Descriptive sensory analysis of broiler breast fillets marinated in phosphate, salt, and acid solutions.

Sensory attributes of fully aged broiler breast fillets marinated in a 6% NaCl solution containing 2% sodium tripolyphosphate (2P), 2% citric acid (2C), 2% acetic acid (2A), 1% citric acid plus 1% phosphate solution (1C), or 1% acetic acid solution plus 1% phosphate (1A) were studied. A 6% NaCl (6S) solution with no additives was used as control. Oven-cooked samples (177C degrees oven; 75 degrees C internal temperature) were evaluated by a 9-member trained descriptive analysis sensory panel that rated the intensities of 26 different flavor and texture attributes using 15-point line scales. Data were analyzed using general linear model SAS procedures to determine significant differences (P < or = 0.05) in individual sensory attributes due to marinade treatment. All sensory attributes were scored in the low intensity range (1.5 to 5.0). Brothy, vinegar, and residual particles were the only individual attributes rated significantly different (P < or = 0.05) due to treatment. Multivariate analyses indicated that all sensory attributes formed 2 dimensions that explained 57% of variation in the data. The low intensity values for texture attributes indicated possible negative consequences due to phosphates, salt, and acids when used with fully aged fillets.

Effect of endophyte type on carcass traits, meat quality, and fatty acid composition of beef cattle grazing tall fescue.

Fourteen Hereford steers were used to compare carcass traits, meat quality, and fatty acid composition of beef from cattle grazing tall fescue infected with either wild-type (E+; n = 6) or novel, nil ergot alkaloid (AR542; n = 8) endophyte for 209 d. Average daily gain, live weight, and HCW were greater (P < 0.05) for AR542 cattle than for E+. No differences in LM color or pH were observed between AR542 and E+. Steaks from E+ cattle tended (P = 0.10) to have higher L* and b* than those from AR542 cattle at 0 d of display. Ground beef from E+ cattle also had higher (P < 0.05) L* than AR542 cattle, with no differences in a* or b* at 0 d of display. Color changes during display did not differ for both steaks and ground beef from E+ and AR542. Lipid oxidation levels increased (P < 0.05) during simulated retail display, but they did not differ between endophyte treatments. Adipose tissues from E+ cattle had a higher (P < 0.05) percentage of SFA, and a lower (P < 0.05) percentage of MUFA than adipose from AR542 cattle. Ground beef and i.m. fat had higher (P < 0.05) concentrations of SFA, MUFA, and cis-9, trans-11 isomer of conjugated linoleic acid, and lower (P < 0.05) concentrations of PUFA and PUFA:SFA ratio than s.c. fat. The n-6:n-3 fatty acid ratio did not differ among fat depots. Ergot-alkaloids were detected in s.c. adipose tissues, and alkaloid concentration was greater (P < 0.05) for E+ than AR542. Warner-Bratzler shear force values did not differ between endophyte types, but it decreased (P < 0.01) across the postmortem aging period. Conversely, sensory panel evaluation detected greater (P < 0.01) chewiness and lower (P < 0.05) juiciness for AR542 than for E+ steaks aged for 14 d. Although grazing cattle on tall fescue pastures infected with nil ergot alkaloid endophyte improved cattle performance, these results suggest that endophyte type has minor effects on carcass traits and meat quality of pasture-fed beef. Moreover, finishing cattle on tall fescue pastures showed the potential to enhance the fatty acid profile of beef from a human health perspective. Alkaloid concentration was greater (P < 0.05) in s.c. fat from E+ than AR542 (2.81 vs. 0.92 ppb; fresh-tissue basis). This is the first published report demonstrating the presence of alkaloids in beef tissues.

Prediction of physical, color, and sensory characteristics of broiler breasts by visible/near infrared reflectance spectroscopy.

The feasibility of predicting pH, color, shear force, and sensory characteristics of chicken breasts deboned at 2, 4, 6, and 24 h postmortem by visible/near infrared reflectance spectroscopy (NIRS) in the 400 to 1850 nm region was determined. Prediction of physical attributes of Commission Internationale de l'Eclairage (CIE) color values (L*, a*, and b*), pH, and shear force had better accuracies than those of individual sensory attributes. Calibration and validation statistics for shear force and sensory traits indicated that visible/near infrared models were not significantly improved for cooked muscles compared with predictions based on raw muscle characteristics. On the basis of predicted shear values from the partial least squares (PLS) model, breast samples were classified into "tender" and "tough" classes with a correct classification of 74.0% if the boundary was set at 7.5 kg. The model developed from measured shears using soft independent modeling of class analogy/principal components analysis (SIMCA/PCA) showed nearly the same classification success.

