Poultry Breast Research Articles

Tenderness and yields of poultry breast are influenced by phosphate type and concentration of marinade

The effect of concentration and type of phosphate on quality of pre-rigor poultry breast was evaluated. Non-aged breasts (NAC) and aged whole birds (AC) were non-injected controls. Injection marination increased the final product yield and moisture content of breasts compared with AC and NAC. Tetrasodium pyrophosphate (TSPP)-injected breast had the highest final product yield. TSPP and sodium tripolyphosphate (STPP) injection had similar effects on purge, net weight increase, moisture and expressible moisture. TSPP could only be used in low-salt marinades. Hexametaphosphate (GLASS)-injected breast had the highest pick-up but the lowest retention and moisture content. The shear force of phosphate-injected breasts was lower than that of NAC and similar to or lower than that of AC breasts. © 2000 Society of Chemical Industry

Effect of pre-heated whey protein level and salt on texture development of poultry meat batters

The combined effect of pre-heated whey protein isolate (WPI) substitution level (0–4%) and salt level (0–2.5% NaCl) on the physical characteristics of raw and cooked poultry breast meat batters (16% protein) was investigated. Pre-heating of WPI resulted in cold set gelation (overnight at 1°C) which significantly increased water holding capacity, reduced cooking loss and improved the rheological properties of raw and cooked batters, particularly at ⩽1.5% NaCl. Overall, the study indicated the potential use of pre-heated WPI in improving water binding and texture of low/no-salt meat products.

Application of the bacteriocinogenicLactobacillus sakeiCTC494 to prevent growth of Listeria in fresh and cooked meat products packed with different atmospheres

The production of sakacin K byLactobacillus sakeiCTC494 at different temperatures and pH was evaluated before its application as a bioprotective culture againstListeriain different meat-based food packaging systems, that is, oxygen-permeable film, under vacuum and under a modified atmosphere (20% CO2: 80% O2) and stored at 7°C. TheLactobacillusculture produced the bacteriocin at a range of temperatures from 4°C to 30°C and at initial pH from 5·5 to 6·5.Listeriainhibition in raw minced pork, poultry breasts and modelized cooked pork could not be achieved by the sole application of vacuum or a modified atmosphere. Inoculation ofLb. sakeiCTC494 or sakacin K inhibited the growth ofListeriato different extents in all the products studied in each system; the greatest inhibition being observed in the vacuum packaged samples of poultry breasts and cooked pork, and in the modified atmosphere packaged samples of raw minced pork. Addition of sakacin K resulted in immediate bactericidal action againstListeriain every product and atmosphere studied.

EFFECTS OF ELECTRICAL STUNNING DURATION ON POSTMORTEM RIGOR DEVELOPMENT AND BROILER BREAST MEAT TENDERNESS

ABSTRACTExperiments were conducted to determine the effect of electrical stunning duration on poultry breast meat postmortem biochemistry and texture. Broilers were stunned with 100 V AC for 0, 5, 10, 20, or 40 s, killed by conventional neck cut, and bled for 180 s to determine percentage blood loss. Breast fillets were removed from the carcass immediately after picking or following 24 h of aging in an ice‐water bath. R‐values and pH were determined at both deboning times and Allo‐Kramer shear values were recorded after holding the samples for 48 h at 2 C. Stunning durations of 10, 20 and 40 s resulted in lower (P < 0.05) blood losses than birds stunned for 0 or 5 s. Stunning inhibited postmortem glycolysis as indicated by higher (P < 0.05) pH values and lower R‐values at 15 min postmortem, but not after 24 h. Stunning had no effect on Allo‐Kramer shear values. Stunning durations from 5 to 40 s at 100 V AC had no significant effect on postmortem rigor development, or meat quality.

