Effect of cooking temperature and time on the physico-chemical, histological and sensory properties of female carabeef (buffalo) meat

The effect of cooking temperature (80-100°C) and time (30-60min) on collagen solubility of Semimembranosus muscle in carabeef were investigated. The pH, cooking loss, shear force value, collagen content, collagen solubility, sensory evaluation and histological observations of water bath cooked and pressure cooked Semimembranosus meat samples were measured. Increase in pH, cooking loss, collagen solubility and tenderness scores with decrease in shear force value and collagen content was observed with increases in cooking temperature and time. However, no statistical difference was observed for shear force values, collagen solubility values and tenderness scores in pressure cooked meat and meat cooked in a water bath at 100°C for 45min, inferring that cooking of buffalo meat at 100°C for 45min improved collagen solubility and tenderness to the same extent as that due to pressure cooking.     

The effect of cooking conditions on the eating quality of pork

Two experiments were conducted to examine the effects of cooking parameters, including final internal temperature (65, 72·5 or 80°C), on the eating quality of pork. Assessments were made by a 10-member trained taste panel. In Experiment 1 on loin steaks (m. longissimus) from 28 carcasses weighing 66 ± 1·9 (SD) kg, increasing the final internal temperature from 65 to 80°C had the following effects on mean scores (1-8): tenderness -1·0; juiciness -1·5, pork flavour +0·6 and abnormal flavour -0·5. The medium temperature of 72·5°C was suggested as ideal. In Experiment 2 on leg roasts (m. gluteobiceps) from 96 carcasses weighing 65 + 2·7 (SD) kg, increasing the final internal temperature from 65 to 80°C had the following effects on mean scores (1-8): tenderness -0·2 (not significant), juiciness -0·6, pork flavour +0·3 and abnormal flavour -0·5. The effects of final internal temperature were therefore smaller in roasts and temperatures towards the upper end of the range would be recommended for ideal eating quality, balancing small losses in tenderness and juiciness against gains in flavour scores. Although the experiments were not designed to examine source and sex effects there was evidence that tenderness can be improved through the use of Duroc genes and pelvic suspension of carcasses and no evidence of differences in eating quality between entire males and females.     

Thermomechanical properties of beef muscle

Differential scanning calorimetry (DSC) was used to follow the three major endothermic transitions (T(1), T(2) and T(3)) of beef muscle during heating. Borchardt and Daniels reaction kinetics were used to predict the three time and temperature treatments required to sequentially eliminate each transition. Longissimus dorsi and semimembranosus muscles were removed from beef carcasses suspended by Achilles tendon or pelvis. Samples prepared by heating for 5 min at 57°C (I), 70°C (II) and 81°C (III) were assessed by sensory panel for tenderness, juiciness and residual connective tissue. Weight loss, Warner-Bratzler (W-B) shear and microstructure using transmission electron microscopy (TEM) were also determined. The I treatment showed a significant difference in tenderness and residual connective tissue between muscles, but not between contraction states. The II treatment produced collagen shrinkage and a significant drop in W-B shear and residual connective tissue, coupled with increased tenderness in semimembranosus muscle. An increased W-B value, decreased juiciness, increased weight loss and a reduction in sarcomere and A-band length accompanied the III transition. Muscles from carcasses that had been suspended by the pelvis were found to be significantly more tender than the same muscles from Achilles hung carcasses. It is concluded that DSC is capable of determining amount of protein denaturation and, hence, degree of cooking.     

Palatability and Storage Characteristics of Precooked Beef Roasts

The palatability and storage characteristics of fresh, frozen and precooked beef chuck roasts prepared using added phosphate-salt and vacuum cooking bags were evaluated. Palatability attributes (tenderness, juiciness, beef flavor intensity, and off-flavor intensity) of precooked roasts prepared in vacuum cooking bags with phosphate-salt were as good or better than freshly cooked roasts. Precooked roasts in vacuum cooking bags had the lowest total bacterial counts after storage for 14 and 28 days. A palatable precooked roast beef product was developed that can be stored for 28 days at 4°C.     

