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Possible Impacts of Changes in USDA Grade Standards and Labeling/~dentification Procedures G. C. SMITH U. S. Department of Agriculture (USDA) grades for carcasses of red meat animals are based on criteria presumed to be related to palatability (flavor, juiciness, and tender- ness) of the meat when cooked and on estimations of relative curability (yield of trimmed cuts from the carcass). Nomencla- ture for the grading systems is not identical for beef, pork, and lamb; but, in general, words (for example, Prime, Choice) are used to characterize palatability and numbers (for example, 1, 4) are used to inclicate curability. Relative palatability assessments for beef and lamb are assigned by USDA graders using a hierarchical arrangement of word descriptors wherein the USDA quality grade names Prime, Choice, Goocl/Select, ant] Standard for beef; Prime, Choice, Good, and Utility for lam~indicate the relative level of palatability or the relative proba- bility that a specific piece of meat will be flavorful, juicy, and tender. A leg roast from a U.S. Prime grade lamb should be more flavorful, juicy, and tender than a leg roast from a U.S. Choice grade lamb; the prob- ability of obtaining a steak that is bland, dry, and tough should be greater if it is from a U.S. Goocl/Select grade beef carcass 332 than if the steak is from a U. S. Prime grade beef carcass. Pork quality is not equated hierarchically. Rather, a bipartite system is used in which quality is judged to be either "acceptable" (in which case the carcass is assigned the grade prefix "U. S." ant] a number 1 through 4 clepending on its relative cutabflity) or "unacceptable" (in which case the carcass is assigned the gracle designation U.S. Utility, regardless of its relative curability, and thus there is no numerical suffix). The USDA meat grading service for red meat animals was instituted as a means for setting and reporting prices of commodities in the wholesale meat trade. It eventually evolved to facilitate trailing in live animals and merchandising of retail cuts. Meat grad- ing was made compulsory under the Office of Price Administration during World War II and then again, under the Office of Price Stabilization (luring the Korean conflict, but not between those periods or since. In 1946, the program was authorizer] by the Agri- cultural Marketing Act and was made vol- untary; packers who wished to use the grading service had to pay for it. The grades, assigned by USDA graders acting in the
GRADE STANDARDS AND LABELING role of a third party, identify the quality/ curability of meat for wholesalers and re- tailers who purchase it without previously viewing it. In 1984, 65.1 percent of steer ant] heifer beef (53.3 percent of total beef) in the U.S. federally inspected slaughter was officially graded and stamped; of that, 3 percent was Prime, 93 percent was Choice, ant] 4 percent was Good, while 3 percent was yield grade 1, 42 percent was yielc! grade 2, 49 percent was yield grade 3, and 5 percent was yield grade 4. Of the 12 billion pounds of red meat (beef, lamb, calf, and veal) that was officially graded and stamped in 1984, more than 90 percent was beef. Assurance of wholesomeness and freedom from disease attributed to red meat by USDA inspection floes not relate to its grade, but USDA grades are assigned only if a carcass has passed inspection. USDA policy is that beef, pork, and lamb can be graded only as carcasses to ensure that grading decisions are accurate and consist- ent; thus, grading is done only at the slaugh- ter site. Once the meat has been cut up and packaged for sale, its equivalent carcass gracie cannot be determinecI. Cutability ("yield") grades are in numer- ical order: USDA yield gracle 1 signifies the highest comparative curability (yield of closely trimmed wholesale or retail cuts as a per- centage of carcass weight); yield gracle 4 for pork carcasses or 5 for lamb and beef car- casses denotes the lowest relative cutability. For pork and beef carcasses, the USDA quality and yield gracles are said to be "coupled"; that is, neither grade can be assignee! without the other. The grading systems are "uncoupled" for lamb carcasses; a lamb carcass can be assigned a quality grade, a yield gracle, or both quality and yield grades. In practice, lamb carcasses are seldom yield graded because the industry does not use yield gracles in the determi- nation of trading price. Trading of cattle and sheep and beef, lamb, and mutton carcasses and wholesale 333 cuts relies heavily on USDA quality/yield grading. For example, price quotations for cattle coming from the feecIlot to a slaughter plant are usually set by specifying a price per hundrecI-weight for animals that are described using a four-part (live weight, sex class, quality grade, yield] grade) system (for example, 1,125 pouncis, steers, Choice, yielc] grade 3). Because descriptions of market animals depenc] heavily on subjective eval- uations of live weight, quality grade, and yield] grade, market reporters often use ranges in weight, the sex class, an estimated percentage expecter! to grade U. S. Choice, and a generalization about yield grades (for example, 1, 075 to 1,200 pouncls, steers, 65 percent Choice, mostly yield granule 2's with a few yield grade 4's). Swine and lambs are similarly described for market reporting purposes; in fact, grades are much more useful for describing live pigs and lambs than for facilitating trading of their carcasses. When it is to the advantage of the seller, the USDA quality grade is used to mer- chandise the commodity. Certain restau- rants, steakhouses, supermarkets, ant! the like advertise and identify beef or lamb that is U.S. Prime or U.S. Choice, but termi- nology related to USDA quality grade is never specified for pork. USDA quality gra(le names are imprintecl, using purple ink, on the surface of beef carcasses and lamb carcasses, but essentially are never imprinted on pork carcasses. To imprint the USDA gracle name, a round metal wheel (known as a grade roll) with a series of identical official USDA shields on its outer surface is continuously coated] with purple ink and used to mark the carcass at strategic locations. The wheel is rolled down the length of the carcass and across it so that the USDA stamp appears on almost every solid-muscle retail cut that can be obtained from that carcass. (A beef ribeye roll is a solid-muscle retail cut but would not show the gracle roll without special care.) Beef en c] lamb carcasses that are not officially graded are clescribed in
334 meat trade vernacular as "No-Roll" car- casses. Pork carcasses are almost never graded for quality or yield ant! are not often sold as intact carcasses to wholesalers and retailers because so many of the cuts for example, the belly, jowl, picnic shoulcler, ham, ant] clear plate are usually cured and smoked before retail sale and because the two major wholesale cuts (Boston butt ant! loin) that are sold fresh (unprocessed) have heavy layers of subcutaneous fat and skin that are removed before preparation of retail cuts. Essentially all beef and lamb carcasses are presented to USDA officials for gracling; but only those that qualify for merchantable grades Prime and Choice quality grades and, for beef, 1, 2, ant! 3 yield grades are normally identified with official gracle stamps. Over the years, quality grade names of GoocI/Select, Standard, ant! Utility have come to signify inferior quality; and yield gracle designations of 4 and 5 result in punitive price discounts, so packers seldom if ever allow such words or numbers to be affixed to carcasses. Most packers have a category of carcasses that they call No-Roll and they attempt to merchandise the con- glomerate as one kind of carcass. Depending on company policy, carcasses from young intact males (bullocks or lambs) and car- nasses from females of advanced are ("heif erettes or young cows and yearling ewes, for example) may also be included in the product mix of No-Rolis; as a result, the palatability and cutabflity of No-Roll beef and lamb may be quite variable within and between lots and over time. USDA quality grades for beef carcasses are baser! on evaluations of (1) the estimated physiological age of the animal at the time of slaughter, called "maturity" and assessed by looking at the color and texture of the exposed ribeye muscle (Iongissimus dorsi muscle exposed by cutting between the 12th and 13th ribs of the carcass), and by eval- uating the amount of ossification of cartilage APPENDIX in the skeletal system and (2) the estimated amount and distribution of intramuscular fat (called "marbling") in the exposed ribeye muscle. The more youthful the carcass and the more heavily marbles! the ribeye mus- cle, the higher the USDA quality grade for beef. USDA quality gracles for lamb carcasses are based on evaluations of (l) the estimated physiological age of the animal at the time of slaughter, called "maturity" and assessed by looking at the color of muscles on the interior surfaces of the body cavity and by evaluating color ant! shape of rib bones ant} ossification of the cannon bones; (2) the amount and distribution of streaks of fat across the surface of the primary flank mus- cle (in the abdominal cavity of the carcass), which is an indirect estimate of the amount of marbling expected in the ribeye muscle; and (3) the conformation of the carcass,. evaluated as the width, bulge, and plump- ness of muscles and thus of the muscle/bone ratio of the carcass. The more youthful the carcass, the more extensive the streakings of fat in the flank, ant] the higher the muscle/ bone ratio, the higher the USDA quality grade for lamb. Quality is assessed for pork carcasses based on evaluations of (1) acceptability of the belly for bacon production, determined by its thickness and firmness; (2) color of the muscles on the interior surfaces of the body cavity; (3) firmness of the fat and lean throughout the carcass; and (4) the amount and distribution of streaks of fat across the surfaces of the primary flank, secondary flank, ant] intercostal muscles. If the belly is firm and thick, the muscles grayish pink or darker, the fat and lean at least slightly firm, and the fat streaking present in at least Slight amounts, the carcass is considered "acceptable" in quality and is then yield graded. The crux of the quality grading systems tor carcasses of red meat animals is intramuscular fat content (the higher the fat content in the muscles, the higher the
