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The objective of this study was to determine whether culled beef cows fed a high-concentrate diet (FED) would have improved live performance, carcass traits and muscle characteristics compared with forage fed (CON) cows. In addition, ractopamine (RAC) supplementation was evaluated for added benefits over high concentrate alone. Live weight, average daily gain, hot carcass weight, ribeye area, marbling, quality grade and carcass fat measurements increased (P ≤ 0.05) by realimentation. As a percent of hot carcass weight, muscle yields did not differ (P > 0.05). Lipid content increased (P ≤ 0.05) in 5 out of the 10 muscles from FED cows. Cows fed ractopamine showed some numeric improvements over feeding alone, but few statistical differences (P > 0.05). This may result from variability associated with cull cows, and warrants investigation into the best dose/duration for ractopamine. However, realimentation by itself was able to improve cull cow quality. PRACTICAL APPLICATION The U.S. beef industry continues to explore new avenues to enhance undervalued sectors of the production system. Through realimentation, cull cow quality can be improved. The data presented herein demonstrate that feeding a high-concentrate diet to cull cows increases both live and carcass weights. In addition, high concentrate-fed cull cows display more marbling and whiter fat cover than those fed at maintenance level. Qualification for premium programs, heavier weights and overall higher quality may lead to increased value for this underutilized sector of the beef industry. more...

From an experiment in which 60 beef cull cows were assigned to one of three feeding treatments, forage fed, high concentrate or high concentrate plus ractopamine, 10 muscles were removed from both sides of the carcass. Muscles from one side of the carcass were enhanced with a solution to target 0.3% salt and 0.3% phosphate in the final product. Minimal to no differences were observed in color, pH, sensory characteristics or shear force as a result of dietary treatment. Enhancement resulted in muscles with higher (P ≤ 0.05) pH and darker color. Sensory scores for juiciness and tenderness were improved (P ≤ 0.05) with enhancement. The Adductor was the only muscle not exhibiting lower shear values due to enhancement (P > 0.05). To add further value to meat from cull cows, enhancement could be utilized, independent of feeding regimen prior to slaughter. PRACTICAL APPLICATIONS The use of enhancement in the beef industry has become common practice, particularly in beef from lower grading cattle. However, research examining the improvement in palatability with enhancement has focused mainly on younger cattle. Our research demonstrates that enhancement is able to improve the sensory characteristics of meat from cull cows. Thus, in meat from older animals, which is usually characterized as being less palatable, enhancement could be used to improve the organoleptic traits. This practice may assist the beef industry in capturing further value from cull cows. more...

Beef complexus (chuck), serratus ventralis (chuck), vastus lateralis (round), vatsus medialis (round), and longissimus dorsi (loin) muscles were enhanced (0.3% salt, 0.4% phosphate), vacuum packaged, and aged for 7 or 14 d. Enhancement increased positive sensory attributes (tenderness, juiciness, beef flavor, saltiness) and decreased negative attributes (off-flavors) of all muscles but had greater effects on some than on others. It increased the oily mouthfeel (10%) and saltiness (40%) and decreased the L* value and chroma of the complexus (chuck). It increased tenderness, juiciness, and beef flavor and decreased off-flavors, visual red and brown colors, shear value, and cook loss of the serratus ventrali (chuck), vastus lateralis (round), vastus medialis (round), and longissiumus dorsi (loin). Aging slightly decreased rancid and liver off-flavor scores, visual brown color, and shear value and increased the hue angle and L* and b* values. more...

The objective of this study was to develop a model system to evaluate the effects of freezing, exposure to enhancement solution and modified atmosphere on discoloration of pork rib bones. Bones were removed from carcasses, split along the transverse plane, then frozen (−20C) or held at 4C for 24 h. Half of each temperature pretreatment group was exposed to a 4% phosphate/4% NaCl enhancement solution, while half served as controls. Samples were packaged in modified atmosphere packaging (80% O2/20% CO2) or air and displayed in a retail case (4C, 24 h). Visual discoloration occurred during the first 10 h of display; additional visual darkening (brown, green/black) occurred in previously frozen samples, while refrigerated samples remained redder. After 24 h, Commission Internationale de l'Eclairage L*, a* and b* values indicated that previously frozen samples were darker and less red. The frozen samples contained more methemoglobin per gram of protein than those that had never been frozen. more...

The objective of this study was to determine the effects of loin muscle location on glycolytic potential (GP) and fresh pork quality traits. Seven sections (5-cm thick) from approximately between the eighth rib and fourth lumbar vertebra were evaluated. Numerous quality measurements were taken within each section. Ultimate pH was similar (P > 0.05) at all locations. Drip loss decreased (P more...

