Effects of dietary vitamin A restriction during finishing on color display life, lipid oxidation, and sensory traits of longissimus and triceps brachii steaks from early and traditionally weaned steers.

Our objective was to determine the effects of vitamin A restriction during finishing on color display life, lipid oxidation, and sensory traits of longissimus lumborum (LL) and triceps brachii (TB) steaks from early and traditionally weaned steers. Forty-eight steers weaned at either 137±26 days (EW) or 199±26 days (TW) were supplemented with either 15,400IU/kg dry matter of vitamin A (HA) or restricted to no supplemental vitamin A (LA) during finishing for 210 and 150 days, respectively. Both LL and TB steaks from the HA steers had the darkest (P<0.05) color scores after 3 days of retail display in PVC packaging at 2°C, and the highest (P<0.05) thiobarbaturic acid reactive substances (TBARS) values. Instrumental a∗, b∗, and saturation index values were lowest (P<0.05) in LL steaks from the HA steers. Instrumental L∗ values were lower (P<0.05) on days 4-6 in TB steaks from TW steers fed LA than those from EW steers fed HA. No differences were found in Warner-Bratzler shear force values or sensory traits in either muscle. No supplemental vitamin A versus high levels of vitamin A inclusion in finishing diets has potential to increase color display life and reduce lipid oxidation, with no effects on meat palatability.

Effects of dry aging of bone-in and boneless strip loins using two aging processes for two aging times.

This experiment investigated the combined effects of two dry-aging methods (unpackaged and in a bag), two loin-cut styles (bone-in shell loins and boneless strip loins), and two aging times (21 and 28days) on the physical, chemical, sensory, and microbial properties of dry-aged beef. Sections from shell and strip loin were assigned randomly to be aged unpackaged or aged packaged in a bag with high moisture permeability. Weight losses increased with aging time. Shell loins lost more (P<0.05) weight during aging compared with strip loins; dry aging in a bag had less (P<0.05) weight loss than unpackaged aging. There were no differences (P>0.05) in any of the sensory traits between shell and strip loins or dry aging using a traditional method or in a bag. Dry aging in a bag creates positive effects on yields, no negative effects on product quality, and adds flexibility and control of the aging environment.

Effects of data expression, sample location, and oxygen partial pressure on initial nitric oxide metmyoglobin formation and metmyoglobin-reducing-activity measurement in beef muscle.

Methodology for measuring surface and subsurface metmyoglobin-reducing activity (MRA) of beef longissimus lumborum, semimembranosus, and psoas major was evaluated by submerging samples from the upper one half of 2.54cm thick steaks in 0.3% NO(2)(-), vacuum packaging, and incubating at 30°C for 2h to promote pigment reduction. Initial metmyoglobin formation (IMF) and post-reduction metmyoglobin (PRM) were measured and used to calculate relative and absolute MRA values. The subsurface of all muscles maintained more (P<0.05) reducing capacity after 6d of display than the surface. Subsurface MRA was not significantly (P>0.05) correlated with surface colour stability whereas IMF was most correlated with colour stability (|r|>0.77; P<0.05). Longissimus steaks packaged in 20% O(2) had more (P<0.05) surface MRA than steaks packaged in 80% O(2) although measurement of MRA for steaks packaged in high-oxygen with this methodology is questioned. Determination of IMF is a better indicator of MRA for steaks exposed to atmospheric O(2) than more traditional measurements based on the amount of pigment reduced over time.

Efficacy of lactic acid salts and sodium acetate on ground beef colour stability and metmyoglobin-reducing activity.

