Implications of white striping and wooden breast abnormalities on quality traits of raw and marinated chicken meat

One of the consequences of intense genetic selection for growth of poultry is the recent appearance of abnormalities in chicken breast muscles, such as white striping (characterised by superficial white striations) and wooden breast (characterised by pale and bulged areas with substantial hardness). The aim of this study was to evaluate the quality traits of chicken fillets affected by white striping and wooden breast abnormalities. In two replications, 192 fillets were divided into the following four classes: normal (n=48; absence of any visual defects), white striping (n=48, presence of white striations), wooden breast (n=48; diffusely presence of hardened areas) and white striping/wooden breast (n=48; fillets affected by both abnormalities). Morphology, raw meat texture and technological properties were assessed in both unprocessed (pH, colour, drip loss, cooking loss and cooked meat shear force) and marinated meat (marinade uptake, purge loss, cooking loss and cooked meat shear force). Fillets affected by white striping, wooden breast or both abnormalities exhibited higher breast weights compared with normal fillets (305.5, 298.7, 318.3 and 244.7 g, respectively; P<0.001). Wooden breast, either alone or in combination with white striping, was associated with a significant (P<0.001) increase of fillet thickness in the caudal area and raw meat hardness compared with both normal and the white striping abnormality, for which there was no difference. Overall, the occurrence of the individual and combined white striping and wooden breast abnormalities resulted in substantial reduction in the quality of breast meat, although these abnormalities are associated with distinct characteristics. Wooden breast fillets showed lower marinade uptake and higher cooking losses than white-striped fillets for both unprocessed and marinated meats. On the other hand, white-striped fillets showed a moderate decline in marinade and cooking yield. Fillets affected by both abnormalities had the highest (P<0.001) ultimate pH values. In contrast, the effects on colour of raw and cooked meat, drip loss, purge loss and cooked meat shear force were negligible or relatively low and of little practical importance. Thus, the presence of white striping and wooden breast abnormalities impair not only breast meat appearance but also the quality of both raw and marinated meats mainly by reducing water holding/binding abilities.     

Efficacy of marinades against Listeria monocytogenes cells in suspension or associated with green shell mussels (Perna canaliculus).

In order to determine the listericidal efficacies of three marinades used in the production of marinated green shell mussels (Perna canaliculus), decimal reduction times (D values) were determined for a mixture of seven strains of Listeria monocytogenes exposed to marinades in the presence and absence of mussels. With an acetic acid (1.5%, wt/vol) marinade, calculated D values in the presence and absence of mussels were 77.3 and 33.3 h, respectively. Likewise, for an acetic acid (0.75%)-lactic acid (0.75%) marinade and an acetic acid (1.5%)-Glucono Delta-Lactone (0.2%)-based marinade, the D values in the presence and absence of mussels were 125.5 and 26.9 h and 86.3 and 19.3 h, respectively. Various increases in decimal reduction times in the presence of mussels indicated that there was no simple relationship between the listericidal natures of these marinades and the presence of mussels. This result suggests that difficulties may occur in trying to relate acid inhibition studies carried out in model broth systems to "real food" systems.     

Transfer of Campylobacter jejuni from raw to cooked chicken via wood and plastic cutting boards

Aims: We quantified Campylobacter jejuni transferred from naturally contaminated raw chicken fillets and skins to similar cooked chicken parts via standard rubberwood (RW) and polyethylene cutting boards (PE). Methods and Results: RW and PE cutting boards (2·5 × 2·5 cm²) were constructed. RW surfaces were smooth and even, whereas PE was uneven. Scoring with scalpel blades produced crevices on RW and flaked patches on the PE boards. Raw chicken breast fillets or skin pieces (10 g) naturally contaminated with Camp. jejuni were used to contaminate the cutting boards (6·25 cm²). These were then briefly covered with pieces of cooked chicken. Campylobacter jejuni on raw chicken, the boards, and cooked chicken pieces were counted using a combined most‐probable‐number (MPN)‐PCR method. The type of cutting board (RW, PE; unscored and scored) and temperature of cooked chicken fillets and skins were examined. Unscored PE and RW boards were not significantly different in regards to the mean transfer of Camp. jejuni from raw samples to the boards. The mean transfer of Camp. jejuni from scored RW was significantly higher than from scored PE. When the chicken fillets were held at room temperature, the mean transfer of Camp. jejuni from scored RW and PE was found to be 44·9 and 40·3%, respectively. Conclusions: RW and PE cutting boards are potential vehicles for Camp. jejuni to contaminate cooked chicken. Although cooked chicken maintained at high temperatures reduced cross‐contamination via contaminated boards, a risk was still present. Significance and Impact of the Study: Contamination of cooked chicken by Camp. jejuni from raw chicken via a cutting board is influenced by features of the board (material, changes caused by scoring) and chicken (types of chicken parts and temperature of the cooked chicken).     