CT CT CT: Some curr ome curr ome curr ome curr ome current pr ent pr ent pr ent pr ent practices used in the meat industr actices used in the meat industr actices used in the meat industr actices used in the meat industr actices used in the meat industry (blast chilling, enhancement, modified atmo- y (blast chilling, enhancement, modified atmo- y (blast chilling, enhancement, modified atmo- y (blast chilling, enhancement, modified atmo- y (blast chilling, enhancement, modified atmo- sphere packaging (MAP)) appear to result in darkening of the bone in fresh meat. The objective of this study was sphere packaging (MAP)) appear to result in darkening of the bone in fresh meat. The objective of this study was sphere packaging (MAP)) appear to result in darkening of the bone in fresh meat. The objective of this study was sphere packaging (MAP)) appear to result in darkening of the bone in fresh meat. The objective of this study was sphere packaging (MAP)) appear to result in darkening of the bone in fresh meat. The objective of this study was to develop a model system that could be used to evaluate intervention strategies to prevent this discoloration. Beef to develop a model system that could be used to evaluate intervention strategies to prevent this discoloration. Beef to develop a model system that could be used to evaluate intervention strategies to prevent this discoloration. Beef to develop a model system that could be used to evaluate intervention strategies to prevent this discoloration. Beef to develop a model system that could be used to evaluate intervention strategies to prevent this discoloration. Beef rib bones were removed from carcasses, split along the transverse plane from the proximal to the distal end of the rib bones were removed from carcasses, split along the transverse plane from the proximal to the distal end of the rib bones were removed from carcasses, split along the transverse plane from the proximal to the distal end of the rib bones were removed from carcasses, split along the transverse plane from the proximal to the distal end of the rib bones were removed from carcasses, split along the transverse plane from the proximal to the distal end of the rib, and then frozen (-20 °C) or held at 4 °C for 24 h. Half were exposed to a phosphate/salt enhancement rib, and then frozen (-20 °C) or held at 4 °C for 24 h. Half were exposed to a phosphate/salt enhancement rib, and then frozen (-20 °C) or held at 4 °C for 24 h. Half were exposed to a phosphate/salt enhancement rib, and then frozen (-20 °C) or held at 4 °C for 24 h. Half were exposed to a phosphate/salt enhancement rib, and then frozen (-20 °C) or held at 4 °C for 24 h. Half were exposed to a phosphate/salt enhancement solution while half served as the control. Samples were packaged in air or modified atmosphere packaged (MAP: solution while half served as the control. Samples were packaged in air or modified atmosphere packaged (MAP: solution while half served as the control. Samples were packaged in air or modified atmosphere packaged (MAP: solution while half served as the control. Samples were packaged in air or modified atmosphere packaged (MAP: solution while half served as the control. Samples were packaged in air or modified atmosphere packaged (MAP: 80% O 80% O 80% O 80% O 80% O 2 /20% C een/black) was obser een/black) was obser een/black) was obser more...

Pigs from four commercial packing facilities were utilized to characterize the impact of downer pigs on meat quality and the impact of respiratory health on downer pigs. Lungs of downer pigs were evaluated for pneumonia and the pH of the longissimus was measured at approximately 45 min postmortem on 246 carcasses. At approximately 24 h postmortem, subjective color, marbling, firmness of the loin, carcass conformation, gender, objective loin color and ultimate pH of the longissimus were determined on 229 carcasses. Muscle score, 45 min pH and lung score averaged 2.14, 6.32 and 1.67, respectively. Subjective color, marbling, firmness, Minolta L-value, pH and drip loss averaged 3.75, 2.72, 3.16, 45.72, 6.00 and 1.91%, respectively. Downer pigs tended to produce pork that was dark in color with a relatively high ultimate pH and low drip loss. Virtually no relationship was observed between downer pigs and lung score. more...

The objective of this study was to characterize the sensory properties of four common meat products (ground beef, fresh pork sausage, smoked sausage, and frankfurters) all manufactured with nonsolvent extracted textured soy protein (NSTSP) used as a lean meat replacement. High levels (45%) NSTSP added to ground beef and fresh pork sausage resulted in products which were more mushy with much more off-flavor than control samples, whereas juiciness was unaffected. Addition of 30% or 45% NSTSP increased ( P 0.05) neither texture and mouth feel nor off-flavor of smoked sausage. Up to 30% NSTSP had no effect on either texture or mouth feel nor on off-flavor of frankfurters. Addition of NSTSP increased off-flavor of all products except frankfurters. Practical levels of lean replacement appear to be less than 30% for these meat products. more...

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. more...

