Warner-Bratzler Shear Values Research Articles

Influence of post-mortem aging in tenderness of chicken breast fillets

In this work, analysis of chicken breast fillets was performed for shear values and sensory evaluation after different times of aging. Aging process was carried out by holding carcasses in covered plastic boxes, in a cold room, at 3 +/- 1ºC; groups of 5 carcasses were stored and classified according to the period of storage in cold room as 0 (control), 2, 4, 8, 12 and 24 hours. The variation in pH of chicken carcasses during rigor decreased from 6.4 to 5.9. However, during the process of aging, the pH values increased up to 6.2 in the first 12h, probably as the result of proteolysis. The Warner-Bratzler shear values decreased as aging time increases, resulting in a first order kinetic. The carcasses presented a more accentuated decline in shear values in the first two hours of aging. After this period, the curve had a similar performance, achieving values of less than 1 kgf in 4 hours or more, with complete aging being accomplished at 8 hours. The samples with higher period of aging (8, 12 and 24 hours) were preferred in sensorial analysis, without significant differences among them.

Methods to increase tenderness of individual muscles from beef rounds when cooked with dry or moist heat

Muscles ( n=9) from beef rounds ( n=40) were subjected to one of the four tenderization strategies: control, blade tenderization, enzymatic tenderization or salt/phosphate injection. Treated muscles were aged, cut into steaks, cooked using one of the two cooking methods (dry-heat or moist-heat), and Warner–Bratzler shear (WBS) force values were determined. For dry-heat cookery, injection with a salt and phosphate solution resulted in the lowest WBS values, however, WBS values for blade tenderization and enzymatic tenderization were comparable in the M. adductor, M. vastus lateralis, M. rectus femoris, and M. semimembranosus (cranial and caudal aspects). The M. gluteobiceps (cranial and caudal aspects, and ischiatic head) and M. semitendinosus showed little improvement in WBS values with any of the tenderization treatments. For moist-heat cookery, only the M. rectus femoris and M. semimembranosus, caudal aspect, showed significant decreases in WBS values, and those improvements were only associated with salt and phosphate injection and enzymatic tenderization. Within each cooking method and tenderization treatment, the M. rectus femoris, M. semimembranosus, cranial aspect had the lowest WBS values, whereas the M. gluteobiceps, ischiatic head and M. semimembranosus typically had the highest WBS values. All tenderization strategies increased the frequency of muscles being rated as “very tender” (WBS < 31.4 N) and “tender” (31.4 N < WBS < 38.2 N), with salt and phosphate injection being the most effective treatment for both dry- and moist-heat cookery.

Early postmortem biochemical factors influence tenderness and water-holding capacity of three porcine muscles.

The objective of this study was to determine whether differences in pork tenderness and water-holding capacity could be explained by factors influencing calpain activity and proteolysis. Halothane-negative (HAL-1843 normal) Duroc pigs (n = 16) were slaughtered, and temperature and pH of the longissimus dorsi (LD), semimembranosus (SM), and psoas major (PM) were measured at 30 and 45 min and 1, 6, 12, and 24 h postmortem. Calpastatin activity; mu-calpain activity; and autolysis and proteolysis of titin, nebulin, desmin, and troponin-T were determined on muscle samples from the LD, SM, and PM at early times postmortem. Myofibrils from each muscle were purified to assess myofibril-bound (mu-calpain. Percentage drip loss was determined, and Warner-Bratzler shear (WBS) force was analyzed. Myosin heavy-chain (MHC) isoforms were examined using SDS-PAGE. The pH of PM was lower (P < 0.01) than the pH of LD and SM at 30 and 45 min and 1 h postmortem. The PM had a higher (P < 0.01) percentage of the MHC type IIa/IIx isoforms than the LD. The-LD had the greatest proportion of (P < 0.01) MHC IIb isoforms of any of the muscles. The PM had the lowest (P < 0.01) percentage of MHC IIb isoforms and a greater (P < 0.05) percentage of type I MHC isoforms than the LD and SM. The PM had less (P < 0.01) drip loss after 96 h of storage than the SM and LD. The PM had more desmin degradation (P < 0.01) than the LD and SM at 45 min and 6 h postmortem. Degradation of titin occurred earlier in the PM than the LD and SM. At 45 min postmortem, the PM consistently had some autolysis of mu-calpain, whereas the LD and SM did not. At 6 h postmortem, some autolysis of mu-calpain (80-kDa subunit) was observed in all three muscles. The rapid pH decline and increased rate of autolysis in the PM paralleled an earlier appearance of myofibril-bound mu-calpain. The SM had higher calpastatin activity (P < 0.05) at 45 min, 6 h, and 24 h and had higher WBS values at 48 h (P < 0.01) and 120 h (P < 0.05) postmortem than the LD. At 48 and 120 h postmortem, more degradation of desmin, titin, and nebulin were observed in the LD than in the SM. These results show that mu-calpain activity, mu-calpain autolysis, and protein degradation are associated with differences in pork tenderness and water-holding capacity observed in different muscles.