This study examined two concentrations (0.6 and 1.0mol) of three lactic acid salts (calcium lactate, CaL; potassium lactate, KL; and sodium lactate, NaL), with and without 0.01mol sodium acetate (n=3 replications), for effects on ground beef colour stability and metmyoglobin-reducing activity (MRA). Ground beef with CaL was least colour stable (P<0.05). Increasing CaL and NaL concentration decreased (P<0.05) colour stability. Ground beef with acetate only was most colour stable (P<0.05), but it did not result in more MRA (P>0.05) than control ground beef. Including both lactate and acetate was not as effective (P>0.05) in increasing colour stability as acetate alone. In general, both KL levels were equal (P>0.05) to the lower NaL concentration, and all three were superior in colour stability (P<0.05) to CaL and the higher NaL concentration. More MRA was generated by including lactates (P<0.05); KL and NaL had more MRA than CaL (P<0.05). However, these increases in MRA did not result in improved colour stability. Overall, adding KL to ground beef would not increase ground beef colour stability over adding nothing, but CaL and high levels of NaL would decrease colour stability. Using 0.01mol sodium acetate maximized ground beef colour stability.

Influence of carbon monoxide in package atmospheres containing oxygen on colour, reducing activity, and oxygen consumption of five bovine muscles.

Steaks from five bovine muscles [psoas major (PM), longissimus lumborum (LL), deep semimembranosus (DSM), superficial semimembranosus (SSM), and semitendinosus (ST)] were packaged in atmospheres containing 20% or 80% oxygen, with and without 0.4% carbon monoxide. Steaks were evaluated on d 0, 4, and 7 of retail display for instrumental (CIE L(∗), a(∗), and b(∗)) and visual colour, total- and metmyoglobin-reducing activity, and oxygen consumption rate. Combining carbon monoxide with either oxygen level had no effect (P>0.05) on any measured attribute. Using higher oxygen levels increased colour stability and reduced variability (P<0.05) among muscles for all measured attributes. In general, colour stability and reducing activity for the muscles were LL>ST>SSM>PM>DSM. Including 0.4% carbon monoxide with 20% or 80% oxygen may not have impacted colour, due to preferential formation of oxymyoglobin, rather than carboxymyoglobin, at these oxygen levels.

Effects of ascorbic and citric acid on beef lumbar vertebrae marrow colour.

Citric acid was evaluated as a way of improving ascorbic acid's ability to stabilize beef lumbar vertebrae colour in high-oxygen packaging (MAP; 80% O(2)/20% CO(2)). Vertebrae were treated with citric acid (1%, 3%, or 10%), ascorbic acid (1%, 3%, or 10%), or a combination of both. Citric acid demonstrated no positive effects (P>0.05), compared with ascorbic acid, which inhibited (P<0.05) discolouration throughout the 7d display. Although ascorbic acid inhibited discolouration (visual colour and a(∗); P<0.05), 3% and 10% ascorbic acid were most effective. However, if vertebrae are displayed for less than 7d, there may be no significant colour-stabilizing advantages associated with increasing ascorbic acid from 3 to 10%. The significant oxidizing effects of citric acid at 10% were reversed (P<0.05) by ascorbic acid. Combining citric and ascorbic acid had no synergistic affect (P>0.05) on vertebrae colour.

Comparison of ascorbic acid and sodium erythorbate: Effects on the 24h display colour of beef lumbar vertebrae and longissimus lumborum packaged in high-oxygen modified atmospheres.

Sodium erythorbate and ascorbic acid were compared as a means to stabilize surface colour of bone-in beef steaks in high-oxygen modified atmosphere (80% oxygen and 20% carbon dioxide). Bone-in strip loins (n=8) were fabricated into 1.9-cm thick steaks, of which both the lumbar vertebrae and longissimus lumborum were topically treated with either ascorbic acid or sodium erythorbate (0, 0.05, 0.1, 0.5, 1.0, or 1.5%, wt/wt basis). Colour (L(∗)a(∗)b(∗)) was evaluated before treatment and 24h after packaging (display at 1°C). Sodium erythorbate was as effective as ascorbic acid for inhibiting vertebrae discolouration (P>0.05). Either reducing agent at 0.5, 1.0, or 1.5% improved (P<0.05) vertebrae redness (compared with 0%, 0.05% and 0.1%). No detrimental effects on muscle colour were observed. When selecting antioxidants intended for bone-in beef steaks displayed in high-oxygen packaging, sodium erythorbate may be a cost effective substitute for ascorbic acid.