SHELF-LIFE ESTIMATION OF APPLE-BABY FOOD

The aim of the present work was to study the evolution of the color of an apple‐baby food and to estimate its sensory shelf life. Samples of apple‐baby food stored at 25C were analyzed using trained assessors and a consumer panel. A zero‐order reaction kinetics was found for the evolution of sensory color with storage time. Color was highly correlated with consumers' rejection percentage and overall acceptability, which indicates that consumers consider this attribute when deciding to accept or reject this product and in assigning their acceptability scores. Using this correlation, the sensory cutoff point for color, corresponding to a 25% consumer rejection, was calculated. Sensory shelf life was estimated using consumer data. Sensory shelf life estimated by survival analysis was in agreement with that calculated considering an acceptability limit of 6.0 in a 9‐point hedonic scale.     

THE PSYCHOPHYSICAL RELATIONSHIP BETWEEN COLOR AND SALT CONCENTRATIONS IN CHICKEN FLAVORED BROTHS

Taste panelists evaluated the effect of color on salt perception in chicken flavored samples using magnitude estimation. Samples were colored to simulate commercial chicken broth. Five color intensities were added to 5 NaCl concentrations ranging from 0.34 to 0.66% (w/v). Color had no influence on salt perception. Panelists were able to perceive color differences among samples (P <0.001) and these were correlated with the objective color function cot⁻¹ (a/b) calculated from the L,a,b values obtained from the Gardner XL-23. Overall flavor preference was evaluated by a taste panel using the technique of magnitude estimation. NaCl concentrations ranged from 0.52 to 0.80% (w/v). Overall flavor preference was unaffected by color. A reduction in NaCl concentration from 0.80% (w/v) to 0.52% (a 35% reduction) did not alter flavor preference. A 50 member consumer panel using a paired comparison test found no difference in flavor preference between an uncolored sample containing 0.80% (w/v) NaCl and a colored sample containing 0.72% (w/v) NaCl.     

SENSORY AND INSTRUMENTAL EVALUATION OF STRAWBERRY YOGURT COLOR

Eleven samples of strawberry yogurt prepared with different red color concentrations using Ponceau 4R (E-124) were evaluated by instrumental and sensory methods. Color intensity evaluation was carried out by a panel of eight assessors specifically trained to measure strawberry color in yogurt. Color acceptability was measured with 120 regular and frequent consumers of yogurt. Color was measured with a Minolta Chroma Meter CR-200b, obtaining parameters L*, a* and b*. Principal component analysis was performed on the instrumental variables. Regression models between the instrumental first principal component, red color concentration, sensory intensity, and acceptability allowed determining quality control limits for red color attribute. These limits may be controlled by selecting either instrumental or sensory methods, being the latter easy to implement and providing dependable results.     

DEVELOPMENT OF A LEXICON FOR BEEF FLAVOR IN INTACT MUSCLE

ABSTRACT

A lexicon describing the flavor characteristics of beef across different cuts, grades, and cooking temperatures and methods was developed. Four major cuts of the United States Department of Agriculture (USDA) quality grade beef were cooked to five endpoint temperatures using braising, broiling (oven broiling and electric charbroiling), roasting and grilling (indoor and outdoor grilling). Six highly trained panelists identified and defined a total of 38 aroma and flavor characteristics in 176 beef samples. Beef identity, brown/roasted, bloody/serumy, metallic, fat‐like, overall sweet, sour aromatics and five tastes were present in practically all samples. Other attributes were present only in certain samples, depending on either the sample group or the cooking method/endpoint temperature combination used. This lexicon potentially offers the beef industry a standard tool to identify and quantify flavor attributes as impacted by temperature, cooking method, aging process, storage time, diet regime, packaging, USDA quality grades, etc.

PRACTICAL APPLICATIONS

Until now, the beef industry's main focus has been to assess beef tenderness and juiciness, with an emphasis on ways to improve beef texture. Meat companies and academic institutions have been using the 1995 American Meat Science Association guidelines to assess the flavor of beef, which are not comprehensive. Recent work has focused on flavor, and the industry needs a standardized flavor lexicon that can be used for many projects. It is important for the industry to be able to systematically identify and quantify flavor attributes that drive consumer acceptance.     