GRADE STANDARDS AND LABELING quality grade), because marbling improves the chance that the meat will be flavorful, juicy, and tender when cooked. USDA yield gracies for beef carcasses are based on evaluations of (1) carcass weight; (2) surface area of the ribeye muscle at the juncture of the 12th ant] 13th ribs; (3) thickness of external fat at the specified point over the ribeye exposed in the cross- sectional surface exposer] between the 12th and 13th ribs; and (4) the estimated per- centage weight as kidney, pelvic, and heart fat. At a given carcass weight, the larger the ribeye, the less the external fat thick- ness; and the lower the percentage of kid- ney/pelvic/heart fat, then the lower the yield grade number (thus, the higher the cuta- bility). USDA yield grades for lamb carcasses are based on evaluations of (1) bulge and plump- ness of muscles in the leg, (2) thickness of external fat at the specified point opposite the ribeye muscle between the 12th and 13th ribs, and (3) the estimated percentage of carcass weight as kidney and pelvic fat. The more muscular the leg, the less the external fat thickness; and the lower the percentage of kidney and pelvic fat, the lower the yield grade number (thus, the higher the cutabflity; in other words, the greater the amount of the carcass that can be sold as trimmed, boneless cuts). Cutabflity in pork carcasses is determiner] by assessments of (1) length or weight of the carcass, (2) thickness of external fat at the specified point on the midline of the carcass, and (3) bulge and plumpness of muscles in the carcass. At a given carcass weight or length, the less the external fat thickness and the more muscular the car- cass, the Tower the yield! grade number (thus, the higher the curability; in other words, the greater the amount of the carcass that can be sold as partially trimmed, bone- in, ham/Ioin/shoulcler). The crux of the yield grading systems for carcasses of red meat animals is the muscle/fat ratio-the higher 335 the fat content of the carcass (as external, seam, and body cavity depots), the higher the yield gracle number (thus, the lower the cutabflity). Yielc! gracle predicts the amount of the carcass that will be salable as whole- sale (pork) or retail (beef ant! lamb) cuts and is intended for use by the packer, whole- saler, and retailer but never by the con- sumer (since by the time the consumer sees the piece of meat, its excess fat has been removed). Although the USDA quality and yield grade systems may appear to be paradoxi- cal one (quality grade) encourages fatness, the other (yield grade) penalizes fatness- it must be understood that fat is deposited in an animal's body in a number of specific anatomical locations called fat depots and that the depots are filled with fat in an ordered sequence. The fat depots are (1) the mesenteric region around the stomach and intestines; (2) those adhering to the thoracic/abdominal/pelvic cavities around the heart as a sac, around the kidney as a capsule, and lining the pelvic cavity; (3) the subcutaneous region under the skin of the live animal anal over the external surfaces of the skinned carcass; (4) the intermuscular seam areas between two muscles and be- tween a muscle and bone/cartilage; an(l (5) the intramuscular sites within muscles. Accumulation of fat in depots (1), (2), (3), and (4) listed above is of little or no conse- quence in assessing prospective flavor, jui- ciness, or tenderness of the muscles from that carcass; deposition of fat as marbling, in fat depot (5) above, is positively related to palatability of cooked beef, pork, and lamb. Unfortunately, in most red meat an- imals, deposition of fat in depots 1 through 4 occurs earlier in the animal's life than deposition of fat as marbling, so that gen- erally by the time the animal has deposited enough intramuscular fat to qualify for the highest USDA quality grades, it has depos- ited too much fat in the body cavity, be- tween the muscles, and over the exterior of
336 the skinned carcass to have desirable com- position (proportions of muscle and fat). Also, as animals are fed high-concentrate diets for progressively longer periods of time to increase chances that they will have enough marbling to grade Choice or Prime (for lamb or beef, but not for pork), their yield grade suffers because of a greater probability that the trimmable fats are pres- ent in excessive quantities. The USDA quality grading system per se can be a deterrent to increasing leanness of beef cattle and their carcasses because in certain market situations it encourages over- fattening. Such is not the case for lambs, because they can attain the Choice grade without ever having been fed grain, or for swine, because the pork grading system is not hierarchical and it is not used by the trade to determine prices. For beef, Choice carcasses are worth 1 to 3 cents more per pound ($6 to $24 per carcass) than Good/ Select carcasses most of the time, but at times-can be worth substantially more than Good/Select carcasses, with premiums for Choice sometimes reaching 7 to 11 cents per pound ($42 to $88 per carcass). Such differences, though they occur infrequently, provide incentive to overfeed] cattle. For some breeds or crossbreeds of cattle and for some lines/strains within breeds and crossbreeds, increasing the time-on-feed wiD result in increased deposition of marbling, but there are cattle that do not have the inherent ability to deposit intramuscular fat ant! that will not achieve the level of mar- bling needed to qualify for the Choice grade regardless of length of feeding period. In these cases, it is futile to extend time-on- feed in the hope of increasing value by improving the USDA quality grade. Rather, the cattle simply get fatter in depots that detract from leanness, lower the yield grade number, and make the end product less acceptable to consumers. However, lengthening time-on-feec] al- most always increases the "dressing per- centage" (the ratio of carcass weight to live APPENDIX weight, expressed in percentage points) for cattle, swine, and lambs, regardless of their genetic capability to respond to beetling by depositing more intramuscular or superficial streaks of fat. The extent to which meat packers encourage producers to lengthen time-on-feec! in order to (1) increase the number of animals achieving a certain USDA quality gracle versus (2) increase dressing percentage and thereby decrease the cost per pound of the carcass differs depending on the genetics of the livestock involved and cannot be precisely assessed because quality grade and dressed yield are highly related to each other. When buyers for meat packers purchase cattle, sheep, and swine on a live-animal basis, they do so by deciding on a price per pound alive that will minimize the cost per pounce of the carcass and that is still high enough to beat out other buyers. Price determination starts with estimations of car- cass value plus drop (eclible and inedible offal) value minus cost to slaughter/fabricate; that sum is (livi(led by estimated carcass weight to obtain carcass value per pound. The price a buyer will then pay per pound for a live animal is determined by multiply- ing carcass value per pound times the (lress- ing percentage; as the ciressing percentage increases, the price paid increases. Knowing that the dressing percentage increases as the fatness ofthe animal increases, the buyer will push for greater fatness (by encouraging that the animals be fee] longer) up to, and sometimes beyond, the point at which a yield grade line (between 3 and 4, for example) will be crossed at a punitive dis- count. For example, suppose a buyer eval- uates a pen of lambs that he estimates will have a dressing percentage of 50. If he bills 75 cents per pound for the live animals and they dress 50 percent, the carcasses will have cost him hanging on the rail $1.50 per pound. If he believes the lambs could be fed an additional 3 weeks without be- coming yield grade 4's and because they are much fatter~ress 54 percent, he will
GRADE STANDARDS AND LABELING encourage the producer to feed them longer, because although he will still pay 75 cents per pound alive, he can rail the carcasses at a cost of $1.39 per pound. Unfortunately, though, the composition of the carcasses of lambs fed for the additional 3 weeks will have suffered greatly. The same scenario applies for beef; additional time-on-feed to increase ciressing percentage and decrease carcass cost has been abetted by the fact that, until very recently, primal cuts of beef moved freely in the tracle with as much as 1 inch of external fat covering. If dressing percentage (and carcass cost) could somehow be removed from the pricing logic currently used for the purchasing of red meat animals, the incentive to feed the animal longer would be greatly lessened. In fact, the practice of fattening the animal to increase dressing percentage has worked only because wholesalers and retailers tol- eratec] the additional fat knowing they could pass it along to their customers, the ens] product consumer. As that changes and it is doing so rapidly with the advent of quarter- inch fat trim at retail and adoption of three- eighths to one-halfinch fat trim at the packer level the impetus to minimize carcass cost by encouraging overfattening to improve dressing percentage will decline. Indeed the dressing percentage/carcass cost pricing logic used routinely in the trading of live red meat animals is a deterrent to improving leanness, as are the USDA quality grading standards. So long as feeders clemanc] to sell cattle on a live weight basis rather than on the basis of carcass grade and weight~lressecl yield/carcass cost is an im- perative component of the pricing system. There remains incentive to increase the fatness of rec] meat animals if it is true that as fatness increases, the flavor, juiciness, and tenderness of