Relationship between beef consumer tenderness perception and Warner-Bratzler shear force

The aim of this study was to determine consumer ability to discern different levels of beef tenderness established by Warner-Bratzler shear (WBs). A panel of 220 people evaluated 60 samples of longissimus thoracis using a 5-point intensity scale (1: very tough; 5: very tender). Samples differed for commercial category, breed of animals and ageing length of meat. Shear force was measured by Instron equipped with a Warner-Bratzler device on 1.27cm diameter cores. Correlation coefficient of WBs measurements with tenderness sensory ratings was -0.72. WBs value corresponding to class 3 of the sensory tenderness was 47.77N. From this value, the range of WBs (22.96-72.59N) was split into five categories to which connect the five classes of sensory tenderness. The results suggest consumers' difficulty in discriminating category 1 (WBs>62.59N) from category 2 (WBs: 52.78-62.59N) and a greater inclination to distinguish category 5 (WBs<32.96N). As WBs category boundaries were probably too restrictive for the panel's selective ability, WBs scale was reduced to 3 categories by joining the two extreme categories (i.e. category 2 with 1 and category 4 with 5). In this case, 55.6% of consumers significantly discriminated tough from intermediate and tender meat and 62.3% distinguished tender from intermediate and tough meat (P<0.01). Hence, WBs values >52.68N and <42.87N allow classification of tough and tender beef in a sufficiently reliable way.     

Cookery method and end-point temperature can affect the Warner-Bratzler shear force, cooking loss, and internal cooked color of beef longissimus steaks

Steaks from 60 beef ribeye rolls were used to test the interactive effects of cookery method and end-point temperature on Warner-Bratzler shear force (WBSF) and internal cooked color. Pairs of longissimus thoracis (LT) steaks were assigned to combinations of 3 different end-point temperatures and 5 cookery methods. The forced-air convection oven (FAC) required the longest time and produced the reddest internal color, regardless of end-point temperature. The clam-shell grill (CLAM) required the least cooking time and resulted in the lowest cooking losses, but CLAM-cooked steaks also had the greatest WBSF values and least red internal color. Repeatability values for WBSF were acceptable (>0.60) for all degrees of doneness when steaks were cooked in the FAC and impingement oven, but steaks cooked on the CLAM were not repeatable. The relationship of myofibrillar toughening, moisture loss and cooked color changes in beef LT steaks also differed due to cookery methods.     

Effects of muscle shortening and proteolysis on Warner-Bratzler shear force in beef longissimus and semitendinosus

The effect of the addition of the fungal protease EPg222 on the sensory characteristics of dry fermented sausage "salchichón" ripened with commercial starter cultures was investigated. Sausages were prepared with purified EPg222 and Staphylococcus carnosus, Staphylococcus xylosus, and Lactobacillus sakei as starter cultures, ripened for 145 days and compared with a control batch only inoculated with the starter cultures. Dry fermented sausages ripened with EPg222 and starter cultures showed higher amount of NPN and volatile compounds derived from amino acid catabolism, than control ripened only with starter cultures. Several branched aldehydes, acids and alcohols such as 2- and 3-methylbutanoic acid and 2-methylpropanol were detected only in enzyme treated samples. Sensory analysis reflected higher values for aroma intensity of sausages treated with EPg222 and lower values of hardness than control. The effect of EPg222 may be of great interest to improve sensory characteristics of dry fermented sausages ripened with starter cultures.     

Pork tenderness estimation by taste panel, Warner-Bratzler shear force and on-line methods

