Quality of Restructured Steaks: Effects of Days on Feed, Fat Level, and Cooking Method

Top rounds from steers fed grain 0, 28, or 56 days were flaked and formed into restructured steaks containing 15, 20, or 25% fat. Steaks were cooked on a browning dish in a microwave oven or broiled. Microwave-heated steaks appeared more well done, were less tender, released less moisture, and had greater cooking losses and penetration hardness and chewiness than broiled steaks. As fat level increased, tenderness, moisture release, and greasiness increased. Length of time on grain influenced Warner-Bratzler shear values but did not affect sensory scores. Results of the study suggest that the use of meat from grain-fed animals in the production of restructured steaks is feasible.     

Tenderization of Meat with Ginger Rhizome Protease

Beef steaks and sliced beef marinated with different levels of crude ginger extract were evaluated for the tenderness and structural changes. A significant (P<0.05) enhancement of tenderness with increasing amounts of ginger extract was observed at low levels of extract (0, 0.05, 0.1, and 0.2 mL/6.5 cm² for the steaks; 0, 0.25, 0.5, and 1 mL/lOOg for the sliced beef), whereas further improvement of tenderness at more than 0.2 mL/6.5 cm² or 1 mL/lOOg was minimal. Electron microscopy of the treated beef revealed the preferential degradation of thin filaments in the I-bands, resulting in extensive fragmentation of myofibrils. Thus, ginger rhizome protease is an effective meat tenderizer and the tenderization is achieved through preferential degradation of thin filaments.     

A Modified Sample Preparation Method for Measuring Meat Tenderness by the Kramer Shear Press

Tenderness of steaks and diced meat was evaluated by sensory panel, Wainer-Bratzler shear press and modified Kramer shear press which employed coarse grinding of meat through a food chopper and shearing duplicate 20g samples of ground meat by the Kramer shear device. Highly significant (P < 0.01) correlation coefficients of -0.88 and -0.80 were obtained for the steaks and diced meat, respectively, between sensory score and modified Kramer shear value. A correlation value of 0.90 between W-B shear values and modified Kramer shear values was also highly significant. The results strongly indicate that the modified sample preparation method is a simple, reliable and versatile method which is less influenced by experimental variables and is applicable to almost any kind of meat products.     

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.     

MECHANICAL MEASUREMENTS OF MEAT TENDERNESS USING THE NIP TENDEROMETER

Abstract. A series of evaluations to compare the sensory panel ratings for tenderness with the Warner-Bratzler shear force and the Nip Tenderometer values was conducted using 150 pork chops, 239 lamb chops and 674 beef steaks. The Warner-Bratzler shear force values were more highly correlated with panel tenderness ratings than were the Nip Tenderometer readings for samples of pork, lamb and beef tested after cooling to room temperature (23 °C). Nip Tenderometer determinations on hot samples of beef (75 °C) were more closely related to panel tenderness ratings ( r =— 0.80) than were Nip Tenderometer readings ( r =— 0.58) or shear force values ( r =— 0.63) obtained on cold samples (23 °C). The combined advantages of ease and speed of application, correlation with sensory panel ratings and the demonstrated accuracy in identifying 'tough' vs 'tender' steaks suggest that the Nip Tenderometer has potential as an objective means for evaluating meat tenderness.     

Effect of Muscle Type and Mixing Time on Sectioned and Formed Beef Steaks

Sectioned and formed beef steaks were manufactured from Standard beef rounds, Choice beef plates and Choice, Yield Grade 3, Meat Buyers Guide (126) 3-piece chucks. Replicates were established by slaughter day. A trained sensory panel evaluated juiciness, flavor, tenderness, and connective tissue residue. Color scores were assigned to steaks from each treatment. Instron Kramer shear was used to evaluate tenderness and thiobarbituric acid (TBA) was used to measure rancidity. Reflectance spectrophotometry indicated oxymyoglobin and metmyoglobin content. Mixing improved tenderness (P < 0.01) by 20% after 18 min. An 8% improvement occurred after 6 min. Mixing increased sensory juiciness (P < 0.01) and flavor (P < 0.05). Subjective and objective measures indicated that steaks processed from chuck were less tender (P < 0.01). Cooking yields improved linearly (P < 0.01) due to mixing. The TBA values were low and did not change due to treatment or after 90 days storage at –30°C. Subjective and objective color analyses indicated highly desirable color for fresh beef. Steaks processed from chuck meat were higher in percent metmyoglobin.     