cooked meat improves. There is, however, enough genetic varia- bility among swine, sheep, and cattle to make it possible to select animals that will deposit marbling in the muscles to a degree sufficient to qualify them for the U. S. Choice 337 or even Prime grades without having de- posited excessive quantities of subcuta- neous, intermuscular, or kidney/pelvic/heart fat. Also, U.S. consumers are attuned to the presence of certain quantities of fat intermingled with lean such that "accepta- ble" or superior palatability in beef, pork, and lamb depends on deposition of marbling in specific amounts. This is especially the case for customers in hotel, restaurant, ant] foot] service establishments who, because they pay high prices for a meal, expect consistently high palatability in the meat they are served. Therefore, meat purveyors sell Prime or Choice beef ant] lamb to restaurateurs and fooc3-service-unit opera- tors who serve affluent clientele. Because such products are in limiter] supply yet in substantive demand, their prices are higher than those of beef and lamb of lower quality gracles. Price incentives encourage packers an(1 feeders to strive to produce beef of the highest grades. For most animals, the like- lihood that they will grade Prime or Choice is improved with increased fee(ling time. That being the case, cattle producers will- especially if grain prices are low feed their cattle longer than is economically optimal from growth, efficiency, and carcass com- position standpoints, striving for the mini- mum intramuscular fatness required to achieve the U. S. Choice grade. The Choice grade is achieved in beef when a chemical fat level of about 4.3 percent is attained in the longissimus dorsi, or "ribeye," muscle. That fatness level is very low ant] well within caloric constraints for a healthful (lies. How- ever, by the time-chronologically or in time-on-feed that the 4.3 percent intra- muscular fat level is attained, the entire carcass will be composed of 25 to 40 percent fat (subcutaneous, intermuscular, intramus- cular, ant! kidney/pelvic/heart). Because deposition of fat in subcutaneous, inter- muscular, and kidney/pelvic/heart regions usually prececles deposition of fat as mar- bling, feeding cattle to achieve some set point in marbling deposition will far too
338 often result in production of carcasses that are excessively fat. A possible way to recluce the overall fatness of lamb and beef carcasses is to lower the marbling requirement for each USDA quality grade. If, for example, the minimum marbling requirement for the U. S. Choice grade in beefwere reducecI from 4.3 percent (described as a Small amount of marbling in official USDA quality grade stan(lards) to 3.0 percent (a Slight amount), time-on-feec3 could be reduced by about 30 days and percentage of fat in the carcass by about 10 percentage points. However, this solution ignores the fact that beefof3.0 to 4.3 percent. intramuscular fatness is currently available (as USDA Good/Select grade beef) yet has found only limited consumer demand. The National Cattlemen's Association (NCA) concluded in January 1986 that (1) consumers want lean beef regarcIless of USDA quality gra(le, (2) changing the USDA beef quality grading standards is not a pre- requisite for producing leaner beef, (3) the retail consumer market is segmented be- tween those who emphasize taste and those who emphasize leanness, (4) combining the Choice and Good/Select grades into one graclelwould recluce the industry's ability to market beef effectively to either market segment, and (5) any attempt to change the USDA beef quality grading standards will be interpreted by consumers as negative. In 1981, NCA asked USDA to allow part of the Good/Select grade of beef to be desig- nated Choice (because such beef was leaner but still tasty); USDA rejected the idea partly because of opposition by some re- tailers, consumers, and cattle producers but largely because of opposition by restaura- teurs and purveyors as well as consumer groups who contended that the proposal was a ploy to sell lean meat at higher prices. Nevertheless, for more than 10 years consumer advocates have been calling for a change in the USDA beef quality grading standards so that the system will not (lis- criminate against leaner beef. Adclitional APPENDIX consumer efforts have called for a complete overhaul of USDA grades to reflect nutri- tional content of meat rather than the sub- jective characteristics of taste. In 1974, the National Consumers League recommended that the USDA beef quality gracling system be modified so that one additional grade designation be added between Choice and Good/Select in order to "encourage the production ant] marketing of leaner beef which uses less grain, costs less to procluce, and at the same time would allow prices to reflect this producer-cost reduction." Six years later, the Community Nutrition In- stitute stated that"the marketplace is ready and eager to accept a leaner, cheaper beef that must be promoted without imposing subjective opinions of eating pleasure" and that "the discrimination against lean beef inherent in the nomenclature of the present system could be eliminated by developing a new gracle name They suggested 'USDA Choice Lean,' 'USDA Choice Light,' or 'USDA Lean Choice'] to replace USDA Good." In February 1986, the Public Voice for Foot] and Health Policy suggested that USDA could either create a new grade (e.g., "Choice Lean," "Leaner Choice") that is lower in fat than Choice but that is clearly palatable and that could perhaps replace Choice, or restructure the entire quality grading system to reflect nutritional content of the meat. In the 1985 National Consumer Retail Beef Study, beef of two quality levels was offered to participants (U. S. Choice as Choice and U.S. Good as Select). Overall accept- ability of the two kinds of beef was the same, but for different reasons. Consumers who preferred Choice beef did so because of its advantages in palatability, while those who preferred Select beef clic] so because of its advantages in leanness. Choice beef was recognized as being somewhat fatter and Select beef as somewhat less desirable in palatability; yet consumers preferring each type of beef were willing to make the trade-oR to achieve the attribute most im
GRADE STANDARDS AND LABELING portent to them. (A more thorough discus- sion of the National Consumer Retail Beef Study is given by Saved and Cross in this volume. ~ Results of the National Consumer Retail Beef Study were sufficiently encouraging to prompt the Public Voice for Food ant! Health Policy to petition USDA to "chance the name of the 'Good' federal beef gracle to reflect that it is leaner than 'Prime' or 'Choice' and to stop discrimination against lean beef." Public Voice asked that the wore! "Select" replace the word "Good" as a grade name for beef carcasses having a Slight amount of marbling en c] thus containing 3.0 to 4.3 percent fat in the longissimus dorsi muscle. The USDA ruler! in late September 1987 to implement the name change from Good to Select, effective November 23, 1987. The National Academy of Sciences (NAS) Committee on Technological Options for Nutritional Improvements in the Food Sup- ply with Emphasis on Animal Products concluded that such change in grade no- menclaturc- though purely semantic would be in the best interest of all con- cerned. At present, essentially no beef is officially identified as U. S. GoocI; as a result. those who might wish to buy such beef cannot find it so identified. Packers sell the equivalent of U. S. Good beef as a part of the No-Roll category, for which there is no minimum quality indicator (marbling or maturity) level. As a result, no true test of the acceptability of Good grade beef to consumers can be achieved because the beef is in a mixture of the commodity (No- Rolls) that is highly variable in palatability. In May 1986, the American Meat Institute supported the Public Voice objective of changing the nomenclature of the Good grade to give leaner beef a more positive image. The NAS committee also consiclered recommending changes in the U.S. stancI- ards for beef grading that would parallel those made in 1972 by Canada. The Cana- dians premised their changes in beefgrading 339 on the following conclusions: (1) Although fatness helps to ensure tenderness and fla- vor, beef does not have to be fat to be flavorful ant] tender; (2) it is wasteful and inefficient to produce overeat cattle only to have their carcasses trimmed to retail stand- ards; (3) a potent force encouraging excess fatness is the obvious desire of packer buyers to purchase cattle as cheaply as possible on the rail by increasing dressing percentages so as to lower carcass cost; and (4) changes in cattle through breeding would be a long ant] difficult process and rapid changes in carcass characteristics through changes in cattle feeding are unlikely, so by far the most important change that could be made a change that would! result in an immediate and dramatic response would be to "har- vest" the cattle as they reach the point of optimum finish. Before 1972, the Canadian beef carcass grading system was similar to that currently used in the United States; in 1972, the Canadians adopted a system based on dual gracing. This system consists of five quality/maturity designations (A, B. C, D, E) and four subgrades (1, 2, 3, 4) baser] on single fat thickness measurements taken opposite the ribeye muscle between the 11th and 12th ribs. Since implementation of those gracle standards, the percentage of beef carcasses grading A-1 has increased from about 32 percent in 1972 to about 52 percent in 1986. The primary (difference between quality grading in Canada versus that in the United States is the essential disregard of marbling as a grade-determin- ing factor in the Canadian system. The NAS committee received testimony from Canadian officials acknowledging that they have a perceived and possibly real problem with unsatisfactory tenderness, jui- ciness, ant] flavor of their beef and that this inadequacy in eating satisfaction may well be the result of ignoring marbling in (leter- mining quality grade. Much of the beef sold to the food service trample in Canada is Prime or Choice beef produced in the United States. Therefore, the NAS committee could
