Tenderness Of Broiler Breast Meat Research Articles

Exudate Protein Composition and Meat Tenderness of Broiler Breast Fillets

The relationship between meat tenderness and the protein composition of muscle exudates collected from broiler breast fillets deboned at different postmortem times was investigated. A total of 85 broilers were processed and breast fillets from each carcass were deboned at either 2 h (early-deboned, EB) or 24 h (control) postmortem. One fillet per carcass was used for 1 d postmortem meat tenderness measurements and the other fillet was stored at 4°C until 6 d postmortem for the collection of exudate prior to tenderness evaluation. Protein content and composition of muscle exudates were determined by a biuret assay and SDS-PAGE. Fillet pH, color, drip loss, and cook loss were also measured. Early-deboned fillets exhibited greater (P < 0.05) Warner-Bratzler shear force (WBSF) than controls at 1 d (7.4 vs. 3.1 kg) and 6 d (4.1 vs. 2.5 kg). Deboning time did not influence pH or color values (L*a*b*). Control fillets exhibited less drip loss after 6 d of storage (P = 0.005) and less cook loss at 1 and 6 d (P < 0.001). Exudate protein concentration was not influenced by deboning time. From the SDS-PAGE profiles of the exudates, the relative abundances of seventeen protein bands were quantified. Electrophoresis analysis revealed that, in general, the protein profiles of exudates from control and EB fillets were not distinct from each other. However, the band corresponding to 225 kDa was more abundant in controls (P = 0.021). Although the protein concentrations and SDS-PAGE profiles of muscle exudates varied widely between breast fillets, variations in exudate protein characteristics were not strongly associated with changes in the tenderness of broiler breast meat due to the combined effects of postmortem deboning time and post-deboning aging.

Electron microscopy of contractile bands and quality characteristics in high-voltage electrical stimulation broiler breast meat

In this study, 20 broilers were used to examine the effect of high-voltage electrical stimulation (HVES) on meat quality and the microstructure of the pectoralis muscle. After slaughter, carcasses were randomly distributed into 2 treatment groups (n = 10). In the first group, carcasses were electrically stimulated (500 V, 100 Hz) for 60 s. Carcasses in the second group (nonelectrical stimulation) were used as a control. Meat quality was evaluated by the rate of pH, water-holding capacity, cooking loss, color (L*, a*, b*), shear force, and sarcomere length. As a result, HVES increased the rate of muscle pH decline (P < 0.001). High-voltage electrical stimulation had no effect on water-holding capacity and cooking loss values. Only L* (lightness) values were improved during the storage time (P < 0.01). Tenderness (P < 0.001) and sarcomere length (P < 0.05) values were significantly increased at 2 and 5 d postmortem. In addition, microstructure examination demonstrated that the stimulated muscles had longer sarcomeres; however, the A-, I-, and Z-bands and the mitochondrial membrane structure were intact in HVES and nonelectrically stimulated carcasses. The results showed that HVES is a useful method for improving the tenderness of broiler breast meat.