Influence of ultimate pH, sarcomere length and cooking loss on the textural variability of cookedM. pectoralis majorfrom free range and standard broilers

1. An experiment was conducted to quantify the extent of variability in the texture of cooked poultry breast meat and to attempt to identify which intrinsic and extrinsic factors contribute to this. 2. Free range (FR) and standard (STD) broilers were killed and processed under commercial conditions and the M. pectoralis major muscle assessed for ultimate pH (pH(u)), sarcomere length, cooking loss and texture 24 h and 7 d after slaughter. . 3. Although FR broilers were females with an average age of 60 d, whereas the STD broilers were 45 d old and predominantly male, there were no significant differences in mean values obtained for pH(u), sarcomere length, cooking loss and shear force results between the two bird types. 4. While aging for 7 d increased the pH(u) and cooking loss means, sarcomere length means remained unchanged and shear force values decreased by 6% and 9% for FR and STD birds respectively. 5. Variability in shear force values also decreased on aging for 7 d, no birds having values above 4 kg/cm2 on day 7 whereas 16% were above this value on day 1. 6. There were significant correlations between the results for shear force, pH(u) and sarcomere length, indicating that increased shear force values were associated with a decrease in both pH(u) and sarcomere length. 7. These correlations suggest that variability in the texture of cooked M. pectoralis major from FR and STD chickens is strongly influenced by those post-mortem biochemical changes which lead to the development of rigor during the early stages of processing.

Lactate Dehydrogenase as Safe Endpoint Cooking Indicator in Poultry Breast Rolls: Development of Monoclonal Antibodies and Application to Sandwich Enzyme-Linked Immunosorbent Assay (ELISA)

A sandwich enzyme-linked immunosorbent assay (ELISA) was developed to detect lactate dehydrogenase (LDH) as a marker protein for verifying endpoint cooking of uncured poultry products. Monoclonal antibodies were prepared against chicken muscle LDH and used with rabbit polyclonal antibodies developed against turkey or chicken muscle LDH for capture and detection in the assay, respectively. Minimum assay detection limits for turkey and chicken muscle LDH were 1 ng/ml. Turkey and chicken muscle LDH, but not LDH from other species cross reacted in the ELISA. The ELISA was further verified using extracts of turkey breast rolls processed to internal temperatures between 68.3 and 72.1°C. The LDH content of extracts diluted 3- to 6-fold was below 15 ng/ml for turkey rolls processed to 70.9 and 72.1°C. At a 6-fold dilution, LDH content of extracts from rolls processed to 69.7°C was approximately 10 times greater than those processed to 70.9°C. A survey of market precooked poultry products indicated assay validity with precooked turkey roast, but not turkey hams with maximum internal temperature requirements of 68.3°C. Results suggested the sandwich ELISA should be applicable for determining whether turkey breast rolls are processed to the required U.S. Department of Agriculture endpoint temperature of 71.1°C.

The freezing and thawing of water in poultry meat and vegetables irradiated by electrons at doses of 0.1-4 kGy.

Poultry meat and some vegetables, irradiated by 5 MeV electrons (0.1-4 kGy), were analysed by differential scanning calorimetry, from 24 h after irradiation. The temperature and enthalpy transitions of the water contained in the irradiated samples were measured and compared with those of unirradiated samples. We analysed 18 meat and 10 vegetable samples for each irradiation dose together with a similar number of unirradiated controls. The mean supercooling temperatures of water in the irradiated poultry meat samples and in some vegetables are significantly lower than those of controls. Moreover, the freezing enthalpies of the irradiated poultry breast are significantly lower than those of controls, while they are unchanged in the other cases. The mean ice melting temperatures and enthalpies are similar for all samples. The amount of the lowering of the water-ice transition depends on the nature of the sample and is highest in poultry breast and lowest in vegetables.

Research Note: Film-to-Meat Adhesion Strength with a Cook-in-the-Film Packaging System for a Poultry Meat Product

Film-to-meat adhesion strength for a comminuted product of poultry breast meat processed by a cook-in-the-film procedure ranged from 4.42 to 4.18 g (In force) across a width of 2.54 cm when sufficient raw tissue was used in the blends of raw tissue and precooked meat. The adhesion strength was reduced (P<.05) when less than 50% of the meat blend was raw tissue. The results suggested that film-to-meat adhesion development is a functional property dependent on the availability of undenatured, extractable, myofibrillar protein present in the initial meat blend.

