Sensory Tenderness Scores Research Articles

Effects of supplemental fat on growth performance and quality of beef from steers fed barley-potato product finishing diets: I. Feedlot performance, carcass traits, appearance, water binding, retail storage, and palatability attributes1

To measure the effects of dietary fat on feedlot performance, carcass characteristics, and beef appearance, moisture binding, shelf life, and palatability, 168 crossbred beef steers (317 +/- 1.0 kg) were allotted randomly, within weight blocks, to a randomized complete block design with a 3 x2 + 1 factorial arrangement of dietary treatments. Main effects were level of yellow restaurant grease (RG; 0, 3, or 6%) and level of alfalfa hay (AH; 3.5 or 7%), with the added treatment of 6% tallow and 7% AH in barley-based diets containing 15% potato by-product and 7% supplement fed for 165 d (all dietary levels on a DM basis). Dietary treatment did not (P >0.10) affect DMI, LM area, beef brightness, or beef texture. Level of RG linearly increased (P <0.05) ADG from 1.48 to 1.60 kg/d, diet NE(m) from 2.4 to 2.6 Mcal/kg, diet NE(g) from 1.7 to 1.9 Mcal/kg, and internal fat from 2.1 to 2.4%. Level of RG linearly increased (P <0.05) G:F from 0.184 to 0.202, but decreased (P <0.05) beef firmness score from 3.0 to 2.8 and fat luster score from 3.1 to 2.8. Level of AH did not (P >0.10) affect any of the measurements; however, AH interacted with level of RG on fat thickness and yield grade (linear; P <0.05), as well as marbling score and percentage of carcasses grading USDA Choice (quadratic; P <0.05). Fat thickness and yield grade increased with increasing RG level in 3.5%, but not in 7%, AH diets. In steers fed 3.5% RG, marbling scores and percentage of carcasses grading Choice were greatest when fed with 3.5% AH, and least when fed 7% AH. Steers fed tallow had lower marbling scores (P = 0.01) and percentage of carcasses grading Choice (P = 0.066) than those fed RG. Retail storage attributes, including visual and instrumental color, decreased during storage (P <0.01), but were not (P >0.10) affected by diet. Trained sensory panel scores for initial tenderness increased quadratically (P = 0.07) as dietary RG increased, but diet did not (P >0.10) affect drip loss, cooking loss, or trained sensory panel scores for sustained tenderness, initial and sustained juiciness, and beef flavor. Therefore, RG increased diet energy, improved performance, and increased carcass fatness; however, dietary fat and AH did not affect most measurements of water retention, color stability, or palatability of beef.

Establishment of consumer thresholds for beef quality attributes

Acceptability threshold values for Warner-Bratzler shear (WBS) and trained sensory panel attributes were determined through regression analyses against consumer scores for overall tenderness, juiciness, flavour desirability and overall palatability for both the longissimus lumborum (LL) and semimembranosus (SM) muscles. Although consumers were not as sensitive to changes in tenderness as trained panellists, the relationship between consumer scores and trained panellist scores was moderate (r value = 0.64; P = 0.001). Based on the 50% confidence levels for WBS (7.85 and 8.15 kg for the LL and SM, respectively), 20% of LL steaks and 28% of SM roasts collected from commercial abattoirs and aged 6 d exceeded these thresholds. When assessed on the basis of subjective sensory panel scores for overall tenderness, 25.3% of LL steaks and 39.9% of SM roasts exceeded the 50% confidence level. Clearly, without intervention strategies beyond 6 d of aging, there was a significant portion of beef steaks and roasts which did not meet consumer expectations for tenderness. The fact there was a very poor relationship between tenderness in the LL and SM muscles suggests strategies used by industry to improve tenderness may need to be muscle specific. Key words: Beef quality, consumer, threshold, tenderness, Warner-Bratzler shear

THE EFFECTS OF FEEDING ELEVATED LEVELS OF VITAMINS D3 AND E ON BEEF QUALITY

ABSTRACT Yearling (12 Angus, 12 Wagyu≥Angus) and 2‐year old heifers (12 Angus, 12 Wagyu≥Angus) were fed elevated levels of Vitamin D3and/or Vitamin E to evaluate beef quality. Warner‐Bratzler shear force (WBS) and sensory characteristics were determined on steaks from the Longissimus lumborum (LL) aged 21 days and on steaks from the Gluteus medius (GM) and Psoas major (PM) aged 7 days. Steaks were cut from all muscles, displayed for 5 days then L*value and hue angle were determined. Vitamin E supplemented heifers received the highest sensory tenderness and juiciness scores, while no differences were observed among other treatments. D3+E supplemented Angus LL had higher WBS values than other treatments and breeds. Display time affected both color measures for all muscles, but especially hue angles of GM and PM. Vitamin treatment affected LL and GM color measures in yearlings to a greater extent than in 2‐year olds.