The extent to which modification of Warner–Bratzler shear force (WBSF) determinations, relating to storage and preparation of the meat, aperture of the V-shaped cutting blade and shearing velocity, improve the relationship with sensory tenderness perception of pork was studied. Additionally four on-line methods: pH1, FOP1 (light scattering), PQM1 (conductivity) and DDLT (Double Density Light Transmission), were evaluated for their ability to predict tenderness. Sensory tenderness evaluation was conducted on 120 frozen (at −18°C for several months) samples of m. longissimus thoracis et lumborum. After overnight thawing, the meat was grilled to an internal temperature of 74°C and scored on an eight-point scale, from extremely tough to extremely tender. The standard WBSF procedure (protocol A) consisted of heating fresh meat samples (stored for 48 h at 4°C post slaughter) at 75°C for 50 min, cooling in cold tap water for 40 min, taking cylindrical cores parallel to the fibre direction, and shearing at a velocity of 200 mm/min with a blade aperture of 60°. For the prediction of sensory tenderness, the WBSF standard procedure (protocol A) showed the lowest variance (R²=15%) and the highest standard error of the estimate (SEE=0.97 N) compared to the other WBSF protocols. A decrease in shearing velocity, from 200 to 100 mm/min and, a replacement of the cutting blade with an aperture of 60° by one with an aperture of 30° led to improvements of R² (respectively, 19% vs. 13% and 47% vs. 23%) and SEE (respectively, 0.93 N vs. 0.97 N and 0.80 N vs. 0.97 N) and thus were better predictors of tenderness. A blade aperture of 30° instead of 60° also led to considerably lower WBSF values (22.1 N vs. 30.0 N). Freezing, frozen storage and thawing of the meat, prior to WBSF measurement, resulted in higher shear force values (32.7 N vs. 28.7 N) and a better prediction of tenderness, R² (25% vs. 15%) and SEE (0.94 N vs. 1.00 N). Furthermore, preparing the frozen stored meat for WBSF determination in the same way as for the sensory evaluation, namely grilling instead of boiling, led to higher WBSF values (35.5 N vs. 32.7 N) and a further improvement in the prediction of tenderness (R²=31% vs. 25% and SEE=0.90 N vs. 0.94 N). From the on-line instruments: pH, FOP and PQM, pH was best in predicting tenderness. Linear regression with tenderness as dependent variable and the on-line techniques as independent variables revealed the following R²: 16, 8, 8 and 10% and SEE: 0.96, 1.01, 1.01 and 1.00 N for, respectively, pH1, FOP1, PQM1 and DDLT. Thus, the classical instruments and the DDLT technique, which is analogous to the CGM (Capteur Gras/Maigre), an officially accepted carcass grading apparatus in France and Belgium, are not good predictors of tenderness.     

The effects of quality grade, aging, and location within muscle on Warner-Bratzler shear force in beef muscles of locomotion

Aging patterns of nine muscles from the chuck and round from two quality classifications of beef: USDA Select and upper 2/3 of USDA Choice grade were determined. The following muscles were evaluated: infraspinatus, triceps brachii - lateral head, triceps brachii - long head, serratus ventralis, complexus, splenius, rhomboideus, vastus lateralis and rectus femoris. Muscles were divided into four portions, progressing from anterior to posterior or dorsal to ventral orientation to the carcass depending on muscle fiber orientation. One steak was removed from each portion and aged for 7, 14, 21, or 28 d postmortem, then Warner-Bratzler shear force (WBSF) analysis was conducted. Consistent aging recommendations can be given for all muscles studied, as there was no aging by muscle interaction. An aging by USDA grade interaction was noted (P<0.05). The upper 2/3 of USDA Choice need not be aged beyond 7 d. USDA Select should be aged at least 14 d. Steak location within muscle had an effect (P<0.05) on WBSF values in four muscles. These data indicate that fabrication and merchandizing decisions should be made on an individual muscle basis.     

Effect of cooking temperature and cooking time on Warner-Bratzler tenderness measurement and collagen content in rabbit meat

The effects of cooking temperature (50-90?°C) and time (10-120 min) on Warner-Bratzler (WB) tenderness measurement of longissimus lumborum (LL) muscle in 70-day-old rabbits were investigated. Cooking losses, total collagen content and collagen solubility of LL muscle were measured in parallel. Increasing cooking temperature caused a four-phase effect on WB measurement. Stress and total energy were significantly increased between raw meat and cooked meat at 50?°C, then they dramatically decreased to a minimum observed at 60-65?°C, and increased again to reach a maximum at 80-90?°C. Cooking losses exhibited an 83% increase between 50 and 80?°C. At 80?°C, stress and total energy values remained constant after 20 and 40 min respectively. LL muscle collagen content was 16.4±2.3 mg/g of dried muscle. Collagen solubility at 77?°C for 1 h was high: 75.3±8.1%.     