Perimysium thickness as an indicator of beef tenderness

Eight bovine muscles were evaluated to determine if perimysium thickness (PT) differed among muscles and carcasses and was affected by electrical stimulation (ES). In addition, the effect of PT on Warner–Bratzler shear (WBS) of steaks divided into tenderness groups was evaluated. Muscle and carcass affected ( P<0.05) PT, but PT was not significantly affected by ES. Correlation coefficients revealed that PT would be a poor indicator of WBS when used alone ( r=0.13). When analyzed within electrical stimulation treatment, PT was correlated ( P<0.05) to WBS of NES ( r=0.21) carcasses and not significantly related to WBS of ES carcasses. Within tenderness groups, PT accounted for 4.5%, 9.5%, 20.0%, and 4.0% of the variation in WBS force at 3, 7, 14, and 21 d, respectively. These results indicate that PT can be used in conjunction with other myofibrillar components of tenderness to account for some variation in WBS values of cooked beef steaks.

Effects of enhancing beef longissimus with phosphate plus salt, or calcium lactate plus non-phosphate water binders plus rosemary extract

Beef strip loins ( n=36) were enhanced with a sodium phosphate plus salt solution (PS); or with a calcium lactate solution (Ca) plus 1% or 2% beef broth (Br) plus natural flavoring (N) containing rosemary extract; or with 1% or 2% kappa carrageenan (Cr) plus N to determine effects of ingredients on color life, water-binding ability, and palatability traits. Enhancement with PS resulted in higher pH, higher pumped yields, greater water-binding ability, and higher tenderness and juiciness scores than enhancement with Ca (all p<0.05). Enhancement with Ca resulted in less color deterioration, less metmyoglobin discoloration, higher L ∗ , a ∗ , and b ∗ values, higher beef flavor intensity scores and lower off-flavor scores than enhancement with PS (all p<0.05). Warner–Bratzler shear values did not differ among treatments. Steaks enhanced with Br had less color deterioration, less metmyoglobin discoloration, and higher L ∗ values than those enhanced with Cr (all p<0.05). Pumped yields were not different between loins enhanced with Br or Cr. The N flavoring containing rosemary extract decreased ( p<0.05) discoloration. Enhancing beef longissimus with PS increased water-binding capacity and sensory tenderness traits, but reduced color stability and increased off-flavors, whereas Ca preserved color stability and enhanced flavor at the expense of pumped yields. The use of Br or Cr had no influence on tenderness or palatability traits.

The influence of season on quality characteristics of hot-boned beef m. longissimus thoracis

Samples of m. longissimus thoracis (LT) muscle were randomly collected from 70 Omani beef cattle 1 h after slaughter between August 2001 and July 2002 in the Muscat Municipality central slaughterhouse to investigate the effect of seasonal parameters on meat quality during the hot and cool seasons of Oman. The collection period (12 months) was divided into two seasons according to ambient temperatures and relative humidity and termed: Cool Season (November–March with average temperature of 21.2±1.40 °C and 57.9±1.61% relative humidity) and Hot Season (April–October with average temperature of 34.3±1.67 °C and 48.8±7.57% relative humidity). The season had a significant effect on meat quality characteristics of the LT muscle. Muscles collected during the hot season had significantly ( P<0.001) higher ultimate pH values (6.24) with significantly ( P<0.001) lower Warner–Bratzler (WB) shear force values (10.12) than those collected during the cool season (5.54 and 15.58). In these hot-boned samples, there was a linear relationship between ultimate pH and WB shear values. Cooking loss was significantly ( P<0.001) higher for cool season samples (26.01%) than from hot season samples (19.75%). Beef from the hot season group had significantly ( P<0.001) darker meat than that of the cold season group, based on L* (31.45 vs 35.58), a* (18.53 vs 23.19) and b* (4.16 vs 6.40) colour measurements. There was a linear relationship between ultimate pH and cooking loss, L*, a* and b*. These results indicated that heat stress (>30 °C) lead to physiological stress in beef cattle, which in turn increased muscle ultimate pH and influenced related meat quality characteristics.