Reducing toughness of beef from Bos indicus draught steers by injection of calcium chloride: Effect of concentration and time postmortem

Calcium chloride (CaCl 2) solution in concentrations of 0, 0.2, 0.3 and 0.4 M was injected at 10% (wt/wt) either 45 min or 24 h postmortem into longissimus dorsi muscles of eight draught steers discharged from work and >4 years of age. Shear force, after 7 days of aging, declined by CaCl 2 injection by up to 50% of control, depending on CaCl 2 concentration. Prerigor treatment was twice as efficient as postrigor injection. Collagen content and solubility were less clearly affected. Sensory tenderness scores were higher by 50% with all CaCl 2 concentrations, but only with prerigor treatment. A bitter taste was noted only with the highest concentration of CaCl 2, but overall acceptance did not increase with CaCl 2 concentration. CaCl 2 enhanced electrical conductivity, reduced redness and luminosity, and increased drip and thawing loss, but not boiling loss, of longissiumus dorsi. Results indicate a high potential of CaCl 2 treatment in extraordinarily tough meat.

The effects of marbling on flavour and juiciness scores of cooked beef, after adjusting to a constant tenderness

Relationship between consumer sensory scores and intramuscular fat percentage were examined using data from 3613 striploin (M. longissimus dorsi) samples. These samples were sensory tested, using consumer taste panels, after 14 days ageing. There were curvilinear relationships between sensory scores for tenderness, juiciness, like flavour and overall liking and intramuscular fat percentage, showing that these relationships plateaued between 15�and 17% intramuscular fat. High correlations (r &gt; 0.86) between sensory scores meant that the individual scores were confounded. In an attempt to minimise this confounding, flavour and juiciness scores were adjusted for an independent measure of tenderness, namely peak force. There were curvilinear relationships between flavour and juiciness scores, with peak force indicating that the relationship plateaued at the higher shear forces. After adjustment for peak force, the relationships between the flavour and juiciness scores and the intramuscular fat percentage (after adjustment for peak force) also showed positive curvilinear relationships. These plateaued at the higher levels of intramuscular fat percentage (14 and 20%, for flavour and juiciness scores, respectively). These results show that if young animals are processed in a manner where myofibrillar toughness is controlled, flavour and juiciness scores for beef samples that are served as grilled steaks to Australian consumers will tend to plateau at the higher intramuscular fat percentage.

Vitamin D3 supplementation of cull cows: Effects on longissimus and semitendinosus muscle tenderness

Previous studies have shown that supplementation of vitamin D3 to cow diets for 4 to 10 d before slaughter lowers Warner-Bratzler shear force (WBSF) values and increases sensory tenderness scores in beef cuts. The present study was conducted to evaluate the effects of vitamin D3 supplementation on muscle calcium concentration, WBSF values, and sensory tenderness ratings of LM and semitendinosus (ST) muscles from cull, predominately Angus, cows (eight cows per treatment). Treatments included 0 (control), 5 million IU, or 7.5 million IU of vitamin D3 supplemented daily for 7 d preslaughter. Twenty-four hours after slaughter, 2.54-cm-thick LM and ST muscle steaks were cut; aged for either 0, 7, 14, or 21 d (ST steaks aged for 7 d only); and frozen at -20 degrees C for WBFS and sensory analysis. Mean values for LM calcium concentration tended to increase (P = 0.14) with vitamin D3 supplementation (154, 176, and 183 microig/g, fresh basis, for 0, 5, and 7.5 million IU/d, respectively). After 7 d of aging, LM steaks from cows fed 7.5 million IU had lower (P < 0.05) WBSF values than 7-d steaks from controls and cows fed 5.0 million IU/d aged 7 d; however, vitamin D3 supplementation had no (P > 0.05) effect on WBSF values of ST steaks aged 7 d. Vitamin D3 supplementation did not (P > 0.05) affect sensory tenderness ratings for either LM or ST steaks at any aging period. Aging, however, had a linear (P < 0.001) effect on tenderness, with an increase in tenderness as aging time increased from 0 to 21 d. Thus, results from the present study indicate that vitamin D3 supplementation, at these levels and duration before slaughter, provided little benefit to muscle tenderness of beef from cull cows.