Effects of potassium lactate, sodium chloride, sodium tripolyphosphate, and sodium acetate on colour, colour stability, and oxidative properties of injection-enhanced beef rib steaks.

This study determined the effects of potassium lactate (KL), sodium chloride, sodium tripolyphosphate, and sodium acetate on colour, colour stability, and oxidative properties of injection-enhanced beef rib steaks. Enhancement solutions (8.5% pump) contained combinations of KL (0% or 1.5%), sodium chloride (0.3% or 0.6%), sodium tripolyphosphate (0% or 0.3%), and sodium acetate (0% or 0.1%). Steaks were packaged in a high-oxygen modified atmosphere (80% O(2)/20% CO(2)). Steaks with KL or KL and sodium acetate were darker but more colour stable (P<0.05) than control steaks. Steaks had less glossy surfaces when they contained acetate (P<0.05) and KL (P<0.11). Increasing sodium chloride content resulted in darker, less colour-stable steaks (P<0.05). Removing phosphate had little impact on colour (P>0.05). Both KL and sodium acetate improved visual appearance of injection-enhanced beef rib steaks, whereas the greater salt level were detrimental.

Effects of potassium lactate, sodium chloride, and sodium acetate on surface shininess/gloss and sensory properties of injection-enhanced beef strip-loin steaks.

The objective was to determine the effects of potassium lactate (0% or 1.5%; KL), sodium chloride (0.3% or 0.6%), and sodium acetate (0% or 0.1%) on injection-enhanced (8.5% pump), beef strip-loin steaks. All treatments contained 0.3% phosphate and 0.058% rosemary. Steaks were packaged in a high-oxygen modified atmosphere (80% O(2)/20% CO(2)) and were evaluated on d 2, 9, and 14 for surface shininess/gloss, shear force, and descriptive sensory attributes. As time in MAP progressed, oxidized, stale, and rancid flavours increased (P<0.05) and surface shininess/gloss decreased (P<0.05). Brown-roasted and beef flavours were most intense (P<0.05) on d 9. Using KL increased (P<0.05) brown-roasted and beef flavours and limited rancid flavour. Sodium acetate decreased (P<0.05) shear force. Adding more salt increased salty and rancid flavours (P<0.05). Sodium acetate and KL both improve sensory attributes of injection-enhanced beef.

Shelf life of fresh meat products under LED or fluorescent lighting.

Enhanced pork loin chops, beef longissimus lumborum steaks, semimembranosus steaks (superficial and deep portions), ground beef, and ground turkey were displayed under light emitting diode (LED) and fluorescent (FLS) lighting in two multi-shelf, retail display cases with identical operating parameters. Visual and instrumental color, internal product temperature, case temperature, case cycling, thiobarbituric acid reactive substances (TBARS), and Enterobacteriaceae and aerobic plate counts were evaluated. Under LED, beef products (except the deep portion of beef semimembranosus steaks) showed less (P<0.05) visual discoloration. Pork loin chops had higher (P<0.05) L* values for LED lighting. Other than beef longissimus lumborum steaks, products displayed under LED lights had colder internal temperatures than products under FLS lights (P<0.05). Under LED, pork loin chops, ground turkey, and beef semimembranosus steaks had higher (P<0.05) values for TBARS. LED provides colder case and product temperatures, more case efficiency, and extended color life by at least 0.5d for longissimus and semimembranosus steaks; however, some LED cuts showed increased lipid oxidation.

Current research in meat color.

This review surveyed recent literature focused on factors that affect myoglobin chemistry, meat color, pigment redox stability, and methodology used to evaluate these properties. The appearance of meat and meat products is a complex topic involving animal genetics, ante- and postmortem conditions, fundamental muscle chemistry, and many factors related to meat processing, packaging, distribution, storage, display, and final preparation for consumption. These factors vary globally, but the variables that affect basic pigment chemistry are reasonably consistent between countries. Essential for maximizing meat color life is an understanding of the combined effects of two fundamental muscle traits, oxygen consumption and metmyoglobin reduction. In the antemortem sector of research, meat color is being related to genomic quantitative loci, numerous pre-harvest nutritional regimens, and housing and harvest environment. Our knowledge of postmortem chilling and pH effects, atmospheres used for packaging, antimicrobial interventions, and quality and safety of cooked color are now more clearly defined. The etiology of bone discoloration is now available. New color measurement methodology, especially digital imaging techniques, and improved modifications to existing methodology are now available. Nevertheless, unanswered questions regarding meat color remain. Meat scientists should continue to develop novel ways of improving muscle color and color stability while also focusing on the basic principles of myoglobin chemistry.

