Overview
ISO/TS 17996:2023 - jointly published by ISO and IDF - specifies a laboratory method for determining rheological properties of hard and semi‑hard cheeses using uniaxial compression at a constant displacement rate. The test compresses a defined cylindrical cheese sample while measuring force and displacement to derive stress–strain data, identify an apparent fracture point, and calculate parameters such as modulus of deformability and fracture work. The document updates the 2006 edition and includes standard conditions for sampling, testing, data presentation and basic precision information.
Key topics and technical requirements
- Scope and limits
- Applies to hard and semi‑hard cheeses; unreliable for very short, brittle, sticky or soft varieties.
- Principle
- Compression of a cylindrical test portion at a constant crosshead speed; force measured by a load cell; displacement from crosshead or time × rate.
- Apparatus
- Typical lab compression instrument with load cell and parallel plates; cork‑borer for extracting cylindrical plugs; parallel‑wire cutter for trimming sample height; measuring cell with stiff, smooth parallel plates.
- Sampling and test portion
- Representative sample required (ISO 707 | IDF 50 is recommended for sampling practice).
- Test plugs taken from specified loaf locations and oriented consistently.
- Thermal equilibration
- If loaf stored above measuring temperature: equilibrate at measurement temperature for at least 50 h.
- If stored below measuring temperature: bring to measurement temperature for at least 12 h (exceptions allowed with documented rationale).
- Avoid dehydration and deformation during equilibration.
- Test conditions and data
- Defined relative deformation, crosshead speed, number of compression cycles and test portions; measuring temperature and interface conditions specified.
- Data representation, calculation of stress/strain, and derived parameters (modulus of deformability, apparent fracture point, apparent fracture work) are described.
- Precision and reporting
- Includes results of an interlaboratory trial and guidance on repeatability/reproducibility and test reporting.
- Annexes
- Non‑standard sample conditions, example compression curves and interlaboratory trial data.
Applications and who uses it
ISO/TS 17996:2023 is intended for:
- Dairy quality‑control laboratories monitoring texture and consistency
- Product development/R&D teams characterizing new formulations or processing changes
- Process engineers optimizing pressing/maturation steps linked to texture
- Regulatory bodies and researchers standardizing texture measurements for comparisons and publications
Typical uses include benchmarking cheese hardness, comparing processing effects, shelf‑life studies and validating texture-related claims.
Related standards
- ISO 707 | IDF 50 - recommended sampling of milk and milk products (referenced for representative sample collection)
- Additional ISO/IDF methods for cheese analysis may be used in combination for comprehensive quality assessment.
Keywords: ISO/TS 17996:2023, cheese rheology, uniaxial compression, cheese testing, rheological properties, cheese texture measurement, dairy quality control.