THE MEULLENET‐OWENS RAZOR SHEAR (MORS) FOR PREDICTING POULTRY MEAT TENDERNESS: ITS APPLICATIONS AND OPTIMIZATION

ABSTRACT The Meullenet‐Owens Razor Shear (MORS), recently developed for the assessment of poultry meat tenderness, is a reliable instrumental method. Three different studies were conducted to (1) investigate the adaptation of MORS to an Instron InSpec 2200 tester (InSpec); (2) optimize the number of replications necessary per fillet to obtain a reliable instrumental tenderness mean; and (3) test the efficacy of a blunt version of MORS (BMORS). In study 1, the tenderness of 157 cooked broiler breast fillets was predicted by the MORS performed with both a texture analyzer (MORS standard) and InSpec. The correlation coefficient of 0.95 was reported for the MORS energy obtained from the both tests, indicating that the MORS performed with an InSpec is equivalent to that performed on the more expensive texture analyzer. In study 2, eight shears were taken on each cooked fillet (101 fillets) to determine a recommended number of shears per fillet for the MORS. The composite hypothesis test was conducted considering the average of 8 shears as Y (representative estimated tenderness of a fillet) and the average of 2, 3, 4, 5, 6 or 7 as X (potentials for recommended number of shears). The results showed that the optimal number of replications of the MORS for a reliable estimate of tenderness to be four shears or greater per fillet. A blunt version of MORS (BMORS) was introduced in study 3. A total of 288 broilers (576 fillets) were deboned at eight different postmortem deboning times. Tenderness of cooked fillets was assessed by both the MORS and BMORS on the same individual fillets. Both methods were equivalent in performance for predicting broiler breast meat tenderness, giving a correlation coefficient of 0.99 with all instrumental parameters obtained from both methods. Tenderness intensity perceived by consumers was slightly more highly correlated to BMORS energy (r = −0.90) than MORS energy (r = −0.87). The BMORS was recommended to use especially for tough meat because of its better discrimination ability among tough meat. Overall, both the MORS and BMORS were proven to be reliable predictors for broiler breast meat tenderness.PRACTICAL APPLICATIONSThe incidence of tough meat has been a major issue the poultry industry faces. Therefore, the need to ensure consumer acceptance and the increased recognition of the importance of tenderness has led to the development of instrumental methods for monitoring meat tenderness. To date, a great deal of efforts has been devoted to the development of such instrumental methods. One promising method is the Meullenet‐Owens Razor Shear (MORS). The method has gained in popularity for predicting poultry meat tenderness because of its high reliability as well as simplicity compared with that of other industry standards (Warner‐Bratzler shear or Allo‐Kramer shear). The MORS is not only as reliable as the industry standards, but also more rapid because of the elimination of the sample cutting steps. The application of the MORS will be of benefit to the poultry industry as it could significantly save labor or time to implement for routine quality control.

Effect of Aging on Bioactive Amines, Microbial Flora, Physico-Chemical Characteristics, and Tenderness of Broiler Breast Meat

The objective of this study was to investigate the influence of aging on the levels of bioactive amines, microbial flora, physico-chemical characteristics, and tenderness of broiler breast. Forty-five 1-d-old Cobb broilers were aged at temperatures from 1.0 to 5.7°C for 8 h. Nonaged broiler breast contained spermine, spermidine, and low levels of putrescine. There was prevalence of aerobic mesophiles followed by Pseudomonas. Mean pH, nonprotein N, weight loss after roasting, and shear force were 5.92, 0.46 g of N/100 g, 19.4%, and 5.57 kg, respectively. During aging, there was a significant increase in Pseudomonas and on the levels of amines. Two different amines were detected – tyramine and histamine. Aging resulted in a significant increase in tenderness without affecting pH, non-protein N, and weight loss after roasting. There was significant correlation between aging temperature and total bioactive amine levels. Aging above 4.9°C induced the formation of histamine; therefore, aging should be performed at temperatures ≤ 4.9°C to prevent the formation of this amine, which has been associated with human health hazards. During storage of aged broiler breast at −18 ± 1°C for 89 d, there was no significant difference on pH, nonprotein N, and weight loss after roasting; however, there was a significant decrease on spermine, spermidine, putrescine, and tyramine levels. On the 89th day of storage, histamine was detected, and the shear force was significantly lower when compared with the samples immediately after aging. Therefore, the storage time of aged breast should not exceed 64 d to prevent histamine formation and to avoid excessive softening of the meat. Histamine in aged broiler breast could be used as an index of aging temperatures above 4.9°C and also of frozen storage for more than 64 d.

A Novel Laser Air Puff and Shape Profile Method for Predicting Tenderness of Broiler Breast Meat

The potential application of a new laser air puff system to assess poultry meat tenderness was investigated. Ninety broilers were deboned at either 1.25, 4, or 24 h postmortem. The raw breast fillets were scanned on a conveyor belt longitudinally by a laser distance sensor to obtain overall shape profiles and scanned again with a pressurized source of air (206.8 kPa). The 2 resulting profiles were superimposed to quantify the amount of deformation caused by the application of pressurized air. Five parameters including a height and length of each fillet were calculated and used to establish a model to predict tenderness. Tenderness of cooked fillets was determined instrumentally with the Meullenet-Owens razor shear, Blunt-Meullenet-Owens razor shear, and with sensory analysis. Hardness, Meullenet-Owens razor shear energy, and Blunt-Meullenet-Owens razor shear energy were modeled with the parameters extracted from the air puff system. Predicted values obtained from the models and observed values of individual fillets were subjected to logistic regression to classify fillets into tenderness levels. Tender fillets in the air puff predicted tender group represented 82, 81, and 88% based on hardness, Meullenet-Owens razor shear energy, and Blunt-Meullenet-Owens razor shear energy, respectively. The use of this tool resulted in more than a 20% improvement in the number of tender fillets after classification. The results suggested that this new system could potentially be implemented as an online tool for sorting poultry breast fillets by tenderness levels.