340 not support any change that would eliminate marbling as a gracie-determining factor and thereby eliminate the ability of the industry to differentiate beef of the present Prime, Choice, Good/Select, and Standard grades. Because some consumers want and are will- ing to pay for a product having the charac- teristics of and iclentified as Prime or Choice, it is best to continue such identification protocol. As long as products are identifier] as such, consumers can find them and select or reject them thereby exercising their right to an option in the marketplace. A goal, then, of the NAS committee was to ensure that American consumers have the opportunity to exercise personal in- formec! choice in the selection of foods to include in their diet and that such choices are identifiable and available. A review of the research at the Texas Agricultural Ex- periment Station (reported in more cletail by Savell and Cross in this volume) indicates that a minimum level of 3 percent chemical fat in the ribs and loins of cattle, swine, and sheep is necessary to ensure acceptable palatability in beef, pork, and lamb. They contend that, in terms of nutritional merit, the maximum level of intramuscular fat that should be in the rib and loin cuts is 7.0 percent. A "Winslow of acceptability" (3.0 to 7.0 percent intramuscular fat) is thus created that considers diet/health/nutrition as well as flavor/juiciness/tenderness factors. Within that window are two other thresh- olds of chemical fatness associate<] with progressive increases in palatability at ap- proximately 5 percent chemical fat (mid- point of the Small amount of marbling) and at approximately 7 percent chemical fat (at the lower end of the Moderate amount of marbling). These hierarchical rankings in palatability associated with increasing levels of intra- muscular fatness would allow segmentation of the beef, pork, and lamb supplies into expected palatability groupings that would facilitate targeting and servicing the wants and needs of a segmented consumer market APPENDIX with varying tastes. Identification of beef with 3.0 to 4.3 percent intramuscular fatness with a new grade designation Select will make it possible for those who seek beef of that kind to find it and might encourage grocers/restaurateurs to stock it. Because this change will create "identifiable con- sumer choices" and give customers the option to buy leaner beef in the market- place, the committee encourages merchants to promote the sale of Select beef as an alternative or adjunct to beef of the Choice gracie. If beef of that fatness level is ac- ceptable to consumers, its production will be encouraged by price, encouraging a sup- ply commensurate with the demand ex- pressed at that price. The committee evaluated the trend to- ward promotion of red meat products la- beled "Natural" ant! "Light" (with the var- iant "Liter". The exact implications of such claims are in the purview of the USDA Standards and Labeling Division, Foot! Safety ant] Inspection Service (FSIS). While the term "Natural" is being promoted by some elements of the industry as representing meat from animals that have not been ex- posed to drugs, growth promotants, hor- mones, antibiotics, pesticides, or feed ad- clitives and by others as representing meat from animals that are reared in open spaces (as opposed to feedlots) ant] fed forages/ roughages (rather than grains), such con- notation is not collided in state or federal regulations. USDA FSIS Policy Memo 055 states that the term "Natural" may be used on the label of meat and poultry products providing that (1) the product does not contain any artificial flavoring, coloring in- gredient, chemical preservatives, or any other artificial or synthetic ingredient and (2) the product and its ingredients are not more than minimally processed ("minimal processing" may include smoking, roasting, freezing, drying, fermenting, and grinding). This being the case, all fresh red meat could be labeled "Natural." The committee considers present use of
GRADE STANDARDS AND LABELING the term "Natural" by certain producers/ processors to connote that meat from ani- mals produced by use of health and growth/ efficiency aids is somehow unnatural and thus unhealthy to be misleading and inap- propriate. Because it is not in the best interest of the consumer to create unwar- ranted fear about the safety/healthfulness of the foot! supply, the committee recom- mends that use of the term "Natural," in the manner that some promoters now use it, not be allowed. By the same token, the terms "Light" and "Lean" are being used inappropriately by some elements of private enterprise to imply superiority in leanness when such is not the case. USDA FSIS Policy Memos 070A ant! 070B state that the terms "Lean" and "Low Fat" can be used only on meat and poultry products containing less than 10 percent fat and that the terms "Light," "Leaner," and "Lower Fat" can be used only on products that contain at least 25 percent less fat than the majority of such products in the marketplace. Before issu- ance of these policy memoranda, fat claims such as "Light," "Lean," and "Extra Lean" could! be used interchangeably on meat and poultry products containing 25 percent less fat than a comparable product and on prod- ucts containing no more than 10 percent fat. The committee is concerned about the use of descriptive adjectives like "Light," when verification of relative fatness/leanness is made at the carcass level (comparing carcass traits of two kinds of beef, pork, or lamb), because retail cuts from fat or lean carcasses can be either fat or lean (and not cli~erent from each other) after fabrication and trimming at the retail level. The com- mittee strongly urges USDA not to allow certification as "Light" or "Lean" on the basis of carcass (lata an(l to restrict use of such terminology to products as they would be presented to consumers at the retail level. Fresh rec] meats or poultry, if they are to be labeler] as "Light" or "Lean" at the retail level, must in fact be low in fat 341 or the industry will super further loss of consumer confidence. The USDA should consider (leveloping a program to certify fatness of wholesale and retail cuts and should offer a "Certi-Light" or "Certi-Trim" specification that industry could use as a third-party verification that fatness floes not exceed some critical set point (for example, no more than 10 percent chemical fat). Such USDA certification, although it might be perceives! as government intervention, would make possible industry standardization of the term "Light" ant! would] make feasible equal opportunity for market entry by firms of small, medium, or large size. UnIess USDA controls the use of terms like "Nat- ural" and "Light," these terms will soon lose credibility and the red meat industry will lose the opportunity to capitalize on well-documented desires of certain seg- ments of the consumer market to purchase lower calorie or residue-safe meat products. The committee also supports action to uncouple the yield grading/ quality grading of beef carcasses. At present, carcasses that are categorized as No-Roll because they have too little marbling to grade Choice are not identified for curability (specifically, they are not yield graded). Those carcasses that are categorized as No-Roll because they have too much fat to qualify for the 3 or better yield Grade are not identifie(1 for expected palatability (specifically, they are not quality graded). This disrupts the com- municative function of the grappling system ant] is thus a deterrent to increasing leanness of cattle. Furthermore, carcasses that are trimmer] before presentation for grading cannot be accurately yield grader] and so are ineligible for quality grading. Some packers would remove, at the time of slaugh- ter, most or all of the subcutaneous or ki(lney/pelvic/heart fats from beef carcasses that were too fat if USDA would allow such carcasses to be quality gradecI. There is presently no disincentive in the U. S. marketing system to prevent the feecI- ing of grain when it is cheap-to the point
342 that it causes overfattening of red meat animals. Until such disincentive is in placc and a governmental policy change may be necessary to effect such a change the in- dustry will continue to produce animals with too much fat. The quickest available means to make beef, pork, and lamb leaner and to discourage overfeeding and excessive fat- tening would be to allow packers to remove, during the slaughter/ciressing process, all external fat in excess of that amount (for example, one-fourth inch) that can remain on retail cuts. In late 1986, the American Meat Institute (AMI) decided that trimming of retail cuts to leave only one-fourth inch of external fat, as initiated by some retailers in 1986, is a systematic and real improvement and that the place to accomplish such fat removal is in the packing plant-on the slaughter floor. In November 1986, AMI and NCA members reviewed hot-fat trimming at the Monfort of Colorado plant in Greeley and received results of a Texas A&M University study evaluating that process. AMI suggested that use of hot-fat trimming would (1) remove dressing percentage as a price-determining factor in purchases of live cattle, (2) dis- courage overfeeding and overfattening of cattle, (3) allow for removal of excess fat at a point where its value (as edible tallow) is highest, and (4) make possible payment of the highest prices for the leanest cattle. If excess external fat is removed on the slaugh- ter floor ant! cattlemen are paid only for that amount of fat left on the carcass when the carcass is weighecl, there will be excel- lent incentive to not overfatten cattle. The committee considered AMI's sug- gestions and, as a result, favors uncoupling the yield ant] quality grades to allow for hot-fat trimming of beef carcasses and en- courages USDA to implement such changes in gracling protocol. The yield grades are useful to certain segments of the beef industry (producers, packers, wholesalers, purveyors, retailers) but do nothing to assist the consumer