Utilisation du lysozyme en tant qu'agent régulateur de l'affinage en fromagerie MMV

Abstract

RésuméL'évolution du pH, de la flore microbienne et de l'azote non protéique des fromages Camembert et Saint-Paulin issus de technologies classiques et MMV a été comparée au cours de leur affinage. Si aucune différence significative n'était mise en évidence pour ce qui est des fromages Camembert, il n'en était pas de même pour les fromages Saint-Paulin issus des deux technologies. Les fromages fabriqués à partir de lait ultrafiltré contenaient 10 fois plus de germes aérobies mésophiles ; leur pH restait plus élevé (+ 0,15 unité pH) et leur teneur en azote soluble était plus faible et ce, tout au long de la période d'affinage. Leurs qualités organoleptiques étaient considérées comme légèrement inférieures à celles des fromages traditionnels. L'origine de ces observations est à rechercher dans l'élévation du pouvoir tampon des pâtes découlant de la surminéralisation calcique liée à l'ultrafiltration au pH du lait. L'addition de lysozyme aux préfromages Saint-Paulin et Camembert à la dose de 0,5 g à 1,0 g par kg semble être un moyen intéressant pour accélérer et diriger l'affinage des fromages issus de la technologie MMV. Une telle addition réalisée après acidification lactique des préfromages Saint-Paulin conduisait à des évolutions du pH, de la flore aérobie mésophile, de la protéolyse et par voie de conséquence des qualités organoleptiques des fromages de lait ultrafiltré, similaires à celles observées dans les fromages traditionnels. La flaveur et la texture des fromages Camembert issus de technologie MMV étaient également améliorées.L'ensemble des résultats obtenus conduit à penser à une décomplexation progressive du lysozyme actif à partir des micelles de caséine au cours de l'affinage des pâtes fromagères, hypothèse émise par THAPON et BRULÉ (1986). Les possibilités d'emploi du lysozyme comme enzyme d'affinage en fromagerie classique et MMV sont discutées. Mots clés:Fromagerie -Saint-Paulin -Camembert -Ultrafiltration -LysozymeAffinage. Summary Use of lysozyme for managing ripening of cheeses made through MMV processDuring ripening time, evolution of pH, total mesophilic flora and NPN content was checked in Saint-Paulin (semi-hard) and Camembert (soft) cheeses made through MMV and classical technologies. No significant difference was observed in Camembert cheeses made by both processes but Saint-Paulin cheeses made from ultrafiltrated milk had a higher mesophilic flora, a higher pH and a lower NPN content for aIl the period of ripening. Consequently, their organoleptic qualities were judged as sligthly inferior to these of cheeses made through conventional processes. These observations are probably the consequences of the increase of buffering capacity of UF precheeses, increase due to the concentration of calcium salts bound to casein micelle by UF.Addition of lysozyme to Saint-Paulin and Camembert precheeses (at 5 or 1,0 g/kg) seems to be an interesting mean for accelerating and for managing ripening of cheeses made through MMV process. Such an addition realized after 1actic acidification of Saint-Paulin p...

Impact of broken cells of lactococci or propionibacteria on the ripening of Saint-Paulin UF-cheeses: extent of proteolysis and GC-MS profiles

“…Both enumeration of viable cells of added starters and immunoblotting data related to intracellular enzyme markers con-firm that in cheeses made from milk concentrated by UF at milk pH, no lysis of Lactococcus starter was detected, as previously hypothesized by Goudédranche et al [12] and Mistry and Maubois [30]. Such a change in a phenomenon essential for the normal ripening of cheese can be related to the environmental conditions of Lactococcus in this type of UF-cheeses.…”

“…cremoris E8 alone in traditional Cheddar cheese. Goudédranche et al [12] improved the texture and the flavor of UF-Saint-Paulin and Camembert cheeses by adding 0.5 or 1.0 g . kg -1 of lysozyme to liquid pre-cheese.…”

Formation of heat-induced protein aggregates in milk as a means to recover the whey protein fraction in cheese manufacture, and potential of heat-treating milk at alkaline pH values in order to keep its rennet coagulation properties. A review

“…Promotion or inhibition of primary proteolysis will affect the development of bitterness in cheeses made from heated milk, but also curd fusion, ripening, and melting properties of the cheeses, based on yet debated mechanisms that do not always involve the heat-denatured whey proteins. UF concentration of cheese milk is eventually known to increase the buffering capacity of the cheese curd and to influence growth and lysis of the ripening microorganisms [55]. Its use in combination with heat-treatment to recover the whey proteins in cheese may generate effects on texture and flavour that are independent of properties of the denatured whey proteins.…”

Limited ripening of low-fat UF-cheese due to CaPO4barrier?

“…Many previous studies have reported that the ripening of cheeses made from ultrafiltered milk (UF-cheeses) is slower or delayed in comparison to cheeses manufactured by traditional methods [1,5,6,8,9,14,17,23]. These studies have reported that in UF-cheeses, the level of proteolysis is low in comparison to traditional cheeses and consequently the ripening of these cheeses is delayed.…”