Biochemical and sensorial evaluation of intact and boned broiler breast meat tenderness during ageing

Meat tenderness is the main characteristic demanded by consumers and is affected by rigor mortis development and proteolysis activities, both of which occur during carcass refrigeration. In this work, we demonstrate that broiler breast fillet tenderness can be further increased and its extension depends on whether or not meat is excised from the carcass. Post-harvest samples taken from 0 to 72 h after slaughtering and kept refrigerated at 2 ± 2 °C were evaluated for tenderness by myofibrillar fragmentation index determination, shear force analysis and sensorial testing. The 24 h post-harvested intact samples were 30.6% more tender than excised samples and 41.7% more tender than control samples ( p ⩽ 0.05). The myofibrillar fragments index was 13.2% higher in intact samples than in deboned fillet ( p ⩽ 0.05) and a sensory test showed that the 24 h intact samples were of major acceptability. Our results demonstrated that tenderness was best achieved with intact breast fillet samples stored at 2 ± 2 °C for 24 h.

Early postmortem carcass trim effects on the tenderness of broiler breast fillets

Broiler carcasses are often trimmed during evisceration to remove damaged areas of the carcass. Because deboning before rigor mortis development can toughen meat, trimming during evisceration may toughen the meat. This study evaluated the effects of trimming on the tenderness of broiler breast meat. To evaluate the effect of wing removal on tenderness, breast halves from 2 flocks were collected after chilling at a commercial plant. One-third were untrimmed controls, one-third had small amounts of breast meat removed with wing (WMin), and one-third had large amounts of breast meat removed with wing (Wmax). Salvage fillets from the 2 flocks were also collected from the salvage table of the plant. Carcasses were also processed to evaluate the effect of breast blister trimming that removed a superficial amount of muscle tissue, half of which had breast blister trims, and half did not. All front halves or carcasses were aged until 24 h postmortem and deboned. Salvage fillets were held refrigerated until 24 h postmortem. Fillets were cooked and then sheared in 2 locations on the fillet, upper and lower, to determine if tenderness was more affected at areas close to the trim. Carcasses with wing trims had significantly higher shear values compared with the control, and shear values from the upper portion of the fillets from the WMax and WMin (nearer the trim) were significantly greater than for the lower portion. Location, however, did not affect shear values in the control carcasses. This finding indicated that tenderness of the areas nearest the trim might be affected more by the trim process. Salvage table deboning significantly increased shear values throughout the fillet. There was no significant difference in shear value due to breast blister trimming. The results of this study suggest that trimming carcasses by wing or breast fillet removal results in decreased meat tenderness.

Early Postmortem Injection and Tumble Marination Effects on Broiler Breast Meat Tenderness

Several processors use inline injection and tumble marination practices to decrease labor costs and product handling. However, the stimulation of this early postmortem (PM) muscle may cause increased toughness. Therefore, the objective of this study was to compare marination of early PM meat by using injection, vacuum tumbling, or both to determine their effects on tenderness of broiler breast fillets. Breast fillets from 45 broilers were deboned at 3 h PM and injected, tumbled (30 min, 635 mmHg, 14 rpm), or injected + tumbled with a 10% solution of 0.54%. NaCl + 0.42% sodium tripoly phosphate (STPP). Nonmarinated controls deboned at 3 and 6 h PM were also included. Shear value, sarcomere length, and cook loss were determined on each of the fillets. The control and tumbled fillets had the highest shear value compared with the remaining 3-h treatments. The injected + tumbled and tumbled fillets had the highest cook loss followed by 3-h control and injected treatments. Tumble marination at 3 h PM produced significantly tougher meat then the injection treatment.Experiment 2 was conducted to test marinade penetration through the fillets because penetration could have affected the results of the previous study. Broiler breast fillets were deboned from 60 broilers at 3 h PM and were vacuum tumbled (30 min, 635 mmHg, 14 rpm) with a 15% solution of 0.54% NaCl and 0.42% STPP. We determined shear value and cooked meat moisture of the fillets and sodium ion migration into the fillets. Although there were no significant differences in shear value between control and tumbled fillets, the cooked meat moisture was significantly higher in tumbled fillets when compared with the controls. Sodium ion concentration was significantly higher on the surface (especially the lateral surface) of the fillets when compared with the center, which suggested some uneven distribution.