Staged injection marination with calcium lactate, phosphate and salt may improve beef water-binding ability and palatability traits

Semitendinosus and longissimus muscles from USDA Select carcasses were used to investigate the effects of staged injection of calcium lactate followed by phosphate and salt (PS) on water-binding ability and palatability traits. Calcium lactate (0.2 M) and PS (8.4% and 4.2%, respectively) were sequentially injected (5.5% by weight) into muscles with 0, 1, 3, or 5 h holding time between injections. Treatments also included a double pump of 0.1 M calcium lactate with 0 h holding time between injections and a non-marinated control. Injection of calcium lactate and PS increased ( P<0.05) pumped yield and decreased ( P<0.05) expressible moisture values compared to calcium lactate injection only. No differences in peak force, total energy, or myofibrillar fragmentation index were observed among marination treatments for either muscle; however, longissimus tenderness was unusually high. Trained-panel evaluation of sensory traits did not differ for the semitendinosus muscle. Staged injection of calcium lactate and PS improved ( P<0.05) myofibrillar and overall sensory tenderness scores of longissimus muscle over those of the non-marinated control. However, beef flavor intensity scores were lowered ( P<0.05) by addition of PS. Holding time between injections did not appear to consistently influence water-binding ability or palatability traits. These data suggest that separate solutions of calcium lactate and PS may be injected into longissimus muscle to improve water-binding ability and palatability traits.

Meat texture of lambs from different European production systems

Measurements of meat texture (Warner-Bratzler shear force, WBSF), compression stress at 20% (S20) and 80% (S80) of initial sample thickness, sarcomere length, pH, and sensory tenderness score were determined on the longissimus muscle from lambs from 22 diverse European lamb types from 6 countries. Carcasses chilled to minimise cold shortening. The types ranged from 1-month-old milk-fed lambs to 1-year-old heavy wether lambs reared on the transhumance system (extensive system based on moving animals from valleys to high mountains in search of seasonal resources). Overall, it seems that breed was more important in influencing meat toughness than age or gender. Within breed, there was some evidence of an age effect (the older the animal the tougher the meat), and nutritional handling was, in some cases, significant. The lowest WBSF values were for meat from 16-kg carcasses of pasture-fed animals of the Icelandic breed (average 1.7 kg) and the highest were for meat from 19–20 kg carcasses of the Bergamasca breed (average 4.1 kg). The two youngest types had the highest values for S20 (10.5 and 11.8 N/cm2), the compression value related to myofibrillar component. There was a very good agreement between panels from the different countries in the ranking of tenderness; meat from the Icelandic breed was the most tender and that from the Bergamasca breed the least, in concurrence with the WBSF results, with a significant relationship between tenderness and WBSF values in all the lamb types studied.

Genetic and phenotypic characterisation of animal, carcass, and meat quality traits from temperate and tropically adapted beef breeds. 3. Meat quality traits

