Volatile organic compounds throughout the manufacturing process of Mozzarella di Gioia del Colle PDO cheese

The evolution of volatile organic compounds during the production process of Mozzarella di Gioia del Colle (traditional type) was investigated in comparison with citric mozzarella (industrial type). The total volatile concentration in the traditional curd was ten times higher than milk, versus only twice as much in the industrial type. In both technologies, the concentrations decreased from curd to mozzarella at the same rate, due to losses during the stretching phase. The higher microbial activity in the traditional product was responsible for a much more complex profile, characterised by 2- and 3-methylbutanal, acetoin, ethanol, 3-methyl-1-butanol, acetic acid and ethyl-acetate. In contrast, the industrial mozzarella had a very simple profile, with the most important compounds being directly derived from the milk, the oxidation reactions, or the activity of the adventitious microflora such as acetone, hexanal, nonanal, and hexanoic acid. According to the discriminant analysis, Mozzarella di Gioia del Colle had a very different profile than the milk used, whereas the industrial mozzarella was more similar to the milk.