AG-FO-0856-B MINNESOTA EXTENSION SERVICE Revised 1992 UNIVERSITY OF MINNESOTA AGRICULTURE Meat Tenderness
"Which cut do I choose? How do I cook it? What should be the degree of doneness? Will it be tender?"
Porterhouse steak
Needle tenderlzallon
Richard J. Epley Extension Animal Scientist, Meats Department of Animal Science The decrease in tenderness with tender than cuts from the round. This is increasing age is due to the changing the major reason the tenderloin is the fin~~!=f!~ nature of collagen (gristle), the connec most tender muscle in the carcass. tive tissue protein found in meat. ::~;:r;.•!~•~;i::;:;~ta~,f>•· Collagen becomes more complex and Suspension of Carcass J~~~~~~·ca~· vary·co~.lderahly / stronger with advancing age and thus is 'Jron{one ctif to the next/This folder•• more resistant to tenderization from As mentioned above, stretching of •·····wfi1~1sc~··.so~~•·o!.t1te 111~~t·•·•••·•)•••··.••··•·•.. ·•·• 2.•. moist-heat cooking. Pork and lamb from the muscle during chilling of the carcass older animals normally are processed affects tenderness. This has different •..•.. c.to·mm···•.·•a.·.. •·•.•·•.·.•.•••. ?.. c.··.~. usf·.··.esb·.·.•••.•··.?r.'Y~ii!.!..•.·1?.~. Jb~Ct .. /a·••.(y··•••.·•.·•·.. • •.. yea)/en erness ~ o. . ..ee , por~·.. am .ran .... .· ·••·•·• into sausage items, so toughness due to effects on different muscles according to age usually is not a problem. their anatomical location in the carcass. Although most carcasses are hung from the hind leg, a new method of hanging Genetics Feeding the carcass from the pelvic or hip bone The heritability of tenderness in Contrary to popular belief, what the changes the tension applied to some beef is approximately 45 percent, which animal is fed does not directly influence muscles. This method has been shown to means that 45 percent of the observed tenderness. In the case of beef, an increase tenderness of muscles in the variation in tenderness of cooked beef is indirect effect offeeding on tenderness round; however, it decreases the stretch due to the genetics or parents of the may be observed. Animals that are and consequently the tenderness of the animal from which the beef came. finished with grain tend to reach a given tenderloin. Pelvic suspension of beef carcasses is not used widely in industry A consumer can purchase a USDA slaughter weight sooner than animals Choice rib roast, cook it to a medium that are finished to the same slaughter because it requires changes in plant degree of doneness, and end up with a weight on pasture. Thus, grain-fed layout and cutting procedures. It is a very tender product. The same consumer animals usually are slightly more tender procedure, however, than can be used in can then go back to the same store, buy because they are slaughtered at a slightly home slaughtered animals or wild game the same grade and type of cut, cook it younger age. such as deer. the same way, and it could be less tender. Although there are many other Muscle to Muscle Electrical Stimulation factors involved in tenderness, as discussed below, genetics is one of the Within any species, there is a Electrical stimulation of the hot main reasons such a wide difference in considerable variation in tenderness carcass immediately after slaughter is an tenderness often exists among identical among muscles. For example, tenderloin innovation being used in the meat grades and cuts of meat. is much more tender than the fore shank industry to increase tenderness. Beef or heel of round in beef. This difference carcasses are subjected to approximately is due in part to the amount of connec one minute of high voltage electrical Species and Age tive tissue in the various cuts. The current. The result is an improvement in Beef usually is the most variable in tenderloin usually has a small amount of tenderness of many cuts of the carcass. tenderness followed by lamb, pork, and connective tissue compared with the fore An improvement in tenderness of cuts veal. The tenderness variation from shank or heel of round. The amount of from carcasses of older cows also has species to species is due primarily to the connective tissue present is due to the been observed when electrical stimula chronological age of the animal at time function of the muscles in the live tion has been applied. Electrical stimula of slaughter. Beef normally is processed animal. The fore shank and heel of tion speeds up the post-mortem conver at approximately 20 months of age, lamb round are used quite heavily in locomo sion of muscle to meat and thus reduces at 8 months, pork at 5 months, and veal tion (movement) and