Interrelationships of breed type, USDA quality grade, cooking method, and degree of doneness on consumer evaluations of beef in Dallas and San Antonio, Texas, USA

The objective of this research was to evaluate the consumer controlled factors of cooking method and degree of doneness on top loin steaks from different USDA quality grades (Low Choice, High Select or Low Select) and breed-types (English, Continental European Cross or Brahman Cross). In addition, cities within the same region were evaluated for differences in consumer controlled factors and palatability responses. The in-home product test was conducted in Dallas and San Antonio, Texas, USA. Consumers (n=173) evaluated steaks for overall like (OSAT), tenderness (TEND), juiciness (JUIC), and flavor (FLAV) using 23-point hedonic scales. Respondents in Dallas cooked their steaks to higher degrees of doneness than did those in San Antonio. Outdoor grilling was the most frequently used method of cookery for steaks in both cities. Generally, consumers in San Antonio gave higher palatability ratings to Choice steaks and Dallas consumers gave higher ratings to Select steaks. The interactions of city×cooking method, breed-type×cooking method, and degree of doneness×cooking method were significant for all palatability attributes. In addition, the interaction of cooking method×quality grade was significant for TEND, JUIC, and FLAV. Warner-Bratzler shear (WBS) force was determined on a steak from each strip loin. Steaks from Continental European Cross cattle and Low Choice carcasses had the lowest WBS values. Differences in consumer preparation of beef top loin steaks present very unique challenges for the beef industry. Consumer information programs may serve a valuable role in connecting consumer perceptions with the preparation techniques needed to consistently achieve satisfaction.     

Dry versus wet aging of beef: Retail cutting yields and consumer sensory attribute evaluations of steaks from ribeyes, strip loins, and top sirloins from two quality grade groups

Top Choice (n=48) and Select (n=48) paired bone-in ribeye rolls, bone-in strip loins, and boneless top sirloin butts were assigned randomly to one of two aging treatments, dry or wet, and were aged for 14, 21, 28 or 35d. Cutting tests, performed to determine retail yields and processing times, showed dry-aged subprimals had lower total saleable yield percentages and increased processing times compared to wet-aged subprimals. Sensory and Warner-Bratzler shear evaluation was conducted to determine palatability characteristics. For the most part, aging treatment and aging period did not affect consumer sensory attributes. However, ribeye and top loin steaks from the Top Choice quality grade group received higher sensory ratings than their Select counterparts. For top sirloin steaks, no consumer sensory attributes were affected by aging treatment, aging period, or quality grade group.     

Effects of Electrical Stimulation, Aging, and Blade Tenderization on Hot-Boned Beef Psoas major and Triceps brachii Muscles

Forty-six steer carcasses were used to evaluate shear force values (SFV) for triceps brachii (TB) and psoas major (PM) muscles from sides assigned to three treatments: (1) chilled at 2–4°C for 48 hr (C); (2) hot boned 2 hr postmortem (HB); and (3) electrically stimulated 1 hr postmortem and hot boned 2 hr postmortem (ESHB). Some steaks were cut and frozen immediately after muscle excision or after 6 days of aging, and some were blade tenderized. HB and ESHB steaks had equal or smaller SFV relative to C after aging the TB and PM muscles; however, this was not true when TB steaks were cut after muscle excision. Electrical stimulation or blade tenderization did not improve HB.     

Determination of sensory, chemical and cooking characteristics of retail beef cuts differing in intramuscular and external fat

Top loin (TLS), top sirloin (TSS), and eye of round (EYS) steaks, and loin end (LRR) and blade end (BRR) rib, and eye of round (EYR) roasts were used to determine the effect of USDA quality grade, Choice or Select, external fat trim level, and internal temperature endpoint on sensory, chemical and cooking characteristics. Cuts cooked with external fat required slightly greater cooking times and had higher fat content in the lean than cuts cooked without external fat (p < 0.05). Regardless of quality grade or external fat trim, increasing internal temperature endpoint resulted in tougher, drier cuts with longer cooking times and greater cooking loss (p < 0.05). Choice TLS, TSS and LRR were higher (p < 0.05) in palatability than Select, but quality grade did not affect palatability of BRR, EYS or EYR.     

