Microbiology and biochemistry of taleggio cheese during ripening

Abstract

Abstract A microbiological and biochemical characterization of Taleggio cheese during ripening is reported. Analyses were conducted on the surface, middle and core layers of the cheese from three production batches. In the 42 day-old cheese there were high numbers of starter lactic acid bacteria and surface growth of yeasts and moulds. Coliforms were present at low number and a moderate increase of micrococci and contaminating bacteria also occurred at the cheese surface. A gradient of salt-in-moisture from the surface to the core persisted until about 21 days. A marked increase in pH was observed only on the cheese surface. Initially, the concentration of pH 4.6-soluble N was similar in the three layers, but from 21 days onwards, hydrolysis was more pronounced in the external region. No pronounced differences were observed in the proteolytic (peptidases and proteinase), esterolytic and lipolytic activities of the three cheese layers during the first 21 days of ripening but thereafter a marked gradient of the enzymatic activity was noted from high at the cheese surface to low in the core. Electrophoresis showed hydrolysis of α s 1 - rather than β-casein and primary proteolysis was very similar to that in Cheddar cheese. Electrophoresis of pH 4.6-soluble, ethanol-insoluble fractions showed that little production of various sized peptides occurred before 21 days and greater hydrolysis was detected in the cheese surface. The ratio of volatile to non-volatile free fatty acids did not change during ripening; butyric, palmitic, myristic and oleic acids were the principal fatty acids.