therefore have the incidence of "cold shortening" at approximately 2 months of age. relatively large amounts of connective (discussed below). The use of electrical tissue. Conversely, the tenderloin stimulation in the beef industry is Within a given species such as beef, provides a support function in the animal widespread. age of the animal at slaughter also and therefore has less connective tissue. influences tenderness. Beef hormally is slaughtered between 9 and 30 months of Another source of muscle-to-muscle Chilling Rate age. Usually the meat from the animals variation in tenderness is the amount of stretch or tension applied to each muscle Immediately after slaughter, many is fairly tender; however, if a female changes take place in muscle that beef animal has been used for breeding while the carcass is being chilled. This stretching is due to the weight of the convert muscle to meat. One of the purposes, meat from such an animal changes is the contraction and stiffening becomes progressively less tender as the carcass and prevents shortening (con traction) of the muscle, which in tum of muscle known as rigor mortis. Muscle animal gets older. Cows up to 15 years is very tender at the time of slaughter. of age may be processed for beef steaks results in more tender meat. The major muscle in the rib and the loin is stretched However, as rigor mortis begins, muscle and roasts, but ideally these should be becomes progressively less tender until tenderized because of the increased more during the chilling process than are the major muscles in the round; there rigor mortis is complete. In the case of probability of less tender meat in older beef, 6 to 12 hours are required for the animals. fore, cuts from the rib and loin are more completion of rigor mortis, whereas in USDA Prime, Choice, Select, Standard, Chemical the case of pork, only 1 to 6 hours are and Utility grade designations. Carcasses required. from beef animals older than 40 months Salt is a chemical that at certain concentrations increases the tenderness The carcass is chilled immediately are eligible for USDA Commercial and of meat. The presence of salt is one of after slaughter to prevent spoilage. If the Utility grade designations. Normally the reasons that cured meats such as ham carcass is chilled too rapidly, the result beef in the young grade designations is are more tender than uncured meats. Salt is "cold shortening" and subsequent more tender than beef from USDA apparently exerts its influence on toughness. Cold shortening occurs when Commercial or Utility grade carcasses tenderness by softening the connective the muscle is chilled to less than 60" F and, therefore, is much more common in tissue protein, collagen, into a more before the completion of rigor mortis. If the marketplace. tender form. the carcass is frozen before completion Marbling, the visible specks of fat of rigor mortis, the result is "thaw rigor" in the lean, also is a factor used in There are a number of vegetable and subsequently extremely tough meat. determining the USDA quality grade. enzymes such as papain (papaya), Under normal chilling conditions, it However, information in the last decade bromelin (pineapple), and ficin (fig) appears that unprotected carcasses with indicates that marbling exerts only a used to tenderize meat both commer less than 0.50 inch of fat over the rib eye small influence on tenderness of meat, cially and in the home. These tenderizers probably will have some reduced primarily by acting as a lubricant during can be applied either in liquid form or in tenderness because of cold shortening. chewing. powder form. Their primary.effect is to Aging a carcass affected by cold dissolve or degrade the connective Texture of the lean has a small tissues collagen and elastin. The shortening or thaw rigor will not influence on tenderness. Lean that has a alleviate the detrimental effects on limitation of vegetable enzymes is that fine, smooth, velvety texture generally is their action is sometimes restricted to the tenderness caused by these two condi somewhat more tender when cooked tions. To ensure more tender meat, home surface of meat. Also, on occasion, they than lean that has a coarse, open, or can impart a characteristic "tenderized" slaughtered animals and wild game rough texture. should be protected from very rapid flavor to meat. cooling during the first 6-12 hours after Lean that is pale, soft, and exudative death. or watery (most often found in pork) may have a tendency to be less tender Marinading when cooked than normal, bright Marinading is a way consumers can Aging