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.

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.

Accelerated chilling of carcasses to improve pork quality.

Our objectives were to determine the optimal accelerated chill time immediately postmortem necessary to improve the quality of pork muscle and to decrease the incidence of pale, soft, and exudative pork. Carcasses from 81 market hogs were cooled either by conventional chill (CC) at 2 degrees C or by accelerated chill (AC) at -32 degrees C for 60, 90, 120, or 150 min, and then placed into a 2 degrees C cooler for the remainder of the 24-h chill period. Loin muscle pH was higher (P < 0.05) for the carcasses that were accelerated chilled longer than 60 min. Although loin visual color, texture, and firmness scores increased (P < 0.05) with AC time, no improvements were noted beyond 60 min. Color, pH, texture, firmness, and CIE L*a*b* values of fresh ham muscles were not (P > 0.05) affected by AC. In addition, AC did not (P > 0.05) affect purge, drip, or thaw loss of fresh products, sensory scores of loins or processed hams (except initial juiciness; P < 0.05), water-holding capacity of processed hams, or processing characteristics of hams. Cooking loss and Warner-Bratzler shear values for hams and loins were not (P > 0.05) affected by AC. Accelerated chilling caused loins to be darker (lower L* value; P < 0.05) and to have lower (P < 0.05) b* values (less yellow) than CC loins. Accelerated chilling increased water-holding capacity in fresh hams, bound water being the greatest (P < 0.05) in the 120- and 150-min AC groups. These results demonstrate that improvements in pork loin quality can be made using freezer-accelerated chilling for carcasses.

Warner‐Bratzler Shear Force Repeatability in Beef Longissimus Steaks Cooked With a Convection Oven, Broiler, or Clam‐shell Grill

ABSTRACT: Repeatability of Warner‐Bratzler shear (WBS) force in beef loin strip steaks was determined using a small kitchen clam‐shell grill (GRILL), oven roasting (OVEN), or oven broiling (BROIL). Cooking time for the GRILL method (7.0 min) was shorter, and the OVEN method (22.8 min) was longer compared with the BROIL cooking method (17.5 min, P&lt; 0.001). WBS values across all cooking methods ranged from 1.5 to 7.5 kg. Repeatability of WBS was relatively high for BROIL (r = 0.83), GRILL (r = 0.88), and OVEN (r = 0.88) cooking methods. Grilling beef loin steaks with an inexpensive clam‐shell grill is an acceptable method for cooking steaks for research purposes.

PHOSPHATE MARINATION OF PORK LOINS AT HIGH AND LOW INJECTION PRESSURES

ABSTRACTWhole, boneless pork loins, divided into anterior and posterior sections, were injected with deionized water or sodium tripolyphosphate/NaCl solution at an injection pressure of 200 or 345 kPa with a constant injection level of 13%. A vacuum tumbling process subsequent to injection at 345 kPa was also evaluated. Increasing injection pressure of STPP/NaCl marinades improved cook loss, overall yield, but increased Warner‐Bratzler shear values of water‐only injected controls. Overall yield ranged between 84.6–98.1% for phosphate treated loins compared with yields of that ranged between 61.0–67.7% for no treatment and water injected controls. Posterior loin sections exhibited greater weight loss after 4 days storage than anterior sections. A significant marinade/position interaction was observed for total moisture. Tumbling of pork loins after needle injection increased overall yield.

