Milk Fat Thermal Properties and Solid Fat Content in Emmental Cheese: A Differential Scanning Calorimetry Study

Differential scanning calorimetry curves recorded during cooling at|dT/dt|= 2°C/min, from 60 to −5°C, of rennet-induced curd (A), heated curd grains before pressing (B), and Emmental cheese after pressing (C), at 1 d (D), after brining (E), and at the end of ripening (52 d; F). Heat flow is given in arbitrary units; Endo>indicates the direction of the endothermic reaction.

Differential scanning calorimetry curves recorded during heating at 2°C/min, from −5 to 60°C, of rennet-induced curd (A), heated curd grains before pressing (B), and Emmental cheese after pressing (C), at 1 d (D), after brining (E), and at the end of ripening (52 d; F), after cooling at 2°C/min from 60 to −5°C (Figure 1). Heat flow is given in arbitrary units; Endo>indicates the direction of the endothermic reaction.

Differential scanning calorimetry curves recorded during cooling of cream and anhydrous milk fat extracted from the cream, from 60 to −5°C at 2°C/min. Heat flow is given in arbitrary units; Endo>indicates the direction of the endothermic reaction.

Differential scanning calorimetry curves recorded during heating of cream and anhydrous milk fat extracted from the cream, from −5 to 60°C at 2°C/min, after cooling from 60 to −5°C at 2°C/min. Heat flow is given in arbitrary units; Endo>indicates the direction of the endothermic reaction.

Confocal laser scanning micrographs of Emmental cheese taken after the main stages involved during manufacture: A) rennet-induced curd, B) heated curd grain before pressing, C) Emmental cheese after pressing, D) Emmental cheese after brining. Fat is colored red; proteins are colored green; the serum phase is black.

Fat globule size distribution measured after dissociation of the casein matrix of (♦) rennet-induced curd, (○) heated curd grains, and (△) Emmental cheese after pressing.

Differential scanning calorimetry melting curves recorded upon heating of Emmental cheese from the temperature of ripening to 60°C at 2°C/min: A) after 16 d at T_ripening = 12°C; B) after 28 d at T_ripening = 21°C; C) after 7 d at T_ripening = 4°C; and D) Emmental cheese at the end of ripening, stored at 4°C. Heat flow is given in arbitrary units; Endo>indicates the direction of the endothermic reaction.

Differential scanning calorimetry melting curves recorded on heating at 2°C/min of milk fat globules concentrated in a cream stored for A) 7 d at 4°C, and B) 8h at 20°C. Heat flow is given in arbitrary units; Endo>indicates the direction of the endothermic reaction.

Evolution of the solid fat content as a function of temperature determined in Emmental cheese at the end of ripening (52 d), using differential scanning calorimetry.

Differential scanning calorimetry melting curves recorded during heating of Emmental cheese from −5 to 60°C at 2°C/min, following different kinetics of cooling; 1) after cooling from the temperature of ripening (T_ripening) to −5°C at 2°C/min (solid line), and 2) after heating cheese to 60°C to eliminate the thermal history and cooling from 60 to −5°C at 2°C/min (dashed line). The melting properties of Emmental cheese were determined after the main stages involved during its ripening: A) T_ripening = 12°C, B) T_ripening = 21°C; the insert shows the crystallization curve recorded on cooling from 21 to −5°C; C) T_ripening = 4°C; and D) Emmental cheese at the end of ripening, stored at 4°C. Heat flow is given in arbitrary units; Endo>indicates the direction of the endothermic reaction.