Water mobility and thermal properties of smoked soft cheese

Abstract

The main goal of the present study was to characterize the functional parameters of smoked soft cheese, with the emphasis on the behavior of water and milk fat, as analyzed by DSC, which was used to directly measure the melting/freezing phase transitions in the cheese. This study was complemented by NMR measurements of the organization and distribution of the aqueous phase within the emulsions constituting the cheese. The smoked and unsmoked cheeses were characterized by similar compositions in terms of protein (19.08-19.12 g∙100 g-1), fat (18.86-19.02 g∙100 g-1), and water content (59.86-60.27 g∙100 g-1). The water activity was higher in the unsmoked cheese (aw = 0.9736) than in the smoked cheese (aw = 0.9615). This result was confirmed by DSC (higher ice melting enthalpy) and NMR (higher T1 value) measurements. The smoking process led to differences in the distribution and binding of water to the lipid-protein matrix of the cheese. There was more non-freezed bound water in the smoked cheese which resulted in a more fragile and loosened structure in the smoked cheese than the unsmoked, which manifested in lower values of stretching and meltability. The meltability of the mozzarella smoked cheese was 1.5 times less than that of the unsmoked cheese (tube test and Schreiber test).

Keywords

• cheese
• NMR
• water activity
• differential scanning calorimetry