Beef longissimus lumborum, biceps femoris, and deep pectoralis Warner-Bratzler shear force is affected differently by endpoint temperature, cooking method, and USDA quality grade

Effects of endpoint temperature, cooking method, and quality grade on Warner-Bratzler shear force (WBSF) of beef longissimus lumborum (LL), biceps femoris (BF), and deep pectoralis (DP) muscles were evaluated. Eighteen of all three subprimals were selected from USDA Select and 18 from USDA Choice (Certified Angus Beef) carcasses for the respective muscles. Muscles were vacuum packaged and held at 1 °C for 14 days, frozen (-29 °C), sawed into 2.54-cm thick steaks, vacuum packaged, and stored frozen until cooking. Thawed steaks were cooked by either a Magikitch'n(?) electric belt-grill (BG) at 93 °C, or a water-bath at 93 °C, to one of nine endpoint temperatures: 40, 45, 50, 55, 60, 65, 70, 75, or 80 °C. Belt-grill cooking was much faster and resulted in distinctly less cooking loss than water-bath cooking. Water-bath cooking resulted in higher (P<0.0001) Instron(?) WBSF (31.92 N) than BG (28.25 N) for LL. The combination of Select quality grade and higher endpoint temperatures resulted in higher (P<0.05) WBSF for LL. Two distinct phases of tenderization/toughening occurred for BF. Between 40 and 60 °C, WBSF decreased from 43.95 to 38.16 N (P<0.01), whereas between 60 and 70 °C, WBSF increased from 38.16 N to 44.44 N (P<0.05). Water-bath cooling resulted in higher (P=0.0001) DP WBSF (71.12 N) than BG (59.25 N). The DP had a distinct (P<0.0001) decline in WBSF between 45 and 65 °C, irrespective of the cooking method, followed by an increase between 65 and 80 °C (P<0.01).     

Contribution of myofibrillar and connective tissue components to the Warner-Bratzler shear force of cooked beef

Myofibrillar (MF-SF) and connective tissue (CT-SF) peak shear forces were interpolated from Warner-Bratzler shear force (SF) deformation curves of cooked bovine M. gluteus medius (GM) and M. semitendinosus (ST) from 112 crossbred steers in a 2×2×2 factorial experiment examining the interactions between slaughter age, growth promotants and breed cross (British versus Continental). Mixed model analyses, Pearson correlations and stepwise multiple regression identified relationships between shear forces, meat quality measurements and production treatments. Connective tissue contribution to SF increased with slaughter age and implantation in the ST and with slaughter age only in the GM. Myofibrillar contribution to SF increased with slaughter age for the ST and with Continental genetics for the GM. Variation in ST SF and MF-SF was best described by muscle weight, which increased with animal age, while GM SF and MF-SF variation was best described by cooking loss, indicating that ST and GM SF were most affected by connective and myofibrillar proteins, respectively.     

Relationships of slice shear force and Warner-Bratzler shear force of beef strip loin steaks as related to the tenderness gradient of the strip loin

This study was conducted to investigate the effects of steak location within a strip loin and USDA quality grade on muscle fiber angle, slice shear force (SSF), and Warner-Bratzler shear force (WBSF) and to determine the relationship between SSF and WBSF. Steak location influenced both SSF and WBSF values, as steaks from the anterior portion were typically tenderer than steaks from the posterior end. Although there is some discrepancy between the two shear force methods, both agree that at least the first 5 anterior-most steaks are comparable. Muscle fiber angle was affected by steak position within the strip loin, as the fiber angle shifted between steaks 7 and 8. Quality grade had a significant effect on beef tenderness for both SSF and WBSF. Finally, there was a strong relationship between lateral SSF and average WBSF (r = 0.64), which are currently the most commonly used measurements for instrumental tenderness.     

Effect of electrical stimulation and cooking temperature on the within-sample variation of cooking loss and shear force of lamb

Electrical stimulation decreased the shear force and increased the cooking loss in seven paired lamb Longissimus dorsi (LD) muscles. This treatment did not have any effect on the within-sample variation. Cooking in 55°, 65° and 75°C water baths for 90 min caused a linear increase in the cooking loss and shear force. There was no stimulation-cooking temperature interaction observed. Cooking temperature also had no effect on the within-sample variation. A possible explanation as to why electrical stimulation did not affect the within-sample variation is given.     

