Bacillus subtilis neutral proteinase was encapsulated in conventional dehydration-rehydration liposomes and, co-encapsulated with a phospholipase, in triggered liposomes. Triggered liposomes had released in buffer 58.0% of the encapsulated proteinase after 180 min at 30 degrees C, whereas only 1.1% was released from conventional liposomes. Addition of triggered liposomes to milk resulted in only 70.4% residual beta-casein after 240 min at 30 degrees C compared to 90.7% in control milk. If triggered liposomes were added to milk with lactic starter and rennet, residual p-casein was only 52.3% after 240 min, compared to 80.3% in milk without liposomes.