Obiettivo To reduce the level of contaminants at the very origin (from the animal, in slurry) and study the actual sources of contamination of the milk itself on the farm in order to eliminate them; To develop new technology to improve the safety of raw milk while maintaining its quality for cheese manufacture. This implies studying the possibility of decontaminating the milk by means of physical techniques (microfiltration, centrifugation); To make use of the potential of lactic starter microorganisms and also of the fungi, yeast or bacteria produced during the maturing process to inhibit harmful flora (in particular, the pathogenic Listeria monocytogenes). A large number of European cheeses are still made from raw milk in order to obtain the characteristic taste desired by consumers. In view of the potential risks associated with the use of raw milk, research has been carried out in order to develop a full system of protection against the bacteria which endanger consumers.The level of contamination by Listeria monocytogenes on farms has been found to be low. Hygiene during milking and in particular when cleaning the cows' teats is essential to guarantee that the milk is free from Listeria monocytogenes.The origin of the large number of contaminant bacteria found on the surface of teats has not yet been established. Determination of the strains of Listeria found is still in progress and may provide further information and possibly confirm the theory regarding their origin.Of several thousand bacteria tested,only a few strains of Lactococcus, Pediococcus and Enterococcus have been found to inhibit Listeria. In some of thse strains, it was found that this activity was due to the production of bacteriocins.There is no reduction in antimicrobial activity following neutralization of the medium or the additon of catalase. These substances are thus inhibited or destroyed under the effects of certain proteolytic enzymes.The effects of the culture medium on the quantity of bacteriocin produced have been studied. Purification of Pediococcus and Enterococcus bacteriocins is in progress.The effects of the technological production parametes on the kinetics of the development of Escherichia coli and Staphylococcus aureus in Camembert have been studied. A statistical study of the results is in progress but long prematuring in the presence of bacteria has been found to have positive effects on slowing down the development of contaminating flora.Finally, the internal and external flora of Camembert cheese has been characterized.Problems of hygiene and quality of che eses are a constant preoccupation of t he entire dairy industry. In order to insure consumer safety, the milk under goes various heat treatments in order to eliminate any potentially pathogeni c flora. The obvious result of these t reatments is to concomitantly destroy the microbial flora which participate in the process of cheese manufacture: lactic acid bacteria, yeasts and bacte ria responsible for ripening. In addit ion, pasteurising destroys various enz yme systems (oxido-reduction enzymes) which may participate in the productio n of final characteristic flavors. There is thus a degradation of the org anoleptic qualities of products manufa ctured from pasteurised milk. In addit ion, a non-negligible proportion of gu aranteed origin cheeses is always manu factured from raw milk in order to obt ain the taste highly appreciated by co nsumers. Furthermore, these technologi es also lead to added profit from milk in regions where agriculture is diffi cult, notably mountainous regions, and the dry Mediterranean zone; sheep mil k may also be concerned by this. The s ocio-economic impact is thus very impo rtant for southern Europe and France. In light of the potential dangers asso ciated with the use of raw milk, it is indispensable to develop an entire sy stem of defense against bacteria which pose a risk for man. This will insure that the safety of these products, re sponding to high consumer demand and a lso benefiting agriculture in difficul t regions, will be as great as that of products manufactured with pasteurise d milk and which will preserve their o rganoleptic qualities. The project includes several main axes : 1. The reduction in the level of con taminants at the level of the animals and the study of sources of contaminat ion, in order to be able to eliminate them. 2. The development of new technologies to improve the quality and safety of raw milk used in cheese manufacture. Possibilities of decontamination by ce ntrifugation, creaming or microfiltrat ion will be studied in particular. 3. Microbial antagonisms will be sough t by the selection of lactic acid bact eria producing factors which inhibit u ndesirable, even pathogenic, organisms . Special attention will be paid to th e production of bacteriocins and/or ni sin. A crucial point of the research w ill be the effect of technological par ameters on the behavior of new lactic acid bacteria starters which will be s elected and their effect on the elimin ation of undesirable flora. All this research will be applied to d ifferent Camembert, Fontina, Asiago an d Manchego type cheeses. Campo scientifico natural scienceschemical sciencesorganic chemistryorganic acidsnatural sciencesbiological sciencesmicrobiologybacteriologyagricultural sciencesanimal and dairy sciencedairyagricultural sciencesagriculture, forestry, and fisheriesagriculturenatural sciencesbiological sciencesbiochemistrybiomoleculesproteinsenzymes Programma(i) FP2-FLAIR - Multiannual research and development programme (EEC) in food science and technology (FLAIR), 1989-1993 Argomento(i) Data not available Invito a presentare proposte Data not available Meccanismo di finanziamento CSC - Cost-sharing contracts Coordinatore Besnier SA Contributo UE Nessun dato Indirizzo 10 Rue Adolphe Beck 53000 Laval Francia Mostra sulla mappa Costo totale Nessun dato Partecipanti (4) Classifica in ordine alfabetico Classifica per Contributo UE Espandi tutto Riduci tutto INSTITUT NATIONAL DE LA RECHERCHE AGRONOMIQUE Francia Contributo UE Nessun dato Indirizzo Domaine de Vilvert 78352 JOUY-EN-JOSAS Mostra sulla mappa Costo totale Nessun dato Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria Spagna Contributo UE Nessun dato Indirizzo 28080 Madrid Mostra sulla mappa Costo totale Nessun dato Istituto Sperimentale Lattiero-Caseario Italia Contributo UE Nessun dato Indirizzo Via A. Lombardo 11 20075 Lodi Milano Mostra sulla mappa Costo totale Nessun dato Rijkszuivelstation Belgio Contributo UE Nessun dato Indirizzo 370,Brusselsesteenweg 9090 Melle Mostra sulla mappa Costo totale Nessun dato