Sensory Properties of Rib and Round Muscle Roasts from Two Beef Breed-Types on Two Feeding Regimes

Roasts from the rib and three round muscles obtained from Angus and Simmental Angus (SA) steers on two feeding regimes, high concentrate (HC) and pasture followed by short term HC, were roasted to an internal temperature of 65–68°C. Time of roasting, cooking losses, shear values, and pressed juice were determined. A trained sensory panel evaluated flavor, tenderness, juiciness, and overall acceptability. Sensory panelists scored flavor acceptability higher in SA roasts (P < 0.05) than in roasts from Angus steers. Flavor acceptability, overall acceptability, and tenderness were found to be higher in round muscle roasts from the HC feeding regime (P < 0.05) than in round roasts from the cattle fed pasture followed by short term HC.     

Effect of marination and microwave heating on the quality of Semimembranosus and Semitendinosus muscles from Friesian mature cows

Semimembranosus (SM) and Semitendinosus (ST) muscles from 8 mature cows were used to evaluate the effect of marination, power of microwave heating, and internal temperature of cooking on the quality of calibrated beef roasts. Four treatments, using combinations of power (182W and 654W) and temperature (60 and 80°C) were applied to marinated (10% added brine: salt, sodium lactate, lactose, and ascorbate) and control roasts from SM (15×5×3cm) and ST (10×4×3cm) muscles in a 2×2×2 factorial arrangement. Microwave cooking was heterogeneous resulting in a gradient of temperatures within the roasts. Either high or low microwave power were appropriate for cooking ST roasts, but SM roasts cooked at 654W showed higher cooking losses, and lighter and less red cooked color than 182W. Cooking to 80°C increased cooking and color losses in both muscles and decreased tenderness of SM roasts compared with 60°C. Marination can be used successfully to enhance beef tenderness of ST and SM muscles cooked in microwave.     

Cooked yields, color, tenderness, and sensory traits of beef roasts cooked in an oven with steam generation versus a commercial convection oven to different endpoint temperatures

A CVap steam generation oven was compared with a Blodgett convection oven to examine effects on yields, cooked color, tenderness, and sensory traits of beef Longissimus lumborum (LL), Deep pectoralis (DP), and Biceps femoris (BF) muscles cooked to 1 of 3 temperatures (65.6, 71.1, or 76.7°C). Four roasts were cooked in the CVap for a constant time, and 2 roasts were cooked in the Blodgett until they reached target temperatures (3 replications). Cooking yields were higher (P<0.05) for BF and LL roasts in the CVap. Slice shear force (SSF) for BF roasts was lowest (P<0.05) in the CVap but lowest (P<0.05) for DP roasts in the Blodgett. No oven effect (P>0.05) was found for LL roasts. Sensory tenderness for BF roasts in the CVap was higher (P<0.05) than those in the Blodgett. Juiciness was higher (P<0.05) for LL roasts in the Blodgett. The CVap oven offers some tenderization (BF) and cooking yield advantages (BF and DP) over forced-air convection cooking.     

AGING AND COOKING EFFECTS ON SENSORY TRAITS OF PORK FROM PIGS OF DIFFERENT BREED LINES

The effects of postmortem aging time (2, 9, and 16 days) and endpoint cooking temperature (60, 70, and 80C) on the eating characteristics of pork longissimus (LD) muscle were evaluated. Gilts (n=60) were from 4 different commercial hybrid genotypes (15 pigs/genotype) selected to produce a range of intramuscular fat. Results suggest that LD muscle from genotype 2, which was selected for its propensity to increase marbling had higher intramuscular fat content, tenderness and juiciness scores than that from the other genotypes (P < 0.05). Increasing aging time from 2 to 16 days increased sensory juiciness and tenderness, and decreased instrumental shear force and cooking loss (P < 0.05). Aging for nine days decreased shear force (P < 0.05) but had no effect on tenderness and juiciness scores and cooking loss when compared to 2 days aging. Increasing endpoint temperature increased cooking loss and shear force, and decreased tenderness (P < 0.05) and juiciness.     