Effects of Electrical Stimulation, Hot Boning and Chilling on Bull Semimembranosus Muscle

Taste panel, Warner-Bratzler shear force (WBS) and cooking loss characteristics of semimembranosus (SM) muscles from thirty electrically stimulated and hot-boned (ESHB) or control young bull sides were evaluated. At 2 hr postmortem, muscles were excised from electrically stimulated sides and chilled in a tray or in a cardboard box. All control sides and ESHB muscles were chilled at 5–7°C until 24 hr postmortem; then 2–4°C for 24 hr. At 48 hr postmortem, steaks were cut, vacuum packaged and aged (2–4°C) for 4 days. Beef flavor was more intense for control steaks than for steaks from either ESHB chilling treatment. No other differences were noted.     

Effects of quality grade on the chemical, physical and sensory characteristics of Hanwoo (Korean native cattle) beef

The effects of quality grade (which reflects relative marbling) on the chemical, physical and sensory properties was investigated using Korean native cattle (Hanwoo) beef. Thirty-six Hanwoo cows were slaughtered and the carcasses were graded at 24h postmortem according to the Korean carcass grading system. The quality grade 1 (high quality), grade 2 and grade 3 (low quality) were based on the marbling score of longissimus dorsi (LD) muscles. The effects of quality grade on the meat quality parameters of beef LD muscle were assessed during aging. Loin-eye area, fat thickness and yield grade were all similar for the three quality groups. Mean lean color, fat color and maturity scores did not differ among quality grade groups (P>0.05). pH, Sarcomere length, WHC, collagen content, cooking loss, shear force and MFI were not affected by quality grade groups. Drip loss for grade 1 group was significantly lower than that for grade 3 groups (P<0.05). At initial tenderness evaluation of steaks, no differences among the three grades were observed; however, with additional days of storage, grade 1 steaks had higher tenderness score than grade 3 steaks (P<0.05). Increased postmortem aging time improved tenderness attributes regardless of quality groups. No significant differences were found among the quality grade groups for flavor (P>0.05). The grade 1 group had the highest juiciness score, and grade 3 groups had the lowest score (P<0.05), but postmortem aging did not influence flavor and juiciness. The quality grades were more strongly related to juiciness than tenderness or flavor.     

Effect of Freezing of Beef on Subsequent Postmortem Aging and Shear Force

Seventy-two steaks were used to determine effects of freezing postrigor muscle on aging of meat and shear force. Steaks were removed from each carcass 24 hr postmortem and aged at 2°C for 2 or 6 days; or frozen at ? 30°C for 27 days, thawed 24 hr and aged 2 or 6 days at 2°C. After aging, steaks were cooked and shear force determinations made. Aging of meat reduced shear force values; however, meat aged after freezing had lower (P < 0.03) shear force values than meat aged before freezing. Meat cooked after freezing had greater (P < 0.05) cooking losses. Freezing enhances the aging process and improves shear values of meat.     

Beef longissimus lumborum, biceps femoris, and deep pectoralis Warner-Bratzler shear force is affected differently by endpoint temperature, cooking method, and USDA quality grade

Effects of endpoint temperature, cooking method, and quality grade on Warner-Bratzler shear force (WBSF) of beef longissimus lumborum (LL), biceps femoris (BF), and deep pectoralis (DP) muscles were evaluated. Eighteen of all three subprimals were selected from USDA Select and 18 from USDA Choice (Certified Angus Beef) carcasses for the respective muscles. Muscles were vacuum packaged and held at 1 °C for 14 days, frozen (-29 °C), sawed into 2.54-cm thick steaks, vacuum packaged, and stored frozen until cooking. Thawed steaks were cooked by either a Magikitch'n(?) electric belt-grill (BG) at 93 °C, or a water-bath at 93 °C, to one of nine endpoint temperatures: 40, 45, 50, 55, 60, 65, 70, 75, or 80 °C. Belt-grill cooking was much faster and resulted in distinctly less cooking loss than water-bath cooking. Water-bath cooking resulted in higher (P<0.0001) Instron(?) WBSF (31.92 N) than BG (28.25 N) for LL. The combination of Select quality grade and higher endpoint temperatures resulted in higher (P<0.05) WBSF for LL. Two distinct phases of tenderization/toughening occurred for BF. Between 40 and 60 °C, WBSF decreased from 43.95 to 38.16 N (P<0.01), whereas between 60 and 70 °C, WBSF increased from 38.16 N to 44.44 N (P<0.05). Water-bath cooling resulted in higher (P=0.0001) DP WBSF (71.12 N) than BG (59.25 N). The DP had a distinct (P<0.0001) decline in WBSF between 45 and 65 °C, irrespective of the cooking method, followed by an increase between 65 and 80 °C (P<0.01).     