Exclusion of oxygen from modified atmosphere packages limits beef rib and lumbar vertebrae marrow discoloration during display and storage.

Visual and instrumental color (L*a*b* and reflectance from 400 to 700 nm) were used to evaluate packaging atmosphere as a way of minimizing beef marrow discoloration. In experiment 1, rib ends (n=24) packaged in 80% O(2)/20% CO(2) discolored more than ribs packaged in 100% N(2), which resulted in a relatively stable purplish marrow color through a 7-day display at 1 °C. In experiment 2, lumbar vertebrae (n=10) packaged in 80% O(2)/20% CO(2) had a rapid and significant discoloration within 24 h after packaging, likely because of the formation of methemoglobin. Conversely, vertebrae packaged in 80% N(2)/20% CO(2) and 0.4% CO/30% CO(2)/69.6% N(2) remained color stable during 2 and 6 weeks of storage at 4 °C, respectively. Exclusion of oxygen from MAP packages and the addition of low concentrations of CO minimized beef rib and lumbar vertebrae discoloration compared with high-oxygen MAP.

Acyl-CoA thioesterases belong to a novel gene family of peroxisome proliferator-regulated enzymes involved in lipid metabolism.

Acyl-CoA thioesterases hydrolyze acyl-CoAs to the corresponding free fatty acid plus coenzyme A. The activity is strongly induced in rat and mouse liver after feeding the animals peroxisome proliferators (PPs). To elucidate the role of these enzymes in lipid metabolism, the authors have cloned the cDNAs corresponding to the inducible cytosolic and mitochondrial type I enzymes (CTE-I and MTE-I), and studied tissue expression and nutritional regulation of expression of the mRNAs in mice. The constitutive expression of both mRNAs was low in liver, with CTE-I expressed mainly in kidney and brown adipose tissue, and MTE-I expressed in brown adipose tissue and heart. As expected, the expression in liver of both the CTE-I and MTE-I mRNAs were strongly induced (> 50-fold) by treatment with clofibrate. A similar level of induction was observed by fasting and a time-course study showed that the CTE-I and MTE-I mRNAs were increased already at 6 h after removal of the diet. Refeeding normal chow diet to mice fasted for 24 h normalized the mRNA levels with a T1/2 of about 3-4 h. Feeding mice a fat-free diet further decreased the expression, possibly indicating repression of expression. The strong expression of MTE-I and CTE-I in the heart was increased about 10-fold by fasting. To further characterize these highly regulated enzymes, the authors have cloned the corresponding genes and promoter regions. The structures of the two genes were found to be very similar, consisting of three exons and two introns. Exon-intron borders conform to general consensus sequences, and, especially, the first exon appears to be highly conserved. The promoter regions of both the CTE-I and MTE-I genes contain putative PP response elements, suggesting an involvement of PP-activated receptors in the regulation of these genes.

Yields, chemical composition, and value of beef shank tissues obtained using Baader processing.