colored lean. Part of this effect may be improve tenderness and add taste variety After the completion of rigor mortis, due to the fact that pale, soft, and watery to the meat component of meals. The changes take place in beef that result in lean loses more moisture upon cooking. basic ingredients of a marinade include the beef becoming progressively more Meat that is less juicy usually is per salt (or soy sauce), acid (vinegar, lemon, tender. This holding of beef in a cooler ceived to be less tender when eaten, Italian salad dressing, or soy sauce), and (carcass or vacuum packaged subprimal) especially when cooked to a high degree enzymes (papain, bromelin, ficin, or or beef in the refrigerator is commonly of doneness, as frequently occurs with fresh gingerroot). Some marinade referred to as the "aging period." The pork. recipes call for addition of an alcohol increase in tenderness is due to natural source (wine or brandy) for flavor. The enzymatic changes taking place in the Mechanical addition of several tablespoonfuls of muscle. The increase in beef tenderness olive oil will seal the Grinding is a very popular means of continues only for approximately 7 to 10 surfaces from the air increasing tenderness of meat, especially days after slaughter when the beef is and thus result in the beef. The popularity of hamburger and held at approximately 35°F. Beef held at meat staying fresher ground beef is due in part to the fact that higher temperatures will tenderize more and brighter in color texture and tenderness is more uniform rapidly, but it also may spoil and than tenderness of steaks and roasts. develop off-flavors. Cubing is another means of mechani Lamb and pork are rarely aged. A cally tenderizing meat. The small blades lack of tenderness usually is not encoun of a cuber simply sever connective tissue tered because of lamb and pork's in boneless retail cuts so that the relatively young age when slaughtered. connective tissue is broken into smaller pieces. Quality Grade Blade or needle tenderization of cuts recently has increased in popularity. Age of the animal also plays a This method of tenderization is em major role in tenderness as it applies to ployed on wholesale cuts that are in turn quality grading in beef. The quality processed in the normal manner into grades of beef are USDA Prime, Choice, retail cuts. Blade tenderization cuts and Select, Standard, Utility, and Commer punctures some of the connective tissue cial. Carcasses from young animals (up contained in the lean. to 40 months of age) are eligible for for a longer period of time. The tenderiz Cooking However, consumers often fail to make ing action of marinades occurs through this time adjustment and the result is the softening of collagen by the salt, the As cooking progresses, the contrac overcooked beef that lacks tenderness. increased water uptake, and the hydroly tile proteins in meat become less tender, Some consumers cook low fat beef in sis and breakage of the cross links of the and the major connective tissue protein the frozen state for the same time as they connective tissue by the acids and (collagen) becomes more tender. Thus, would higher fat, thawed beef. This alcohols. Mix the desired marinade for cuts that are low in connective procedure helps prevent overcooking. tissue-such as steaks and chops from components in an earthenware dish (acid It is recommended that pork be will affect a metal container and give an the rib and loin-the recommended method of cooking is dry heat, including cooked to approximately 160° F or 1700 off-flavor). Cut the meat into thin strips F internal temperature for desirable or pieces to get a more complete pan frying, broiling, roasting, or barbecuing. Dry heat raises the tempera flavor. Although this temperature range penetration of the marinade into the corresponds to well-done in beef, pork center of the meat. Place the meat in the ture very quickly and the flavor of meat will develop before the contractile still may be slightly pink. Since dish, add some water only if necessary, Trichinella spiralis (trichina) is de and refrigerate for a minimum of 4-8 proteins have the opportunity to become significantly less tender. stroyed at 137° F, an internal tempera hours. (Less than 4 hours is an insuffi ture of 16G°-170°F for pork is definitely cient amount of time for the tenderizing For cuts with a high amount of safe. Therefore, it is not necessary to action of the marinade to be completed.) connective tissue-such as those from cook pork beyond this stage of Do not overcook. It should be noted that the fore shank, heel of round, and