Meat quality measures, including objective measures of tenderness (shear force and compression), were taken on 2 muscles [M. longissimus thoracis et lumborum (LTL) and M. semitendinosus (ST)] from 7566 carcasses from temperate (TEMP) and tropically adapted (TROP) beef cattle breeds. Animals were finished to 1 of 3 market carcass weight end-points (220, 280, or 340 kg) either on pasture or in a feedlot, and in 2 different geographic regions for TROP. Both the phenotypic and genetic expression of the traits were estimated at each market weight and for each finishing regime. Heritabilities and correlations between the traits were estimated for TEMP and TROP separately. Smaller additive variances and heritabilities were observed for temperate breeds compared with tropically adapted breeds for most of the traits studied. For TROP, the heritability of traits measured on the ST muscle [compression (ST_C), shear force (ST_SF), and L* Minolta lightness value (ST_L*)] was 0.27, 0.42, and 0.16, respectively, and for traits measured on the LTL muscle [compression (LTL_C), shear force (LTL_SF), L* Minolta lightness value (LTL_L*), a* Minolta redness value (LTL_a*), cooking loss% (LTL_CL%), and consumer assessed tenderness score (LTL_TEND)] 0.19, 0.30, 0.18, 0.13, 0.20, and 0.31, respectively. For TEMP, the heritability of traits measured on the ST muscle [ST_C, ST_SF, ST_L*, a* Minolta redness value (ST_a*), cooking loss % (ST_CL%)] was 0.12, 0.11, 0.17, 0.13, and 0.15, respectively, and of traits measured on the LTL muscle (LTL_C, LTL_SF, LTL_L, and LTL_TEND) were 0.08, 0.09, 0.17 and 0.18 respectively. Genetic correlations were moderate to high for tenderness measures (shear force and compression) between muscles for the same tenderness measure (e.g. LTL_SF and ST_SF was 0.46 for TROP) and within a muscle for the different measures (e.g. ST_C and ST_SF was 0.83 for TROP). Phenotypic and genetic correlations between LTL_L* and all objective measures of tenderness were negative (e.g. LTL_SF and LTL_L* for TROP was –0.40). The genetic relationship between LTL_SF and LTL_TEND was –0.79 and –0.49 for TROP and TEMP, respectively. Finishing system affected the phenotypic expression of all traits. Pasture-finished, compared with feedlot-finished, animals had higher shear force and compression measures, darker meat colour, and lower sensory tenderness scores for both TEMP and TROP. For TROP, heifers had higher shear force and compression measures, lower sensory tenderness scores, and darker meat colour (lower L* values) than steers. Genetic correlations between markets were generally high and close to unity with the exception of the ST_L*, LTL_L*, ST_C, and ST_SF for TEMP. Geographic region had little effect on the phenotypic and genetic expression of meat quality traits for TROP. Genetic correlations between finishing regimes for all traits were positive and close to unity, with the exception of ST_C and LTL_SF for TEMP, and LTL_L* and LTL_CL% for TROP. Genetic improvement of meat quality traits is a possibility for tropically adapted breeds given the moderate heritabilities, adequate phenotypic variance, generally favourable genetic correlations between traits, and little evidence of genotype by environment interactions.

The tenderisation of shin beef using a citrus juice marinade

The effectiveness of organic acids (acetic, citric, lactic) and a citrus juice marinade as tenderising agents in shin beef muscle was investigated. At 0.2 M, citric acid was more effective as a tenderising agent than acetic or lactic acid. Immersion of shin beef strips in citric acid (0–0.05 M) showed that a significant tenderising effect was obtained above a concentration of 0.013 M. When shin beef strips were immersed in the citrus juice marinade (31% orange juice, 31% lemon juice, 38% distilled water) mean pH decreased from 5.7 to 3.1 and mean sample weight increased by ∼65%. The mean Warner–Bratzler shear force value decreased from 178 to 44 N cm −2 following marination while mean sensory analysis scores for tenderness and juiciness increased following marination. A mean total collagen content of 1.4 g/100 g was recorded in shin beef of which 9% was soluble in unmarinated samples and 29% was soluble in marinated samples. The results indicated that the tenderisation of beef samples using a citrus juice marinade could be attributed to marinade uptake by muscle proteins and also to solubilisation of collagen.

Correlations among selected pork quality traits.

Establishing relationships among specific quality traits is important if significant progress toward developing improved pork quality is to be realized. As part of a study to examine the individual effects of genes on meat quality traits in pigs, a three-generation resource family was developed. Two Berkshire sires and nine Yorkshire dams were used to produce nine F1 litters. Sixty-five matings were made from the F1 litters to produce four sets of F2 offspring, for a total of 525 F2 animals used in the study. These F2 animals were slaughtered at a commercial facility upon reaching approximately 110 kg. Carcass composition traits, pH measurements, and subjective quality scores were made at 24 h postmortem. Loin samples (n = 525) were collected at 48 h postmortem, and meat quality traits were evaluated. These traits included pH (48 h), Hunter L-values, drip loss, glycolytic potential, ratio of type IIa/IIb myosin heavy chains (IIa/IIb), total lipid, instrumental measures of tenderness using the Star Probe attachment of the Instron, cook loss measurements, and sensory evaluations. Significant phenotypic correlations were found between many carcass, instrumental, and biochemical measurements, and sensory quality traits. Star Probe measurements were significantly correlated with drip loss (0.29), glycolytic potential (0.30), pH (-0.29), total lipid (-0.14), and Hunter L-values (0.28). Drip loss was significantly correlated with glycolytic potential (0.36), pH (-0.28), IIa/IIb (-0.10), and Hunter L-values (0.33). Hunter L-values were also significantly correlated with total lipid (0.33) and IIa/ IIb (-0.11). Sensory tenderness, flavor, and off-flavor scores were significantly correlated with drip loss, pH, and glycolytic potential measurements. Marbling score, total lipid, and drip loss were not significantly correlated with sensory juiciness scores, but cooking loss was. Marbling and total lipid were significantly correlated with firmness scores (0.37 and 0.31, respectively). Taken together, the data in this study suggest that changes in some meat quality traits can affect many other meat quality attributes. The correlations yield information that could aid in directing future studies aimed at understanding the underlying biological mechanisms behind the development of many quality traits.

