| Abstract | Kasno nadimanje sira je česta mana tvrdih sireva u mljekarskoj industriji. Ovu manu
sira možemo prepoznati po šupljinama, atipičnim rupicama i po većem broju otvora koji su
razasuti u sirnome tijestu. Osim toga, možemo ga prepoznati i po žilavome sirnome tijestu,
bljutavome okusu i neugodnom mirisu. Još jedna od opasnosti kod sireva sa kasnim
nadimanjem je često površinsko pucanje kroz čije se pukotine otvara put drugim štetnim
bakterijama i plijesnima, u unutrašnjost sira, čime se kvarenje još više pojačava i ubrzava.
Glavni uzročnik kasnog nadimanja sira je gram pozitivna bakterija Clostridium tyrobutyricum
koja najčešće dolazi iz tla ili silaže. Ona provodi maslačno-kiselu fermentaciju, gdje iz laktata
nastaju maslačna kiselina, ugljikov dioksid i vodik. Time dolazi do stvaranja plina koji uzrokuje
stvaranje rupica i pukotina u sirnome tijestu. Osim bakterije C. tyrobutyricum, kasno
nadimanje sira mogu uzrokovati i ostale Clostridium vrste: C. butyricum, C. beijerinckii i C.
sporogenes. One spadaju u termorezistentnu skupinu bakterija koje preživljavaju standardnu
temperaturu pasterizacije (63 °C). Stoga se tijekom procesa proizvodnje sira dodaje enzim
lizozim radi prevencije pogreške nadimanja. Lizozim se proizvodi iz bjelanjka jajeta, može
uzrokovati alergijske reakcije pa ga pri deklariranju na listi sastojaka sira potrebno istaknuti
masnim slovima. |
| Abstract (english) | Late blowing of cheese is a cheese fault of hard cheeses that frequently occurs in the
dairy industry. This defect can be identified by cavities, atypical holes, and an increased
number of openings scattered throughout the cheese mass. Additionally, it can be recognized
by a tough cheese texture, bland taste, and unpleasant odor. Another danger with late
blooming cheeses is that they often develop surface cracks, which provide pathways for other
harmful bacteria and moulds to penetrate into the interior of the cheese, thereby intensifying
and accelerating spoilage. The primary cause of late blowing in cheese is the gram-positive
bacterium Clostridium tyrobutyricum, which usually originates from soil or silage. This
bacterium produces butyric acid, carbon dioxide, and hydrogen from lactate. This results in
gas formation, causing holes and cracks in the cheese mass. Besides C. tyrobutyricum, other
Clostridium species such as C. butyricum, C. beijerinckii, and C. sporogenes can also cause late
blowing of cheese. These bacteria belong to the thermoresistant group, surviving the usual
pasteurization temperatures. Therefore, during cheese production, the enzyme lysozyme is
added to prevent this defect. Lysozyme is produced from egg white, so it needs to be
highlighted in bold letters in the list of cheese ingredients, as it can cause allergic reactions. |