Warner–Bratzler shear evaluations of 40 bovine muscles

Forty muscles from each of 20 beef carcass sides were used to perform Warner–Bratzler shear (WBS) force determinations for within and among muscle effects. The M. triceps brachii differed ( P <0.05) in WBS values between the caput longum and caput laterale, and the M. gluteobiceps differed ( P <0.05) in WBS values between the vertebral, cranial, and caudal portions. The M. trapezius did not differ between the pars cervicalis and pars thoracica. Larger muscles were evaluated for location effects within muscles. The M. pectoralis profundus, M. infraspinatus, M. triceps brachii ( caput longum), psoas major, and M. semimembranosus all had significant location effects. Muscles were allocated into “very tender,” “tender,” “intermediate” or “tough” categories. Those muscles considered “very tender” (WBS <3.2 kg) were the diaphragm (outside skirt or wing of diaphragm), M. spinalis, M. infraspinatus, M. iliacus, M. psoas major, M. serratus ventralis, M. biceps brachii, M. obliquus internus abdominis, and M. vastus medius. Muscles considered “tender” (3.2 kg <WBS <3.9 kg) were the M. tensor fasciae latae, M. pectorales superficiales, M. teres major, M. longissimus lumborum, M. biventer cervicis, M. longissimus thoracis, M. splenius, M. subscapularis, M. rectus femoris, M. gluteus medius, M. gracilis, M. complexus, M. rectus abdominis, M. rhomboideus, and M. triceps brachii. Muscles classified as “intermediate” (3.9 kg <WBS <4.6 kg) were the M. gastrocnemius, M. supraspinatus, M. gluteobiceps, M. obliquus externus abdominis, M. semitendinosus, M. adductor, M. vastus lateralis, M. deltoideus, M. latissimus dorsi, M. transversus abdominis, and M. semimembranosus. Muscles classed as “tough” (WBS > 4.6 kg) were the M. extensor carpi radialis, M. trapezius, M. brachialis, M. pectoralis profundus, and M. flexor digitorum superficialis (hind limb). The diaphragm muscle was the most tender (WBS=2.03 kg), and the M. flexor digitorum superficialis was the toughest (WBS=7.74 kg). Tenderness, as measured by WBS, varied among and within bovine muscles, and knowledge of this variation allows for more appropriate use for specific purposes in the marketplace.

Effect of castration on meat quality in Piemontese cattle

The effect of early (5 month) or late castration (13 month) on meat quality of hypertrophied Piemontese cattle was investigated. Twenty four animals, equally divided into three groups (early castrated, EC; late castrated, LC; intact males, IM) were reared under the same experimental conditions and slaughtered at the same age. Twenty four hours after slaughter the pH was measured on the longissimus thoracis of the right side. After 11 days of ageing the following analyses were performed on the longissimus thoracis et lumborum: water, protein and ether extract contents, hydroxyproline content and collagen solubility, colour ( L, a L, b L, hue and chroma), drip and cooking losses, Warner-Bratzler shear values and sensory analysis (appearance of the raw meat and eating qualities of the cooked meat). Compared with intact males, the castrates had lower water and hydroxyproline contents and higher contents of protein and ether extract. No significant differences were observed between early and late castration, except for cooking losses.

Callipyge gene effects on lamb growth, carcass traits, muscle weights and meat characteristics

Normal (N, n=11) and heavy muscled (HM, n=9) lambs were produced from Polypay dams and Dorset sires heterozygous for the Callipyge (CLPG) gene to study the effects of the gene on live body weights, carcass and meat parameters. Lambs were grown as a single group on a high energy diet to a target slaughter weight of 57 kg. Live body weights were recorded monthly from birth to pre-slaughter. At slaughter, kidney and pelvic fat were recorded and two muscles, biceps femoris-caudal (BFC) and semitendinosus (ST), were removed, weighed, and used for other studies. Carcasses were sectioned between the 12th and 13th vertebrae for determination of ribeye area (REA) and fat depth over the loin and lower rib. Two additional muscles, biceps femoris-major (BFM) and semimembranosus (SM), and four loin chops cut 2.5 cm thick were removed from each carcass, sealed in Cryovac wrap, and frozen for later cooking. HM lambs had greater REA (23.0 vs. 13.6 cm 2; P<0.01), less fat ( P<0.01 for all measures), and greater weight of all dissected muscles (all P<0.01 except BFC for which P=0.13). Chops were cooked by grilling and the leg muscles were individually wrapped in aluminum foil and roasted whole, all to an internal temperature of 70 °C. HM carcasses produced higher Warner–Bratzler shear values for longissimus muscle (4.7 vs. 2.2 kg, P<0.01), but no significant differences were detected for BFM (2.6 vs. 2.5 kg) or SM (4.9 vs. 4.5 kg). The two genotypes did not differ in either percent cooking loss or percent moisture in the cooked meat from any of the three muscles.

