk

Peptides derived from milk beta-casein have potential biological activities, such as antihypertensive and immunostimulating properties. These biological properties increase the demand for the production of specific bioactive peptides. beta-Casein can be isolated directly from renneted skim milk, based on the preferential solubilization of beta-casein at low temperature. This study was conducted to compare the recovery and purity of beta-casein extracted from goat and cow milks. Rennet casein was prepared from both milks, heat treated, and dispersed in demineralized water at various temperatures. beta-Casein recovery in the soluble phase increased with decreasing incubation temperature. Concentration of beta-casein was 43% higher in goat milk than in cow milk, which had a direct effect on beta-casein recovery. Furthermore, beta-casein was extracted more efficiently from goat rennet casein. As a result, the extraction yield of beta-casein was 53% higher in goat milk than in cow milk. The purity of beta-casein extracted from both milks reached approximately 90% after incubation at 0 degrees C.