in APPENDIX making purchasing decisions that would benefit from knowledge of relative fatness/ caloric content of meat cuts. The committee considered numerous options for providing relative fatness information to consumers and decided that at least three alternatives existec! for accomplishing that end. The information could! be provided by mandating nutrition labeling for retail cuts, but there is little evidence that such information would actually be useful or used. Because con- sumers make purchasing decisions very quickly, a system of identification by fatness level that would carry through the market- ing sequence and appear at the retail level in alphanumerical form might be helpful. For example, in the code A-2-3, A could indicate maturity of the animal at slaughter, 2 the amount of marbling (or perhaps mar- bling plus subcutaneous and intermuscular fat), and 3 the yielc] grade of the carcass. Identification as A-l-1 would therefore sig- nify a young animal with a "Moderate" amount of marbling and very high curability. Because not every piece of meat from an A-l-1 carcass would actually be an A-1-1 retail cut, the last number could be dropped and individual cuts from an A-1 could be labeled, at the retail meat counter, as A-1, A-2, A-3, or A-4, depending on their mar- bling level an(l subcutaneous plus inter- muscular fat content. More severe trimming of retail cuts would improve the numerical gracle, moving it, for example, from A-4 to A-1 if trimming was severe enough. A second means for identifying relative fatness/caloric content of retail cuts might involve the use of a color system (re(l, white, blue) or a medal system (gold, silver, bronze) affixed to retail packages. Such a system would be based on the identification of three levels of fatness of retail cuts that would determine the size of serving that coulc] be consumed on a daily basis while conforming to a healthy cliet. Compliance could be voluntary or mandatory depending on local, state, or federal ordinances or laws. The advantage of a color-cocling or medal system
GRADE STANDARDS AND LABELING is that it would be very easy to interpret ant] consumers could] make selections very quickly. As opposed to a system of iclenti- fication baser] solely on a criterion like "calories from fat," which would essentially preclude any consumption of certain animal products (for example, butter), a system of identification baser! on serving size or fre- quency would allow any and all animal products to be consumer! in some amount and at some interval of time as part of a balances] diet. There is a dangerous ten- dency on the part of some health profes- sionals to identify certain animal products as "too high" in calories, "too high" in saturated fatty acids, or "too high" in cho- lesterol and thus to advise consumers never to eat them. The errors in such advice are that not all health professionals agree that all people will benefit from dietary moclifi- cation, not all research indicates that these chemical entities are involved in a causal relationship to heart disease or cancer, and consumption of an undesirable entity per se probably floes not endanger health- rather, it is the amount and frequency of consumption that is critical. Therefore, if a meat product carried a silver sticker and consumers had been told the meaning of that sticker, they would know, instantly, that they could purchase that cut ant] con- sume, say, 6 ounces of it up to three times per week without exceeding a target level of certain dietary substances. Such a pro- ceclure would ensure that consumers have "identifiable choices" and "options in the marketplace" that would assist them in se- lecting foods. A third approach is that of the Nutritional Effects Foundation (NEF), which was es- tablished to encourage the production, proc- essing, marketing, and consumption of lean meat by ensuring the availability of low-fat meat products to replace high-fat meat in the diet. Two levels of composition NEF1 and NEF~would be identified, and seals of approval woulc] be placed on all cuts meeting a predesignatecI standard. Products 343 accepted] for labeling could be eaten in moderate amounts as parts of diets recom- mended by the National Institutes of Health, the Consensus Development Conference Statement-Lowering Blood Cholesterol to Prevent Heart Disease, the U.S. Depart- ment of Agriculture/Department of Health and Human Services Dietary Guidelines for Americans, the American Heart Associa- tion, and the American Cancer Society. It is currently recommended that to re- cluce the dietary risks associated with cor- onary heart disease, cancer, and other chronic diseases, no more than 30 percent of the total daily caloric intake for the general population an(1 no more than 20 percent for the high-risk population should come from dietary fat. To provide a wide range of reasonable portion sizes for use in both the 20 ant] 30 percent calories-from-fat diets, two categories of meat are accepted for labeling: NEF1 products contain no more than 3.5 percent fat Uncooked and NEF2 products contain no more than 6 percent fat (uncooked). In most cases, these meat products, if eaten in a reasonable quantity on any single day, will provide less than 30 percent of the recommended intake of total fat ant] less than 25 percent of the recom- mended intake of saturated fatty acids. In addition, products in both of these cate- gories could contain the minimum level of intramuscular fat (approximately 3 percent) necessary to ensure palatability. Any retail identification system based on total fatness or total caloric content of animal products and means for monitoring compli- ance should] be based on both palatability ant! nutritional merit with the goal of iden- tifying clifferent kinds of retail cuts of beef, pork, or lamb in a simplified manner. I(len- tification according to palatability/nutri- tional merit by USDA, for example, would make possible "identifiable consumer choices" and minimize selection time. In summary, the changes in USDA grade standards or labeling/ identification proce- dures most likely to improve nutritional
344 attributes, increase consumer options in the marketplace, and enhance consumer ac- ceptability of beef, pork, and lamb are (1) changes in gracle nomenclature that would identify a lean yet palatable product with a new name, (2) changes in grade-application regulations that would allow hot-fat trim- ming at slaughter without eliminating the possibility of quality grade identification, (3) APPENDIX control of use of the terms "Light" and "Natural" to prevent confusion in the mar- ketplace, and (4) identification of red meat at the retail level according to fatness level or nutritional merit to signal to consumers that specified quantities of a product could be consumed and still allow for compliance with current dietary guidelines and health recommendations.
The Role of Fat in the Palatability of Beef, Pork, and Lamb I. W. SAVELL anc! H. R. CROSS Within the past two decacles, fat in the diet has come uncier scrutiny with respect to its role in coronary heart disease and other health-related problems. Recent rec- ommendations have centered on eating moderate amounts of lean red meat, but there is a problem with consumer accept- ance when fat is absent from meat. Meat that is tough or dry or that does not taste good probably will not be eaten, even by people on restricted diets. Thus, some fat is necessary to ensure that meat is enjoyed when eaten, but the level should be low enough so that meat can be included in a restricted diet. In this paper we describe the role of fat in improving the tenderness, juiciness, and flavor of beef, pork, and lamb and recom- mend the minimum level of fat necessary to ensure consumer acceptability. FAT'S INFLUENCE ON TENDERNESS, JUICINESS, AND FLAVOR The most comprehensive review of fat and palatability to date is that of Smith and Carpenter (1974), who summarized how fat affects tenderness, juiciness, and flavor in 345 meat. Following is a brief description of these mechanisms. Tenderness Of the three factors influencing the tenderness of meat actomyosin effect, background effect, and bulk density or lu- brication effect-only lubrication effect deals with fat. It is associated with the amount and distribution of intramuscular fat, or marbling. Marbling probably influences meat tenderness based on the individual or col- lective effects of the following mechanisms (Smith and Carpenter, 19741: Bite theory. This theory suggests that within a given bite-size portion of cooker] meat, the occurrence of marbling decreases the mass per unit volume, lowering the bulk density by replacing protein with lipid. Because fat is much less resistant to shear force than is coagulated protein, the cle- crease in bulk density is accompanied by an increase in real or apparent tenderness. Strain theory. As marbling is depositecl in the perivascular cells inside the walls of the perimysium or endomysium, the con
