Assessing Texture and Tenderness in Meat Sensory Evaluation

Texture and tenderness are two of the most scrutinized sensory attributes in meat quality evaluation. Research consistently shows that among all eating quality attributes – flavor, juiciness, and overall liking – tenderness is the most sensitive to changes in pre- and post-slaughter parameters, and it is the attribute consumers care most about when making purchasing decisions. Understanding how these attributes are defined, measured, and influenced is essential knowledge for anyone working in meat science, quality control, or food production.

What texture and tenderness actually mean 🔗

Texture and tenderness are related but distinct sensory concepts. Texture refers to the collective physical sensations perceived during biting, chewing, and swallowing – whether the meat feels smooth, fibrous, crumbly, or elastic. Tenderness, more specifically, describes how easily the meat yields to the force of the teeth. The two attributes work together: a cut of meat can have the right textural character yet still be unacceptable if it requires excessive effort to chew through.

Meat is structurally complex. It is composed of muscle fibers, connective tissue, intramuscular fat, and water – all arranged in layers and bundles. A comprehensive review published in Meat Science confirms that each of these structural components – myofibrillar proteins, connective tissue cross-links, sarcomere length, and intramuscular fat – acts as a major determinant of final tenderness. No single factor governs the outcome; it is always a combined effect.

Physical properties that define texture 🔗

In sensory science, the texture of meat is not a single dimension but a profile of several measurable physical properties. The American Meat Science Association’s sensory evaluation methodology classifies these properties into primary mechanical characteristics, secondary characteristics derived from them, and geometrical attributes related to fiber orientation.

Hardness 🔗

Hardness is defined as the force required to compress a substance – in practical terms, the initial resistance felt when the teeth first contact the meat surface. It is largely governed by how tightly muscle fibers are bound together and by the amount of connective tissue present. Studies on dry-aged beef show that hardness is mainly influenced by protein and water content, and that collagen – linked by intermolecular bonds – provides much of the structural strength. As collagen solubilizes during aging, meat hardness decreases.

Chewiness 🔗

Chewiness describes the total work required to reduce the meat to a state ready for swallowing. It is a secondary textural property derived from hardness, cohesiveness, and springiness. Meat from muscles that are used heavily during the animal’s life – such as the shoulder or hindquarter – tends to score higher in chewiness because those muscles develop denser fiber packing and stronger protein cross-links. Texture Profile Analysis (TPA), a standardized two-cycle compression test, is the most common instrumental method for measuring chewiness alongside hardness, cohesiveness, springiness, gumminess, and adhesiveness in a single experiment.

Fibrousness 🔗

Fibrousness refers to how perceptibly the meat separates along its natural grain lines – the longitudinal arrangement of muscle fiber bundles. High fibrousness is characteristic of working muscles where fibers are long, closely packed, and strongly bound by the surrounding connective tissue sheaths (perimysium). Texture analysis guidelines from Brookfield Engineering note that cutting meat perpendicular to the grain shortens these fiber bundles and makes the sample more malleable, while cutting parallel to the grain preserves long fibers that resist chewing.

How sensory assessment is conducted 🔗

Sensory evaluation of texture and tenderness follows a structured, sequential protocol. The AMSA Research Guidelines for Cookery, Sensory Evaluation, and Instrumental Tenderness Measurements provide the most widely adopted framework for this process, covering sample preparation, cooking standardization, and panel methodology.

Ease of penetration (initial bite) 🔗

The first evaluation stage assesses ease of penetration – the effort required for the teeth to break through the surface of the meat on the first bite. Panelists apply a controlled biting force and register the level of resistance. A tender sample yields readily with minimal force; a tough one requires significant muscular effort. This stage primarily reflects the hardness component of texture, but it also captures initial juiciness release, since moisture expelled at the first bite affects the perception of both softness and succulence.

Fragmentation during chewing 🔗

Once the initial bite is taken, evaluators assess ease of fragmentation – how the meat breaks apart during mastication. Sensory evaluation research shows that the overall consistency assessment involves evaluating three aspects: the ease of initial dental penetration, the ease with which the meat breaks into fragments, and the amount of residue left after chewing. Ideal fragmentation produces uniform, progressively smaller pieces. Poor fragmentation results in irregular breakdown: some portions become mushy while others remain tough and stringy – a sign of uneven connective tissue distribution or variable muscle fiber integrity.