Effects of diet and feed withdrawal on the sensory descriptive and instrumental profiles of broiler breast fillets.

Effects of diet and feed withdrawal times on the sensory profile and shear values of broiler breast meat were determined. Feeds were formulated with 3 dietary carbohydrate sources (corn, milo, and wheat). Birds (n = 192) were processed between 42 and 52 d of age. Feed was withdrawn for 0 or 8 h prior to pilot plant processing under simulated commercial conditions. Pectoralis major muscles were removed 4 h postmortem and frozen until evaluated. Thawed breast fillets were cooked in heat-seal bags immersed in 85 degrees C water until an internal temperature of 80 degrees C was reached. Color, shears, and sensory profiles (18 attributes) were determined. Meat from corn-fed birds required significantly less force to shear (6.0 kg) than meat from birds fed milo (6.7 kg) or wheat (7.1 kg). Feed withdrawal did not affect the flavor profile; however, meat from birds at 0 h feed withdrawal were darker and redder. Diet significantly affected the sensory profile. Brothy scores were significantly higher in meat from corn-fed birds than in meat from birds fed wheat or milo. Diet and feed withdrawal significantly affected sensory texture. Meat from wheat-fed birds was harder, more cohesive, and more chewy and exhibited larger particle size than meat from birds fed corn or milo. Moisture release values were lower and toothpack values were higher in meat from birds processed at 0 h feed-withdrawal time compared with meat from birds held 8 h without feed. Dietary carbohydrate source appears to have a measurable impact on flavor and texture of broiler breast meat.

Principal component analysis of physical, color, and sensory characteristics of chicken breasts deboned at two, four, six, and twenty-four hours postmortem.

The effects of various postchill deboning times on functional, color, yield, and sensory attributes of broiler breast meat were determined. Broiler breast muscles were deboned at 2, 4, 6, and 24 h postmortem, and pH, color change, cooking yield, shear force values, and sensory traits of the breast meat were recorded. Data were examined by multivariate data analysis, namely principal component analysis (PCA). Averages of 13 variables (pH, delta a*, shear force, and sensory attributes of cardboardy, wet feathers, springiness, cohesiveness, hardness, moisture release, particle size, bolus size, chewiness, and metallic aftertaste-afterfeel) decreased gradually as deboning time increased from 2 to 24 h, especially for shear values after 4 h of postmortem aging. Univariate correlation coefficients among 24 variables indicated several significant correlations. Warner-Bratzler shear force had high positive correlations with 5 sensory texture attributes (cohesiveness, hardness, particle size, bolus size, and chewiness). The parameters of pH, delta L*, delta a*, delta b*, and cooking yield were not obviously correlated with shear force values or any of the 18 sensory characteristics. PCA score plot showed no clear separation of the breast muscles deboned at different postmortem times, but it was still possible to differentiate them. The loading biplot suggested that 18 variables were effective in sample differentiation, including delta L*, shear force, cooking yield, 6 sensory flavor attributes (brothy, cardboardy, wet feathers, blood/serumy, salty, and sour), all sensory texture attributes except springiness, and all afterfeel-aftertaste properties.

The effect of age, dietary carbohydrate source, and feed withdrawal on broiler breast fillet color.

An experiment was conducted to determine the effect of bird age, diet (feeds formulated with 69.5% corn, 69.7% milo, or 73.6% wheat), and feed withdrawal times (0 or 8 hours) on color (CIE L*, lightness; a*, redness; and b*, yellowness) of raw broiler breast fillets. Broilers were placed on diets at 28 d of age. Replicate groups of 24 birds (eight each from different diet and four each either full fed or feed withdrawn) were processed (slaughtered and eviscerated under simulated commercial conditions) each day from 42 to 45 and 49 to 52 d of age (n = 192). Carcasses were chilled and deboned 4 h postmortem, and triplicate color measurements taken from the medial (bone) side of the fillet. Bird age did not significantly affect fillet color values. Fillets from the birds fed the wheat diet were significantly lighter than fillets from the corn or milo fed birds (48.9 vs. 46.9 and 46.7, respectively). The milo diet resulted in significantly redder fillets than corn or wheat (3.9 vs. 3.5 and 3.3, respectively). The corn diet produced significantly more yellow fillets than milo or wheat (4.8 vs. 2.4 and 2.6, respectively). Feed withdrawal significantly increased fillet lightness from an average of 46.1 to 48.9, decreased redness from 4.1 to 3.1, and increased yellowness from 2.8 to 3.7. Raw broiler breast fillet color is significantly affected by both diet and feed withdrawal, but not by age.