Effect of some ante-mortem stressors on peri-mortem and post-mortem biochemical changes and tenderness in broiler breast muscle: a review

The effects of ante-mortem stressors such as stunning, struggling, environmental temperature and feed withdrawal on the biochemical changes of broiler breast muscle are assessed in relation to post-mortem biochemical changes and the subsequent tenderness of broiler breast meat. The findings of investigations concerned with broiler meat are presented alongside more fundamental studies addressing such aspects as Ca2+ release and sequestration, endocrine changes during periods of stress and the role of fatty acids as regulators of membrane bound channels. An attempt is made to assimilate the pertinent facts associated with this topic and to give directions for future research. It is concluded, however, that, whilst tenderness in meat is often associated with a loss of ATP, glycogen breakdown and lactic acid accumulation within muscles, current data are insufficient to enable a definitive decision to be made as to which have adverse effects on broiler meat tenderness.

Comparison of a Modified Atmosphere Stunning-Killing System to conventional electrical stunning and killing on selected broiler breast muscle rigor development and meat quality attributes

Two experiments were conducted to compare the effects of a 70:30 argon:carbon dioxide Modified Atmosphere Stun-Kill (MASK) system to both a low voltage (LV) and a high current (HC) electrical stunning and conventional killing system on broiler breast rigor development and meat quality. In Experiment 1, the effects on breast muscle pH and meat tenderness of the MASK system and the LV system were compared. In Experiment 2, the MASK system was compared to both HC and LV stunning for pH, R-value, C.I.E. L*, a*, b*, cooked yield, and tenderness of broiler breast meat. In Experiment 1, there were no significant differences in breast muscle pH between LV and MASK, except at 24 h. Only at 5 h post-mortem did the MASK system result in significantly tougher breast meat. In Experiment 2, there were no significant differences between treatments in breast muscle color or cooked yield at any sampling time. The breast muscle from birds subjected to the HC stun had consistently higher pH values until 5 h post-mortem, at which time the breast meat from birds subjected to the MASK system had higher pH. R-value data showed a similar trend, with the HC stunned birds having the lower R-values until 5 h post-mortem. Breast meat tenderness values for the three treatments were significantly different only at 3 and 5 h post-mortem, when birds stunned with HC had the highest shear values. The MASK system did not exhibit any rigor accelerating benefits when compared to LV stunning and conventional killing, and only minimal rigor acceleration when compared to HC killing.

Effect of muscle opposition during rigor on development of broiler breast meat tenderness

Two experiments were conducted to determine the effect of mutual opposition of breast muscles during rigor development on ultimate tenderness of the cooked meat. In each experiment, 32 broilers were conventionally processed. Immediately after evisceration, the supracoracoideus tendon was cut at the humeral insertion on one wing (treatment) and the opposite wing was sham-operated with the tendon exposed but not cut (control). The tendon of insertion for the Pectoralis minor muscle was cut to prevent the opposition of breast muscles during rigor, while avoiding confounding effects caused by making cuts on the muscles, as would occur during typical deboning. Cutting the tendon significantly (P < 0.05) increased Warner-Bratzler shear values after cooking for both the Pectoralis major and P. minor. Deboning at 2 h post-mortem resulted in shear values for the P. major of 7.22 kg for controls and 9.08 kg for treated carcasses; P. minor shear values were 2.98 kg for controls and 4.04 kg for treated carcasses. Deboning at 24 h post-mortem produced P. major shear values of 4.68 kg for controls and 5.68 kg for treated carcasses. On whole carcasses, breast muscle opposition during rigor contributes to the tenderness of the cooked meat.