A study was conducted to characterize the relationship between Longissimus thoracis ultimate pH (LTpH) and pork quality. Animals (n =47) were selected based on LTpH measured at 24 h postmortem. Data were analyzed using regression procedures with ultimate pH as the independent variable, and relationships were determined to be linear (L), quadratic (Ql or cubic (C). Ultimate pH explained 79% (C) of the variation in subjective color, which increased as pH increased. Drip loss, purge loss and L* value decreased as LTpH increased (R2 = 0.57C, 0.77 Q and 0.68 Q, respectively). Shear force decreased and sensory juiciness increased as LTpH increased (R' = 0.26 Q and 0.46C, respectively). However, offlavor intensity increased as LTpHfell below pH 5.2 or exceeded 6.1(R2= 0.52C). Increasing LTpH, up to a point, will improve fiesh pork quality and processed meat properties, whereas, above approximately 6.1, of-jlavor may increase. more...

The objective of this study was to evaluate shelf-life, color and sensory characteristics of pork chops from loin sections (n = 12/treatment) injected (110% original weight) with a potassium lactate/potassium acetate solution (2%) + phosphate (0.35%)/salt (0.35%), compared with those injected with sodium lactate (3 %) + phosphate/salt, or phosphate/salt alone, to control loins. After 96 h of display, aerobic plate counts (CFU/cm 2 ) were significantly lower (P more...

Chemical, physical, and sensory characteristics of low-fat beef patties containing carbohydrate-lipid composites (CLCs) were compared with those of all-beef patties. The CLC gels contained high-amylose cornstarch, maltodextrins, and canola oil. CLC patties had higher moisture, cooking yield, and fat retention than 20%-fat control patties. CLCs improved tenderness and juiciness and decreased cohesiveness of low-fat beef patties compared with 10%-fat control patties. Despite differences in CLC gel firmness, patties made with CLC gels containing corn, potato, and tapioca maltodextrins had similar physical and sensory properties. These results suggest that CLC gels perform well as a partial fat replacer in beef patties while providing flexibility in gel firmness selection. more...

Intact sides were subjected to accelerated chill (AC: -3OC for 2.5 h, 4C for 20-22 h) or conventional chill (CC: 4C for 22-24 h). Color, drip loss, and pH were evaluated 24 h postmonem at three sites (inner, mid, and outer) in the Semimembranosus (SM) and Biceps femoris (BF) with the inner site closest to the femur. Zle Longissimus thoracis (LT) and the Longissimus lumborum (LL) were also evaluated. Accelerated chill improved color and drip loss of the Longissimus muscle. Accelerated chill had no fleet on the quality measurements of the ham, although site differences occurred. The fleets of genotype on color, drip loss, andpH in the loin and ham muscles were not consistent in the muscle groups studied. Compared to CC, AC has beneficial fleets on fresh pork quality of the Longissimus muscle, but not the ham muscles. more...

Beef round roasts were injected (to 110% of original weight) to result in 0.4% sodium chloride and 0.4% phosphate on a finished weight basis. Steaks from enhanced roasts were more (P

ABTRACT Boneless, paired pork loins (n=120) were selected based on pH at 14 h postmortem. Ultimate pH, drip loss, instrumental color (L*, a*, and b* values), and proximate analysis were determined prior to pumping. Paired loins were cut into four sections and pumped to 100%, 106%, 112% or 118% of original weight to result in a product containing 0.4% sodium tripolyphosphate (STP) for Experiment 1 (Exp. 1) and 0.4% STP plus 0.4% salt for Experiment 2 (Exp. 2). In Exp. I, additional pump level increased (P more...

Halothane negative Durocs (n=36) were slaughtered, and subjected to: accelerated chill (AC: -30C for 2 h, with air circulation, followed by equilibration at 4C for 20-22 h), conventional chill (CC: 4C for 22-24 h with water sprayed every 2 h until 12 h postmortem), and slow chill (SC: 10-12C for 12 h followed by equilibration at 4C for 10-12 h). Color, pH, and drip loss were determined for the Semimernbranosus (SM) Biceps femoris (BF), Longissirnus thoracis (LlJ, and Longissirnus lumborum (LL). In the ham muscles, AC decreased b * values and drip loss. Decreased drip loss was restricted to the outer sites. Ham muscles were darkest in the mid location and lightest in the inner locations. In the Longissirnus, AC decreased pH but did not afect color or drip loss. Compared to SC, ACproved beneficial, however, AC had no advantages over CC in pigs with minimal predisposition to quality problems. more...

Pork loins were pumped to 110% of original weight with solutions containing 0.35% salt and 0.35% phosphate (P), salt and phosphate plus 3% sodium lactate (SL), or salt and phosphate plus 2.5% potassium lactate/potassium acetate (PL/PA). Chops were evaluated freshly cooked and precooked, stored (4C, 2 days) and reheated. Chops from SL and PL/PA chops experienced lower cook losses than unpumped controls. Reheating produced additional cook losses which were unaffected by enhancement treatment. Enhancement produced reheated chops with lower shear values and higher tenderness scores than those of freshly cooked controls, and addition of either SL or PL/PA produced even more dramatic results. Warmed-over flavor after reheating precooked chops was reduced by the SL enhancement solution. more...