Relationship between objective measurements and taste panel assessment of beef quality

The relationship between objective measurements (shear force, compression, drip loss, cooking loss) and sensory evaluation of tenderness and juiciness of samples of M. longissimus thoracis et lumborum was examined using data from 2 experiments which imposed different electrical stimulation and aging treatments post mortem, with resultant differences in sensory and objective measures of tenderness. The relationships were tested first in separate models for each objective measurement, and then in multiple regressions containing all measurements. These models were then repeated with the inclusion of stimulation and aging treatments and their interactions with each objective measurement. Shear force by itself was a useful predictor of sensory tenderness score, with which it had a quadratic relationship. Compression and cooking loss, when used by themselves, accounted for substantially less variation in sensory tenderness scores than did shear force, with larger residual standard deviations (r.s.d.). Drip loss had no significant relationship with sensory tenderness scores. Inclusion of post-slaughter treatment in the analyses increased the amount of variation in sensory tenderness scores accounted for by only a small amount in the case of shear force, with a substantial increase in the case of compression and cooking loss. Use of all objective measurements in the 1 model had a similar predictive ability (r2 , r.s.d.) as the use of shear force plus treatment variables. Aging affected the sensory tenderness scores given by taste panellists, in that they gave 14-day aged meat higher tenderness scores (more tender) than they gave 1-day aged meat with the same shear force, compression or cooking loss values. Electrical stimulation did not affect the relationship between sensory tenderness scores and shear force, but did affect that between sensory scores and compression. The effect was similar to that seen for aged meat, with stimulated meat being scored as more tender by a taste panel than non-stimulated meat, at the same compression values. Post-slaughter treatment did not affect the slope of these relationships. When all objective measurements were analysed together, aging period affected the relationship between tenderness scores and objective measures, with tenderness scores being lower in 1-day aged samples than 14-day aged samples at the same combination of objective measures. There was only a poor relationship between shear force, compression, drip loss, cooking loss and sensory juiciness scores.

Meat tenderization by proteolytic enzymes after osmotic dehydration

The treatment of proteolytic enzymes is one of the popular methods for meat tenderization. In this case, it is very important how to introduce the enzymes into the meat cut. This paper describes meat tenderization by dipping the meat cut in a solution containing proteolytic enzymes after contact-osmotic dehydration. After the dehydration of each piece of meat from culled cow for 18 h by contact-dehydration sheet, each sample was dipped for 3 h in a solution containing papain or proteinases from Aspergillus traditionally used for soysauce production in Japan. It was stored at 3∼4°C for 24, 48 and 168 h, and subjected to texture measurement, sensory evaluations, biochemical analysis and histological observations. The penetration efficiency of the enzyme solution (of around 80%) after the contact-osmotic dehydration seemed to be sufficient. A marked decrease in hardness by texture measurements was observed in the meats treated with proteolytic enzymes and higher sensory scores for tenderness were observed in the meats treated with enzymes as compared with the untreated meat. The papain-treated meat received the highest score in tenderness, but the scores given to juiciness and taste were lower than that of the control. The rapid increases of the fragmentation of myofibrils from the enzyme-treated meat were observed at first 24 h of storage as compared with that of the control. Remarkable degradation of myosin molecule in the myofibrils from the enzyme-treated meats was observed on SDS-PAGE profiles. Considerable degradation of myofibrilar structure especially due to proteolytic removal of Z-lines, was observed among the myofibrils from enzyme-treated meats by electronmicroscopy. The remarkable deformation and disruption of honeycomb-like structure of endomysium were also observed in the meats treated with enzymes. From these results, it was shown that treatment after osmotic dehydration, was effective in tenderizing.