Color of uncooked and cooked broiler leg quarters associated with chilling temperature and holding time.

Discoloration of raw or cooked tissue can occur from cell disruptions and blood migration caused by slow or variable chilling rates. Color parameters established by the Commission International D'Eclairage for measuring lightness, redness, and yellowness (L*, a*, and b* respectively) were determined on two groups (A and B) of uncooked and cooked leg quarters chilled at +4, 0, -3, -12, or -18 C. At Day 7, group A was evaluated for color, and group B was moved to -18 C for seven additional days and then evaluated. Group B represented cooling, freezing, thawing, and cooking steps. Color was measured on surfaces of thawed, uncooked parts (UCS), on surfaces of cooked parts (CS) 75 or 85 C internal temperature), and on cooked meat (CM) adjacent to the femur. UCS samples at -3 C were significantly redder (a* = 8.91) than -18 C samples (a* = 5.04). The A-CS a* values showed a significant interaction between chill temperature storage and internal temperature (IT). Samples at 75 C IT had higher a* values (redder). CM samples held at +4 and 0 C were significantly lighter (higher L* values). A significant interaction effect occurred for CM a* values due to storage chill temperature and IT. Generally, 75 C IT samples were redder (higher a* values). UCS and CS color was not influenced by chilling at +4 to -18 C for 7 d and then at -18 C for 7 d. CM was affected by a combination of chill temperature history and IT.

Acid phosphatase activity and color changes in consumer-style griddle-cooked ground beef patties.

The U.S. Department of Agriculture and the Food and Drug Administration have issued temperature requirements to help consumers cook beef patty products that are free of pathogens. Verification of end-point temperature (EPT) is needed in cooked meat products due to concerns over outbreaks of Escherichia coli O157:H7. Acid phosphatase (ACP) activity was studied as a potential method for determination of EPT in ground beef patties cooked nonfrozen, patties frozen 7 days and thawed at room temperature 4 h in a refrigerator or by microwave, and patties made from ground beef frozen in store packages, then thawed in a refrigerator overnight. Pressed-out meat juices were analyzed from patties (n = 314) cooked to 57.2 degrees C (135 degrees F). 65.6 degrees C (150 degrees F), 71.1 degrees C (160 degrees F), and 79.4 degrees C (175 degrees F) target EPTs. Expressed meat juice and internal meat patty color decreased in redness as EPT increased. Freezing whole packs with slow refrigerator or room temperature thawing caused significantly greater loss of redness in expressed cooked meat juice than did other handling methods. Log10 ACP had a significant linear (R2 = 0.99) response to EPT. Results show that the 3- to 5-min ACP test could be used to verify EPT in griddle-cooked hamburger patties.

Visual color and doneness indicators and the incidence of premature brown color in beef patties cooked to four end point temperatures.

An interlaboratory study was undertaken to assess the frequency that cooked color of ground beef patties appeared brown at internal temperatures of 52.7 degrees C (135 degrees F), 65.6 degrees C (150 degrees F), 71.1 degrees C (160 degrees F), and 79.4 degrees C (175 degrees F). In general, as internal cooked temperature of the patties increased, the following results were observed in the patties: (i) more brown meat color, (ii) less pink or red juice color, and (iii) more cooked texture. However, brown meat color occurred prematurely at the two lower internal temperatures (57.2 degrees C/135 degrees F and 65.6 degrees C/150 degrees F) that are insufficient to eliminate foodborne pathogens without holding times. The common consumer practice of freezing bulk ground beef, followed by overnight thawing in a refrigerator, led to substantial premature brown color in patties cooked from this product. In addition, at 71.1 degrees C (160 degrees F), recognized to be the lowest temperature for cooking ground beef safely in the home, meat color, juice color, and texture appearance were not fully apparent as doneness indicators. In fact, at no temperature studied did 100% of the patties appear done when evaluated by the criteria of no red or pink in the meat, no red or pink in the juices, or by texture appearance. Patties in this study were evaluated under a set protocol for forming the products, cooking, and viewing under the same lighting conditions. Other preparation conditions are possible and may produce different results. Thus, temperature to which patties have been cooked cannot be judged by color and appearance. This study provided the evidence to support the message to consumers regarding cooking of beef patties of "use an accurate food thermometer and cook beef patties to 160 degrees F (71.1 degrees C)" in place of messages based on consumer judgment of cooked color.

