In the present study, a national consumer evaluation was conducted for beef tenderness on USDA Select strip loin steaks of known Warner-Bratzler shear (WBS) force values, ranging from tough (> 5.7 kg) to tender ( or = 86% consumer acceptability. Consumer acceptability for tenderness decreased from 86% at 4.3 kg for a "slightly tender" rating to 59% at 4.9 kg for a "slightly tough" rating. Data from the present study suggested that consumer WBS tenderness values of 4.9 kg would result in 100, 99, 94, 86, and 25% customer satisfaction for beef tenderness, respectively. Seventy-eight percent of the consumers would purchase steaks if the retailer guaranteed them to be tender. The retail steak value differences found in this study would result in the opportunity for a premium to be paid for a guaranteed tender ( 5.7 kg) classification. A premium of $66.96 could be paid to the tender classification carcasses vs the tough (> 4.9 kg) classification carcasses, and a premium of $36.58 could be paid for the tender classification carcasses vs the intermediate (> 3.0 to < 4.6 kg) classification carcasses. Results from the present study show that consumers can segregate differences in beef tenderness and that consumers are willing to pay more for more-tender beef.

Consumer thresholds for establishing the value of beef tenderness

A fresh look at meat flavor

To determine the average tenderness and sensory ratings of beef subprimal cuts sold in retail cases across the United States, retail cuts were purchased through typical retail outlets in 14 metropolitan cities and transported to Texas A&M University for sensory and Warner-Bratzler shear analysis. The overall mean shear force for all cuts was 3.65 kg, and the mean shear force values for chuck, rib, loin, and round cuts were 3.72, 3.36, 3.17, and 4.31 kg, respectively. No difference (P greater than .05) in tenderness was detected among the cuts from the rib. Mean palatability ratings and shear force values of top loin steaks were similar to those of rib cuts. Top sirloin steaks were tougher (P less than .05) and received the lowest sensory ratings compared with other loin cuts. Approximately two to three times as many round and chuck steaks had shear force values in excess of 4.6 kg compared with their roast counterparts. In all cases, roasts tended to be more tender than steaks from the same subprimal source. USDA Choice chuck retail cuts, compared to Select and No-roll chuck cuts, had approximately 10% fewer cuts with shear force values in excess of 4.0 kg. More work is needed to improve meat tenderness, primarily for retail cuts from the round and chuck primals. Future research must investigate the interaction of antemortem and postmortem factors associated with variation in beef tenderness.

National beef tenderness survey.

Intramuscular adipose tissue from the fifth-eighth thoracic vertebrae region of the longissimus dorsi muscle, and portions of the overlying subcutaneous adipose tissue, were obtained at 16 and 18 months of age from Angus steers fed ad libitum either a corn silage (low energy) or ground corn (high energy) diet. Carcass weight, backfat thickness, and kidney, pelvic and heart fat were significantly greater in the steers fed the high energy diet; however, there were no significant differences in marbling scores between diet groups. Additionally, feeding steers the high energy diet did not result in differences in adipocyte diameter or number of adipose cells per gram tissue in either adipose tissue depot. Intramuscular adipocytes had a peak diameter (the diameter represented by the greatest number of cells) of 104 +/- 2 microns; peak diameter in subcutaneous adipose tissue was 141 +/- 5 microns. The activities of ATP-citrate lyase and NADP-malate dehydrogenase increased with age in the subcutaneous adipose tissue; feeding steers the high energy diet increased enzyme activities further. Age and diet had no effect on enzyme activities in intramuscular adipose tissue. A similar pattern was observed for the incorporation of lipogenic precursors into fatty acids. Acetate provided 70-80% of the acetyl units to in vitro lipogenesis in subcutaneous adipose tissue, but only 10-25% in intramuscular adipose tissue. Conversely, glucose provided 1-10% of the acetyl units in subcutaneous adipose tissue, but 50-75% in the intramuscular depot.(ABSTRACT TRUNCATED AT 250 WORDS)

Relative contributions of acetate, lactate and glucose to lipogenesis in bovine intramuscular and subcutaneous adipose tissue.