346 nective tissue walls on either side of the deposit are thinned, thereby decreasing their effective width, thickness, and strength. Lubrication theory. Intramuscular fats, present in and around the muscle fibers, lubricate the fibers and fibrils ant! so make for a more tender and juicier product that potentiates the sensation oftenderness. Thus, tenderness is closely associates! with juici ness. Insurance theory. The presence of higher levels of marbling allows the use of high- temperature, cry-heat methods of cooking and/or a greater degree of doneness without adversely affecting the palatability of the meat. Marbling thus provides some insur- ance that meat that is cooked too long, too rapidly, or incorrectly wfl} still be palatable. Relationship Between Fat and Tenderness Based on their review of the data, Smith and Carpenter (1974) found that fatness had a moderate relationship to tenderness in pork and a low to moderate relationship to tenderness in beef and lamb. Juiciness Juiciness is made up of the combiner! effects of initial fluid release and the sus- tained juiciness resulting from the stimu- lating effect of fat on salivary flow (Weir, 1960~. These two factors can be described as follows (Bratzler, 1971~: (1) initial fluid release the impression of wetness per- ceived cluring the first chews, produced by the rapid release of meat fluids, and (2) sustained juiciness the sensation of juici- ness perceived during continued chewing, created by the release of serum ant! due, in part, to the stimulating effect of fat on salivary flow. According to Pearson (1966), the initial fluid release is affected by degree of aloneness and method of cooking, while sustained juiciness is relatecl to intramus- cular fat content. Fat may affect juiciness by enhancing the APPENDIX water-holding capacity of meat, by lubri- cating the muscle fibers cluring cooking, by increasing the tenderness of meat and thus the apparent sensation of juiciness, or by stimulating salivary flow cluring mastication (Smith and Carpenter, 1974~. Relationship Between Fat and Juiciness According to Smith and Carpenter (1974), fatness has a moderate relationship to juic- iness in lamb, a moderate to high relation- ship to juiciness in pork, and a low to moderate relationship to juiciness in beef. Flavor Hornstein (1971) believes that fat may affect flavor in two ways: (1) Fatty acids, on oxidation, can produce carbony! compounds that are potent flavor contributors, and (2) fat may act as a storage clepot for odoriferous compounds that are releaser! on heating. Volatile compounds released from fat or producer] from triglyceride or phospholipid fractions may be responsible for the species- specific flavors of beef, pork, and lamb. Smith and Carpenter (1974) stated that although the basic meaty flavor is nonlipid in origin, some quantity of fat is uncloubtecily necessary to make beef taste rich, full, and "beefy." Smith et al. (1983) stated that U.S. Department of Agriculture (USDA) beef quality grades are related to flavor of beef because grade indirectly assesses the extent to which flavor and aroma compounds are likely to be present in the meat. Relationship Between Fat and Flavor Fatness has a low relationship to flavor in lamb and a low to moderate relationship to flavor in pork and beef (Smith and Car- penter, 1974). SPECIFIC RESEARCH ON PORK, LAMB, AND BEEF PALATABILITY This section covers pertinent information on species-specific research that helps to
ROLE OF FAT determine how much fat is necessary for acceptable palatability. The work that is reported is from the Texas Agricultural Experiment Station and represents a portion of the palatability/grade/ consumer accept- ance research conducted on pork, lamb, and beef by the Meats en c] Muscle Biology Section during the past three decades. Pork Palatability Research The study by Davis et al. (1975) with 403 pork loins showed that when three cate- gories of loins were created baser] on mar- bling level ("typical-Modest'' or higher, "typical-Slight" to "Modest-minus," ant] "Slight-minus" or lower), scores for juiciness and overall satisfaction were significantly lower in the "Slight-minus" or lower cate- gory. Juiciness, tenderness, and overall sat- isfaction ratings were significantly higher for chops from loins that were from the "typical-Modest" or higher category. Davis et al. (1978), using the same sample of pork loins used by Davis et al. in 1975, designed a system for segmentation offresh pork loins into quality groups of"Superior," "Accept- able," or "Inferior." Using the sirloin end as the scoring surface, loins that were light in color, that were soft, and that had low marbling scores were rated as "Inferior," while those with intermediate color, firm- ness, and intermediate to high levels of marbling were rated as "Superior." With respect to the level of marbling necessary in pork longissimus dorsi muscle to ensure acceptable palatability, Davis (1974) rec- ommendec] between 3.5 and 4.5 percent intramuscular fat. Lamb Palatability Research In a study of lamb rib chops, Carpenter and King (1965) evaluated the influence of cooking method, marbling, color, and core position (for Warner-Bratzler shear cleter- minations) on tenderness. Chemical fat was determined on the rib chops and was strat- ified by marbling score of the longissimus 347 dorsi muscle as follows: Practically Devoid = 2.05, Traces = 2.49, Slight = 3.15, Small = 3. 54, Modest = 4.10, Moderate = 4.79, Slightly Abundant = 4.39, Mod- erately Abundant = 5.17, and Abundant = 6.67. Tenderness (as measured by the Warner-Bratzler shear machine) was most affected by cooking methoc] and core posi- tion. Highly significant correlations were found between tenderness and the fat con- tent of the longissimus clorsi muscle, but the coefficients were of low magnitude. Lamb carcass quality was extensively evaluated by Smith et al. (1970a,b) and Smith and Carpenter (1970~. Smith et al. (1970a), in evaluating the palatability of leg roasts, found that individual or combined USDA scores for carcass quality feather- ing, flank streaking, firmness, and matu- rity were associated with less than 15 per- cent of the variation in overall satisfaction ratings. Segmentation into USDA quality grades indicated that roasts from Prime carcasses possessed the highest percentage of clesirable ratings and the lowest percent- age of undesirable ratings for juiciness, tenclerness, and overall satisfaction com- pared with the other grades evaluated. Small and inconsistent differences appeared be- tween roasts from carcasses in the Choice ant] Goocl/Select grades, but leg roasts from Utility carcasses were ~lecicle(lly inferior in palatability to those from the higher USDA grades. Smith et al. (1970b), in the companion study on palatability of rib, loin, and sirloin chops, fount] that segmentation into USDA quality grades indicated that chops from Prime carcasses were superior to those of the other gracles in percentage of (lesirable ratings for juiciness, tenderness, and overall satisfaction. As grade (lecreased from Prime through Good/Select, there were corre- sponcling decreases in the proportion of chops considerecl desirable In Juiciness, tenderness, and overall satisfaction. With the exception of scores for tenderness, (lif- ferences between chops from Good/Select versus Utility carcasses were small. . . . .
348 When Smith anc] Carpenter (1970) col- lected chemical data from a sample of car- casses used in the studies by Smith et al. (1970a,b), they found that differences in intramuscular fat were associated with sig- nificant changes in juiciness, tenderness, ant! overall satisfaction ratings for all the cuts studiecI. Based on the conclusions of three studies, increased fatness was gener- ally associated with increaser] palatabflity, but fatness appeared to have a greater impact on the cuts from the rack and loin than on the cuts from the leg. Jeremiah et al. (1971) evaluated the im- pact of chronological age and marbling on the palatability of individual muscles from leg steaks of lamb. Marbling appeared to be of little consequence in determining the tenderness of the rectus femoris, vastus lateralis, biceps femoris, semitendinosus, or semimembranosus muscles of the leg, but chronological age was highly related to the tenderness of these muscles. The authors concluded that increased marbling was of little importance for increasing the tender- ness of leg muscles, but that increased marbling was associates] with higher juici- ness scores for the rectus femoris, vastus lateralis, ant] semitendinosus muscles. Smith et al. (1976) evaluated the influence of fatness subcutaneous and marbling-on the palatability of lamb. They found that lamb carcasses that have increased quan- tities of fat chid more slowly, maintain muscle temperatures conducive to autolytic enzyme degraclation for greater periods of time postmortem, sustain less shortening of sarcomeres, have muscles with lower ulti- mate pH values, have less perceptible or softer connective tissue, and are more tender than lamb carcasses that have limited quan- tities of subcutaneous or intramuscular fat. The authors theorized that deposition of increased quantities of subcutaneous or in- tramuscular fat (particularly in carcasses with limited quantities of subcutaneous fat) increases tenderness by changing postmor- tem chflling rate. Thus, an increased quan APPENDIX tity of fat decreases the rate of temperature clecline, enhances the activity of autolytic enzymes in muscle, lessens the extent of myofibrfllar shortening, and thereby in- creases the ultimate tenderness of cooked meat from a fatter carcass. Beef Palatability Research Physical, Chemical, and Histological Studies Davis et al. (1979) investigated variations in tenderness among beef steaks from car- casses of the same USDA quality grade to better understand why some steaks are less palatable than others even when the USDA quality grade is the same. For Choice, A maturity beef loins, the most tender steaks had more intramuscular fat, less intramus- cular moisture, higher water-hol(ling capac- ity, and a lower fragmentation index. Intra- muscular fat percentages for steaks from the four tenderness groups of Choice, A matu- rity beef loins were as follows: very ten(ler = 7.6 percent, moderately tender = 6.1 percent, slightly tender = 5.6 percent, and slightly tough = 4.4 percent. For Choice, B maturity beef loins, very tender steaks had 7.2 percent fat while slightly tough steaks had 5.6 percent fat. Although in the other grade/maturity groups, other physical, chemical, and histological factors were more important than fatness, high tenderness scores were most often associated with intramus- cular fat percentages of 6 to 8. Time-on-Feed and Beef Palatability The length of time that cattle are fed high-concentrate feeds is associated with increased palatability, irrespective of quality gracles. Tatum et al. (1980) reporter! that rib steaks from high Choice ant] average Choice carcasses were juicier, more flavor- ful, and overall more palatable than steaks from low Good/Select and high Standard carcasses; however, steaks from low Choice,