EFFECT OF PRESSING ON MOISTURE LOSS AND SENSORY PROPERTIES OF BEEF

Paired halves of top round (Semimembranosus and Adductor muscles) sub-primals were removed from each of ten, USDA Choice, approximately 272 kg steers, freezer wrapped, frozen, and stored at -24° C for approximately 1 month. Following freeze-tempering, each primal was divided longitudinally with one half being pressed at 344 Newtons/cm² to a specified shape in a Bettcher Model 70 Press, while the other half served as nonpressed control. Moisture loss and sensory properties were determined for 2.54 cm thick steaks. No significant differences were found in juiciness, flavor or Kramer shear values between pressed and non-pressed top round steaks, however, sensory tenderness scores were lower (P < 0.05) for steaks that were pressed than for those that were not pressed. Holding steaks at 2° C for 0, 1, 2, or 3 days did not significantly alter Kramer shear or sensory panel evaluations. Cooking loss, drip loss and total loss were not affected by pressing. Drip loss was lower (P < 0.05) and cooking loss was higher (P < 0.05) for steaks held one day at 2° C than for steaks held 2 or 3 days at 2° C. When drip loss and cooking loss were combined (total loss) there was no difference among the four storage times. Drip loss following portion cutting could result in a problem in fresh merchandising of freeze-tempered cuts.     

不同排酸时间对呼伦贝尔肉羊宰后品质的影响

研究呼伦贝尔羊不同部位肌肉,在排酸库吊挂排酸0、1、2、3、4 d,并分别进行冷冻后肉品质的变化情况,探讨肌肉宰后成熟机理,确定羊肉最佳排酸时间。结果表明,在排酸期间,羊肉pH值、蒸煮损失率、剪切力值差异显著(P0.05)。pH值呈先下降后上升趋势,蒸煮损失率和剪切力值则呈先上升再下降趋势,排酸2 d的剪切力值最低、蒸煮损失率较低、羊肉品质最佳。     

SENSORY AND PHYSICOCHEMICAL CHARACTERISTICS OF PRECOOKED, MICROWAVE-REHEATABLE STEAKS

Precooked, small-portion, microwave-reheatable steaks were processed from three grades (US Choice, US Select⁺, and US Select^-) of top round beef. Marinated/tenderized samples were compared to nonmarinated/nontenderized controls from each grade. Untrained consumers (n=102) rated the sensory attributes, overall acceptability, and willingness to purchase the steaks at various settings (fast food, restaurant/cafeteria, supermarket). Marination and tenderization improved the sensory attributes, overall acceptability, and consumers' willingness to purchase the steaks, regardless of the grade from which they were prepared. Marinated/tenderized steaks from the US Select grade were more acceptable than nonmarinated/nontenderized steaks from the US Choice grade. Marinated/tenderized steaks from each grade required less force and energy to cut, contained about 3% more moisture and 0.5% less fat, and had more cooking loss than their control counterparts. However, consumers rated the marinated/tenderized products as being more tender, juicy, flavorful and more acceptable overall than controls.     