Measuring the effects of phenotype and mechanical restraint on proteolytic degradation and rigor shortening in callipyge lamb longissimus dorsi muscle during extended aging

The purpose of this study was to determine if tenderness of callipyge (CLPG) longissimus dorsi muscle (LM) could be improved by: (1) extending the aging period to 48 days postmortem or (2) preventing rigor shortening by clamping. In CLPG and normal (NML) chops respectively, initial Warner-Bratzler shear values (WBS) were lower ( P<0.05) in clamped (CL) (5.5 and 3.6 kg) compared to unclamped (UCL) (7.4 and 4.9 kg) LM. In CLPG, an acceptable WBS (3.6 kg) was reached at 48 days PM, whereas, NML lambs reached an acceptable level (3.8 kg) by 3 days PM. Sarcomere lengths (SL) of CL (1.68 μm) were longer ( P <0.05) than for UCL (1.44 μm) and were negatively correlated with WBS ( r=−0.55; P<0.1). The appearance of Troponin-T (TNT) degradation product coincided with tender WBS values; 3 days postmortem in NML UCL and 48 days postmortem in CLPG. In conclusion, clamping reduced WBS possibly by reducing rigor shortening. Extended aging resulted in CLPG LM with acceptable WBS values, concurrent with the appearance of TNT degradation products.

Influence of packaging method and storage time on shear value and mechanical strength of intramuscular connective tissue of chevon

The objectives of this study were to determine the effects of storage time (ST) and packaging method (PM) on tenderness and changes in intramuscular connective tissue (IMCT) strength of chevon. Spanish does (8 mo of age, average BW 25 kg) were harvested (n = 12), chilled at 4 degrees C for 24 h, and then fabricated into 2.5-cm-thick leg, shoulder/arm, and loin/rib cuts. The cuts from six carcasses were vacuum-packed and aged at 2 degrees C for 0, 4, 8, or 12 d. To assess the influence of a packaging method that favors oxidation on postmortem tenderization, the cuts from the remaining six carcasses were placed on styrofoam trays, overwrapped with polyvinyl-chloride film, and stored at 2 degrees C for similar periods. At each ST, longissimus (LM), semimembranosus (SM), and triceps brachii (TB) muscles were assessed for Warner-Bratzler shear (WBS) values. The WBS of uncooked meat, myofibrillar fragmentation index (MFI), and collagen solubility were assessed on LM. The IMCT samples were prepared to assess changes in mechanical strengths and for scanning electron microscopy (SEM). Intact honeycomb structures of endomysium, with no muscle fiber elements, were observable under SEM. The PM or ST did not influence the mechanical strength of IMCT preparations, as measured by a texture analyzer. Collagen solubility of LM muscles also did not change during aging. For both PM, cooked meat WBS values were higher (P < 0.01) in SM and TB than in LM. In the SM samples, the average WBS values were higher (P < 0.01) at d 0 than at other ST. Although MFI of LM increased with increasing aging time (P < 0.05), changes in WBS over ST were minimal in TB and LM samples. The WBS of uncooked LM decreased sharply up to 8 d postmortem in both PM (P < 0.05). However, there was no PM x ST interaction to indicate any adverse influence of packaging on tenderization of chevon. The results suggest that aging chevon cuts for more than 4 d may not result in significant additional improvement in tenderness.

Tenderization of Hot-boned Broiler Breast Meat by Clamping During Chilling

Hot-boned broiler breast fillets were tightly clamped between rigid aluminum plates during chilling to determine whether tenderness is increased if breast fillets are not allowed to shorten during rigor. In two experiments, 6-wk-old broilers were processed in a pilot plant. Approximately 5 min after evisceration, the breast fillets (pectoralis major) were deboned, and each fillet was subjected to one of two treatments while chilling for 2 h in ice slush. Fillets were placed in perforated plastic bags (hot-boned control) or clamped between rigid aluminum plates that compressed the meat to a uniform thickness of 7.2 mm during chilling. In Experiment 2, chilling time in ice slush was 1 h, and a third treatment was added to make an incomplete block design in which one breast half was left intact on the carcass and was deboned immediately after chilling. All breast fillets were sealed in plastic bags after the chilling period, held overnight at 4 C, and then cooked at 85 C for 30 min in a steam kettle. In Experiment 1, clamping for 2 h reduced Warner-Bratzler shear values of hot-boned fillets from 11.4 to 2.7 kg. In Experiment 2, shear values for the treatments were 13.0, 9.2, and 5.1 kg for the hot-boned, cold-boned, and hot-boned clamped treatments, respectively, with significantly lower shear values for the clamped fillets. Clamped fillets were significantly thinner than the control fillets in both experiments. Cooked yield as a percentage of postchill weight was significantly higher for the clamped compared to the hot-boned control pieces, 81.1 versus 77.3%, with cold-boned pieces being intermediate and not different from the other treatments. Shear values were reduced, and cooked yield was increased by clamping hot-boned fillets during chilling.