This experiment was designed to determine yield of meat and sinew from beef shanks processed with a Baader desinewing machine and to determine whether this process added value to a beef carcass. Baader desinewing machines use belt pressure against a rotating, perforated steel drum to separate tissues. Boneless beef shanks had 9.8% fat and 14.1 mg/g of collagen. Using the Baader with a 5-mm drum, the first pass lean yield was 73.3% and had fat reduced to 7.1% and collagen to 10.5 mg/g. Second-pass lean yield through the 5-mm drum was 19.6% and had 16.1% fat and 13.8 mg/g of collagen, leaving 6.7% separated sinew. Using a 3-mm drum reduced first-pass lean yield to 66.1% and reduced fat content to 5.8%. Second-pass lean yield, using 3- and 5-mm drums, was 26.1% and had 18.6% fat and 27.8 mg/g of collagen with 6.8% sinew. Desinewed lean is worth more than whole shanks. Furthermore, 95% lean is worth more than 90% lean, and the sinew also has a salvage value. Upgrading shanks with this desinewing device can increase the value of a beef carcass by $2.01 using a 5-mm drum or by $3.20 using both 3- and 5-mm drums.

Proportion of types I and III collagen in longissimus collagen from bulls and steers.

The proportion of types I and III intramuscular collagen in longissimus muscles of Simmental bulls (n = 8) and steers (n = 8) 17 mo of age was studied. Longissimus samples taken 7 d after slaughter were evaluated for total collagen, types I and III collagen, heat-soluble collagen, sensory panel traits and Warner-Bratzler shear force. Intramuscular collagen (IMC) was isolated and digested with cyanogen bromide, and peptides were resolved by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Percentage of type III IMC was calculated from the total of types I and III collagen as determined from the peak area of densitometric scans of the cyanogen bromide peptides alpha 1(I)CB8 and alpha 1(III)CB8. Longissimus muscles from steers had lower (P less than .05) Warner-Bratzler shear values, less (P less than .05) sensory panel-detectable connective tissue and more (P less than .05) tender panel ratings for muscle fiber tenderness and overall tenderness. Muscles from steers had more (P less than .05) heat-soluble collagen than those from bulls, but no differences (P greater than .05) were found for total collagen and percentage of type III collagen. Some intramuscular-collagen characteristics may have contributed to the less tender muscle of bulls. However, the proportion of types I and III collagen did not account entirely for the tenderness difference between steer and bull muscles. Because there were differences in collagen solubility in muscles from steers and bulls, other collagen characteristics such as crosslinking or fiber size may have been more important than collagen type.

Effects of implanting ram and wether lambs with zeranol at birth and weaning on palatability and muscle collagen characteristics.

Thirty-five zeranol-implanted (I) and nonimplanted (NI) ram and wether lambs representing four treatments (implanted rams [IR], nonimplanted rams [NIR], implanted wethers [IW], and nonimplanted wethers [NIW]) were evaluated for meat palatability and muscle collagen characteristics. Rib (longissimus muscle, LM) chops from I lambs were juicier (P less than .05) than rib chops from NI lambs. Chops from IR lambs had more (P less than .05) detectable connective tissue and lower myofibrillar and overall tenderness scores than chops from NIR, IW, or NIW lambs. Warner-Bratzler shear (WBS) values tended to be higher (P = .06) for LM chops from rams than for those from wethers, but WBS values for Biceps femoris (BF) chops were similar (P greater than .05) for rams and wethers. Implanting did not affect (P greater than .05) WBS values. Rams had more (P less than .05) LM heat-labile (soluble, SC), nonheat-labile (insoluble, IC), and total collagen (TC) and a higher (P less than .05) percentage of SC (SC/TC) than did wethers. Soluble collagen, TC, and percentage of SC for the BF were higher (P less than .05) and IC tended (P = .09) to be higher in chops from rams than in those from wethers. Implanting did not affect (P greater than .05) collagen amount or solubility. Serum nonprotein hydroxyproline (NPHP) was higher (P less than .05) in rams than in wethers throughout the feeding period and tended (P = .05) to be higher at slaughter. Implanting did not affect (P greater than .05) serum NPHP.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of postexsanguination vascular infusion of cattle with a solution of saccharides, sodium chloride, phosphates, and vitamins C, E, or C+E on meat display-color stability.