The microbiological profile of chilled and frozen chicken.

To determine the effect of different refrigeration and freezer temperatures on the microbiological profile of chicken, 50 commercially processed broiler chickens were each split in half on the day of processing. Equal groups were held at 4, 0, -4, -12, and -18 degrees C (40, 32, 26, 10, and 0 degrees F), respectively for 7 days. One half of each group was then transferred to a 0 degrees F holding chamber for an additional 7 days. Carcass halves were rinse sampled with 100 ml of phosphate-buffered saline and the diluent sampled for mesophilic, psychrotropic, coliform, and salmonellae counts after the initial 7 days at different temperatures and after 7 additional days at -18 degrees C. Ten carcass halves were sampled on the day of processing to give baseline counts. Mesophilic bacteria counts/ml were about log 4.6 on day 0, increased by 2 log after 7 days on carcasses held at 4 degrees C, and were unchanged at all other storage temperatures. Psychrotropic counts/ml were about log 3.6 on day 0 and increased during the initial 7 days by about 3.9, 1.9, and 1.4 logs, respectively on carcasses held at 4, 0, and -4 degrees C and had less than 1 log increase at -12 and -18 degrees C. Coliform counts were about log 2.2/ml on day 0 and had declined to about log 1.5/ml or less by day 7 for all storage temperatures. Escherichia coli counts/ml were about log 2 on day 0 and were reduced about 1 log or more at other storage days. Salmonellae counts were about log 1.5 on salmonellae-positive carcasses and did not change appreciably at any storage temperature. No counts for any organism significantly changed after placement at -18 degrees C.

Assessment of three devices used in shear tests of cooked breast meat.

Methods that increase processing efficiency to save energy costs and to improve yield and volume must be evaluated in terms of maintaining or improving final product quality. Shear tests measure the force to cut through fibers of cooked samples. They are the simplest and most common tests used to document cooked meat texture. However, information obtained from shearing devices that perform in a similar way may not be interchangeable. In this study, three shearing devices were assessed. Eight treatments were imposed on broiler breasts processed under commercial conditions to represent ranges of texture characteristics. Treatments included electrical stimulation (S), or no stimulation (NS) of carcasses; postchill deboning at 2 or 6 h; and marination (M), or no marination (NM). Shear force values of cooked breasts were obtained from the benchtop Warner-Bratzler (BT-WB) machine, the Warner-Bratzler blade attachment (TA-WB) and a 45 degrees chisel-end blade attachment (TA-WD). The TA-WB and TA-WD were attached to Model TA.XT2 texture analyzer. For each device, shear value differences were significant (P < 0.05) for deboning time. Marination effects were significant (P < 0.05) for BT-WB and TA-WB. Stimulation by debone interactions were significant (P < 0.05) for BT-WB and TA-WD. The TA-WD values varied the greatest over all treatments (SD = 5.52; SE = 0.65). Variations of BT-WB and TA-WB shear values were similar (SD = 3.25, 2.97, respectively; SE = 0.38, 0.35).

Texture evaluations of cooked, diced broiler breast samples by sensory and mechanical methods.

The texture of cooked chicken breast is usually determined on intact pieces or strips that are representative of the muscle. Researchers emphasize the importance of uniformity of sample size and orientation of fibers to the shearing blades to ensure consistent data from instruments such as shear devices. For sensory evaluations, sample pieces of chicken breasts presented to panelists are often sized as single 2-cm2 or several 1-cm2 pieces. In this study, two sensory and two mechanical procedures were evaluated for efficacy in discerning texture differences in 1-cm2 pieces of cooked chicken. Three postmortem deboning times (2, 6, and 24 h) provided a texture quality spectrum. Sensory characteristics were evaluated by descriptive analysis trained panel (DA-TP) and by category scales-untrained panel (CS-UP). Twenty-gram breast portions of 1-cm2 pieces were evaluated using a multi-blade Allo-Kramer (AK) shear blade. Warner-Bratzler (WB) shear values of intact 1.9-cm-wide strips were also recorded. Discriminant analysis classification based on CS-UP gave higher error rates (probabilities of misclassification) than classification based on DA-TP. The CS-UP error rates were 0.36 (tender) and 0.65 (juiciness). The error rate of classification by DA-TP was 0.21. Error rates for classification by mechanical devices were 0.30 for WB and 0.21 for AK. Sample size is a consideration in texture evaluation protocols. Smaller sample pieces appear to mask differences in initial chew characteristics and in juiciness that are due to deboning time.