Elucidation of the relationship between cooking temperature, water distribution and sensory attributes of pork - a combined NMR and sensory study

Low-field NMR T(2) relaxation was measured continuously during cooking of pork samples (m. longissimus dorsi) to a final temperature of 75 °C. Simultaneously the remaining muscle was cooked in an oven to a core temperature of either 62 or 75 °C and subsequently evaluated by a sensory panel. Highly significant effects of final cooking temperature on the sensory attributes juiciness (initial and final), hardness, tenderness, crumbliness and chewing time were found. Juiciness and tenderness decreased with increasing temperature, while hardness, crumbliness and chewing time increased with increasing temperature. Distributed T(2) relaxation data revealed marked effects of temperature (62 vs. 75 °C) on the water distribution within the meat. Partial least squares (PLS) regressions were used to examine a potential prediction of sensory attributes from the distributed T(2) relaxation data, and high correlations were obtained. Moreover, loadings from the PLS regressions were analysed to evaluate the alterations in the water distribution as a function of temperature that contribute to changes in juiciness. This analysis revealed that the reduction in juiciness at 75 °C can be ascribed to changes in the size of the pores confining the myofibrillar water together with an expulsion of water.     

PALATABILITY OF BEEF ROASTS PREPARED WITH DIFFERENT FOODSERVICE COOKING METHODS

Effects of cooking rate, fat trim, aging, endpoint temperature and oven type (conventional, forced air convection and forced air/steam combination) on the palatability of beef foodservice roasts were investigated. Clods, chuck rolls, ribeyes, tenderloins, knuckles, inside rounds, gooseneck rounds and steamship rounds were included in the study. Differences in palatability, due to the cooking methods evaluated, were not consistent across all roast types, but the cooking method affected (P < 0.05) palatability traits in all roasts. Inconsistency was most likely due to varying size, composition and shape. Longer aging periods increased tenderness in ribeyes and gooseneck rounds. Palatability was only affected by oven type in round subprimals. First principal component scores (PRINI) were related to palatability and were used to rank treatment levels within main effects when substantially different from zero. Palatability was maximized within main effects inconsistently across different roast types when sorted by PRINI.     

Shrouding, Spray-chilling and Vacuum-packaged Aging Effects on Processing and Eating Quality Attributes of Beef

Sixteen beef sides were shrouded or unshrouded and then chilled using a conventional air or a water spray-chilling system. After chilling, the semitendinosus (ST) muscle was excised from each side, cut into four roasts, vacuum-packaged and aged for 3, 10, 24, or 38 days. Spray-chilling of shrouded and unshrouded sides was more effective than air chilling in lowering muscle temperature after cooling 8 hr. Unshrouded, spray-chilled sides had the least shrinkage after 24 hr. Trained panel scores and instrumental analysis of cooked roasts showed meat tenderness and juiciness were unaffected by shrouding and chilling methods; however, roasts aged 24 and 38 days were more tender than those aged 3 days.     

Relationships between post-mortem pH changes and some traits of sensory quality in veal

The aim of this study was to evaluate the relationships between the rate and extent of post-mortem pH changes and the colour, the cooking loss and the eating quality of veal. The experiment used 12 calves aged 18 weeks. Variations in ultimate pH were induced by adrenalin administration (0.1–0.4 mg/kg liveweight) to six of the animals. Measurements were made on the Longissimus thoracis muscle. pH and osmotic pressure were measured at 0.5 h, 4 h and 29 h after slaughter. Pigment content, drip loss and cooking loss were measured at 29 h after slaughter, and colour was measured at 2 days and 9 days after slaughter. Cooking loss, tenderness, juiciness and flavour of roasts were assessed at 9 days after slaughter.