Cooking method and endpoint temperature effects on sensory and color characteristics of pumped pork loin chops

The objective of this study was to evaluate the effects of pumping, cooking method and endpoint temperature on quality of fresh pork chops. The longissimus was removed from 30 paired pork sides. One side was pumped to 110% of original weight (0.4% phosphate, 0.4% salt+added water). Chops were cut (2.5 cm thick) then fried or grilled to 70 or 80 °C. As endpoint temperature increased from 70 to 80 °C, pork flavor increased ( P<0.05) from 95 to 104 (on a 150 point scale) for pumped samples but remained constant in unpumped samples. Juiciness decreased when unpumped samples cooked to 80 °C (62) rather than 70 °C (78). Warner–Bratzler shear values were lower ( P<0.05) in pumped chops than in unpumped controls. Pork flavor was higher and off-flavor was lower in fried chops. Pumping loins appears to enhance sensory attributes of chops even when cooked to abusive endpoint temperatures with limited detrimental effects on physical characteristics.

Unheated Water in the First Tank of a Three-Tank Broiler Scalder

Scalding with unheated water in the first tank of a simulated three-tank scalder was tested to determine whether carcass bacteria, efficiency of feather removal, and cooked breast meat tenderness are affected as compared with carcasses scalded at the same temperature (57 C) in all tanks. This experiment was performed on 3 d using 6-wk-old broilers. On each day, eight birds per treatment were processed. During the first 40-s scalding period, one carcass was placed in approximately 24 C water. The other carcass was placed simultaneously in a scalder unit containing approximately 2,050 L of water at 57 C. Carcasses were then held out of the water for 15 s, after which both were placed for 40 s in opposite ends of the scalder containing water at 57 C. After the second scalding period, both carcasses were again removed from the water for 15 s, followed by another 40 s in the 57 C water. Total scald time was 2 min for each treatment. After picking, carcasses were rinsed with 200 mL of sterile 0.1% peptone water for 1 min. Aerobic bacteria and Escherichia coli were enumerated and incidence of salmonella was determined by standard methods. After rinsing, carcasses were eviscerated by hand and chilled for 30 min in ice slush. All carcasses were scored for the presence of feathers, and the appearance and condition of the skin were noted. Four hours postmortem, breast fillets were removed from carcasses and chilled overnight at 2 C. The next morning, breast fillets were cooked to an internal endpoint temperature of 75 to 80 C. Warner-Bratzler shear values were measured to determine tenderness. No differences were found in numbers of aerobic bacteria and E. coli, incidence of salmonellae, tenderness of cooked breast meat, or number of feathers left on carcasses.

Hydrodynamic shockwave tenderization effects using a cylinder processor on early deboned broiler breasts

In separate experiments, chicken broiler breasts were deboned (45 min postmortem, 52 min, respectively) and either exposed to high pressure hydrodynamic shockwaves (HSW) 25 min after deboning (77 min postmortem) or after 24 h of storage (4°C) respectively, and compared to companion control breasts. HSW were produced in a cylindrical HSW processor with 40-g explosive. Warner-Bratzler shear (WBS) values of the HSW breasts treated at 77 min postmortem were not different than the controls. HSW treatment decreased (P<0.05) the WBS values of the stored and cooked breasts by 42.0% as compared to non-treated controls. Cooking losses were not affected by HSW. In general, raw and cooked color characteristics (CIE L*a*b*) were not affected by the HSW. HSW treatment at 25 min after deboning (77 min postmortem) may require a higher pressure front or delayed treatment after postmortem aging to improve tenderness.