Pork loins were pumped to 0, 6, 12 or 18% over initial weight (0.4% sodium tripolyphosphate, 0.4% sodium chloride), and vacuum-packaged. In retail supermarkets, consumers (n = 196) evaluated acceptability of color, purge in the package, texture appearance, overall appearance acceptability, and purchase intent. Seventy percent of these consumers were 26 to 55 years of age; 70% were female; 70% consumed pork at least twice per month, usually at home (>88%). More than 36% of the consumers would purchase “enhanced” pork, but expressed concern about ingredients on the label: phosphate (60%), salt (74%), and water (26%). Based on visual evaluation, 57% of the consumers “probably” or “definitely would buy” the unpumped product. The percentage of consumers rating loins in the higher two purchase intent categories decreased as pump level increased from 57% for 0% pump to 46% for 18% pump. Percentages of the ratings falling in the higher two categories for acceptability of liquid in the package decreased from 58% for 0% pump to 42% for 6% pump, and more...

High pressure water (110 kPa) was compared to the Whizard knife (WK) with respect to quantity and composition of tissue recovered from thoracic, lumbar, and cervical vertebrae of swine and beef carcasses. High pressure water (HPW) recovered tissue contained less collagen than that recovered using the WK. A higher percentage of tissue was recovered from beef bones by WK than by HPW, but HPW tissue was higher in noncollagen protein. Recovery differed due to vertebral location; thoracic and lumbar vertebrae yielded a higher percentage of tissue than did cervical vertebrae. Centrifugation at 4000 x g was required to reduce the moisture content of HPW-recovered tissue to that of WK-recovered tissue, Fat content of HPW-recovered beef tissue was lower than that of WK-recovered tissue, however the reverse was true for tissue recovered from pork vertebrae. Recovery method had no effect on total protein or ash content. more...

Animals (n = 72) with longissimus glycolytic potential (GP) values ranging from 113.8 to 301.1 μmol/g of tissue, were classified as having low (n = 24), moderate (n = 24), and high (n = 24) GP levels. Meat quality measurements such as longissimus ultimate pH and subjective color score decreased, while Hunter L* values, percentage drip loss and purge loss increased for animals classified as having either high or moderate GP levels compared to those with low GP values. Animals with higher GP had decreased longissimus protein content and improved taste panel tenderness scores and lower shear force indicating superior eating quality. Increasing aging time from 2 to 21 days decreased shear force and improved taste panel tenderness scores. These data indicate that both glycolytic potential level within the muscle and aging time can have significant effects on pork quality characteristics. more...

Eight hybrid gilts of Hampshire descent were selected at 110 kg live weight, grouped together in one pen and given a one-week adaption period prior to sampling. Longissimus samples (approximately 0.5 g) were taken using spring-loaded biopsy equipment with animals either unrestrained and free to move in the pen or, 3 h later, restrained with a nose snare for two minutes prior to sampling. There was no difference among the two handling approaches for glycolytic potential (P > 0.05). Animals were slaughtered and four longissimus samples (0.5 g) were taken from each carcass immediately following exsangination to evaluate four sample storage methods. Two viable storage methods, freezing in liquid nitrogen followed by freeze drying or immediate homogenization in perchloric acid, yielded relatively high and similar values for muscle glycolytic potential. more...

Phosphate-salt pump effects were evaluated on sensory characteristics of pale, soft, exudative (PSE) pork, normal and dark, firm and dry (DFD) pork. Water-holding capacity, instrumental color (L*, a*, b*), pH, and muscle color scores were determined at 24 h postmortem on pork loin pairs (n=21 pairs). Based on color score, paired loins were assigned to PSE, normal or dark, firm, dry groups. PSE muscles were lighter, redder and more yellow than normal or DFD muscles; hue angle indicated that DFD muscles were actually closer to the true red axis of the CIE Lab Color Space. Drip and purge losses were higher (p more...

Effects of fat content (8 or 24%), processing temperature (–2, 1, 4C), plate size (2, 5, 5 mm), mixing time (3, 5, 8 min), and patty formation pressure (50, 100, or 150 kg) on characteristics of low-fat ground beef patties were evaluated. Reduced fat patties required less force to break when ground at –2C (2 mm plate) than when ground at 4C. Rubberiness increased as plate size increased. Rubbery scores were lowest at 4C/2 mm plate. Reduced-fat patties had lower cook losses. Increasing grinding temperature from –2 to 4C decreased break force, Kramer shear and cohesive texture. Break force was highest for patties mixed 8 min at –2C. Patty forming pressure affected breaking strength, cohesiveness, and cook loss. Production of reduced-fat ground beef patties by grinding through a 2mm plate at 4C, mixing for 2 min and forming patties at 150 kg pressure minimized rubbery texture and instrumental measures of patty hardness. more...