EFFECT OF POSTMORTEM CONDITIONS ON CERTAIN CHEMICAL, MORPHOLOGICAL AND ORGANOLEPTIC PROPERTIES OF BOVINE MUSCLE

Paired sides from U.S. Choice grade beef were aged immediately after slaughter at 2 and 16°C. Samples were removed from longissimus and semitendinosus at slaughter and at 1, 3 and 7 days postmortem for ATPase assay, phase microscopy, shear and organoleptic evaluation. Rib steaks from sides aged at 16°C for 1-day postmortem were as tender as steaks from sides aged at 2°C for 7 days postmortem. Flavor development of rib steaks also was more rapid at 16°C than at 2°C. Tenderness of semitendinosus steaks was improved by aging sides at 16°C; the difference in improvement of tenderness of semitendinosus, however, was not as great between 2°nd 16° as it was for rib steaks. Ca⁺⁺, Mg⁺⁺ and EGTA-modified ATPase activity of myofibrils from both muscles increased with postmortem time, with myofibrils from muscles held at 16°C having slightly higher ATPase activity than myofibrils from muscles held at 2° Increased EGTA-modified ATPase activity was indicative of loss of calcium sensitivity of the myofibril. Sarcomeres of myofibrils from longissimus were longer at 1-day postmortem than those from at-death longissimus and they remained essentially unchanged during the remainder of postmortem aging; however, tenderness improved at 16°C for 1 day and at 2°C for 3 days. Also greater fragmentation of myofibrils from longissimus postmortem aged at 16°C for 1 day and at 2°C for 3 days was observed, suggesting that the rate of myofibril fragmentation is an important factor in tenderization.     

Evaluation of the Tenderness of Beef Top Sirloin Steaks

Top sirloin butts and strip loins were obtained from both sides of 20 U.S. Choice beef carcasses and cut into six steaks (2.54 cm thick). These steaks were assigned randomly to one of six aging treatments (0, 7, 14, 21, 28 or 35 days). Top sirloin steaks were less tender and more variable in tenderness than top loin steaks. This difference in tenderness appeared to be due to higher amounts of collagen in top sirloin steaks and a tendency toward lower collagen solubility, shorter sarcomere length and higher (less tender) fragmentation index.     

Dry versus wet aging of beef: Retail cutting yields and consumer palatability evaluations of steaks from US Choice and US Select short loins

Paired beef short loins from US Choice (n=48) and US Select (n=48) carcasses were assigned to be dry or wet aged for 14, 21, 28 or 35d. After aging, short loins were processed to determine retail yields and processing times. Upon completion of cutting tests, steaks were served to consumers to assess palatability characteristics. Retail cutting tests showed that dry-aged short loins had reduced yields and increased cutting times when compared to wet-aged short loins. Consumers were unable to determine differences between dry- and wet-aged steaks and for aging periods; however, USDA quality grade had a significant impact on consumer perception of palatability attributes.     

Fatty acid and proximate composition of raw and cooked retail cuts of beef trimmed to different external fat levels

Beef steaks and roasts from US Choice, US Select and US Standard quality grades were used to determine the effect of 0·64 cm external fat trim and zero (no external fat) trim on the proximate and fatty acid composition of cooked cuts of beef. Total fat percentage of the cooked lean was affected by external fat trim, quality grade, cooking and degree of doneness. Fat retention percentages were higher in tenderloin and clod samples when cooked with external fat attached than when cooked with no external fat. No consistent effect of fat trim level or degree of doneness on the percentage of specific fatty acids was observed.     

牛肉排酸成熟过程中的品质变化

为探究排酸成熟过程中肉类品质的变化,以牛肉为研究对象,测定排酸1～7 d肉样的硬度、保水性、pH值、肌原纤维小片化指数（myofibril fragmentation index,MFI）、菌落总数、大肠菌群数以及排酸1、3、5d时肌原纤维的超微结构。结果表明：牛肉排酸3 d时出现最大僵直期,硬度达到最高,保水性达到最低,pH值降到最低值5.56;随着解僵及成熟的进行,牛肉嫩度、保水性回升,排酸7 d时pH值回升到5.84,达到排酸成熟肉标准（5.8～6.2）;排酸1 d时,肌原纤维的Z线、粗细丝清晰可见,随着肌原纤维小片化程度的不断加深,排酸5d时,Z线变得模糊,几乎消失,成为晕染状,几何构型发生明显变化。上述结果表明,牛肉在0～4 ℃条件下排酸成熟需要7d,前3 d是排酸的关键时期。     

