Rheological Properties of Cheddar Cheese During Heating and Cooling

Abstract

Rheological properties of different Cheddar cheeses were characterized using a dynamic test. Cheddar cheeses with four fat contents (15.3, 22.8, 37.3, and 45.6% fat in the dry matter—FDM) and two moisture contents (58.1 and 62.4% moisture in non fat portion—MNFP) at 2, 4, 12, and 24 wk old were used in this study. Time sweep mode was used to characterize the elastic (G ^′) and viscous (G ^″) properties of Cheddar cheese at a constant frequency of 1 Hz and strain 0.5%. G ^′ and G ^″ of the cheese were determined during heating from 25 to 60°C and cooling from 60 to 25°C. G ^′ decreased from 9.0 to 0.07 MPa during heating and increased from 0.07 to 9.0 MPa during cooling of Cheddar cheese. G ^″ showed similar trend as that of G ^′ although magnitude of change were about one log higher. The reduction in % FDM of Cheddar cheese increased G ^′ from 5.5 to 9.0 MPa and increased G ^″ from 2.5 to 6.0 MPa at 25°C. A similar trend was observed at other temperatures. Proteolysis during ripening of cheese lead to decrease in G ^′ and G ^″ value for different fat Cheddar cheese at 60°C but differences were not statistically significant at 25°C. However, G ^′ increased for high moisture Cheddar cheese (62.4% MNFP) from 1.6 to 4.4 MPa at 25°C and difference were not significant at 60°C.

Keywords:

• Cheese
• Cheddar
• Mozzarella
• Elastic
• Viscous

Acknowledgments

Published with the approval of director of the South Dakota Agricultural Experiment Station as Publication Number 3230 of the Journal Series. College of Agriculture and Biological Sciences at South Dakota State University supported this research, through funds from the Agricultural Experimental Station. The authors wish to thank Howard Bonnemann and John Jaeggi for assistance in cheesemaking and chemical analyses of cheeses.

NOMENCLATURE
G ′	=	Elastic modulus, Pa
G ″	=	Viscous modulus, Pa
FDM	=	Fat in the dry matter, %
MNFP	=	Moisture in non fat portion, %