Objective The manufacture of over 800.000 tons of highest quality hard/semi-hard cheese in Europe is very much dependent on precise control of the propionic acid fermentation during cheese maturation. Specific strains of propionic acid bacteria (PAB) are responsible for the development of the characteristic eyes in cheeses such as Emmental, Gruyere, Comte, Leerdamer, Maasdamer, etc. PAB play on important role in the formation of aroma in these cheeses and in hard italian cheeses (Grana, Padano, Parmigiano Reggiano). During ripening these bacteria convert the lactates, produced by the starter lactic acid bacteria (LAB), to propionate, acetate and C02. The C02 collects in weak pockets in the cheese curd leading to eyes formation and the propionic acid contributes strongly to the final cheese flavour. Though extremely important, the PAB have not attracted a great deal of research attention and most of the published work on these bacteria has been done with pure cultures. In cheeses however, the PAB must establish a successful symbiosis with the starter LAB. The starter bacteria provide the energy substrate in the form of lactates which the PAB ferment to propionate, acetate and CO2.The objectives of this project are :1- to clarify the relationshipsbetweenthe starter LAB and the PAB in the cheese environment,2- to determine the factors wihich permit selection of strains of LAB and PAB such that they interact in a beneficial symbiosis which affords a predictable consistent propionic acid fermentation in the cheese environment,3- to define the conditions which bring about a cessation of the propionic acid fermentation when it has developed to optimum, characteristic of a particular cheese,4- to identify combinations of LAB and PAB which are ideal for the manufacture of specific propionic acid cheeses, leading tohigh quality cheeses,5- to identify LAB strains which are antagonistic to PAB so as to curtail their development in cheeses in which the propionic acid fermentation causes an openess defect.Organisation of the project :* Refinement of a model system which simulates as far as possible the cheese environment,* Identification of beneficial symbiotic combinations of PAB and LAB,* Identification of LAB generally antagonistic to PAB, useful for Italian hard cheeses, * Idenfification as far as possible of the factors responsible for the beneficial and antagonistic reactions in 3 and 4 respectively,* Establishment of the significance of the model system by testing the beneficial combinations of PAB and LAB identified in the model system, in pilot plant and commercial Emmental-type cheese making. Industrial partners will participate to these trials,* Establishment of the significance of the model system by testing LAB identified as antagonistic to PAB in Italian cheesemaking trials,* Characterisation of the PAB and LAB strains being used in the project so as to establish a bank of strains which can be used by cheese makers to make specific cheese varieties. Fields of science natural scienceschemical sciencesorganic chemistryorganic acidsnatural sciencesbiological sciencesmicrobiologybacteriologynatural sciencesbiological sciencesbiological behavioural sciencesethologybiological interactionsengineering and technologyindustrial biotechnologybioprocessing technologiesfermentation Programme(s) FP4-FAIR - Specific research, technological development and demonstration programme in the field of agriculture and fisheries (including agro-industry, food technologies, forestry, aquaculture and rural development), 1994-1998 Topic(s) 3.4.5 - Food microbiology Call for proposal Data not available Funding Scheme CSC - Cost-sharing contracts Coordinator INSTITUT TECHNIQUE DU GRUYERE EU contribution No data Address RUE DE SAINT-BRIEUC, 73 - B.P. 6224 35062 RENNES France See on map Total cost No data Participants (6) Sort alphabetically Sort by EU Contribution Expand all Collapse all AGRICULTURAL UNIVERSITY OF ATHENS Greece EU contribution No data Address IERA ODOS STR., 75 118 55 ATHENS - VOTANIKOS See on map Total cost No data BESNIER BRIDEL France EU contribution No data Address RUE ADOLPHE BECK, 10 53089 LAVAL See on map Total cost No data Consiglio Nazionale delle Ricerche (CNR) Italy EU contribution No data Address Via Celoria 2 20133 Milano See on map Total cost No data ENTREMONT S.N.C. France EU contribution No data Address B.P. 7 - FOVENO 56140 MALESTROIT See on map Total cost No data UNIVERSITY COLLEGE CORK Ireland EU contribution No data Address WESTERN ROAD CORK See on map Total cost No data VALIO LTD. Finland EU contribution No data Address MEIJERITIE, 4 - P.O. BOX 390 00370 HELSINKI See on map Total cost No data