Grain-finished, high-percentage Charolais steers (n = 36) were selected for uniformity. Immediately after jugular vein exsanguination, 27 steers were infused at 10% of live weight via the carotid artery with a solution developed by MPSC, Inc. (St. Paul, MN) consisting of 98.52% water, 0.97% saccharides, 0.23% sodium chloride, and 0.28% phosphate blend plus either 500 ppm vitamin C (MPSC+C; n = 9), 500 ppm vitamin E (MPSC+E; n = 9), or 500 ppm vitamin C + 500 ppm vitamin E (MPSC+C+E; n = 9). Uninfused controls (CON) were exsanguinated conventionally. Carcasses were fabricated at 48 h postmortem. Longissimus thoracis (LT), psoas major (PM), and semimembranosus (SM) muscles were removed, vacuum-packaged, and stored at 2 degrees C until 14 d postmortem. Then, steaks 2.54 cm thick were sliced from the three muscles, placed on foam trays, and overwrapped with polyvinyl chloride film. Ground beef (GB) was formulated from the quadriceps femoris to contain 20% fat, mounded into 0.45-kg portions, placed on styrofoam trays, and wrapped with polyvinyl chloride film. Steaks were visually evaluated for uniformity and initial color on display d 0. Instrumental color measurements of L*, a*, b* and trained sensory panel color evaluations were obtained daily for 4 d (PM and GB) or 5 d (LT and SM) of display. No display time x treatment interaction existed for L*, a*, or b* values. The LT from CON cattle had more uniform color (P < 0.05) and was more cherry red than that from all infused cattle on d 0. Visual scores indicated that GB from MPSC+E cattle was more red (P < 0.05) than that from MPSC+C infused cattle throughout display, and GB from MPSC+E cattle was more red (P < 0.05) than that from CON cattle for the last 3 d of display. The vascular infusion solutions generally did not improve color or display-color stability of steaks, but the infusion solution with vitamin E did improve display-color stability of GB.

Evaluation of attributes that affect longissimus muscle tenderness in Bos taurus and Bos indicus cattle.

Biological tenderness differences between longissimus muscles (LM) from Bos indicus and Bos taurus breeds were evaluated. Steers and heifers of Hereford x Angus (H x A, n = 10), 3/8 Sahiwal x H, A or H x A (3/8 SAH, n = 6) and 5/8 Sahiwal x H, A or H x A (5/8 SAH, n = 11) crosses were utilized. Muscle temperature and pH were monitored every 3 h for the first 12 h and at 24 h. Samples were obtained within 1 h and at 24 h postmortem from the LM for determination of calcium-dependent protease (CDP) -I and -II and CDP inhibitor (INH) activities. At 1 and 14 d postmortem, LM samples were removed for determining cathepsin B and B + L activity, soluble and total collagen, sarcomere length, muscle-fiber histochemistry, shear force and sensory-panel traits. Data were analyzed using least squares procedures with fixed effects of breed cross, sex and their interaction. No significant breed cross effects were observed for carcass traits or rates of pH and temperature decline. Steaks from H x A had lower (P less than .05) shear-force values and higher (P less than .05) sensory scores for tenderness at 1 and 14 d postmortem than steaks from 3/8 and 5/8 SAH. Correspondingly, 5/8 SAH had lower (P less than .05) myofibril fragmentation indices than H x A at 1, 3, 7 and 14 d postmortem. Breed cross effects were not significant for sarcomere length, fiber types, soluble and total collagen, cathepsin B and B + L specific activity, CDP-I and -II activity and INH activity within 1 h postmortem. However, INH total activity/100 g of muscle was greater (P less than .01) at 24 h postmortem for 5/8 SAH (208.8 +/- 14.8) and 3/8 SAH (195.6 +/- 19.3) than for H x A (136.3 +/- 14.9). For H x A, SDS-PAGE revealed that by d 1 desmin had been subjected to proteolysis, and by d 14 desmin could not be detected, but a 30,000-dalton component was clearly evident. However, in 5/8 SAH, desmin remained visible at d 14 without a 30,000-dalton component appearing. This reduced protein hydrolysis may account for less tender meat in SAH; INH apparently influences this process.

Effects of postexsanguination vascular infusion of cattle with a solution of saccharides, sodium chloride, and phosphates or with calcium chloride on quality and sensory traits of steaks and ground beef.