Consumers (n=556) rated pink color, wet/dry appearance, overall acceptability and purchase intent of normal, pale, soft and exudative (PSE), and dark, firm and dry (DFD) pork loin slices in PVC packages in five retail supermarkets. DFD samples appeared driest and PSE samples appeared wettest. Samples in the higher ranked two purchase intent categories appeared more wet than those in the lower three categories. The pinker PSE samples and all DFD samples were in the higher ranked purchase intent categories. Purchase intent generally paralleled overall acceptability; however, prediction equations indicated that wet/dry appearance, color and overall acceptability all contributed to purchase intent decision depending on muscle condition. more...

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. more...

Consumers (n = 116) evaluated color (pink intensity), appearance (wet/dry), overall acceptability and purchase intent of normal, PSE and DFD pork loin slices in PVC and in vacuum packages. Packaging x muscle condition affected (p < 0.05) appearance, overall acceptability and consumer purchase intent of pork slices. Color differences were perceptible to consumers between packaging treatments. PVC-packaged pork was pinker than vacuum-packaged pork. Vacuum-packaged, PSE pork appeared drier than PVC-packaged PSE pork. Normal pork was more acceptable than PSE pork regardless of packaging. DFD pork acceptability was not different from that of normal pork when vacuum packaged. In general purchase intent paralleled consumer evaluation of overall acceptability. Instrumental color data and pH for samples evaluated are also presented. more...

Three thicknesses (2.54, 1.90 and 1.27 cm) of pork chops were cutl alternately from 20 paired loins of similar quality. Chops were cooked on Farberware grills or in a convection oven to internal temperatures of 60, 70 and 80°C for sensory and objective evaluations. Juiciness, percent moisture and tenderness decreased and cooking losses increased (P 0.05) on tenderness, juiciness or total cooking loss of oven-prepared or grilled chops. The thickest chops received the highest (P < 0.05) pork flavor scores. more...

The objective of this study was to evaluate the effects of fat (10, 20, and 30%, postrigor; 10 and 30% pre-rigor), rigor state, plate size (3 and 5 mm), and mixing time (2 and 5 min) on cooking loss and instrumental texture characteristics of reduced-fat pork sausage. High-fat products exhibited greater cook loss and lower breaking force than low-fat products. Rigor state of raw materials had no effect on the characteristics evaluated. Increasing plate size and mixing time increased initial force required to compress a 2.5 cm core to 20% of its original height but had no effect on other characteristics. Reduction of fat content can be accomplished without addition of nonmeat ingredients by limiting plate size to 3 mm and mixing time to 2 min. more...

Whole, boneless pork loins were pumped to result in a final concentration of 0% to 2% sodium lactate (SL) and/or 0% to 0.4% sodium tripolyphosphate (STP) resulting in a 3 × 3 factorial design. Three replications were randomly presented to 10 trained sensory panelists for evaluation. Physical properties of the loins were also evaluated. Sensory evaluation results suggested that there was a trend for juiciness and tenderness to be enhanced by the addition of STP. Pork flavor, salt intensity, and alkalinity were enhanced by SL. Pump yields increased while purge loss was reduced with the addition of STP. Color was not affected by SL or STP. No difference in peak force and energy required to shear samples was observed. Results from this study suggest that pork loins pumped with SL and STP had enhanced moisture retention with few detrimental effects on sensory characteristics. more...

A surimi-like material was made from finely minced beef or pork by water washing followed by screening to remove connective tissue. Changes in component proteins, amino acid composition and vitamin, mineral and cholesterol content occurring during preparation were investigated. Total amino acid nitrogen contents of water-washed beef and pork were higher than those of the respective muscle by 7% and 6.5%. Among 16 amino acids measured, histidine and glycine decreased in both water-washed beef and pork, while others increased compared to original muscle. Thiamin content decreased after washing. Surimi-like beef and pork had less cytoplasmic minerals (K, Na, Mg) but more minerals associated with proteins or subcellular organelles (Ca, Cu, Zn, Fe). Fat content decreased, although cholesterol concentration was not changed by washing. more...