Physical,chemical and organoleptic properties of ram lamb carcasses from four fat-tailed genotypes

Physical, chemical and organoleptic characteristics of 20 ram lambs representing four fat-tailed genotypes Awassi, Red Karaman, Tushin and Awassi×Tushin were compared. After slaughter, carcasses were chilled at 5°C for 24 h, graded and evaluated. Then, the carcasses were dissected into wholesale cuts and longissimus dorsi (LD) and semimembranosus (SM) muscles were excised. The muscles were subjected to moisture, protein, fat and ash analyses and they were cooked to evaluate palatability. Cold carcass weight of RK and A×T lambs were heavier (P<0.01) than those of A and T lambs. A×T crossbreds had higher (P<0.05) cold dressing percentage and larger LD area than T lambs. However, the influence of genotype on the proportion of boneless retail cuts and marbling were not significant. Most of the proportions of wholesale cuts except for sirloin and flank were not affected by the genotype. The sensory panel found the meat from all genotypes acceptable (tenderness, juiciness, flavor and acceptability). Chemical composition of meat from the different genotype was not significantly different. The study reveals generally insignificant differences in chemical, physical and organoleptic properties between fat-tailed lambs with different genetic backgrounds.     

GRAPES: A METHOD AND A SAS® PROGRAM FOR GRAPHICAL REPRESENTATIONS OF ASSESSOR PERFORMANCES

GRAPES computes individual and global analyses of variance for sensory profiling data, consisting of several sessions in which all the panelists gave scores to all the products for a number of attributes. The fitted model takes into account the session effect. GRAPES summarizes the results by means of graphical assessor scatterplots which allow to check and to compare panelist performances, such as the way of using scale, the reliability, the discrimination power and the agreement with the panel. In addition, GRAPES detects the outliers for each of these criterion. The usefulness of GRAPES for the panel leader will be demonstrated using texture and flavor profiling of 4 restructured steaks by 12 assessors for 15 attributes. The SAS® program GRAPES, available by e-mail from the author, requires the SAS/BASE®, SAS/STAT®, SAS/GRAPH® and SAS/IML® softwares.     

DETECTION AND INTERPRETATION OF VARIATION WITHIN AND BETWEEN ASSESSORS IN SENSORY PROFILING

In this paper we discuss methods that can be used to evaluate the performance of sensory panels. In particular we concentrate on detection of variation within and among panelists. A systematic presentation of some simple, graphically oriented tools will be given. Interpretation aspects of the tools will be emphasized. The methods will be illustrated by computations from a sensory experiment based on 4 sausage products. The example demonstrates how the tools can be used to evaluate the reproducibility of the assessors and also how they can be used to detect different types of individual differences among the assessors.     

COMPARISON OF THE SENSORY PROPERTIES OF ULTRA-HIGH-TEMPERATURE (UHT) MILK FROM DIFFERENT COUNTRIES

Shelf-stable milk, also known as ultra-high-temperature (UHT) milk is the most common form of milk in many parts of the world. This study compared the differences in flavor and texture of 37 commercially available UHT and sterilized milk samples including whole, 2% reduced-fat and low-fat milk obtained from markets in seven countries: France ( n =  2), Italy ( n =  11), Japan ( n =  1), Korea ( n =  2), Peru ( n =  3), Thailand ( n =  13) and the U.S.A. ( n =  5). Five highly trained panelists used flavor and texture profiling to describe the sensory properties of each milk sample. Data were analyzed by principal component analysis and hierarchical cluster analysis. Higher levels of processed, chalky, brown and cooked flavor notes generally corresponded to lower levels of fresh dairy flavor characteristics. In general, samples did not vary consistently within a country. Fat content did not correlate with dairy fat flavor or with viscosity. This research suggests that companies' manufacturing processes for UHT milk may have more impact than country or fat content in determining sensory properties of UHT milk.

PRACTICAL APPLICATIONS

Sensory properties of UHT milk from different countries developed in this study could be used by the dairy industry to understand the similarities and differences of UHT milk characteristics from different regions and to modify UHT milk characteristics to meet consumers' criteria or expectation. The study suggests that manufacturers who want to improve quality of UHT milk by modify flavor and texture properties should focus on improvements to the manufacturing processes.     

NOTE ON COMPUTERIZED DATA COLLECTION IN CONSUMER SENSORY EVALUATION

Panelists with computer experience (n = 24) and without (n = 26) rated three foods representing liked, neutral and disliked categories using a 9-point hedonic scale on computer and paper ballots. In paired t-test results between computer and ballot ratings, no differences were found in overall acceptance, flavor and appearance attributes. Regression analysis indicated a significant (p<0.01) linear relationship between computer and paper ballot ratings. Computer ballot ratings for overall acceptance were comparable to paper ballot ratings in a consumer sensory evaluation test. Slight differences in overall acceptance were found between computer and paper ballot responses from panelists with and without computer experience. GLM indicated the group without computer experience rated overall acceptance and flavor attributes for cereal, and appearance and flavor attributes for potato chips significantly higher (p<0.05) than panelists with computer experience.     