Correlations between colour traits and pH values were higher with ultimate pH than with pH at 0.5 h or 4 h after slaughter. Lightness, redness and reflectance decreased when the ultimate pH increased. Drip loss was correlated with the rate of pH fall (r = −0.80, P < 0.01 with pH at 4 h), while cooking loss was correlated with ultimate pH (r = −0.94, P < 0.01). Ultimate pH and the sensory quality traits were linearity and positively correlated (r = 0.83) for tenderness, 0.81 for juiciness and 0.71 for flavour, respectively).     

Processing Ingredients Affecting Oxidative and Textural Stability of Restructured Beef Roasts

Restructured beef roasts containing 0.3% sodium tripolyphosphate (STP) and 1% soy protein isolate (SPI); or STP only; or SPI only; or no STP or SPI were cooked at 70 or 100°C to an internal temperature of 65°C, then stored at 4°C for 0 and 3 days. In control roasts, the higher cooking temperature resulted in higher (p ≤ 0.05) TBA values. STP and SPI inhibited oxidation but the effect was not detected sensorially. Significant interactions (p ≤ 0.05) indicated that STP was more effective at higher cooking temperatures and SPI at lower temperatures. Total moisture of the cooked product was significantly greater with STP but no differences in juiciness and tenderness were detected sensorially.     

PHYSICAL CHARACTERISTICS OF BEEF ROASTS PREPARED WITH DIFFERENT FOODSERVICE COOKING METHODS

Effects of cooking rate, fat trim level, aging period, endpoint temperature and oven type (conventional, forced air convection and forced air/steam combination) on yield, composition and cooking parameters for eight types of beef roasts were investigated. Generally, fast cooking, higher endpoint temperatures, complete removal of external fat and the use of forced air/steam combination ovens increased cooking losses. Fast cooking rates and forced air/steam combination ovens increased moisture loss in some roasts. Reduced levels of external fat did not dramatically affect yields or relative changes in composition due to cooking, but did increase cooking time per unit weight. Forced air/steam combination ovens may reduce the required length of preparation per unit raw weight while conventional ovens may increase cooking time. Rapid cooking of larger roasts with moist heat increased postcooking temperature rise. These results should aid in the revision of foodservice beef cookery guidelines.     

Analysis of Warner-Bratzler shear pattern with regard to myofibrillar and connective tissue components of tenderness

Force-deformation curves from the Warner-Bratzler (WB) shear device were used to evaluate specific changes in the myofibrillar (WB M-force) and connective tissue component (WB C-force) of tenderness in samples from beef semitendinos. Cores were heated in a water bath to end point temperatures of 60°C and 80°C by using combinations of slow and fast heating rates. Increasing the end point temperature from 60°C to 80°C was found to increase the WB M-force and to decrease the WB C-force, whereas the WB peak force was least affected. Comparisons between different heating rate combinations to samples heated to 80°C showed that the WB M-force was affected by a heating rate both below and above 60°C, while the WB C-force was most influenced by a heating rate above 60°C. Slower heating rates and higher endpoint temperatures resulted in greater cooking losses and increased solubility of collagen. The WB M-force and WB C-force were found to be more significant estimators of sensory evaluations of tenderness and collagen solubility in this experiment than the usually measured WB peak force.     

Evaluation of an Accelerated Processing System for Precooked Beef Products

Twelve beef carcasses were used to determine the effects of accelerated processing (hot-boning) on cooking, palatability and storage characteristics of precooked beef products. The conventional (CS) and the accelerated processed (AS) sides were fabricated into rib roast, strip loin, chuck roll, and pizza topping and products were precooked by convection oven, broiling, water bath or in a steam kettle, respectively. Products from the AS sides had lower cooking losses for strip loin steaks and chuck rolls and shorter cooking times for loin steaks and rib roasts than did product from CS sides. Rib roasts and chuck rolls from both processing systems were very acceptable in tenderness, but AS loin steaks were unacceptable in tenderness. Loin steaks and rib roasts from AS had less off-flavor than roasts from CS sides.     