Classic AMSA sensory methodology further divides tenderness into softness, muscle fiber characteristics, and connective tissue amount. Muscle fiber characteristics include ease of fragmentation across the grain, mealiness, and the apparent adhesion between fibers – where at the extreme end, fibers appear almost fused together rather than separable.

Residue after chewing 🔗

Residue after chewing is the final stage of texture assessment and is often the most revealing. After a standard number of chews, the evaluator registers what remains in the mouth: the quantity of particles, whether they are soft or hard, and how readily they can be swallowed. High-quality, tender meat leaves minimal residue – small, uniform particles that disperse easily with saliva. Tough or fibrous meat leaves persistent residue: hard particles that cling to the teeth and cheeks, or stringy strands that resist breakdown. This stage directly reflects both the myofibrillar integrity and the connective tissue content of the sample evaluated.

Instrumental methods that complement sensory panels 🔗

Sensory panels provide the gold standard for tenderness evaluation, but instrumental methods are used routinely to quantify physical properties objectively and at scale. The two most established tools are the Warner-Bratzler Shear Force (WBSF) test and Texture Profile Analysis (TPA).

The WBSF test measures the maximum force needed to shear through a standardized meat core using a V-shaped blade positioned perpendicular to the muscle fibers, simulating the cutting action of the first bite. Research establishing tenderness thresholds for beef found that a cut can be classified as tender when WBSF falls below 39.60 N and TPA hardness is simultaneously below 31.89 N. A Texas A&M study using descriptive and consumer panel data found that WBSF values of 28 N or below provide assurance of moderately tender beef as defined by trained sensory evaluators.

TPA, by contrast, subjects the sample to two successive compression cycles and generates a full profile of hardness, cohesiveness, springiness, gumminess, chewiness, and resilience in a single test run. Texture Technologies’ analysis of TPA methodology notes high linear correlations between instrumental and sensory hardness values (r = 0.76), with the correlation improving to r = 0.96 when logarithmic transformation is applied – indicating that TPA hardness is a particularly reliable proxy for perceived firmness in trained panel assessments.

Pre-slaughter factors affecting texture and tenderness 🔗

The textural qualities of meat begin taking shape long before slaughter. Several animal-related and management-related factors set the baseline tenderness that processing can later enhance but rarely fully correct.

Species, breed, and age 🔗

Species differences are substantial: poultry is generally more tender than beef or mutton due to differences in connective tissue structure and fiber composition. Within species, a review integrating pre- and post-slaughter factors affecting beef eating quality identifies breed, sex, age, muscle type, and growth potential as the primary animal-related determinants of tenderness. Older animals accumulate more collagen cross-links in their connective tissue, which are heat-stable and resist softening during cooking – making age one of the clearest predictors of toughness.

Muscle type and location 🔗

Not all muscles are equivalent in texture. Muscles used heavily for locomotion – the round, chuck, and shank – develop greater connective tissue content and stronger fiber cross-links than postural or lightly worked muscles such as the tenderloin or longissimus. Muscles with a higher proportion of fast-twitch fibers, used for powerful, rapid contractions, generally produce tougher meat than those with more slow-twitch fibers. Intramuscular fat (marbling) physically separates fiber bundles and lubricates the chewing process, contributing both to perceived tenderness and juiciness.

Pre-slaughter stress 🔗

Stress experienced during transport, lairage, and handling directly affects post-mortem biochemistry. A scoping review published in Frontiers in Animal Science identified transport duration, handling practices, and ambient temperature as key pre-slaughter variables affecting beef quality outcomes including tenderness. Chronic stress depletes muscle glycogen before slaughter, leading to insufficient lactic acid production post-mortem and an abnormally high ultimate pH – resulting in dark, firm, and dry (DFD) meat with compromised texture and shortened shelf life.

