Tensile testing to quantitate the anisotropy and strain hardening of mozzarella cheese

Abstract

a b s t r a c tWe explored anisotropy of mozzarella cheese: its presence is debated in the literature. Tensile testing proved a good method because the location and mode of failure were clear. Mozzarella cheese cut direct from the block showed no significant anisotropy, though confocal microscopy showed good structure alignment at a microscale. Deliberately elongated mozzarella cheese showed strong anisotropy with tensile strength in the elongation or fibre direction~3.5Â that perpendicular to the fibres. Temperature of elongation had a marked impact on anisotropy with maximum anisotropy after elongation at 70 C. We suggest the disagreement on anisotropy in the literature is related to the method of packing the mozzarella cheese into a block after the stretching stage of manufacture. Tensile stress/strain curves in the fibre direction showed marked strain hardening with modulus just before fracture~2.1Â that of the initial sample, but no strain hardening was found perpendicular to the fibre direction.

Influence of compression parameters on mechanical behavior of mozzarella cheese

“…In tensile test on Mozzarella cheese, Ak & Gunasekaran (1997) found differences between mechanical results according to axis direction, while Bast et al (2015) did not found. Such author suggests that the isotropic behavior in tensile test with Mozzarella cheese may be found due to changes in cheese structure during the molding process.…”

“…Disruption may also occur in the direction perpendicular to the fibers where a weak interaction between protein and fat exists (Taneya, Izutsu, Kimura, & Shioya, ), resulting in a low mechanical resistance. In tensile test on Mozzarella cheese, Ak & Gunasekaran () found differences between mechanical results according to axis direction, while Bast et al () did not found. Such author suggests that the isotropic behavior in tensile test with Mozzarella cheese may be found due to changes in cheese structure during the molding process.…”

Multiphase effects in forming anisotropic calcium caseinate materials

“…5C showed strain hardening in the parallel direction but not in the perpendicular direction in all materials. A similar behaviour was reported byBast et al (2015) for mozzarella cheese andGrabowska et al (2014) for an anisotropic soy-gluten structure.…”

“…In the perpendicular direction, the fibres are just pulled apart. Here, the air bubbles work as a weak phase, similar to the role of the fat droplets in mozzarella cheese (Bast et al, 2015), which results in lower fracture strain and no strain hardening.…”

Temperature and Time‐Dependent Relaxation of Compressed Cheese Curd Cubes: Effect on Structuring of Pasta‐Filata Cheese

“…The few studies at processing temperatures (55–65C) highlight the complexity of the stretching process and that strain‐hardening is an important factor to consider during pasta‐filata cheese production (Ak and Gunasekaran ; Bast et al . ). We hypothesize that the relaxation behavior during production is a further crucial factor, which needs to be considered, because similar elongation parameters and different degrees of relaxation results in a different microstructure.…”