Effects of Electrical Stimulation, Boning Time and Cooking Method on Beef Roasts

Sixteen steer carcasses were selected to study effects of electrical stimulation, boning time and cooking methods on palatability traits, cooking loss and chemical composition of beef biceps femoris muscle. Eight carcasses were electrically stimulated and eight carcasses served as controls. The biceps femoris muscle was removed from one side of each carcass within 2 hr of exsanguination and from the remaining side following a 48-hr chill. Muscles were subdivided and cooked in either a convectional electric or a microwave oven. Electrical stimulation resulted in longer (P < 0.01) sarcomeres for cooked product but did not affect palatability traits, cooking loss or chemical content. Hot boning reduced (P < 0.01) cooking loss and tenderness, resulted in less (P < 0.05) total, soluble and insoluble collagen and increased the juiciness score and moisture percentage when compared with 48-hr boning. Microwave cooking produced a greater (P < 0.01) cooking loss and a higher shear force value than convectional electric cooking.     

Differences Between Conventionally Cooked Top Round Roasts and Semimembranosus Muscle Strips Cooked in a Model System

Roasts cooked at 177°C by dry (OR) or moist (OFB) heat to 60°C were compared with muscle strips cooked in a model system to 60°C at a rate similar to oven raosting 1.4-kg roasts at 177°C. OFB roasts were less tender, less juicy, had less rare beef flavor, less red and yellow color, more total cooking loss, and shorter cooking time than did OR roasts. Strips had lower values for Instron measurements of hardness, chewiness, shear cohesiveness, and firmness than did OR or OFB roasts. Although strips were cooked in a moist atmosphere, they were more like OR roasts than like OFB roasts. Variance for a given measurement was similar between roasts and strips.     

STUDIES OF COW BEEF TENDERNESS ENHANCEMENT THROUGH SUPERSONIC-HYDRODYNAMIC SHOCK WAVE TREATMENT

Longissimus samples were removed from each side of 17 U.S. Commercial and Utility carcasses (Experiments A, B, and C). The samples were randomly assigned to supersonic-hydrodynamic shock wave treatment (SSW) or no treatment (C). Total energy and maximum peak force data were obtained for all treatments. Sensory evaluation (for Experiments A and C) included subjective ratings for myofibrillar tenderness. juiciness, connective tissue amount, and overall tenderness. Also, thaw loss, cooking loss, and collagen solubility were determined. The effects of supersonic-hydrodynamic shock treatment on the reduction of shear force and sensory values for all studies were minimal. Thaw loss (Experiment B only), cooking loss, CIE L* a* b* values, collagen solubility and standard plate counts were unaffected (P>0.05) by treatment. Further research with less tender beef should indicate if tenderness improvement can be attained through a closer accoustical match with water and improved techniques for administering shock wave treatment.     

Sensory and functional meat quality characteristics of pork derived from three halothane genotypes

The effect of the halothane gene in pigs on the meat and sensory qualities thereof were determined. Meat derived from 60 Landrace×Large White pigs of three halothane genotypes was used. The sensory qualities, cooking loss, colour, shear value and proximate analysis of the cooked pork loin roasts were determined. The three genotypes did not differ significantly (P>0.05) with regard to the colour of the cooked meat, percentage cooking loss and percentage moisture. There were significant differences (P<0.05) between the genotypes in the percentage protein, ash and fat. Meat from the three genotypes also differed significantly (P<0.05) in juiciness, an analytical sensory panel scored the juiciness of meat from the NN-genotype the highest with a value of 71.3 when using a structured line scale. Meat from the nn-genotype had the lowest score for juiciness (62.8). Meat from the three genotypes did not differ significantly (P>0.05) with regard to tenderness, pork flavour and no mealiness. Correlation values showed a positive correlation (r=0.46, P<0.05) between juiciness and tenderness. These results indicate that the inclusion of the halothane gene in pig production programmes results in meat with an inferior quality and it can be recommended to exclude the halothane positive genotype from any pig production system where fresh pork quality is considered a primary goal.