Bacterial contamination of milk and cheese

U toku ovog rada vršena su istraživanja kontaminacije mlijeka i polutvrdog sira bakterijama. Ogledi su izvođeni tokom jedne godine (u sva godišnja doba), a bakteriološkim analizama bili su obuhvaćeni sljedeći uzorci: sirovo mlijeko, mlijeko nakon pasterizacije, mlijeko, gruš i surutka iz kade za sirenje, salamura, sir nakon kalupljenja i sir za vrijeme zrenja. Ustanovljeno je da su svi uzorci mlijeka i sira bili kontaminirani bakterijama. Ukupan broj bakterija u sirovom mlijeku često je bio veći od dozvoljenog. Pasterizacijom se broj bakterija nije dovoljno smanjio, pa je pasterizirano mlijeko najčešće bilo higijenski neispravno. U siru za vrijeme zrenja također nije zapaženo značajnije smanjenje ukupnog broja bakterija.Bacterial contamination of milk and a semi-hard cheese was tested. The experiments were carried out during all seasons of one year. The bacterial analyses were performed on: raw milk, pasteurized milk, cheese milk, crud, whey, cheese after moulding, brine and cheese during the ripening. All samples of milk and cheese were contaminated with bacteria. The plate counts of bacteria in raw milk was very often higher than the count permitted by legislation. By using pasteurization the plate counts of bacteria in milk was not reduced to the level required by high hygienic standards. The bacterial counts in cheese during the ripening were not considerably reduced