ROLE OF FAT high GoocI/Select, en c] average GoocI/Select carcasses did not differ in palatability. In- creased time-on-feed was associated with increased carcass maturity, increased fat deposition, clecreased yielcl grade, ant] in- creased percentage of carcasses grading: Choice. Increased feeding time from 100 to 160 days had a beneficial effect on flavor desirability but die] not significantly affect juiciness, tenderness, or overall palatability. Tatum et al. (1980) suggester! that a knowl- eclge of feeding history may be a useful adjunct to-or substitute for-USDA qual- ity grade for predicting beef palatability. Dolezal et al. (1982a), in a stucly offeeding groups of steers and heifers for periods ranging from 30 to 230 clays, found that extending feeding time beyond 90 to 100 days dill little to ensure additional palata- bility. Within time-on-feecT strata from 100 through 230 days, few differences in palat- ability were found between rib steaks from carcasses of different USDA quality grades. Dolezal et al. (1982a) recommended that the minimum marbling requirement for the Choice grade could be lowered with no appreciable loss in palatability if it was stipulated that cattle had been fed a high- concentrate diet for at least 90 days. Subcutaneous Fat Thickness and Marbling Several studies have been conducted that explorer! the combined role of subcutaneous fat ant] marbling in the palatability of beef. Tatum et al. (1982) found that compared with marbling, fat thickness was ineffective as a predictor of cooked beef palatability and, therefore, would appear to be an un- suitable substitute for marbling. However, marbling, user! in combination with a min- imum subcutaneous fat thickness constraint of 7.6 mm for carcasses with a Slight amount of marbling, facilitated more equitable strat- ification of carcasses according to their ex- pected palatability than clid marbling alone. Dolezal et al. (1982b) fount] that assigning 349 carcasses to three expected palatability groups baser! on fat thickness was at least equivalent to, and perhaps slightly more precise than, the use of USDA quality gracles for grouping the carcasses according to expected palata- bilitY. There were progressive increases in palatability of cooked beef as fat thickness of carcasses increased from less than 2.5 to 7.6 mm, but quantities greater than 7.6 mm die] not further improve palatability. In studies involving young bulls, Riley et al. (1983a,b) found that the combination of subcutaneous fat and marbling was an im- portant factor in the determination of beef palatability. Subcutaneous fat thickness was found to be more important than "mascu- linity" in ensuring that beef from young bulls would! be acceptably tender (Riley et al., 1983a). Riley et al. (1983b) recom- mendec! that the USDA grade standards for beef could be revised to allow those car- casses with Slight marbling and at least 7.6 mm of fat thickness to grade Choice, irre- spective of sex. When steaks from Standard bulls ant! steers and steaks from Good/Select bulls and steers that hac] less than 7.6 mm of fat thickness were compared with steaks from Choice steers or steaks from Good/ Select bulls with at least 7.6 mm of fat thickness, they were fount! to be signifi- cantly less palatable (Riley et al., 1983b). USDA Beef Quality Study In the mid-1970s, the Texas Agricultural Experiment Station conclucted a compre- hensive study for the U.S. Department of Agriculture on USDA beef quality grades and palatability. This study involved 1,005 carcasses ranging in maturity from A to E and in marbling from Moderately Abundant to Practically Devoid. In their report on the eject of maturity groups on palatability, Smith et al. (1982) fount] that in comparison to carcasses of B. C, or E maturity, carcasses of A maturity pro(lucecl broiled steaks that hail higher palatability ratings in 62 to 86 percent of comparisons, were decidedly less
350 variable in sensory traits, were more likely to be assigned high (26.00) and less likely to be assigned low (c2.99) sensory panel ratings, and were more likely to have low ~ 3.63 kg) shear force values. They found that position within the A or A + B maturity groups explained 4 percent (loin steaks) and 10 to 18 percent (round steaks) of the observed variation in overall palatability ratings and/or shear force values. In the report on the relationship between marbling and palatability, Smith et al. (1984) fount! that as marbling increaser! from Prac- tically Devoid to Moderately Abundant, loin steaks were more palatable about two-thirds of the time. round steaks were more nal atable about one-eighth of the time, ant] loin steaks were more likely to be assigned high ~-6.00) panel ratings and to have low ~ 3.63) shear force values. However, in- creases in marbling from Slight to Moder- ately Abundant (A + B maturity) had little or no effect on percentage incidence of loin or round steaks with pane] ratings 2.99 or 24.00, or with shear force values 26.35 kg or 4.99 kg. Differences in marbling ex- plained about 33 percent (loin) and 7 percent (top round) of the variation in overall pal- atability ratings in A, B. C, and A + B maturity carcasses. Smith et al. s (1987) report on the influ- ence of USDA quality gra(les on beef pal- atability indicates] that Prime carcasses pro- clucecl loin and round steaks that were more palatable than the steaks from Choice through Canner carcasses in 85.7 percent of com- parisons and more palatable than the steaks from Choice through Standard carcasses in 69.0 percent of comparisons. Comparable percentages were 71.4 percent (for Choice through Canner), 42.9 percent (for Choice through Standard), 74.3 percent (for Goocl/ Select through Canner), and 35.7 percent (for Good/Select compared to Standard). Among Prime through Standard carcasses, grade preclicted flavor, tenderness, ant] overall palatability of loin steaks with 30 to 38 percent accuracy, but could only explain APPENDIX about 8 percent of the variation in sensory pane} ratings or shear force values of round steaks. National Consumer Retail Beef Study The National Consumer Retail Beef Study was an industry-wide program supported by government, producer, feecler, packer, and retailer segments of the industry (Cross et al., 1986~. The program was led by the Texas Agricultural Experiment Station of the Texas A&M University System with coordination of the Beef Industry Council of the National Live Stock & Meat Board and the National Cattlemen s Association. The beef industry identified two challenges to achieving a market-(lriven orientation: What are the demands of specific segments of consumers, and what kinds of beef will satisfy them? The relationship between quality grade and taste appeal was first addressed by Savell et al. (1987~. The study (called Phase I) was carrier] out in Philadelphia, Kansas City, and San Francisco. Steaks from car- casses that varier! in marbling were evalu- ated by 540 households. For the first time, a nationwide study was conclucted to see (1) if consumers, rather than trained sensory panelists, could detect differences in pal- atability of steaks that (liffere~l in marbling ant] t2) if there were regional consumer preferences for steaks according to level of marbling. Results showed that consumers could detect palatability differences clue to marbling ant] that there were indeed re- gional differences with respect to the way consumers rated steaks that differed in mar- bling. Consumers in all three cities rated steaks with high marbling the same. Con- sumers in San Francisco and Kansas City gave consistently high ratings that were only slightly reduced as marbling decreased from Slightly Abundant to Traces. But ratings given by Philadelphia consumers were sharply reduced as marbling decreased. Itus, it appeared that different consumer market
ROLE OF FAT segments might need to be identified to more effectively reflect consumer tastes in each city. Because the information gatherer] in Phase I acIdressed only one issue in the selection of beef taste-specific demands for the other major selection criteria price and leanness remained unanswered. There- fore, it became necessary to conduct Farther research (Phase II) to determine (1) what amount of taste, if any, would be sacrificed by the consumer to obtain the leanness advantages of lower gracling beef and (2) what degree of external fat trim would consumers seek ant] be willing to pay for. Phase II of the National Consumer Retail Beef Study (Cross et al., 1986; Swell et al., in press) was conducted in San Francisco en cl Philadelphia (the two cities in Phase I with the greatest clifference between con- sumer ratings of steaks from the various marbling levels). With respect to the mar- bling or quality grade findings from Phase II, retail cuts from Choice ant! Good/Select carcasses were rated equally high for con- sumer acceptance, but for different reasons. Choice retail cuts were rated high in taste, but when objections were voiced, they con- cerned fatness. Good/Select retail cuts were rated high in leanness, but when objections were voiced, they concerned taste or tex- ture. A major recommendation from this study was to merchandise the two grades of beef baser! on their strengths Choice should be marketed for its taste appeal and Good/ Select for its leanness. MINIMUM FAT IN MEAT NEEDED FOR ACCEPTABLE PALATABILITY Before a recommendation can be made with respect to the level of fatness needecl for acceptable palatability, it is important to know how much chemical fat is present in steaks from the various marbling levels. Savell et al. (1986) reported the amount of chemical fat in the uncookec! longissimus dorsi muscle of 518 beef carcasses that 351 ranged in marbling from Moderately Abun- dant to Practically Devoid (Figure 1~. Mean values for chemical fat ranged from 10.42 percent in Moclerately Abundant to 1.77 percent in Practically Devoid. The authors generated a regression equation to calculate the amount of chemical fat in a raw loin steak for known marbling level: Percentage ether-extractable fat = (Marbling score x 0.0217) - 0.8043. For this equation (r2 = 0.78), marbling score is converted to a numerical code where Moderately Abundant = 800-899, Slightly Abundant = 700-799, Moderate = 600- 699, Modest = 500-599, Small = 400-499, Slight = 300-399, Traces = 200-299, and Practically Devoid = 100-199. Using the equation, the amounts of fat in Traces, Slight, Small, Modest, ant! Moderate are 1.74, 3.00, 4.28, 5.55, and 6.82 percent, respectively. These levels of fat are low compared with the 10 to 50 percent levels in processes! meat products. The key question asked of us was, what level of fatness is necessary for acceptable palatability? After reviewing the research we have concluctec] over the years under many different circumstances and with many different objectives, we conclude that the minimum fat percentage required for ac- ceptable palatability of broiling cuts (rib, loin, sirloin, and so on) is 3 percent on an uncooked basis (associated with the mini- mum Slight degree of marbling). As in all biological relationships, there is no magic point where at one concentration or level something is acceptable and at the next increment it is not, but our findings are basest on the overwhelming evidence of many observations where steaks with less than 3 percent animal fat (or the marbling levels associated with less than 3 percent fat Practically Devoid and Traces) are tougher, drier, and less flavorful, whether evaluated by trained panelists or by con- sumers. Note that this is only a minimum