USE OF MECHANICAL TENDERIZATION TO INCREASE THE TENDERNESS OF BULLOCK BEEF1

The biceps femoris (BF), semimembranosus (SM) and longissimus dorsi (LD) muscles from bullocks and steers were passed through a mechnical tenderizer zero (OX), once (1X), twice (2X) or three times (3X). All three muscles were evaluated for cooking loss, cooking time and textural properties on an Instron Universal Testing machine. In addition, LD muscle steaks were presented to a sensory panel for evaluation. The passing of the SM and LD muscles through a mechanical tenderizer one or two times decreased peak load and fail energy and increased peak elongation and fail load values. LD steaks from bullocks not passed through the mechanical tenderizer (OX) were least esy to fragment, had the most detectable connective tissue and had lowest overall tenderness ratings. Passing bullock beef once (1X) through a mechanical tenderizer improved palatability ratings to a level comparable to untenderized steer beef.     

Cooking Temperature, Bird Type, and Muscle Origin Effects on Sensory Properties of Broiled Emu Steaks

Trained sensory panel scores and Warner-Bratzler shear values (WBS) of emu meat cooked to three end-point temperatures (60, 66, and 75°C), obtained from two bird types (breeder quality, BQ; and nonbreeder quality, NBQ), and from five carcass locations were determined and compared in three studies. NBQ birds had obvious conformational defects. Full rumps and inside drums broiled to 60°C were more tender and juicy than those broiled to 66 or 75°C (P<0.05). Cooking temperature did not affect meat-flavor intensity (p>0.05). BQ vs NBQ sources had no effect on tenderness or juiciness (p>0.05). Differences in tenderness, juiciness, meat-flavor intensity and WBS were found among the five meat cuts (P<0.05).     

Vacuum Mixing Influence on Characteristics of Sectioned and Formed Beef Steak

Choice, Yield Grade 3 chucks were purchased vacuum packaged within 48 hr of slaughter. They were randomly allocated to treatments of vacuum or no vacuum mixing and 6 or 12 min mixing periods. The meat was formulated into sectioned and formed steaks. A trained sensory panel evaluated all samples and color scores were assigned to each steak. Instron adhesion measured binding of meat pieces, Kramer shear indicated tenderness, mg exudate/cm² measured binding proteins. Reflectance spectrophotometry measured oxymyoglobin and metmyoglobin. Electrophoresis was used to separate and quantitate individual myofibrillar proteins. Sensory analyses indicated vacuum processed steaks had superior bind (P < 0.01) while juiciness, flavor and tenderness remained unchanged. Instron analyses indicated no difference in tenderness or bind strength due to vacuum. Subjective color analyses indicated less desirable color for vacuum mixing (P < 0.05) and the amount of oxymyoglobin and metmyoglobin were not changed due to treatment. There was less exudate at the bond site for vacuum mixing (P < 0.01). Sarcoplasmic and myofibrillar proteins were similar over vacuum treatment.     

Effect of Storage and Cooking on Qualities of Loin and Top-Wound Steaks

SUMMARY— Boneless, trimmed steaks (U. S. Good) from the longissimns dorsi muscle (loin) and semimembranosus muscle (top-round) and conventionally cut loin steaks were removed 8 days post-mortem, quick-frozen and stored at −18°C to −23°C for three storage periods, 0, 6, and 9 months. Steaks were sampled at each storage period and cooked to an internal temperature of 70°C in a microwave oven and electric range. Quality was evaluated by chemical tests, sensory evaluations and cooking loss data.
Storage up to 6 months had little effect on loin steaks with the exception of TBA values, but significant changes occurred between 6 and 9 months. Loin steaks had increased cooking losses and decreased juiciness scores, percent moisture, and juice content. TBA values increased with each storage period. Top-round steaks at the 9-month period showed a decrease in collagen content and juiciness and flavor scores, and an increase in TBA values. Storage up to 9 months did not influence tenderness in either muscle.
Conventionally broiled loin steaks had higher palatability scores, cooking losses, percent moisture, percent total proteins, and lower percent total lipids than did microwave cooked loin steaks. Electronically cooked top-round steaks had higher total cooking losses and percent total proteins and lower collagen values than did conventionally roasted top-round steaks.
The qualities of boneless loin steaks did not differ significantly from those of conventionally cut loin steaks when compared at each storage period.     