Relationship of texture profile analysis and Warner-Bratzler shear force with sensory characteristics of beef rib steaks

Cyclical texture profile analysis (TPA) parameters measured using a star-shaped probe with two cycles of 80% penetration and Warner-Bratzler shear force (WBS) were compared as predictors of objective tenderness and subjective sensory characteristics of rib steaks from 52 beef loins. The TPA parameters of hardness, cohesiveness and chewiness were negatively correlated (P<0.05) with trained panel sensory characteristics of initial tenderness (r=−0.64, −0.41, −0.62, respectively), amount of connective tissue (r=−0.57, −0.27, −0.55, respectively), overall tenderness (r=−0.68, −0.39, −0.64, respectively) and overall palatability (r=−0.56, −0.37, −0.53, respectively). These sensory characteristics were also negatively correlated (P<0.05) with WBS (r=−0.61, −0.49, −0.60, −0.56, respectively). Stepwise regression analysis generated prediction equations that included the TPA parameters of hardness and adhesiveness, which accounted for 47, 36, 51 and 38% of the variation in initial tenderness, amount of connective tissue, overall tenderness and overall palatability, respectively. Prediction equations using WBS accounted for 37, 24, 36 and 31% of the variation in initial tenderness, amount of connective tissue, overall tenderness and overall palatability, respectively. Hence, TPA explained more of the variation in subjective sensory tenderness of the rib steaks than WBS.     

Influence of pH on the Warner-Bratzler shear properties of mutton

Initial yield and peak shear force values obtained for stretched muscles cooked at 80°C for different times decreased linearly at a similar rate with increasing pH, which is consistent with the prime effect of pH being on the myofibrillar structure. The tenderising effect of pressure-heat treatment on stretched and cold-shortened muscle decreased rapidly with increase in ultimate pH until, at values near 7, the effect disappeared. Increased ultimate pH effectively eliminated the large increase in shear force values, occurring in cold-shortened muscle of normal pH and attributable to heat denaturation of myosin, as cooking temperature was increased above 60°C.     

A mapping method for the description of Warner-Bratzler shear force gradients in beef Longissimus thoracis et lumborum and Semitendinosus

A novel approach to mapping Warner-Bratzler shear of whole muscles was explored. The procedure was used on the Longissimus thoracis et lumborum (LTL) and Semitendinosus (ST) from six beef cattle by first marking skeletally defined anatomical landmarks on the muscle in situ. After removal from the carcass, further divisions were made while preserving sample orientation during cooking and preparation for shearing. Shear gradients were observed in all planes of the LTL, particularly the medial-lateral. The mid-section of the ST had the lowest shears while superficial locations of the cross-section had greater values. Muscle comparison indicated the ST was more uniform than the LTL. The mapping technique was subsequently used to identify localized effects of altered carcass suspension on shear values and sarcomere length in the lumbar Longissimus from four beef cattle. This mapping method will provide guidance for further intensive investigation across the carcass musculature and under varying carcass conditions.     

Preliminary investigation on the relationship of Raman spectra of sheep meat with shear force and cooking loss

A prototype handheld Raman system was used as a rapid non-invasive optical device to measure raw sheep meat to estimate cooked meat tenderness and cooking loss. Raman measurements were conducted on m. longissimus thoracis et lumborum samples from two sheep flocks from two different origins which had been aged for five days at 3–4 °C before deep freezing and further analysis. The Raman data of 140 samples were correlated with shear force and cooking loss data using PLS regression. Both sample origins could be discriminated and separate correlation models yielded better correlations than the joint correlation model. For shear force, R² = 0.79 and R² = 0.86 were obtained for the two sites. Results for cooking loss were comparable: separate models yielded R² = 0.79 and R² = 0.83 for the two sites. The results show the potential usefulness of Raman spectra which can be recorded during meat processing for the prediction of quality traits such as tenderness and cooking loss.     

The effects of cooking method on selected quality traits of broccoli and green asparagus

Broccoli and green asparagus were cooked using boiling water, steam, microwave oven and combi oven with overheated steam and combination of hot air with overheated steam (only broccoli). Vegetables were analysed for chlorophylls a and b, carotenoids, total polyphenols, antioxidant activity, colour parameters and sensory properties. Cooking in the combi oven with overheated steam was an effective method to achieve the highest levels of polyphenols and antioxidant activity, but it negatively influenced the contents of chlorophylls in both vegetables and carotenoids in asparagus. Boiling and cooking in the combi oven with overheated steam or hot air and steam ensured the best and comparable sensory properties of broccoli. Asparagus showed a lower susceptibility to heat treatments than broccoli as none of the treatments applied caused significant differences in colour redness and yellowness, polyphenol content and sensory properties of this vegetable.     