Gel forming ability, measured by cooked gel hardness, and water-holding capacity of surimi-like pork were enhanced by addition of NaCl at 1.5 or 3% although 4.5% or 6% NaCl did not further increase hardness. Cooked gel strength was unaffected by freezing of beef or pork surimi-like materials for 48 hr. Addition of cryoprotectants (3% or 6% sorbitol, 3% glycerol, or 3% sucrose) before freezing had no effect on gel forming ability. Gel hardness was not increased by preheating prior to cooking. Preheating surimi-like pork at 50 degrees C resulted in formation of weaker gels which corresponded to myosin proteolysis. Myosin heavy chain (mw 200 kD) decreased, and new peptide fragments of mw about 138 kD, 128 kD, 120 kD, 86 kD, 77 kD, and 64 kD appeared. Proteolysis was salt-dependent and occurred at pH 6.8-7.5. more...

As part of the Pork Chain Quality Audit, pork manufacturing companies were surveyed to identify and quantify factors influencing pork quality. Surveys were designed to evaluate the quality of pork at the slaughter and fabrication segments of the chain. Meat firms provided information based on 57% of the 88 million barrows and gilts slaughtered in federally inspected plants in 1992. All major hog-producing areas of the U.S. were represented. Results of the survey indicated that the primary concerns about the quality of pork at the packing level were: (1) excessive fat; (2) inadequate muscle-color/water-holding-capacity; (3) inconsistent live weights; (4) too many abscesses; and (5) excessive bruising. The results of the survey were used to determine costs associated with quality deficiencies. It was determined that $10.10 or approximately 10% of the live-animal value is lost per slaughter barrow/gilt due to quality nonconformities. more...

As part of the “Pork Quality Audit,” an extensive review of the literature relative to pork quality has been conducted which describes the scientific basis which the United States pork industry can utilize when addressing quality defects. Specific pork quality characteristics that are discussed include muscle color, firmness and texture (specifically pale, soft and exudative muscle); intramuscular fat; meat palatability (tenderness, juiciness and flavor); ecchymosis; broken bones; meat shelf-life; and food safety. Specific factors are discussed in detail as to how they influence pork quality characteristics. Factors which are discussed include carcass composition, genetics, nutrition, growth promotants, preslaughter handling, immobilization, postmortem handling and chilling, packaging, and long-term storage. This review provides a foundation for the identification of factors which impact pork quality nonconformity. more...

Heat-induced gelation properties of the semimembranous muscle from induced DFD (dark, firm and dry) and normal pigs were characterized to evaluate the effect of muscle pH on strength and cooking loss of gels induced by a heating at 0.7C/min. The pH of muscle slurries (10% protein with 2% Nacl) were adjusted to 5.5, 6.0, 6.5, or 7.0 with 1 M 2-[N-Morpholino] ethanesulfonic acid buffer. Muscle with a high initial pH (DFD) had lower cooking losses at all adjusted pHs. Force required to penetrate the gel (Pf), force required to move plunger through the gel (Fp), and viscosity index of the gel were consistently higher for DFD muscle at each adjusted pH except pH 5.5. These results indicate that ultimate pH influences the thermal gelation properties of a meat product if the pH is ≥ 6.0. DFD muscle had desirable protein functionality and cooking yield. more...

This study was conducted to evaluate the effects of belly thickness on processing, sensory and visual characteristics, moisture and fat of bacon made from 45 bellies of various thicknesses. Belly thickness had a linear effect (P < 0.05) on raw, cured, and cooked weights, and water and fat content. A linear relationship (P < 0.05) was observed between belly thickness and slice integrity, appearance, and lean-to-fat ratio of bacon. Saltiness, texture and mouthfeel, bacon flavor intensity, and off-flavor intensity were unrelated to raw belly thickness. more...

Effects of heating rate (3°C or 0.7°C/min) and pH (5.5, 6.0, 6.5, or 7.0) on thermal gelation properties of different muscle systems were evaluated (10% protein, 2% NaCl) using pork, beef, fish, and chicken and turkey (breast and thigh) muscles. Results indicated that, at pH 6.5 and 7.0, force required to rupture the gel (Pf), force required to move plunger through the gel (Fp), and viscosity index (Ni), using a slow heating rate, were higher than with rapid heating. All muscles (except breast muscles with the slow heating rate) yielded higher (P more...

Myofibril gels with 5, 7, or 10% protein and 2% NaCl were prepared from pork, beef, fish, chicken and turkey muscles using a heating rate of 0.7°C/min and pH 6.0 to compare the thermal gelation properties of myofibrillar protein from different species. The force required to rupture gel (Pf), force required to move plunger through gel (Fp), viscosity index (Ni), and elasticity (Ea) increased and cooking loss decreased with increasing protein contents. Myofibrils of chicken breast and thigh had lower and fish and turkey thigh had higher cooking loss at protein contents of 7% or 10%. more...