Injection of marinade with actinidin increases tenderness of porcine M. biceps femoris and affects myofibrils and connective tissue

BACKGROUND: Marination of beef muscles with brine solutions containing proteolytic enzymes from fruit extracts has been shown to tenderize meat. However, the effect of marination with actinidin on tenderness of pork muscles has not been investigated. Tenderness and eating quality of porcine M. biceps femoris was investigated by Warner–Bratzler (WB) shear test and sensory evaluation after injection of brine containing up to 11 g L^?1 actinidin‐containing kiwi fruit powder and 2, 5 or 9 days of storage. RESULTS: Actinidin decreased WB shear force, increased tenderness and did not affect flavour and juiciness. Injection of 2.8 g L^?1 actinidin powder and storage for 2 days resulted in WB shear force values similar to control samples stored for 5 or 9 days. In samples injected with 10 g L^?1 actinidin powder, degradation of desmin and percentage of heat‐soluble collagen (P < 0.05) increased compared to control samples. Myofibrillar particle size tended to decrease (P < 0.1) with increasing actinidin concentration. No major changes were observed by proteome analysis. Atomic force microscopy showed actinidin‐induced damage of endomysium surrounding isolated single muscle fibres. CONCLUSION: Our results indicate that actinidin tenderizes pork M. biceps femoris by affecting both the myofibrils and connective tissue. Copyright © 2009 Society of Chemical Industry     

Comparison of clam-shell cookers and electric broilers and their effects on cooking traits and repeatability of Warner-Bratzler shear force values

Clam-shell (CS) type cookers were investigated as an alternative cookery method for objective tenderness evaluations of beef strip loin steaks. This study was conducted in two phases: Phase I determined the most effective clam-shell cooking temperature setting (Low, Medium or High) and Phase II compared the repeatabilities of cooking traits and Warner-Bratzler shear (WBS) values from steaks cooked on electric broilers (EB) to steaks cooked on CS. Data from Phase I showed that cooking time was reduced (P<0.05) substantially for steaks cooked on CS with the shortest cooking times associated with the highest temperature settings. EB steaks had higher cooking losses compared with CS steaks (P<0.05), while the CS-Low temperature setting yielded the lowest cooking losses. WBS values did not differ except for steaks cooked on the CS-Medium setting, which were lower (P<0.05) than EB and CS-Low cooked steaks. CS-High setting was determined to be the optimum temperature setting for CS cooking because it required the least amount of time to cook and produced WBS values that were not different from steaks cooked on EB. Therefore, repeatability of cooking traits and WBS values of CS-High and EB were investigated in Phase II. Data from Phase II showed similar trends for cooking traits and WBS values between CS and EB cooked steaks as were observed in Phase I. Repeatabilities for WBS values were higher for steaks cooked on CS (R=0.86) compared with EB (R=0.41). The CS method appears to be an acceptable alternative to EB for cooking steaks used in meat tenderness research.     

SENSORY ATTRIBUTES AND RETAIL DISPLAY CHARACTERISTICS OF PASTURE- AND/OR GRAIN-FED BEEF AGED 7,14 OR 21 DAYS

Strip loin steaks were removed from steer carcasses fed on; (1) wheat-rye-grass pasture only, (2) wheat-ryegrass pasture followed by grain feeding, or (3) grain feeding. The steaks were analyzed for sensory panel attributes, Warner-Bratzler shear force and storage and display life. Steaks from pasture-fed steers were similar (P>.05) to steaks from grain-fed steers in sensory tenderness and connective tissue amount. Steaks from pasture-fed steers had similar (P>.05) shear force values to steaks from grain-fed steers. Off flavor incidence was greater (P<.05) in steaks from steers on pasture only than from steers on grain and pasture/grain. No differences (P>.05) due to treatment were found in visual color and discolor scores. The C.I.E. a* values showed steaks from steers fed pasture only and pasture/grain retained higher (P<.05) redness values than steaks from steers grain-fed during the 10 day display period. The results indicate pasture finishing systems could be as effective in maintaining beef tenderness and color shelf-life characteristics as grain finishing systems.     