The effect of an acetic acid dip on carcass appearance, microbiological quality, and cooked breast meat texture and flavor.

In Experiment 1, broiler carcasses were subjected to a 10-min prechill treatment with and without a food grade vinegar at a concentration of .6% acetic acid. After treatment the carcasses were monitored for visual appearance and microbiological quality. Color change and skin appearance were subjectively monitored. Microbiological quality was determined using the low volume whole carcass rinse. Shear values of cooked muscle were determined using a Warner-Bratzler attachment to an Instron. In a second experiment using the same treatment protocol, treated carcasses were chilled in an ice slush for 30 min and held overnight at 2 C. The breast muscles were removed and cooked by two methods. Triangle tests to determine sensory differences due to acetic acid were conducted. The skin color of treated carcasses turned a light yellow, and the feather follicles were protruded or puckered. Total aerobic counts were not affected by any of the treatments, but Enterobacteriaceae (ENT) counts of treated carcasses were significantly lower than the counts for the water control carcasses. Log10 ENT counts ranged from 4.51 for the control to 3.80 for the carcasses treated with acetic acid. Based on sensory triangle tests using a trained panel, there were no significant differences in the samples from either cooking method.

Effect of Heating on Water Soluble Biuret-Positive Compounds of Canned Cured Pork Picnic Shoulder.

Protein solubility loss as a result of heat denaturation/coaguiation was followed by a ratio of extractable biuret positive compounds (EBPR). Extracts of water-soluble proteins were evaluated by isoelectric focusing (IEF) on polyacrylamide gels. Four heat treatments (60°C, 62.8°C, 65.6°C and 68.8°C) were employed in processing canned (No. 300×407) cured pork. Center cores from canned samples were ground for water soluble protein extraction utilizing a 1:3.3 meat-to-water ratio by high-speed blending (Sorvall Omni-mixer) for 1 min at 0-2°C, centrifuging 10 min at 27,000 ×g at 0-2°C and filtering (0.45-µa.m) with vacuum assist. Eight ml of the clear extract was re-heated in a glass tube for 15 min at 70°C, removed, and chilled (0-2°C) immediately. Coagulum was removed by filtration. EBPR was calculated from mg of protein/ml of initial muscle extract divided by mg of protein/ml of reheated extract for each temperature treatment. EBPR values were 1.75, 1.24, 1.13, and 1.10, respectively. Using 70°C as the critical temperature, an upper 95% confidence limit EBPR value of 1.12 was calculated. Portions of protein extract were isoelectrofocused on thin layer (0.8 mm) low concentration (5% monomer) polyacrylamide gels (pH gradient 3-10). IEF gels generally showed resolution of 12 to 23 protein bands in the muscle extracts, depending upon temperature treatment. Certain bands with apparent isoelectric points (pis) ranging from 7.4 to 8.5 decreased in staining intensity (silver stain) as temperature increased. The general protein separation profiles correlated with decreasing EBPR values as temperature increased.

Detection of blood (hemoglobin) contamination in poultry muscle tissue.

Incidence of blood spots in fresh marketed poultry and batter or breaded frozen fried chicken may be related to certain processing parameters (i.e., stunning, bleed-out time). Spectrophotometric and cation exchange high performance liquid chromatography (HPLC) procedures were evaluated as potential methods to test for hemoglobin (Hb) contamination in poultry tissue. Muscle tissue was blended with TRIS-ethylenediaminetetraacetate buffer, pH 7.4, centrifuged and the extract scanned for absorbance at 540 and 580 nm. Tests with model systems gave a linear regression coefficient of r + .98 for detection of 0 to 1% blood in experimentally contaminated tissue. Analyses of extracts by cation exchange HPLC (545 nm) showed three separation peaks characteristic of hemoglobin. Isoelectrofocusing of the extracts on thin-layer polyacrylamide gels (pI 3 to 10) was also evaluated. These procedures could prove useful in subsequent studies to determine the cause of blood spotting in muscle tissue.