Thermal gelation properties of myosin, actin, myofibrils (MF), sarcoplasmic protein (SP) and connective tissue (CTS) from pork semimem-branosus and chicken breast (CB) were evaluated. Gels were prepared at pH 6.0, 2% NaCl and cooked to 70°C at 0.7°C/min. Pork myosin had a higher gel strength and a lower cooking loss than CB myosin at 7% protein. Actin from both species did not form a measurable gel. MF gels from pork and CB had the lowest cooking loss while CTS and SP had the highest cooking loss. Difference in gel strength between muscle and MF+SP+CTS at 7% protein was not consistent with that at 10% protein. more...

Data concerning the sensory attributes of chevaline, although limited, are of interest particularly to markets where it is sold as a human food. Thus, this study was conducted to characterize the sensory attributes of steaks from chevaline longissimus muscle from both younger (2–4 years of age: N = 10) and older animals (4 years and older: N = 10). Uncooked steaks (2.5 cm thick) were evaluated for moisture, fat, and protein content as well as color, instrumentally (L*, a*, and b*) and visually (lightness, redness, and brownness). Steaks were cooked to 70C (internal temperature) and then served to a sensory panel and evaluated by Warner-Bratzler shear. No differences (P < 0.05) were observed between age groups for sensory or color characteristics. Steaks from young animals had lower (P < 0.05) shear force values and protein content. Results suggest that age has limited effects on the composition, sensory, and color characteristics of chevaline steaks. more...

Continuous variables, salt, fat, and either soy protein or iota-carrageenan, were evaluated using response surface methods to formulate a lower salt/ lower fat franktirter with acceptable palatability attributes. Soy protein increased hardness and off-flavor, and decreased juiciness, saltiness, and flavor intensity. Soy protein should be added to frankfurters at 15%. Flavor intensity increased as carrageenan and fat level increased at 1.3% salt. At 1.65% salt, off-flavor intensity decreased as fat content increased and carrageenan decreased. more...

Acceptable processing and flavor profile characteristics of frankfurters were achieved near a pH of 6.0. As salt increased, hardness, juiciness, saltiness, and flavor intensity scores increased. As fat increased, juiciness scores decreased (at salt levels > 1.3%) due to substitution of water for fat. In addition, increased fat resulted in decreased off-flavor. Model predictions suggested that acceptable frankfurters could be manufactured with a minimum of 11.25% fat and 1.3% salt at pH 6.0. more...

This study was designed to evaluate the visual and palatability characteristics of boneless cured hams and fresh loin chops from pigs fed diets containing 0, 5, 10 or 20 ppm of the phenethanolamine, ractopamine hydrochloride (RAC). Sixty pigs were blocked by starting weight and randomly assigned to pens (four pigs/pen) within each of three blocks. Treatments were then randomly assigned to pens (six pens of the 0–ppm level and three pens each for the 5, 10 and 20 ppm RAC levels). Animals were slaughtered by weight block after approximately 48 days on trial. Fresh pork hams and loin sections (10–14th rib) were removed from the right side of the carcasses for subsequent analysis. Boneless hams were manufactured using commercial curing procedures. RAC had no effect (P > 0.05) on visual or palatability attributes of ham slices or boneless loin chops. Moisture content of the longissimus muscle from RAC treatments was lower (P < 0.05) than controls; however, this difference was small. These results indicate that RAC had no affect on the visual or palatability characteristics of boneless cured and smoked hams or fresh boneless pork loin chops. more...

Special fed veal calves (N = 75) were slaughtered in study 1 and assigned to the following treatments; control (C), electrical stimulation (ES) immediately postmortem for 20 s (ES20–IP) or 40 s (ES40–IP), and ES 10 min postmortem for 20 s (ES20–10) or 40 s (ES40–10) using a Jarvis BV 80 electrical stimulator. Temperature, pH and 24 h carcass traits were evaluated. ES durations of 40 s produced more desirable carcass traits. In study 2, 40 calves were slaughtered and assigned to C or ES40–IP treatments. Temperature, pH, carcass characteristics, purge loss, percent free water, color stability, Warner-Bratzler shear force and palatability of biceps femoris slices were evaluated. ES reduced (P < 0.05) pH (at 45 min, 3 h and 24 h) and decreased (P < 0.05) percentage free water, but did not affect color stability, palatability or shear force values of veal from study 2. Low voltage ES enhanced postmortem pH decline in both studies (especially in study 1) and improved the 24 h (postmortem) longissimus characteristics of veal in study 1. more...

The purpose of this study was to evaluate the effects of different reheating methods (steeping, broiling, or microwaving) and end-point reheating temperatures (66C, 77C, or 88C) on the physical and sensory characteristics of frankfurters. Instron hardness, shear force, sensory hardness, and saltiness scores increased and juiciness scores decreased with additional reheating temperature when frankfurters were microwaved or broiled. Frankfurter density decreased with higher ultimate temperature which was attributed to additional gas volume. Expressible moisture increased with a higher ultimate temperature when frankfurters were steeped. Free water was the highest at 77C. Neither cooking procedure nor ultimate temperature influenced protein denaturation as determined by gel electrophoresis and enzymatic digestion. more...