Post-slaughter factors affecting texture and tenderness 🔗

Once slaughter occurs, a new set of biochemical and physical processes governs how texture develops. Post-mortem changes in muscle involve complex interactions between intrinsic enzymatic processes and extrinsic handling conditions – and the outcome varies with time, temperature, and pH combinations.

Rigor mortis and chilling rate 🔗

After slaughter, muscles enter rigor mortis as ATP is depleted and actin-myosin filaments lock together. The rate at which this occurs – and the temperature at which it happens – has a direct bearing on final tenderness. AHDB’s guidelines on post-slaughter factors in red meat quality state that cooling too rapidly, or too soon after slaughter, causes muscle shortening (cold shortening), increasing toughness. As a general rule, muscle temperature should not fall below 10°C within the first 10 hours post-slaughter. Suspending beef carcasses from the hip rather than the Achilles heel stretches key muscles and prevents shortening, improving tenderness in the leg and loin.

Aging and enzymatic tenderization 🔗

Aging is the single most important post-slaughter intervention for improving tenderness. ScienceDirect’s overview of meat tenderness explains that during aging, a lower post-mortem pH activates proteolytic enzymes – notably calpains – that progressively break down myofibrillar proteins, weakening the structure of muscle fibers and reducing perceived hardness and chewiness. Wet aging in vacuum packs and dry aging in controlled environments both achieve this tenderization, with dry aging additionally concentrating flavor through moisture evaporation. For beef, AHDB recommends aging grilling and roasting cuts for up to 21 days for optimal tenderness gains.

Electrical stimulation 🔗

Electrical stimulation (ES) applied immediately after slaughter accelerates rigor development by rapidly depleting muscle glycogen and ATP. In poultry processing, ES after death acts like a nerve impulse, causing the muscle to contract, use up energy, and enter rigor quickly – enabling deboning within two hours post-mortem with comparable tenderness to meat aged for six hours without stimulation. In beef and lamb, ES also promotes rapid pH decline, which accelerates calpain-mediated proteolysis and reduces the risk of cold shortening when fast chilling is used.

Cooking temperature and method 🔗

The final stage of texture development occurs during cooking. Texture analysis literature reports that at temperatures above 55°C, myofibrillar proteins denature and coagulate, causing fiber shrinkage and tightening of myofilaments. This increases evaporation and drip loss, producing a drier, firmer texture. Cooking temperature therefore has a marked effect on measured shear force and sensory tenderness scores – and standardizing cooking method and endpoint temperature is essential when comparing sensory results across studies or production batches.

What do you think? Given that tenderness is shaped by decisions at every stage from farm to kitchen, which part of the production chain do you think offers the greatest opportunity for consistent quality improvement? And how should sensory panel findings and instrumental measurements best be integrated in a practical meat quality control system?

References

1. https://www.sciencedirect.com/science/article/abs/pii/S1871141321004030
2. https://www.sciencedirect.com/article/abs/pii/S0309174021002333
3. https://meatscience.org/docs/default-source/publications-resources/rmc/1986/sensory-texture-evaluation-methodology.pdf
4. https://pmc.ncbi.nlm.nih.gov/articles/PMC9141253/
5. https://www.sciencedirect.com/science/article/abs/pii/S1878450X24000222
6. https://www.brookfieldengineering.com/-/media/ametekbrookfield/articles/texture/texture-analysis-for-assessing.pdf
7. https://meatscience.org/docs/default-source/publications-resources/research-guide/2015-amsa-sensory-guidelines-1-0.pdf
8. https://www.researchgate.net/publication/230045240_Texture_Measurement_in_Meat_by_Sensory_Evaluation
9. https://pubmed.ncbi.nlm.nih.gov/37611462/
10. https://texturetechnologies.com/resources/texture-profile-analysis
11. https://www.frontiersin.org/journals/animal-science/articles/10.3389/fanim.2022.1065002/full
12. https://www.sciencedirect.com/topics/food-science/meat-tenderness
13. https://ahdb.org.uk/knowledge-library/post-slaughter-factors-affecting-red-meat-quality
14. https://www.poultryproducer.com/factors-affecting-poultry-meat-quality/