LITERATURE ABSTRACTS

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The Relationship of Objective Shear Values and Sensory Tests to Changes in Tenderness of Broiler Breast Meat

The relationships were established between two objective shear procedures and sensory responses to tenderness for broiler Pectoralis major muscles. Birds were processed and the breasts removed at one of four post-mortem (PM) deboning times: 0 h (after picking), 2, 6, and 24 h. After deboning, the individual muscles were placed in boilable bags and frozen. The meat was cooked from the frozen state by immersing in 85 C water or by microwave. Two strips, 1.9 cm wide, were removed from each breast for objective and sensory evaluation. A 24-member untrained panel evaluated the samples for juiciness, tenderness, and overall texture acceptability. The samples were evaluated objectively using the Warner-Bratzler (W-B) and Allo-Kramer (A-K) shear devices.Objective shear values and sensory scores were significantly affected by PM deboning time and cooking method. The data indicate that W-B values in the range of 6.5 to 3.5 kg and A-K values in the range of 8.8 to 6.0 kg per g would correspond to the “slightly tender” to “moderately tender” portion of the sensory scale.

THE EFFECTS OF DELAYED PICKING AND HIGH‐TEMPERATURE CONDITIONING ON THE TEXTURE OF HOT‐ AND COLD‐BONED BROILER BREAST MEAT

ABSTRACTFour trials were conducted to evaluate the effects of delayed picking for 30 min versus normal picking, high temperature conditioning at 32°C versus low temperature conditioning at 0°C, and hot boning versus cold boning on broiler breast meat tenderness, pH, sarcomere length and R‐values. None of the treatments affected cold‐boned shear values. Within the hot‐boned group, delayed picking significantly increased shear value (14.5 kg) compared with normally picked samples (12.5 kg). Conditioning at 32°C significantly lowered shear values (12.5 kg) compared with 0°C (14.6 kg). High‐temperature conditioning lowered muscle pH immediately after evisceration, but delayed picking had no effect. Following 24 h aging, treatments had no effect on muscle pH or R‐value. These results indicate that 32°C conditioning temperature and early picking significantly reduced meat toughness, but not to a commercially practical degree.

Effects of Post-Mortem Wing Restraint on the Development of Rigor and Tenderness of Broiler Breast Meat

Treatments of wing restraint (WR) were applied to broiler carcasses immediately after picking in an attempt to increase tension in the pectoralis (p.) major and restrict muscle shortening during rigor development. In the course of the study, the time allowed for aging prior to deboning of the breast meat was decreased from 4 h to 2 h post-mortem, and the effect on tenderness was determined.Results of deboning at 4 h indicated significantly longer sarcomere lengths for the p. major of wing-restrained carcasses, but shear values of the meat were not decreased. A second experiment tested a modification of the WR, combining a 3-h tie with a “release” interval of 1 h. This treatment combination resulted in higher lactate contents at 4 h, longer sarcomeres, and lower shear values than those of earlydeboned muscles without WR. A modified-WR in abbreviated schemes of deboning at 3 h and 2 h, respectively, resulted in a slight acceleration of post-mortem metabolism in p. major muscles of the WR treatment, a significant increase in sarcomere lengths, and a reduction in the meat toughening associated with early post-mortem deboning. In all of the experiments, WR resulted in significantly reduced sarcomere lengths and toughened meat in the p. minor muscle, consistent with the expected effect of treatment on opposing muscle.

Effect of Post-Mortem Boning Time During Simulated Commercial Processing on the Tenderness of Broiler Breast Meat

Broiler breast fillets were harvested at selected times post-mortem during simulated commercial broiler processing, chilling, and aging prior to objective evaluation of cooked meat tenderness and moisture content. Fillets harvested within the first .25 h post-mortem were significantly less tender and had a lower moisture content than all other fillets, even though these fillets had a significantly greater water uptake during chilling. Fillets harvested from chillled carcasses at 1.08 to 2.33 h were significantly more tender than hot-boned fillets but significantly less tender than fillets harvested at 3.33 h or later times up to 24.33 h. Fillets harvested 24.33 h post-mortem were significantly more tender than fillets harvested at any other time. Moisture contents of fillets harvested after the chilling process were not significantly different.