Boneless pork loins sliced into 1.9 cm fresh chops were dipped to retain 0, 1.5 or 3% sodium lactate (SL) and packaged in polyvinylchloride (PVC) or vacuum-packaged (VP), Color of fresh chops was monitored visually and objectively. Boneless pork loins were cured by injection with 0, 1.5 or 3% SL, or were dipped after slicing to retain 0, 1.5 or 3% SL. Cure for the dipped loins contained no SL. Color and aerobic plate count (APC) of vacuum-packaged chops were evaluated over 70 days of retail storage (4C). Visual color was darker (P 0.05) from controls. No consistent trends were found in APC of cured chops. Injection of SL prior to cooking darkened the color of cured pork loin chops. more...

This study's objective was to identify the range of physical and sensory properties of commercially available frankfurters. Twenty-five types of frankfurters were evaluated by a six-member sensory panel and subjected to Instron texture profiling. A wide range of sensory and textural characteristics was observed for acceptable frankfurters. Salty flavor and juiciness were correlated with fat content, but salt and fat content were inversely correlated. Negative correlations occurred between fat content and Instron fracturability and compression; fat content decreased resistance to force from mechanical stress. Firmness was positively correlated with Warner-Bratzler shear force. The development of an accurate regression equation to predict sensory hardness was not possible with this data set. more...

Semitendinosus steaks were injected, dipped or tumbled to contain 50 or 100 ppm bromelin (B) or papain (P), frozen, cut into steaks and cooked. Cooked, P-treated steaks had more mushy texture, more intense off-flavor and more bound water than B-treated steaks. Steaks treated with 100 ppm enzyme were more mushy and contained more bound water in the raw state, but not in the cooked state, than those with 50 ppm. Halved ST roasts were injected or tumbled with 10 or 20 ppm B, or 2.5 or 5 ppm P, precooked, refrigerated and reheated. Injected roasts lost more weight during cooking and were more mushy and contained less connective tissue than those which were tumbled. more...

Fresh (FL) and precooked (PL) longissimus chops and fresh semi-membranosus/adductor (SM) roasts were evaluated to determine acceptability of marinated pork. Citric acid and sodium acid pyrophosphate lowered pH (CAP), sodium acid pyrophosphate attained intermediate pH (SAP), and sodium tripolyphosphate increased pH (TPP). In FL and SM cuts, TPP improved sensory characteristics, water-holding capacity (WHC) and processing yields. CAP reduced microbial growth in FL chops and improved tenderness in SM roasts. In PL cuts, TPP improved juiciness and reheating yields. Marinating at low pH reduced microbial growth; marinating at high pH improved sensory properties, WHC, fresh pork processing yields and precooked pork juiciness and reheating yields. more...

Samples from subcutaneous, intermuscular and internal fat depots of 30 crossbred pig carcasses with tenth rib fat thickness ranging from 1.5 to 4.3 cm were used to evaluate the relationships of backfat thickness and fat depot composition (moisture, lipid and cholesterol contents). Moisture and cholesterol were highest and lipid content was lowest in intermuscular fat while cholesterol was lowest (P < 0.05) in subcutaneous fat when compared to the other fat depots. Significant (P < 0.01) linear effects of tenth rib fat depth on moisture and lipid contents of all fat depots were observed. Linear effects (P < 0.05) of tenth rib fat thickness on cholesterol content of subcutaneous and internal fat depots were observed on both a wet and dry bases. However, the linear effect (P < 0.05) of tenth rib fat depth on cholesterol content in the intermuscular fat depot was observed only on a dry basis. When the three fat depots were combined, increased tenth rib fat depth resulted in decreased moisture and cholesterol contents on a dry basis while percentage lipid increased (P < 0.05). more...

Pork and beef muscles were used to evaluate assay and storage condition effects on yields of salt soluble protein (SSP). Assay conditions included pH (5.5, 6.0 or 6.5), extraction volume (6, 9, 12 or 15 X sample weight), homogenization time (30, 60, 90 or 120 set) and centrifugal force (2500, 4000 or 5500 ×g). Storage conditions included postmortem aging (4°C for 0, 7 or 14 days) and freezing conditions (rapid freezing, slow freezing, and freezing-thawing-freezing). Highest yield of SSP was obtained using pH 6.0, extraction volume 15 X sample weight, centrifugation at 4000 ×g and homogenization time 90 to 120 set for both pork and beef. Freezing conditions did not affect measurement of SSP. Aging beef for 7 and 14 days postmortem reduced the yield of SSP; however, such differences were not observed for pork. more...