Préparation de phosphocaséinate natif par microfiltration sur membrane

Abstract

Native micellar casein separation through cross flow membrane microfiltration. Native phosphocaseinate (PPCN) was separated from raw milk by tangential membrane microfiltration (pore diameter 0.2 mum) followed by purification through water diafiltration. Analytical survey of both liquids issued by membrane treatment showed permeation rates matching mathematical laws for the main whey proteins (beta-lactoglobulin and alpha-lactalbumin), lactose and soluble mineral salts. On the contrary, a high retention of high molecular weight soluble components and proteose-peptone fraction was observed. Final diafiltrated retentate was spray-dried. Its protein (N x 6.38) and ash contents in total solids were respectively 89% and 9%. Rennet coagulating ability of PPCN reconstituted solution was compared to that of raw milk. Coagulation time was reduced by 53%. gel development kinetics (estimated by K20) and final firmness (estimated at 30 min) were increased by more than 50%. When a severe heat treatment (100-degrees-C - 5 min) was applied milk lost its ability to coagulate after rennet action; PPCN solution did not, but its coagulation time was increased and the curd was slightly weaker.