Grain-finished Hereford x Angus steers (n = 36) were assigned to one of three treatmentgroups. Immediately after jugular exsanguination, 12 steers were infused at 10% of live weight via the left carotid artery with a solution developed by MPSC, Inc. (St. Paul, MN) consisting of 98.52% water, 0.97% saccharides, 0.23% sodium chloride, and 0.28% phosphate blend (MPSC); 12 steers were infused at 10% of live weight with 0.30 M CaCl2 (CaCl2); and 12 steers were exsanguinated conventionally and served as noninfused controls (CON). Declines in pH for three muscles were measured. CaCl2-infused carcasses exhibited extensive muscle contraction at the time of cooler entry. Carcasses were graded at 24 h postmortem and fabricated at 48 h postmortem. Longissimus lumborum (LL), semitendinosus (ST), and quadriceps femoris (QF) muscles were removed, vacuum packaged, and stored at 2 degrees C until 14 d postmortem. Then, 2.54-cm-thick steaks were cut from the LL and ST for shear force and sensory evaluations. Ground beef was formulated from the QF to contain 20% fat. Steers infused with MPSC and CaCl2 had 4.0 and 2.3% higher dressing percentage points, respectively, than CON steers. Calcium concentrations of the LL muscle for CaCl2- and MPSC-infused carcasses, as well as the CON carcasses, were 892.0, 158.9, and 216.6 ppm, respectively. For the TB and longissimus thoracis muscles, pH decline was more rapid for CaCl2- and MPSC-infused carcasses than for CON carcasses, but there were no differences in 24-h pH. Warner-Bratzler shear force values were much higher (P < 0.05), and descriptive attribute sensory panel tenderness scores much lower (P < 0.05), for the LL from CaCl2-infused carcasses than for MPSC-infused and CON carcasses. Flavor intensity of the LL of CaCl2-infused carcasses was reduced (P < 0.05); however, overall tenderness and flavor of the ST were unaffected (P > 0.05) by CaCl2 infusion. Beef flavor identification, brown-roasted flavor, and bloody/serumy flavor were lowest and soapy/chemical flavor was highest (P < 0.05) for both freshly cooked and warmed-over LL from CaCl2-infused carcasses. There were no distinct meat quality advantages for infusing cattle with a solution of saccharides, sodium chloride, and phosphates. Infusion with 0.30 M CaCl2 increased dressing percentage, but caused severe muscle contraction early postmortem, decreased LL tenderness markedly, and reduced flavor of LL steaks and ground beef.

Growth, carcass traits, boar odor and testicular and endocrine functions of male pigs fed a progestogen, altrenogest.

Crossbred (Chester White X Yorkshire X Duroc) boars were used to evaluate the effects of feeding a progestogen (altrenogest) on body growth, endocrine function (determined during feeding and after withdrawal of altrenogest), carcass composition, boar odor and testicular function (determined after a 30-d withdrawal from altrenogest). Boars from 18 litters were assigned at 12 wk of age to three treatments: 1) 18 control boars; 2) 18 boars fed altrenogest (20 mg/day) for 6 wk from 15 to 21 wk of age, followed by 30 d with no treatment; and 3) 18 boars castrated at 2 wk of age (barrows). Daily gains were greater (P less than .05) in boars fed altrenogest than in barrows through 21 wk of age but were lower (P less than .05) than those of control boars and barrows during the 30-d withdrawal period. Boars fed altrenogest weighed less (P less than .05) than control boars and barrows at 25 wk of age (at slaughter). Both groups of boars were similar in percentage of muscle and had less (P less than .05) backfat than barrows, whereas control boars had the largest (P less than .05) loineye areas. Based on evaluations by a trained sensory panel, intensity of boar odor in fat samples was similar for both groups of boars and was greater (P less than .05) than that for barrows. Weights of accessory reproductive glands and weight and sperm content of testes and epididymides were reduced (P less than .05) in boars fed altrenogest.(ABSTRACT TRUNCATED AT 250 WORDS)