Key Factors That Affect Meat Tenderness: From Farm to Table

Meat tenderness is one of the most important quality traits that determines whether a consumer enjoys their meal or pushes the plate away. It influences satisfaction, repeat purchases, and even willingness to pay premium prices. But tenderness isn’t random – it’s shaped by a chain of factors that starts on the farm and ends in the kitchen. Understanding these factors is essential for anyone involved in meat production, processing, or preparation.

What is meat tenderness? 🔗

Meat tenderness refers to the ease with which meat can be chewed and broken down during eating. It depends on three primary structural components: muscle fibres, connective tissue (mainly collagen), and intramuscular fat (marbling). The interplay between these three elements – how much of each is present and how they behave during processing and cooking – ultimately determines whether a piece of meat feels soft and pleasant or tough and chewy.

According to research published in Meat Science, tenderness is a complex quality trait influenced by both antemortem (before slaughter) and postmortem (after slaughter) factors. Among all eating quality attributes – flavour, juiciness, and overall liking – tenderness is the most sensitive to changes in pre- and post-slaughter parameters.

Pre-slaughter factors affecting tenderness 🔗

Several animal-related and management-related factors influence meat tenderness long before the animal reaches the processing plant. These are often called antemortem factors, and they set the baseline for how tender the meat can eventually become.

Species and breed 🔗

Different animal species produce meat with distinctly different tenderness profiles. Poultry meat is generally more tender than beef or mutton because of differences in connective tissue structure and muscle fibre composition. Within a single species, breed also plays a significant role. For example, Angus cattle are known for producing well-marbled, tender beef, whereas breeds developed for draught or endurance work tend to have tougher muscle structures. As noted in a fact sheet by the Beef Checkoff program, genotype is among the inherent animal factors that directly affect tenderness.

Age of the animal 🔗

Age is arguably the most significant pre-slaughter factor affecting tenderness. As animals grow older, the collagen in their connective tissue undergoes a process called cross-linking. Young animals have mostly reducible (immature) collagen cross-links that break down easily during cooking. With age, these are gradually replaced by mature, thermally stable cross-links that resist breakdown.

Research published in The Professional Animal Scientist confirms that the proportion of mature to reducible cross-links increases with age, which is why older animals generally yield less tender meat. This is precisely why veal – meat from young calves – is far more tender than beef from mature cattle, even though veal may actually contain more total collagen. The difference lies not in the amount of collagen but in the nature of its cross-links.

Sex of the animal 🔗

The sex of the animal influences tenderness through hormonal effects on muscle and connective tissue development. Bulls (intact males) tend to produce tougher meat compared to steers (castrated males) or heifers because testosterone promotes greater muscle fibre development and increased collagen cross-linking. Castration reduces testosterone levels, which in turn leads to less collagen stabilisation and more tender meat. According to a review published in Foods journal, animal sex, diet, stress levels, and genetic background all play established roles in determining final meat quality.

Nutrition and feeding 🔗

What an animal eats – and for how long – can indirectly affect tenderness. Animals on higher-energy diets typically reach market weight at a younger age, which means less collagen cross-linking and more tender meat. Grain-finished cattle, for instance, often produce more tender beef than grass-finished cattle of the same weight, partly because grain feeding promotes greater intramuscular fat deposition (marbling) and earlier slaughter age.

Pre-slaughter stress and handling 🔗

How animals are handled during transport and in the hours before slaughter has a measurable impact on meat quality. Stressed animals deplete their muscle glycogen reserves before slaughter. This leads to abnormal post-mortem pH decline, resulting in conditions like DFD (dark, firm, dry) meat in cattle or PSE (pale, soft, exudative) meat in pigs – both of which negatively affect tenderness and overall quality. Research from Frontiers in Animal Science highlights that the pre-slaughter management period is a critical juncture where cattle exposure to stressors can directly impact meat quality outcomes.

The role of muscle type 🔗

Not all muscles within the same animal are equally tender. Muscles that are used heavily during the animal’s life – such as the legs and shoulders – have more connective tissue and tougher fibres. In contrast, muscles that do relatively little work, like the psoas major (tenderloin) or the infraspinatus (flat iron), are naturally tender.

According to a ranking compiled from 60 years of tenderness research, the tenderloin, top blade, and ribeye-area muscles consistently rank as the most tender beef cuts based on Warner-Bratzler shear force values. Muscles from the round and chuck – the working muscles – rank lower. The differences come down to the amount and type of connective tissue present, fibre diameter, and the level of intramuscular fat within each muscle.

Muscles with a higher proportion of fast-twitch fibres (used for quick, powerful movements) generally tend to be tougher than those with more slow-twitch fibres (used for sustained, low-intensity activity). Fat content within the muscle also matters – greater marbling physically separates muscle fibre bundles, making the meat easier to chew.

Post-slaughter factors affecting tenderness 🔗

Once the animal is slaughtered, a new set of factors takes over. Post-mortem handling, temperature management, and aging all play critical roles in determining final tenderness.

Rigor mortis and pH decline 🔗

After slaughter, muscles undergo rigor mortis – a stiffening process caused by the depletion of ATP (adenosine triphosphate) and the formation of permanent cross-bridges between actin and myosin proteins. During this phase, meat is at its toughest. As rigor resolves over the following hours and days, natural enzymatic processes begin to break down structural proteins, gradually improving tenderness.