352 14 13 Ill 12 n 11 fit 10 ~ 9 ;5 8 s 7 Ill 6 -A 5 , 4 3 2 1 o 1 l I I I I I I I I MAB SLAB MD MT SM SL TR PD Marbling Score FIGURE 1 Marbling score and ether extractable fat. NOTE: MAB is moderately abundant; SLAB, slightly abundant; MD, moderate; MT, modest; SM, small; SL, slight; TR, traces; and ED, practically devoid. tat percentage tor ~~acceptable palatability; it is our belief that there are two other levels or plateaus of chemical fat associated with increasing palatability: approximately 5 percent (midpoint of the Small amount of marbling) and approximately 7 percent (the lower end of the Moderate amount of mar- bling). These hierarchical rankings in pal- atability as associated with increasing fatness allow the beef supply to be sorted into expected palatability groups that can best serve a segmented consumer market with widely varying tastes. The following discussion will help to fur- ther defend our choice of 3 percent or Slight marbling as the minimum level offal neecled for acceptable palatability. Tatum et al. (1982) found that marbling hack a low, but positive, relationship to all the palatability traits of beef, but that more than 90 percent of the steaks with Slight or higher degrees of marbling were desirable in tenderness, flavor, and overall palatability. In unpub- lished data generated by the USDA Beef Quality Study, the relationship between actual chemical fat levels and overall pal- atability shows a distinct downturn in ratings once fat is below 3 percent. The relationship APPENDIX between overall clesirability ratings and marbling level for the three cities user! in Phase I of the National Consumer Retail Beef Study supports our contention that once marbling drops below minimum Slight, consumers are likely to find the meat less palatable. Finally, in Phase II ofthe National Consumer Retail Beef Stucly (Cross et al., 1986; Savell et al., in press), although con- sumers could detect differences in taste between steaks ant] roasts from Choice and Good/Select, they still rater] those from Good/Select (Slight amount of marbling) very high in overall acceptance primarily because of the leanness and absence of waste of the cuts. Our recommendation of a minimum 3 percent fat is only for those cuts from the rib and loin. Palatability evaluations of cuts from the chuck and round fad] to show strong relationships between fatness and palatabil- ity. Griffin et al. (1985) fount] that consumers could detect differences in palatability be- tween steaks from the rib and loin of higher grading steer carcasses when compares! with steaks from lower grading bull carcasses, but that they could not (letect differences in palatability between roasts from the chuck
ROLE OF FAT and round fiom the two groups. Smith et al. (1984, 1987) reported that neither mar- bling nor quality grade was closely associ- ated with the sensory pane} ratings or shear force values of steaks Dom the round. Over- all palatability of the strip loin does reach a point- at minimum Slight that the ratings start to diminish quite drastically, but the overall palatability ratings for the top round are fairly level from Slightly Abundant to Practically Devoid marbling. Therefore, it is our opinion that in young cattle, there is no minimum level of marbling or chemical fat necessary to ensure acceptable palata- bility for cuts from the round or chuck, primarily because ofthe way they are cooked (moist-heat roasting, braising, pan frying, and so on) and because of lower consumer expectation for these cuts compared with higher parcel steaks from the rib and loin. Although the data for minimum chemical 7r ~ - ~ 6 - = CIS ~ 5 o 4 353 fatness are not as well documented for pork and lamb as they are for beef, because most studies have focused their attention on the relationship between general fatness of car- casses and palatability, we still recommend a minimum level of 3 percent chemical fat for those cuts from the loin of pork and from the loin and rack of lamb. Most of the studies mentioned earlier in the sections on pork and lamb found that there were certain levels of fatness where undesirable chops were encountered. Chemical fat is less im- portant for palatability in the cuts from the shoulder and leg of pork or lamb because in pork they are further processed and in lamb they are most often roasted, which probably minimizes the influence of fat on palatability. For lamb leg roasts, we rec- ommend a minimum of 2 percent chemical fat to ensure acceptable palatability. Overall Palatabillty Strip Loin 0 Grams of Fat In Two Servings of Meat L so' o' I I I 1 1 ~I I I 1 1 1 1 1 2 3 4 5 6 7 Percent of Fat 22.5 17.5 _ 7.5 1 1 1 1 1 1 2.5 8 9 10 11 FIGURE 2 Window of acceptability for fat content of meat (palatability versus grams of fat, two servings). The window is based on a fat content range of 3 percent to 7.3 percent. This is equivalent to meat cuts that grade in the lower range of Good/Select (3 to 4.27 percent fat content) to those that grade in the high range of Choice (4.28 to 8.0 percent fat content). of - -
3s4 MAXIMUM FAT ALLOWABLE IN MEAT FOR ACCEPTABLE NUTRITIONAL MERIT The point at which fat stops being an asset (in terms of taste) and starts becoming a liability (in terms of health) must also be considerecI. We conclude that the maximum amount of fat that should be present in cuts of meat to ensure nutritional merit is 7.3 percent (uncooked basis). We arrived at this figure based on the following assumptions: · An intake of 2,000 kcal/clay; · No more than 30 percent of calories from fat, baser! on the American Heart Association's Dietary Guidelines; · Of the calories from fat, no more than 25 percent from fat in beef, pork, and lamb; · No more than 600 kcal from fat ant] no more than 150 kcal from fat from red meat; · A maximum of 16.6 grams of fat from red meat per clay; · Two servings per day from the meat group, based on good nutrition practice; and 4 ounces, uncooked, per serving; · 16.6 grams offal diviclec] by 226.8 grams (number of grams in 8 ounces) = 7.3 percent chemical fat in uncooked! portion. Baser] on these calculations and our rec- ommendations of 3 percent minimum fat, Figure 2 was clevelopecl, which shows the "window of acceptability" of fat in meat products. This target is amply wide, since it allows most cuts from carcasses that grade low Good/Select to the middle of high Choice to qualify. In a(lclition, smaller or fewer servings of red meat per day would accommodate a slightly higher fat level without exceeding the American Heart As- sociation's Dietary Guidelines. This "win- clow" will cause some controversy from those who are proponents of fat for taste reasons (minimum level set too low) and those who are opponents of fat for health reasons (maximum level set too high), but APPENDIX we feel that these levels are very realistic goals from both production and consump tion points of view. REFERENCES Bratzler, L. J. 1971. Palatability factors and evaluation. Pp. 328~48 in The Science of Meat and Meat Products, 2nd ea., J. F. Price and B. S. Sehweigert, eds. San Franeiseo: W. H. Freeman. Carpenter, Z. L., and G. T. King. 1965. Tenderness of lamb rib chops. Food Teehnol. 19411~:102. Cross, H. R., J. W. Savell, and J. J. Francis. 1986. National Consumer Retail Beef Study. Pp. 112-116 in Proceedings of the 39th Reciprocal Meat Confer- enee. Chicago, Ill.: National Live Stock & Meat Board. Davis, G. W. 1974. Quality Characteristics, Compo- sitional Analysis and Palatability Attributes of Se- lected Muscles from Pork Loins and Hams. Master's thesis. Texas A&M University, College Station. Davis, G. W., G. C. Smith, Z. L. Carpenter, and H. R. Cross. 1975. Relationships of quality indicators to palatability attributes of pork loins. J. Anim. Sci. 41:1305. Davis, G. W., G. C. Smith, Z. L. Carpenter, and R. J. Freund. 1978. Segmentation of fresh pork loins into quality groups. J. Anim. Sei. 46:1618. Davis, G. W., G. C. Smith, Z. L. Carpenter, T. R. Dutson, and H. R. Cross. 1979. Tenderness varia- tions among beef steaks from carcasses of the same USDA quality grade. J. Anim. Sei. 49:103. Dolezal, H. G., G. C. Smith, J. W. Savell, and Z. L. Carpenter. 1982a. Effect of time-on-feed on the palatability of rib steaks from steers and heifers. J. Food Sei. 47:368. Dolezal, H. G., G. C. Smith, J. W. Savell, and Z. L. Carpenter. 1982b. Comparison of subcutaneous fat thickness, marbling and quality grade for predicting palatability of beef. J. Food Sci. 47:397. Griffin, C. L., D. M. Stiffler, G. C. Smith, and J. W. Savell. 1985. Consumer acceptance of steaks and roasts from Charolais crossbred bulls and steers. J. Food Sci. 50:165. Hornstein, I. 1971. Chemistry of meat flavor. Pp. 348- 363 in The Science of Meat and Meat Products, 2nd ea., J. F. Price and B. S. Schweigert, eds. San Francisco: W. H. Freeman. Jeremiah, L. E., G. C. Smith, and Z. L. Carpenter. 1971. Palatability of individual muscle from ovine leg steaks as related to chronological age and mar- bling. J. Food Sci. 35:45. Pearson, A. M. 1966. Desirability of beef its char
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