Effect of the Degree of Comminution on Sensory and Texture Attributes of Low-fat Beefburgers

The effect of mincer plate orifice diameter (2, 5 or 10 mm) on sensory and texture attributes of low-fat (59 g/kg) beefburgers was studied. Proximate analysis of raw and cooked burgers was not affected by degree of comminution. The degree of comminution influenced sensory scores for tenderness, fattiness (P<0.001), meaty flavour, overall appearance (P<0.01), overall acceptability, crumbliness, residual connective tissue, overall flavour and moistness/juiciness (P<0.05). Scores for tenderness, crumbliness and residual connective tissue increased as the degree of comminution increased while the opposite trend was observed for the other characteristics. Warner Bratzler peak force (P<0.01) and energy (P<0.001) and Kramer shear maximum load (P<0.01) and energy (P<0.001) were also affected with higher values for burgers with larger particle size. The degree of comminution did not affect any texture profile analysis parameter. For all sensory and Warner Bratzler attributes no difference was found between burgers minced through plates with orifices of 5 and 10 mm diameter. Finely comminuted burgers were the least acceptable.

Effect of electrical stimulation on protease activity and tenderness of M. longissimus from cattle with different proportions of Bos indicus content

The effect of electrical stimulation on protease activity (at approx. 3 h postmortem), sensory tenderness scores and shear force was determined on M. longissimus samples from three Bos indicus genotypes (0% Hereford, 50% Brahman×Hereford and 100% Brahman). The samples were divided and aged for 1 or 30 days. Electrical stimulation resulted in a general reduction in calpastatin activity suggesting that it accelerated proteolysis. Calpastatin activity increased commensurate with increasing Bos indicus content. Several significant interactions were shown, the most relevant of these was the interaction between Bos indicus content×electrical stimulation. In contrast to the other genotypes, calpain I and calpain II activities were shown to increase (significant for calpain II only) following stimulation in the purebred Brahmans (100%). There was a significant reduction in tenderness with increasing Bos indicus content. However, breed differences in shear force were reduced by electrical stimulation. The improvement in shear force following ageing was smaller for stimulated carcasses compared to the controls. This tends to reinforce the premise that electrical stimulation accelerates proteolysis. The results of this study show clear genotypic differences in proteolytic activity and tenderness. However, electrical stimulation can be employed to reduce breed differences in tenderness of the M. longissimus.

The influence of goat genotype on the production of Capretto and Chevon carcasses. 2. Meat quality

The effect of five goat genotypes, Boer×Angora (BA), Boer×Saanen (BS), Feral×Feral (FF), Saanen x Angora (SA) and Saanen x Feral (SF) on the meat quality of Capretto and Chevon carcasses obtained from 50 buck kids, was assessed. Genotype had an influence on cooking loss and longissimus thoracis muscle colour coordinates (CIE L *, a *, b * values). BS kids from the Capretto group had paler muscle colour compared to other genotypes; pale muscle colour being required for Capretto carcasses. Total pigment concentration, fat colour, shear force values and sensory scores for flavour, tenderness, juiciness and overall acceptability did not differ significantly between genotypes. Muscle colour became darker and fat colour became more yellow with increasing animal age. Tenderness decreased with animal age as indicated by higher shear force values. Age had no significant influence on cooking loss and sensory scores.

Image texture features as indicators of beef tenderness

Image processing techniques were developed to predict cooked-beef tenderness from fresh-beef image characteristics. Cattle from different finishing treatments were processed in a commercial plant. Two short loin steaks were sampled from each carcass; one used for sensory evaluation and the other for imaging. The samples varied significantly in both US quality grades and sensory tenderness scores. Color, marbling and texture features were extracted from the beef images. Statistical and neural network analyses were performed to relate the image features to sensory tenderness scores. Image texture features were found to be useful indicators of beef tenderness. Partial least squares and neural network models were able to predict beef tenderness from color, marbling and image texture features to R 2-values up to 0.70.