Influence of post‐mortem treatments on turkey and chicken meat texture

SummaryToughness of poultry breast muscle was influenced by the rate of rigor onset, the rate of cooling and chilled storage time. The pH of the breast muscle at 20 min after stunning (pH20) in 52‐day‐old chickens varied from 5.9 to 6.9, and in 70‐day‐old turkeys from 6.2 to 6.8. In turkey meat with pH20 &gt; 6.4, toughening was induced by immersion chilling to 7°C within 65 min post mortem and subsequent ‘tanking’ in iced water. Unaged, thawed meat from chicken carcasses, in which freezing commenced about 2 h after stunning was tougher than that from carcasses chilled for 16 h before freezing. Both were tender after 7 days chilled storage. Electrical stimulation of carcasses using 94 V decreased pH20 by an average of 0.3 unit in turkey, with no overall increase in tenderness. In chicken, it decreased the pH20 by 0.5 unit, but caused an overall toughening due to increased rigor shortening in carcasses with pH20 &lt; 5.8.

Thermal Transitions of Natural Actomyosin from Poultry Breast and Thigh Tissues

Natural actomyosin was isolated from broiler breast and thigh tissues, characterized by sodium dodecylsulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and examined for thermal transitions (Tm) during heat-induced aggregation. Electrophoresis showed some variation in the quantity of each subunit protein present between the tissue actomyosins and, with Amido Black staining, yielded actin to myosin molar ratios of 5.71 and 6.33 for breast and thigh natural actomyosins, respectively. The heat-induced initiation of protein to protein interactions occurred at 30 to 31 C for actomyosin of breast tissue and at 42 to 44 C for actomyosin of thigh tissue. Two distinct thermal transitions were found for each actomyosin. Derivative curves from the plot of differential change in optical density or absorbance (A) as a function of temperature (T) (dA/dT) between 28 C and 70 C showed Tm1 at 49.2 C and Tm2 at 60.2 C for breast actomyosin with corresponding values of Tm at 52.6 C and 57.9 C for thigh actomyosin. The interval between Tm1 and Tm2 (ΔTm) for thigh actomyosin (5.3 C) was less than that of breast actomyosin (11.0 C). This result suggests that less thermal energy is required for aggregation of actomyosin from thigh tissue. The differences in thermal characteristics between the two actomyosins may be related to differences observed in heat-processed products prepared from breast and thigh tissues.

Further Studies on the Composition of Commercially Prepared Mechanically Deboned Poultry Meat

Mechanically deboned poultry meat (MDPM) from several areas in the United States produced by three different deboning machines was obtained from commercial plants and analyzed for proximate composition, purines, and amino acids. Adenine, guanine, and xanthine levels were very similar to those found in poultry breast and thigh meats. Hypoxanthine was lower in MDPM than what has been reported in breast or thigh. The amino acid profile was also similar to the typical animal muscle amino acid profile except MDPM contained about .3% hydroxyproline. This level of hydroxyproline indicates that 2.3% collagen was present in the MDPM. Proximate composition values ranged from 62.2 to 70.0% moisture, 13.8 to 22.9% fat, and 11.9 to 16.7% protein.

Antimicrobial Efficacy of a Potassium Sorbate Dip on Freshly Processed Poultry

Fresh poultry breasts were dipped in a solution containing either 0, 2.5, 5.0 or 10.0% potassium sorbate for 1 min. Another lot of fresh poultry breasts was dipped in a suspension of either 103 or 105 cells of three strains of Salmonella/ml before being dipped in one of the potassium sorbate solutions. Use of a potassium sorbate dip significantly reduced the total number of viable bacteria on the poultry parts when compared to the untreated control parts after 7 days of storage at 10 C and after 8 days at 6 C. Use of a 10.0% sorbate dip significantly reduced the total plate count as related to the total plate count of the control parts after 5 days of storage at 22 C. Application of a 10.0% sorbate dip resulted in a significantly lower Salmonella count than of the untreated parts after 7 days of storage at 10 C and a 5.0% or greater sorbate dip markedly reduced the growth rate of the Salmonella at 10 and 22 C when compared to the growth rate of the Salmonella on control parts.

Spoilage Odors in Poultry Meat Produced by Pigmented and Nonpigmented Pseudomonas

Twenty isolates identified as Pseudomonas were obtained from spoiled poultry carcasses. Eleven isolates were pigmented strains (P. boreopulis, P. convexa, P. fairmontensis, P. syncyanea) and the other nine were nonpigmented (P. fragi).To determine whether there was a difference in the spoilage capabilities of pigmented and nonpigmented strains of Pseudomonas, each of the 20 organisms was inoculated into four different sterilized media: (1) blended chicken breast meat and water, (2) blended chicken skin and water, (3) chicken bouillon (commercial), and (4) nutrient broth in which poultry breast meat was substituted for beef extract. Incubation was at 20°C. for 7 days or 4°C. for 14 days. Experienced judges individually evaluated coded samples for intensity and character of odor at the end of each incubation period.Statistical analysis showed that there were no differences in mean odor scores among media, between incubation temperatures or in the opinions of judges. However, difference between pigmented and nonpigmented strains was significant (p = .001); the nonpigmented strains produced more intensive “off” odors.