The rate and extent of pH decline after slaughter is critical. Muscle pH typically drops from around 7.0 in the living animal to about 5.4-5.8 in the final meat. If this decline happens too fast while the carcass is still warm, it can cause protein denaturation and PSE-like conditions. If it happens too slowly or incompletely (due to pre-slaughter glycogen depletion), the result is DFD meat.

Chilling and cold shortening 🔗

Rapid chilling of carcasses after slaughter is standard practice for food safety, but it comes with a risk: cold shortening. This occurs when muscle temperature drops below 10°C while the pH is still above 6.0 – meaning the muscle still has energy available for contraction. Under these conditions, muscle fibres contract severely and irreversibly, resulting in extremely tough meat.

As explained in a review in the Asian-Australasian Journal of Animal Sciences, cold shortening is a particular concern with smaller, leaner carcasses such as lamb and goat, which cool down rapidly. The ideal approach involves controlled cooling that allows the carcass temperature to drop gradually over 12-24 hours, balancing food safety with quality.

Electrical stimulation 🔗

Electrical stimulation (ES) is one of the most widely used post-slaughter interventions to improve tenderness. By applying controlled electrical currents to the carcass immediately after slaughter, ES accelerates the rate of glycolysis and pH decline. This causes the muscle to enter and resolve rigor mortis faster, which serves two key purposes: it prevents cold shortening by ensuring rigor sets in before the carcass is fully chilled, and it activates proteolytic enzymes at a stage when conditions are optimal for tenderisation.

ES has been commercially used since the early 1970s and is now standard practice in many large processing facilities worldwide. It is particularly important for lamb and smaller carcasses that are vulnerable to cold shortening due to their rapid cooling rates.

Conditioning (aging) 🔗

Aging, or conditioning, is the process of holding meat at controlled refrigeration temperatures for an extended period after slaughter to allow natural proteolytic enzymes – primarily calpains and cathepsins – to break down structural proteins within the muscle. This enzymatic degradation weakens the myofibrillar structure, making the meat progressively more tender over time.

There are two main aging methods. Dry aging involves storing unwrapped carcasses or primal cuts in a controlled environment at 0-2°C, allowing moisture loss and concentration of flavour. Wet aging involves vacuum-packaging the meat and storing it under refrigeration – this is the more commercially common method. According to the BC Cook Articulation Committee’s meat processing guide, different species require different aging durations to reach optimal tenderness, with beef typically benefiting the most from extended aging periods of up to 14-30 days.

How cooking affects tenderness 🔗

Even perfectly handled meat can become tough if cooked improperly. Cooking affects tenderness through two main mechanisms: its impact on muscle fibres and its effect on connective tissue.

When meat is heated, muscle proteins denature and contract, squeezing out moisture and making the meat firmer. This is why overcooking almost any cut of meat makes it dry and tough. On the other hand, collagen begins to convert to gelatin at temperatures above approximately 70°C, especially with prolonged cooking. This is why slow-cooking methods like braising and stewing are effective for tough, collagen-rich cuts – the extended heat exposure dissolves connective tissue and makes the meat tender.

For naturally tender cuts with low connective tissue content, high-heat, quick-cooking methods such as grilling or pan-searing are ideal. These preserve the natural tenderness without causing excessive moisture loss. For tougher cuts from heavily exercised muscles, low-and-slow moist heat methods are far more effective. Matching the right cooking method to the cut is one of the most practical ways to ensure a tender eating experience.

Intramuscular fat and marbling 🔗

The amount of fat deposited within the muscle – known as marbling – has a well-established positive association with tenderness. Intramuscular fat physically disrupts the muscle fibre structure, making it easier to bite through. During cooking, this fat melts and lubricates the surrounding tissue, contributing to both tenderness and juiciness.

This is why USDA quality grading in beef relies heavily on marbling scores. Higher grades (Prime, Choice) indicate greater marbling and generally correlate with better eating quality. Marbling is influenced by genetics, diet, and time on feed – grain-finished cattle typically deposit more intramuscular fat than grass-finished animals of the same age.

Putting it all together 🔗

Meat tenderness is not determined by any single factor. It is the cumulative result of decisions and processes across the entire production chain – from the breed and age of the animal, to how it was fed and handled, to what happens in the processing plant and finally in the kitchen. Controlling these factors at every stage is essential for producing consistently tender, high-quality meat.

For meat producers and processors, this means paying attention to animal genetics, minimising pre-slaughter stress, managing post-mortem chilling carefully, using technologies like electrical stimulation where appropriate, and allowing adequate aging time. For consumers, it means understanding which cuts suit which cooking methods and why some cuts cost more than others.

What do you think? Have you noticed how different cuts of meat respond to different cooking methods? How might understanding the science behind tenderness change the way you select or prepare meat?

References

1. https://www.sciencedirect.com/science/article/abs/pii/S0309174021002333
2. https://www.sciencedirect.com/science/article/abs/pii/S1871141321004030
3. https://www.beefresearch.org/resources/product-quality/fact-sheets/tenderness
4. https://www.sciencedirect.com/science/article/pii/S1080744615314972
5. https://pmc.ncbi.nlm.nih.gov/articles/PMC8775201/
6. https://www.frontiersin.org/journals/animal-science/articles/10.3389/fanim.2022.1065002/full
7. https://pmc.ncbi.nlm.nih.gov/articles/PMC4093271/
8. https://opentextbc.ca/meatcutting/chapter/aging-of-meat-carcasses/