Biological tenderness differences between longissimus muscles (LM) from Bos indicus and Bos taurus breeds were evaluated. Steers and heifers of Hereford x Angus (H x A, n = 10), 3/8 Sahiwal x H, A or H x A (3/8 SAH, n = 6) and 5/8 Sahiwal x H, A or H x A (5/8 SAH, n = 11) crosses were utilized. Muscle temperature and pH were monitored every 3 h for the first 12 h and at 24 h. Samples were obtained within 1 h and at 24 h postmortem from the LM for determination of calcium-dependent protease (CDP) -I and -II and CDP inhibitor (INH) activities. At 1 and 14 d postmortem, LM samples were removed for determining cathepsin B and B + L activity, soluble and total collagen, sarcomere length, muscle-fiber histochemistry, shear force and sensory-panel traits. Data were analyzed using least squares procedures with fixed effects of breed cross, sex and their interaction. No significant breed cross effects were observed for carcass traits or rates of pH and temperature decline. Steaks from H x A had lower (P less than .05) shear-force values and higher (P less than .05) sensory scores for tenderness at 1 and 14 d postmortem than steaks from 3/8 and 5/8 SAH. Correspondingly, 5/8 SAH had lower (P less than .05) myofibril fragmentation indices than H x A at 1, 3, 7 and 14 d postmortem. Breed cross effects were not significant for sarcomere length, fiber types, soluble and total collagen, cathepsin B and B + L specific activity, CDP-I and -II activity and INH activity within 1 h postmortem. However, INH total activity/100 g of muscle was greater (P less than .01) at 24 h postmortem for 5/8 SAH (208.8 +/- 14.8) and 3/8 SAH (195.6 +/- 19.3) than for H x A (136.3 +/- 14.9). For H x A, SDS-PAGE revealed that by d 1 desmin had been subjected to proteolysis, and by d 14 desmin could not be detected, but a 30,000-dalton component was clearly evident. However, in 5/8 SAH, desmin remained visible at d 14 without a 30,000-dalton component appearing. This reduced protein hydrolysis may account for less tender meat in SAH; INH apparently influences this process.

Evaluation of attributes that affect longissimus muscle tenderness in bos taurus and bos indicus cattle

An in-home beef study evaluated consumer ratings from moderate-to-heavy beef users as influenced by cut (top loin, top sirloin, and top round steaks), USDA quality grade (Top Choice, Low Choice, High Select, and Low Select), and city (Chicago, Houston, Philadelphia, and San Francisco). Consumers (n = 2,212) evaluated each steak for overall like (OLIKE), tenderness (TEND), juiciness (JUIC), flavor desirability (DFLAV), and flavor intensity (IFLAV) using 23-point hedonic scales (23 = like extremely, extremely tender, extremely juicy, like extremely, and an extreme amount of flavor; 1 = dislike extremely, not at all tender, not at all juicy, dislike extremely, and no flavor at all). A USDA grade x cut interaction existed for OLIKE (P .05) able to distinguish OLIKE differences between Low Choice and High Select or between High Select and Low Select. For OLIKE, top sirloin was rated intermediate (P .05) USDA quality grade differences. For OLIKE, top round was the lowest-rated (P < .05) cut. However, consumers preferred (OLIKE, P < .05) Top Choice to the other USDA grades offered. Grade and city interacted to affect TEND, JUIC, DFLAV, and IFLAV. The cut x city interaction was significant for all palatability attributes. Cut and city affected customer satisfaction more than USDA quality grade. Tenderness and flavor were important and equal contributors to OLIKE, r = .85 and r = .86, respectively.

Beef customer satisfaction: role of cut, USDA quality grade, and city on in-home consumer ratings.

