Viscoelasticity of Edam cheese during its ripening

Abstract

Series of the indentation of the ball (10 mm in diameter) by the constant speed into blocks of Edam cheese has been conducted. The indentation tests were performed at different speeds (1, 5, 10, 20 and 100 mm/min), and the corresponding force–displacement responses were fitted with an analytical solution to obtain the time-dependent constants and the instantaneous force–displacement response. The measurement has been performed for the cheeses of different stages of their maturity. The dependence of the indentation force on the penetration depth has been evaluated. This dependence can be fitted by a polynom. The indentation force decreases with cheese fat content. It increases with the loading rate. Its value also decreases with the time of the cheese ripening. The recently proposed method for the indenation of the ball into viscoelastic solids has been used for our data analysis. This procedure, which needs the use of the numeric methods, enables to obtain stress relaxation moduli, which describe the viscoelasticity of the tested materials. The obtained moduli describe the stage of the cheese maturity.

Keywords

• Edam cheese
• indentation
• penetration
• depth
• relaxation
• modulus