QUALITY GRADE, PORTION SIZE, NEEDLE TENDERIZATION AND COOKERY METHOD EFFECTS ON COOKING CHARACTERISTICS AND PALATABILITY TRAITS OF PORTIONED STRIP LOIN AND TOP SIRLOIN STEAKS

Strip Loin (IMP # 1180A) and Top Sirloin Center Cut steaks (IMP # 1184B) purchased from a foodservice purveyor and aged 21 days were used to evaluate cookery method, needle tenderization, quality grade and portion size effects on palatability and cooking characteristics. Both steak types were distributed across 4 quality grade classes (USDA Select = S, USDA Choice = C, USDA Prime = P, and Certified Angus BeefTM= UC), 2 portion sizes (strip loins, 283 and 397 g; top sirloins, 255 and 340 g), 2 tenderization treatments (needle tenderized = T and nontenderized = NT) and 2 cooking methods (Clamshell® broiler-grill = CS and electric grill = FW). Cook time/100 g was lower (P 0.05) sensory tenderness in the strips or sirloin steaks. Sensory tenderness scores were lower (P 0.05) sensory tenderness in the strips steaks but improved sensory tenderness scores in the sirloin steaks. A needle tenderization by quality class interaction in the sirloins showed that T steaks from the S, C and UC classes were more tender than NT steaks; however, tenderization did not affect tenderness of P steaks. Collectively these data suggest that rapid cookery systems (i.e., Clamshell®) can reduce cooking time in portioned foodservice strip and top sirloin steaks without detrimental effects on palatability.

INFLUENCE OF OVEN TEMPERATURE, ENVIRONMENT AND OVEN TYPE ON YIELD AND PALATABILITY CHARACTERISTICS OF CANADIAN BACK AND FRESH HAM ROASTS1

Enhancing pork as a foodservice center of the plate entree benefits both the foodservice and the meat industry. Yield and quality characteristics of Canadian back (CB) and fresh ham (FH) roasts cooked to 71C were evaluated in separate studies using a 3 × 3 × 2 factorial treatment design with three oven temperatures (107.2, 135.0, 162.8C), three oven types (combination, convection, conventional) and two oven environments (moist or dry). Increasing oven temperature to 162.8C decreased CB hold yield and cook time per kg and resulted in a darker external color than CB roasted at 107.2 or 135.0C. Cook time per kg was least for CB roasted in the combination (steam + heat) oven. External surface color was darkest for CB and FH roasted in the convection oven. Roast yields, slice yields and sensory tenderness scores were highest and external color scores lightest for FH roasted at 107.2C. Roasting FH in the convection oven resulted in the lowest slice yields, highest scrap yields and sensory panel tenderness. Oven temperature and type did not influence CB palatability. Kramer shear values of FH or CB were not affected by oven temperature (p > 0.05). Oven environment did not impact CB or FH yield and palatability. Overall, yield and palatability of pork roasts will be maximized at lower equipment conventional or combination oven temperatures.

Tenderness of beef loin steaks as influenced by marbling level, removal of subcutaneous fat, and cooking method.

Loins from 12 carcasses of Small minus marbling and loins from 12 carcasses of Slight minus marbling were selected. Steaks from these loins were either completely trimmed of external fat or trimmed to .6 cm of external fat. Steaks were cooked to 67 degrees C either by a rapid, high-temperature broiler-grill or by a slower, lower temperature electric broiler. Muscle on the dorsal side of steaks (where fat trimming was performed) was used for shear force measurements (five separate core locations), and the ventral portion was used for sensory evaluation of tenderness. Sensory scores for tenderness were affected (P < .05) by various first-order interactions, although differences were minimal. Steaks of Slight minus marbling cooked by broiler-grilling had reduced tenderness scores. Only when steaks were cooked by broiler-grilling did complete fat removal produce cores that appeared more well-done. Broiler-grilling produced more well-done cores than did electrical broiling. Correlations between shear force expressed as peak load and tenderness scores were highest in cores that were more similar in degree of doneness to sensory evaluation samples. Although broiler-grilling produced considerable within-steak variation in degree of doneness, some of the highest correlations between shear core degree of doneness and peak load and between peak load and sensory tenderness were obtained with this broiling procedure. This would imply that rapid broiling is important in creating uniform tenderness in loin steaks of reduced fat, but further modifications in rapid broiling cookery are necessary to improve uniformity of cooked meat color.