RESTRUCTURED STEAKS MANUFACTURED FROM PRE-RIGOR BEEF OF VARYING PARTICLE SIZE

Raw materials were removed from U.S. Choice Yield Grade 3 beef fore-quarters 1 h postmortem. Samples were flaked with an Urschel Comitrol 3600 as three sizes; small (head opening = 3.0 mm), medium (head opening = 6.1 mm) and large (head opening = 9.9 mm). Each flake size was formulated with 1.0% NaCl and 0.25% sodium tripolyphosphate (STP), converted into 25 mm thick restructured steaks and packaged. Subjective evaluations were conducted after 0 and 56 days of frozen storage for color, cohesiveness, muscle cut resemblence and overall appearance. A 7-member panel evaluated tenderness, juiciness, connective tissue amount and flavor. Objective measurements included Hunter Color values, shear force, percentage cooking loss and Thiobarbituric Acid (TBA) values. Small flake particles contributed to improved color, cohesiveness and overall appearance. Particle size had minimal effects on muscle cut resemblence, cooking loss, shear values and all sensory attributes. Color degradation and oxidative rancidity increased with storage time.     

Dry and Wet Aging Effects on Palatability Attributes of Beef Loin and Rib Steaks from Three Quality Grades

Twenty Prime and 20 Choice IMPS 107 ribs, and 20 Prime, 20 Choice and 20 Select IMPS 179 short-cut strip loins were equally divided between dry aging and wet aging treatments. Steaks and Toasts, aged for 21 days, were evaluated by trained and consumer panels for sensory attributes. Some statistically significant palatability differences were observed due to treatment, grade and cut of loin and rib steaks by the trained panel, but no statistical differences in palatability attributes of loin steaks were detected by consumer panelists. A major difference between aging treatments, however, was the greater shrink and trim loss associated with dry aging.     

Effect of freezing on sensory quality, shear force and water loss in beef M. longissimus dorsi

The objective of this study was to determine how sensory quality, shear force and water loss differ between beef stored either chilled or frozen before cooking. Meat tenderness was analysed instrumentally and sensorially using both a consumer panel and a semi-trained panel. Both M. longissimus dorsi (LD) from eight young Holstein bulls were cut into eight samples, weighed, vacuum packed and aged at 4 °C for 2, 7 or 14 days. After ageing, the frozen samples were kept at −20 °C prior to heat treatment. Water holding capacity was recorded as purge or thawing loss and cooking loss or as combined loss. Sensory analyses were performed on samples aged 7 days. Peak force values declined with ageing time and freezing. Frozen meat aged 2 days had the same peak force values as chilled meat aged 7 days. Total energy was the same for both treatments at day 2 and 7, whereas at day 14 frozen samples showed significantly higher values than chilled samples. The sensory panel experienced the chilled meat to be more tender, juicier and having a more intense meat taste than the frozen meat, whereas the consumers could not find any significant difference in degree of liking. Water holding capacity was lower for the frozen samples. The results indicate that conclusions from studies concerning sensory quality of beef will depend on whether the meat has been kept chilled or frozen before testing.     

EFFECTS OF DIFFERENT AGING PROCEDURES ON THE PALATABILITY OF BEEF

Ten pairs of beef strip loins were obtained 48 h postmortem from ten good grade beef carcasses. Three steaks (2.5 cm thick) were cut from the loin end of each strip loin and the remaining portion retained as the subprimal. Steaks and subprimals were aged for 7 days at 2°C in the following treatments: polyvinyl chloride overwrapped steaks (PVC-ST), vacuum packaged steaks (VP-ST), vacuum packaged subprimals (VP-SP), and subprimals held in air (Air-SP). After aging of the subprimal, 3 additional steaks were cut for evaluation. The steaks from all treatments were evaluated for palatability and chemical characteristics. Palatability characteristics did not differ significantly (P > 0.05) between treatments with the exception of the off-flavor intensity of PVC-ST which was higher (P < 0.05) than other treatments. Warner-Bratzler shear values were similar for all treatments. No significant differences (P > 0.05) were observed between treatments for percent moisture, percent lipid, pH or TBA number. The results of this study indicate that aging method (air or vacuum) or type of cut (steaks or subprimals) had little effect on the palatability attributes or chemical characteristics of the beef strip loins.