Effects of cooking beef muscles from frozen or thawed states on cooking traits and palatability

Biceps femoris and longissimus lumborum steaks were cooked from either a frozen or thawed state on an electric belt grill (TBG-60 MagiKitch'n Inc., Quakertown, PA) at 93?°C to the endpoint temperature of 70?°C. Cooking loss, cooking time, Warner-Bratzler shear force (WBSF), and color (Illuminant A, L(?), a(?), b(?)) were evaluated. Trained panelists (n=6) evaluated palatability attributes on an eight-point scale for myofibrillar tenderness, juiciness, flavor, overall tenderness, and connective tissue amount (1=extremely tough, dry, bland, tough, and abundant; 8=extremely tender, juicy, intense, tender, and none). L(?), a(?), WBSF, juiciness, flavor, connective tissue amount, and overall tenderness did not differ (P>0.05) between steaks cooked from frozen and thawed states. However, thawed steaks cooked faster and had lower cooking losses than frozen steaks. The biceps femoris had higher WBSF values than the longissimus lumborum and was rated less tender by trained panelists. L(?), a(?), or b(?) values did not differ (P>0.05) between muscles. The biceps femoris needed more time to cook and had greater cooking losses than longissimus lumborum. Dimensional changes of steaks cooked to either 60 or 70?°C were studied. The width of biceps femoris steaks decreased 12.2%, and width of longissimus lumborum decreased 6.3%. Longissimus lumborum steaks became shorter (P<0.01) than biceps femoris steaks. Thickness of biceps femoris steaks decreased 25.6%, and thickness of longissimus lumborum steaks decreased 23.3%. Muscle type had a more pronounced effect on dimensional changes of steaks than endpoint temperature.     

Comparison of methods for measuring shear force and sarcomere length and their relationship with sensorial tenderness of longissimus muscle in beef

Slice shear force (SSF) and laser diffraction, considered faster methodologies, for measuring beef instrumental tenderness and sarcomere length, were compared with reference methodologies Warner–Bratzler shear force (WBSF) and phase contrast microscopy. Striploin samples (n = 74) were analyzed for pH, sarcomere length, instrumental tenderness, myofibrillar fragmentation index, and sensorial tenderness. Pearson's correlation measured the association of meat evaluation methods with residual analysis of the multivariate analysis of variance model. The n-dimensional profile to evaluated methods was presented by biplot to identify the behavior of the correlation between the methods (variables). There was moderate correlation between SSF and WBSF (r = .63; p < .01) and both presented moderate correlation with sensorial tenderness (r = − .62 and −.55, to SSF and WBSF, respectively; p < .01). However, WBSF was more efficient to classify samples as tender (68%) than SSF (47%), comparing with sensorial tenderness (80%). There was a moderate correlation for laser and microscopy for sarcomere length (r = .57; p < .01). Sarcomeres were shorter when measured by laser than microscopy. Either with low correlation coefficients, sarcomere measured by laser (r = .29; p < .05) presented higher correlation with sensorial tenderness than with microscopy (r = .22; p < .10). Results highlighted that SSF was faster and easier to run, while WBSF was more appropriate to classify samples by sensorial tenderness grades. Laser diffraction is more suitable to explain effects on tenderness; however, microscopy revealed results of sarcomere length that were more realistic, once laser can underestimate sarcomeres.     

Comparison of the effects of microwave cooking and conventional cooking methods on the composition of fatty acids and fat quality indicators in herring

The aim of this study was to examine the changes which occur under the influence of different heating methods in the compositions of fatty acids and selected fat quality indicators in fillets of herring. The results that are compared herein were obtained via conventional culinary techniques and using microwave radiation. Culinary processes like boiling, grilling and frying, whether done conventionally or with a microwave oven, did not lead to a reduction in the n-3 polyunsaturated fatty acids (PUFAs) fraction of the total fatty acids, indicating that these fatty acids have a high durability and a low susceptibility to thermal oxidative processes. The culinary processes used in this study also had an insignificant influence on the fat quality indicators--the peroxide and anisidine value. The fat quality indicators in herring, both after conventional and microwave heating, differ little, and indicate a low content of primary and secondary products of oxidation.