The objective of this research was to evaluate the consumer-controlled factors of cooking method and degree of doneness on Top Choice, Low Choice, High Select, and Low Select top sirloin steaks. The in-home product test was conducted in Chicago, Houston, Philadelphia, and San Francisco. Consumers (n = 2,212) evaluated each top sirloin steak for overall like (OLIKE), tenderness (TEND), juiciness (JUIC), flavor desirability (DFLAV), and flavor intensity (IFLAV) using 23-point hedonic scales. Top sirloin steaks, regardless of city, were consistently cooked to well done or higher degrees of doneness. Dry-heat methods such as outdoor grilling, broiling, and indoor grilling were the most frequent cooking methods used. Four significant interactions existed for OLIKE: USDA quality grade x cooking method (P = .02), city x cooking method (P = .0001), city x degree of doneness (P = .01), and cooking method x degree of doneness (P = .009). Greater differences were found between cooking methods within USDA quality grade than between USDA quality grades within cooking method. Consumers in Houston rated steaks cooked by outdoor grilling higher than those from the other cities, and steaks cooked by indoor grilling were rated the highest among all cooking methods by consumers in Chicago. In Chicago, steaks cooked to more advanced degrees of doneness tended to receive higher ratings, but few differences between degrees of doneness in the other three cities were detected. For outdoor grilling, broiling, and pan-frying, the trend was for OLIKE ratings to decline as degree of doneness increased. The lowest customer satisfaction ratings tended to be given to top sirloin steaks cooked to more advanced degrees of doneness, and consumers most frequently cooked steaks to at least the well done stage. Consumer information programs or the development of postmortem techniques that would ensure acceptable palatability of top sirloin steaks may need to be developed.

Beef customer satisfaction: cooking method and degree of doneness effects on the top round steak.

Trained sensory panel ratings and Warner-Bratzler shear force (WBS) values from the Beef Customer Satisfaction study are reported. Carcasses were chosen to fit into USDA quality grades of Top Choice (upper two-thirds of USDA Choice), Low Choice, High Select, and Low Select. A trained, descriptive attribute panel evaluated top loin, top sirloin, and top round steaks for muscle fiber tenderness, connective tissue amount, overall tenderness, juiciness, flavor intensity, cooked beef flavor intensity, and cooked beef fat flavor intensity. Four steaks from each of the three cuts from each carcass were assigned randomly to one of four cooking endpoint temperature treatments (60, 65, 70, or 75 degrees C) for WBS determination. For all trained panel measures of tenderness and WBS, regardless of USDA quality grade, top loin steaks were rated higher than top sirloin steaks, which were rated higher than top round steaks (P < 0.05). There were significant interactions between USDA quality grade and cut for most of the trained sensory panel traits: USDA quality grade influenced ratings for top loin steaks more than ratings for top round steaks or top sirloin steaks. Three interactions were significant for WBS values: USDA quality grade x endpoint temperature (P = 0.02), USDA quality grade x cut (P = 0.0007), and cut x endpoint temperature (P = 0.0001). With the exception of High Select, WBS values increased (P < 0.05) for each grade with increasing endpoint temperature. Choice top loin and top round steaks had lower (P < 0.05) WBS values than Select steaks of the same cut; however, only Top Choice top sirloin steaks differed (P < 0.05) from the other USDA grades. As endpoint temperatures increased, WBS values for top sirloin steaks increased substantially compared to the other cuts. When cooked to 60 degrees C, top sirloin steaks were closer to top loin steaks in WBS values, when cooked to 75 degrees C, top sirloin steaks were closer to top round steaks in WBS values. Simple correlation coefficients between consumer ratings and trained sensory muscle fiber tenderness, connective tissue amount, overall tenderness, juiciness, flavor intensity, and cooked beef fat flavor were significant (P < 0.05), but values were low. While relationships exist between consumer and trained sensory measures, it is difficult to predict from objective data how consumers will rate meat at home.

J. D. Tatum

Papers

Beef customer satisfaction: role of cut, USDA quality grade, and city on in-home consumer ratings.

Beef customer satisfaction: cooking method and degree of doneness effects on the top round steak.

Beef customer satisfaction: trained sensory panel ratings and Warner-Bratzler shear force values.

Carcass Characteristics, Time on Feed and Cooked Beef Palatability Attributes

Interrelationships Between Marbling, Subcutaneous Fat Thickness and Cooked Beef Palatability