Effect of chemical treatments causing rapid onset of rigor on tenderness of poultry breast meat

Effect of chemical treatments causing rapid onset of rigor on tenderness of poultry breast meat

RELATION BETWEEN ISOMETRIC TENSION, POSTMORTEM pH DECLINE AND TENDERNESS OF POULTRY BREAST MEAT

Postmortem changes in isometric tension, pH and shear force of poultry breast meat were studied to determine the relation between rigor contraction and tenderness. Strips of pectoralis major muscle immersed in isotonic saline solution held at 25°C developed measurable tension when their pH dropped to 6.1–6.3. The tension gradually increased until the pH dropped to a final value of 5.5–5.8, then started to decline. Muscle cooked at the start of tension development had the highest shear force. After that the shear force of the cooked meat gradually declined to a minimum value. The results indicate a high correlation (r=0.97) between ultimate shear force and degree of maximum tension developed during rigor.

EFFECTS OF PRE‐ AND POSTMORTEM GLYCOLYSIS ON POULTRY TENDERNESS

SUMMARYTo study the effects of glycolysis on tenderness of poultry breast meat, premortem and postmortem glycolysis in muscle tissue was controlled either by epinephrine administration at suitable intervals of time before slaughtering or by allowing the birds to struggle freely just before and during slaughtering. Premortem glycolysis, occurring as a result of death struggle or epinephrine administration 1‐2 hr before slaughtering, lowered the pH of the meat at the time of death and caused toughness. Minimization of postmortem glycolysis by epinephrine administration more than 5 hr before slaughtering increased the ultimate pH of meat and the tenderness. The results indicate that a pH value above 6.2 just after slaughtering, and an ultimate pH near 5.7, are desirable for maintaining quality of poultry breast meat, and that these pH values are maintained by minimum premortem and maximum postmortem glycolysis.

LYSOSOMAL ENZYMES IN BRUISED TISSUE.

SummaryLysosomal DNase, RNase, β-glucuronidase and β-galactosidase activities in experimentally inflicted poultry breast bruises increased by the second day post contusion, reached a maximum between the third and fifth day and then declined toward normal as the bruises showed gross morphological healing. The magnitude of enzymatic response as a result of bruising was not the same for each enzyme, but all enzymes showed the same trends in activity. Activities were elevated to a greater extent in the center of the bruise than at the edge. Normal muscle from bruised chickens had activities similar to tissues excised from unbruised chickens. The effects of increasing the severity of muscular injury were to increase the maximum activity response and, also, the time required to reach it. Free, bound and total DNase, RNase and β-glucuronidase activities were determined as a function of age of bruise. All forms of the enzymes were found to increase during the healing process.

Temperature and pH Changes in Poultry Breast Muscles at Slaughter

DURING a study of factors affecting tenderness in poultry meat, an investigation was made of pH and temperature changes in the breast muscles of birds during and after slaughter. pH has been investigated in beef and pork by Bate-Smith and Bendall (1949), and Scaife (1955). However, little or no work has been done on poultry. pH should give an indication of rates and extensiveness of glycolysis in the tissue and would therefore be a consideration in a study of postmortem tenderization (de Fremery and Pool, 1958). In studies of contraction on rabbit and human muscle Marson et al. (1938) found a slight increase in pH after contraction. This is in apparent conflict with Bate-Smith and Bendall as well as Scaife. A preliminary note on this work was published b y Peters and Dodge, (1959).APPARATUS EMPLOYEDA copper—constantan thermocouple was used to determine the temperature within the muscle. The …

Changes in pH and temperature in poultry breast muscles at slaughter.

DURING a study of factors which might affect the tenderness of poultry meats, some observations were made on the changes in pH and temperature occurring in the breast muscle of birds during and after slaughter.