Effects of Electrical Stunning and Hot Deboning on Broiler Breast Meat Quality

The effects were determined of electrical stunning prior to death and hot deboning on pH, percent weight loss due to cooking, and objective tenderness of broiler breast meat. Forty-eight live broilers were obtained from a processing plant and transported to the pilot plant facility of the research center. Half the birds were electrically stunned prior to death, and half were not. Birds were processed in the following manner: bled by outside neck cut for 2 min, scalded for 2 min at 53 C, feathers removed, and left pectorialis major immediately removed. The remainder of carcass was eviscerated, head, neck, and feet removed, prechilled, stored for 24 hr at 2 C, and right p. major removed. The pH was taken at the time of muscle removal, the skinless p. major weighed, cooked in water at 88 C to 82 C, cooled, and weighed. A 2.5-cm wide strip was removed to measure objectively tenderness as force to shear. The entire procedure was replicated twice.There was a significant stun by age interaction for pH and percent weight loss due to cooking. Breast meat from birds stunned prior to death exhibited higher pH 20 min postmortem than meat from nonstunned birds. Stunning had no effect on ultimate postmortem pH. Breast meat cooked 20 min postmortem exhibited lower percentage weight loss than meat cooked 24 hr postmortem. The meat cooked 20 min postmortem exhibited significantly higher shear values–it was less tender–than meat cooked 24 hr postmortem. Postmortem aging had a more pronounced effect on objective texture than electrical stunning.

The Influence of Brine Chilling on Tenderness of Hot-Boned, Chill-Boned, and Age-Boned Broiler Breast Fillets

Fillets (pectoralis superficialis) were harvested from broiler carcasses immediately after picking (hot boned), immediately after chilling (chill boned), or after a 24-hr aging period (age boned). Hot-boned fillets and all carcasses were equally distributed within two chilling solutions; tap water or 5% sodium chloride solution. The pH at the time of boning was ascertained for all fillets. Battered, breaded, deep-fat fried fillets were analyzed for shear force, percent chloride ion, and moisture and sodium concentration.Boning time produced the greatest effect on tenderness of broiler breast meat, with tenderness improving as the length of time between slaughter and boning was increased. Brine chilling improved tenderness of hot-boned fillets to the same level as that observed for fillets harvested from carcasses immediately after chilling but had no effect on fillets harvested postchill or after aging. Improvement in tenderness of brine-chilled, hot-boned fillets could not be explained on the basis of pH or water-holding capacity but was related to higher tissue chloride ion concentration.

PH and Tenderness of Broiler Breast Meat Deboned Various Times After Chilling

The pH and tenderness of broiler breast meat deboned 0, 1, 2, 4, 6, 8, or 24 hr after commercial chilling were determined. The Pectoralis major muscles of Group 0 were deboned immediately after chilling, and held on ice for 24 hr, while front halves from Group 24 were held on ice for 24 hr after chilling, deboned, and the P. majors cooked. Time after chilling and deboning totaled 24 hr for all of the groups; for example, front halves from Group 6 were held on ice for 6 hr after chilling, deboned, and P. majors held on ice for 18 hr prior to cooking. The weight and pH of each P. major was determined at the time of deboning. Pieces were water cooked and tenderness reported as force to shear.The postchilling time prior to deboning had a significant effect on pH and tenderness. Breast meat deboned immediately after chilling had a significantly higher pH and required more force to shear than the other groups. The most rapid pH decline was noted within 1 hr of chilling. There were no significant differences in pH or tenderness after a 4 hr postchilling time prior to deboning.

Effects of Eviscerating Line Trimming on Tenderness of Broiler Breast Meat

Seven-week-old broiler carcasses were subjected to various cutting and trimming techniques to study the effect of muscle incision, cut skin and wing removal on tenderness of breast meat. Treatments were performed immediately after evisceration to be comparable with trimming occurring in processing plants on the eviscerating line. After aging in ice slush, breasts were halved and boiled in water or deep-fat fried for shear press and panel evaluations, respectively.Cutting the breast muscle and removal of a wing at the shoulder joint significantly increased shear values on treated muscles. Cut skin and removal of a wing at the joint distal to the shoulder did not significantly affect shear values. A panel rated breasts with a wing removed at the shoulder significantly less tender than untreated halves. The panel was unable to detect a difference in tenderness due to other treatments. There were significant differences among shear values from different areas of cut muscle. Shear values were highest near the wing and lowest near the sternum when a wing was removed at the shoulder joint.