CONTRIBUTION OF LACTOCOCCUS-LACTIS SSP LA CTIS BIOVAR DIACETYLLACTIS TO THE BROWNING OF BRIE AND CAMEMBERT-TYPE CHEESES

Pink-brown discolorations of commercial Brie and Camembert-type cheese s were investigated. Cheeses did not demonstrate high levels of nitrit e, estimated at less than 1 ppm. The discoloration of the ripened chee ses was prevented by addition of sulfites, lactic acid or by heating ( 75-121-degrees-C), but was accelerated by the addition of NaOH on the surface of the cheese. The mixed culture used for the commercial produ ction showed a high proportion (75%) of Lactococcus lactis ssp lactis biovar diacetylactis. It was possible to provoke the browning of Brie- Camembert as well as Blue-type cheeses, by using pure cultures of L di acetylactis in pilot-scale (100 I) production. (2.1%) reduced the inte nsity of discoloration in the ripened cheeses. The discoloration was a ssociated to the synthesis of acetaldehyde by the lactococci. By modif ying the starter production method in order to reduce the L diacetylac tis population and by adding a Leuconostoc culture, it was possible to prevent the discoloration.