EFFECTS OF A SLIGHT COLOR VARIATION ON CONSUMER ACCEPTANCE OF ORANGE JUICE

Three hundred and forty-two consumers participated in a study examining slight color variation in orange juice. Panelists evaluated two orange juice samples; unadulterd juice and the same juice with a slight green off-color. The color manipulation reduced consumer acceptance of the color of the adulterated sample but had little influence on ratings of flavor, sweetness or overall liking. Older panelists were more strongly influenced by the color manipulation and showed a clear preference for the flavor of the control sample as compared to the adulterated sample. These data suggest that color was important for the visual appeal of orange juice, but the color change alone was not sufficient to alter consumer acceptance of this product.     

Design and optimization of hot-filling pasteurization conditions: Cupuaçu (Theobroma grandiflorum) fruit pulp case study

Cupua?u (Theobroma grandiflorum) is an Amazonian tropical fruit with a great economic potential. Pasteurization, by a hot-filling technique, was suggested for the preservation of this fruit pulp at room temperature. The process was implemented with local communities in Brazil. The process was modeled, and a computer program was written in Turbo Pascal. The relative importance among the pasteurization process variables (initial product temperature, heating rate, holding temperature and time, container volume and shape, cooling medium type and temperature) on the microbial target and quality was investigated, by performing simulations according to a screening factorial design. Afterward, simulations of the different processing conditions were carried out. The holding temperature (T(F)) and time (t(hold)) affected pasteurization value (P), and the container volume (V) influenced largely the quality parameters. The process was optimized for retail (1 L) and industrial (100 L) size containers, by maximizing volume average quality in terms of color lightness and sensory "fresh notes" and minimizing volume average total color difference and sensory "cooked notes". Equivalent processes were designed and simulated (P(91)( degrees )(C) = 4.6 min on Alicyclobacillus acidoterrestris spores) and final quality (color, flavor, and aroma attributes) was evaluated. Color was slightly affected by the pasteurization processes, and few differences were observed between the six equivalent treatments designed (T(F) between 80 and 97 degrees C). T(F) >/= 91 degrees C minimized "cooked notes" and maximized "fresh notes" of cupua?u pulp aroma and flavor for 1 L container. Concerning the 100 L size, the "cooked notes" development can be minimized with T(F) >/= 91 degrees C, but overall the quality was greatly degraded as a result of the long cooling times. A more efficient method to speed up the cooling phase was recommended, especially for the industrial size of containers.     

SENSORY EVALUATION OF VANILLA-DAIRY DESSERTS BY REPERTORY GRID METHOD AND FREE CHOICE PROFILE

“Natillas” are semisolid dairy desserts widely consumed in Spain, with notable differences existing between commercial brands in their composition and sensory and physical properties. The repertory grid method, in conjunction with the free choice profile (FCP), was used to provide data on how consumers perceived eight commercial “natillas” samples. The most frequent terms used were: vanilla flavor, sweetness, consistency and liquid texture as described by 77, 67, 57 and 53% of the consumers, respectively. A three‐dimensional solution was chosen. Dimension 1 accounted for 27.23% of variance and separated the samples largely by yellow‐color intensity and consistency. Dimension 2 (15.88%) was mainly related to the visual attributes of texture, creaminess and different notes of flavor. The third dimension (11.34%) was related to structural‐texture attributes, orange‐yellow color and acid and artificial flavors. The assessors plot showed two clusters. Analysis of each group data revealed differences in their perception of sample variation, mainly regarding texture and color.     

THE EFFECTS OF COLORED TEXTURED SOYBEAN PROTEIN (TSP) ON SENSORY AND PHYSICAL ATTRIBUTES OF GROUND BEEF PATTIES

Defatted soybean flour mixed with a combination of 0.03% Red No. 40 and 0.01% annatto ( Bixa orellana ) colorants was extruded into textured soy protein (TSP) in a counter-rotating twin extruder to produce a red-meat like product suitable for hamburger patties. Ground beef patties were processed replacing the meat (15 and 30%) with resulting hydrated textured soybean protein (TSP) prepared with and without the colorants. The resulting cooked patties were evaluated by eight trained judges for tenderness, juiciness, number of chews, beef flavor and overall flavor quality using a nine point nonstructured horizontal scale. Other patty characteristics examined included cooking losses (weight loss and diameter reduction) and color, by tristimulus colorimetric measurement. The results from sensory analysis revealed that ground beef patties with high TSP level were more tender than control, and they had less beef flavor and overall flavor quality. Weight loss was not significantly (P > 0.05) affected by TSP level but the patties with 30% TSP showed less shrinkage than the others. Results of the study suggested that while patties with 15% TSP had sensory attributes similar to the control, adding 30% TSP with coloring significantly (P < 0.05) increased the redness of the patties.