The Paradox of Toughening During the Aging of Tender Steaks

ABSTRACT:  Aging is the practice of holding meat at low temperatures to improve tenderness that is the most important sensory attribute affecting consumer acceptability of beef. Because of the inconsistencies in measured tenderness changes during aging, we attempted to look at the relationship between aging and initial tenderness irrespective of animal age, genetics, or nutritional status. Cattle were selected to represent a full range of quality grades from Utility to Prime. Steaks from these cattle were aged in vacuum bags for 0, 7, or 14 d and tenderness characteristics were assessed. Steaks were cut from the frozen loin sections, thawed, and cooked on open hearth grills to 70 °C. Sensory evaluation was completed by a 6-member trained sensory evaluation panel and Warner-Bratzler shear was determined. The average shear values decreased with aging time across most grade categories; however, improvement was not uniform. Steaks from Utility grade cattle improved the most while steaks of other grades improved less. Shear values overlapped a great deal across all grades and to gain a better understanding of changes with aging, steaks were grouped based on initial shear value differences of 1 kg. Shear value of the toughest steaks decreased the most during aging (−36%), while those with the lowest shear values increased (16%). The same pattern emerged when steaks were grouped by initial tenderness. These results suggest that initially tough steaks will benefit from aging while very tender steaks may be adversely affected.     

THE MEASUREMENT OF SHEAR FORCE BY CORE LOCATION IN LONGISSIMUS DORSI BEEF STEAKS FROM FOUR TENDERNESS GROUPS1

Sixty-four longissimus muscle steaks obtained from carcasses of Bos indicus or Bos taurus cattle were used to evaluate shear force requirements from the dorsal to lateral portion of the steak. Steaks were assigned to one of four tenderness groups based on preliminary analysis of shear force requirements of adjacent steaks used in the study. Six dorsal to lateral core positions were incorporated into the test procedures. Shear force requirements of cores of steaks in very tender and tender groups tended (P>0.05) to decrease from the dorsal to lateral position. The increase in shear values from dorsal to lateral was dramatic (P<0.01) in the tough and very tough groups. It appears that overall shear value influences the variation in shear values within the muscle. Location effects of tenderness within the longissimus muscle could be useful in future studies of the physical/biochemical effectors of tenderness.     

THE INFLUENCE OF HIGH INTENSITY ULTRASOUND BATHS ON ASPECTS OF BEEF TENDERNESS

Beef Longissimus thoracis et lumborum ( LTL ), Semimembranosus (SM) and Biceps femoris (BF) steaks were sonicated using three commercially available ultrasonic baths of different intensities. The effect of ultrasound on the tenderness of these steaks was examined using peak load bite force tenderometry. Collagen solubility and sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS PAGE) analysis were also conducted on samples of BF and LTL exposed to the most intensive of the ultrasound treatments. Peak force values were not affected by ultrasound treatment (P≤ 0.05). Collagen solubility of LTL or BF did not differ (P ≤ 0.05) between ultrasonicated meat and controls. Similarly, SDS PAGE of myofibrillar proteins showed no differences between control and treated samples in the rates of appearance/disappearance of characteristic aging bands or in the numbers of bands observed on the gels suggesting no obvious effect on myofibrillar proteolysis. It is concluded that under the conditions of treatment employed high intensity ultrasound applied to intact beef steaks had no beneficial effect on meat tenderness. This is in contrast to tenderizing effects reported by other workers with more intensive treatments.     

Calcium chloride marination effects on beef steak tenderness and calpain proteolytic activity

A study was conducted in three phases to examine the effect of calcium chloride marination on tenderness. Steaks obtained 5 days postmortem were marinated in a 150 mM calcium chloride solution for 24 h and 48 h in phase 1, and for 48 h in phases 2 and 3. The steaks utilized were obtained from mature cows 8-11 years of age-phase 1; four control and four β-agonist fed steers-phase 2; and three Peidmontese and two Nelore 18-month-old steers-phase 3. Data were analyzed by analysis of variance for a split-plot design. In phase 1, marination failed to improve (P > 0·05) shear force values. However, shear force values were less than 5 kg which was uncommonly low for mature cows. In phase 2, marination improved (P < 0·05) meat tenderness regardless of diet. Yet, the steaks from the β-agonist fed steers remained less tender, even after marination, than the steaks from the control steers. In phase 3, shear force requirements were decreased (P < 0·01) with marination. Also, the activities of m-calpain and calpastatin decreased (P < 0·05) with calcium marination. It appeared that the improvement in tenderness was through the activation of m-calpain.     

IDENTIFICATION OF THRESHOLD LEVELS FOR WARNER-BRATZLER SHEAR FORCE IN BEEF TOP LOIN STEAKS

Threshold Warner-Bratzler shear (WBS) values were determined by regression analysis of WBS force values and trained sensory panel overall tenderness ratings of beef top loin steaks from A- and B-maturity carcasses (n = 678). Guidelines for retail and foodservice beef were based on 50 and 68% confidence levels, respectively, for overall tenderness ratings of "slightly tender." Due to the extreme variation in tenderness that exists in the current U.S. beef population, more stringent confidence levels were not practical. Threshold WBS values for retail and foodservice beef were 4.6 and 3.9 kg, respectively. When these values were tested against the population of beef in the National Consumer Retail Beef Study, the 4.6 kg value was 88.6% accurate at determining whether or not a steak would be rated less than "slightly tender"by consumers.     

肌肉嫩化方法及其机理分析

嫩度是肌肉重要的食用肉品质特征之一,影响肌肉嫩度的因素多种多样,包括肌原纤维、胶原蛋白、内源酶在内的内部因素,和温度、pH值等外部因素。阐述了物理(电刺激、高压处理、超声波)、生物化学(盐类、有机酸和生物酶)处理技术以及多种嫩化方法结合技术改善肌肉嫩度的方法,分析了不同的嫩化机理,并就肌肉嫩化机理分析研究进行了展望。     

Retail display evaluation of steaks from select beef strip loins injected with a brine containing 1% ammonium hydroxide. Part 2: Cook yield, tenderness, and sensory attributes

The impact of 2 different brines on the palatability and tenderness of select beef strip loin steaks was evaluated. Brines were differentiated by the type of alkaline agent, 4.5% sodium-based phosphate (control brine; CON) or 1% ammonium hydroxide (ammonium hydroxide treatment; AHT), incorporated into the formula. Injected steaks were placed in high oxygen (80% O(2)/20% CO(2)) MAP, stored 4 d at 4 °C in dark storage to simulate transportation, and then placed in retail display. Steaks were selected randomly on day 0, 7, and 14 retail display to measure pH, cook loss, shear force, and sensory characteristics. The pH for AHT steaks (pH 5.96) was slightly higher than CON steaks (pH 5.86; P < 0.05). Cook loss was lower (21%) for CON than AHT steaks (23%). There was neither a treatment nor day effect on tenderness as measured by Warner-Braztler shear force (P > 0.05). Sensory evaluation indicated that on day 0, retail display the initial juiciness, sustained juiciness, tenderness 1st impression, tenderness overall impression, and connective tissue in AHT steaks was not different from CON steaks (P > 0.05). A day effect (decrease) for those sensory parameters was observed only for sustained juiciness (P < 0.05). AHT steaks were rated higher in cooked beef flavor while CON steaks were higher in peppery and salty flavor. There was no difference in soapy and ammonia intensity between treatments. Results indicated that despite lower performance in cook loss the replacement of 4.5% sodium-based phosphate in a meat injection brine with 1% ammonium hydroxide produced a beef loin steak with comparable tenderness and palatability. Practical Application: The research in this study compares steaks that have been injected with a commercial brine formulated with sodium phosphates to steaks that have been injected with a brine where the sodium phosphate in the formulation was replaced with 1% ammonium hydroxide. Ammonium hydroxide is an USDA-FSIS approved ingredient in brines injected into fresh meats. Successful replacement of sodium phosphate with ammonium hydroxide would allow processors to significantly reduce the sodium content of injected fresh meat.