ObjectivesThis study was aimed to determine how electrostatic spray of natural antioxidants impacts chemical quality of grass-finished beef strip steaks.Materials and MethodsTwenty certified grass-finished beef loins from ten animals were purchased from a certified grass-fed beef purveyor. Two loins of the same animals were cut into sixteen 2.5-cm thick steaks (eight steaks per loin) without the gluteus medius muscle. A factorial arrangement of 4 treatments, including a negative control (no spraying; NEG) and 1000-ppm of electrostatic spray of cherry extract rich in ascorbic acid (ES-ACE), electrostatic spray of rosemary and green tea extract rich in polyphenols (ES-RGT), and pressurized spray of ACE (PS-ACE), and 2 retail time points (0 and 5 d) was randomized within an animal, resulting in two steaks receiving a treatment × day combination within an animal. Five loins were randomly selected for chemical analyses (n = 10 per treatment × day combination). Meat antioxidants were extracted in methanol. The extracted antioxidants were reacted with ABTS+ radical cation (2,2′-azino-bis(3-ethylbenzthiazoline)-6-sulphonic acid diammonium salt) solution diluted to an absorbance of 0.85 to measure Trolox Equivalent Antioxidant Capacity (TEAC) at 734 nm. The extract was also reacted with Folin-Ciocalteu (FC) reagent to measure total phenolic compounds at 765 nm. Thiobarbituric acid reactive substances (TBARS) were extracted in 10% trichloroacetic acid and reacted with thiobarbituric acid and the resulted pigment was measured at 532 nm. Data were analyzed by the GLIMMIX procedure of SAS v9.4 and actual probability was reported.ResultsOn d 0, NEG steaks had less FC values than all treatment steaks (P < 0.001), of which the ES_ACE steaks had 14 and 100% more than PS_ACE and ES_RGT steaks, respectively (P ≤ 0.005). Only ES_ACE steaks had greater FC value than NEG steaks on d 5 (P < 0.001). As a result, TEAC value of ES_ACE steaks was 17 and 75% more than that of PS_ACE and ES_RGT steaks (P ≤ 0.005) and remained greater than that of NEG steaks on d 5 (P = 0.064). Greater antioxidant capacity in ES_ACE and PS_ACE steaks decreased lipid oxidation by 56% (0.9 µg MDA/kg less in ES_ACE and PS_ACE on d 5) as compared with NEG steaks in ES_ACE steaks in contrast to the other treatments (P < 0.001).ConclusionElectrostatic spray of cherry extract rich in ascorbic acid was the most effective antioxidant application to prevent lipid oxidation in grass-finished beef strips steaks.

ObjectivesThe objective of the current study was to determine the efficacy of dipping pork trimmings in acetic acid on Salmonella reduction.Materials and MethodsPork loins were purchased from a commercial purveyor and trimmed of external fat and connective tissues, leaving only the longissimus muscle, which was further cut into 2.5 cm (W) × 2.5 cm (L) × 1.3 cm (H) cubes. Pork cubes were randomly assigned to a negative control (no inoculation, no dipping; NEG), a positive control (inoculation, no dipping; POS), acetic acid dipping at 21°C (ACC) and acetic acid dipping at 50°C (ACH) with a 15-, 45-, or 75-s dipping duration (n = 10 per treatment × time combination). Two inoculation levels, 108 Colony Forming Unit (CFU)/cube of bioluminescent gene-modified (Lux) or 105 CFU/cube of nalidixic acid-resistant Salmonella enteritica serovar Typhimurium, were inoculated onto pork cubes to determine the antibacterial effects of each treatment condition by in vivo bioluminescence imaging system (IVIS) or direct CFU measurement on XLD agar, respectively. In Experiment 1, the cubes were dipped for 15 s to measure the reduction effects by employing both IVIS and CFU. In Experiment 2, cubes were dipped with three dipping durations and the CFU were calculated. The common logarithm of Lux and CFU were calculated and analyzed by the GLIMMIX procedure of SAS v9.4 (SAS Institute Inc., Cary, NC). Actual probability values were reported.ResultsIn Experiment 1, at 108 inoculation level, ACC and ACH reduced the growth of Salmonella by 1.8 and 1.6 log, respectively (P < 0.001) without treatment difference (P = 0.207). However, at 105 inoculation level, ACC and ACH reduced Salmonella by 0.2 and 0.3 log, respectively (P ≤ 0.026). In Experiment 2, at 105 inoculation level with three dipping durations, the ACH treatment reduced Salmonella by 0.9 log more than the ACC treatment (P < 0.001). The 75-s dipping duration was the most effective, providing a reduction of 0.7-log more than the 15-s duration (P = 0.001). No 2-way treatment × time interaction was observed (P = 0.104).ConclusionThe present study suggests that the pork trimmings be dipped into 3% acetic acid solution at 50°C for at least 75 s to ensure the safety of further processed pork products.

Body condition score estimates overall adiposity in horses but not fatty acid (FA) composition of fat depots, which is associated with many biological functions and important for horse health. The objectives of the current study were to determine the FA composition of mesenteric (MS), cardiac (CD), abdominal (AB), intermuscular (IM), and subcutaneous (SC) adipose tissues in stock-type horses and identify their relationships with BCS. Twenty-one stock-type horses (BCS 4, n = 7, 468 +/- 13 kg; BCS 5, n = 10, 455 +/- 11 kg; BCS 6, n = 4,493 +/- 12 kg) were humanely euthanized based on 3 primary criteria: geriatric, crippled, and/or unsafe. Fat tissues including MS around the small intestines, CD at the pericardium, AB from abdominal fat located inside the left flank, IM underneath the latissimus dorsi muscle in the thoracic region, and SC on the surface of semitendinosus muscle were collected within 30 min post-mortem, trimmed of connective tissues and muscles, frozen in liquid nitrogen, pulverized into fine powder, and stored at -80 degrees C. Fatty acids were determined by gas chromatography and expressed in percentage of total FA concentration. Influences of BCS (P < 0.05) and fat depot (P < 0.05), but not BCS x fat depot interaction (P > 0.05), were found for most FA, indicating that most FA were independently influenced by BCS and anatomical locations. However, some FA, such as 16:1n7, were influenced by BCS differently in various fat depots (P-BCS (x) (fat) (depot) = 0.043). The major FA were palmitic (24.85%), stearic (5.54%), oleic (27.34%), linoleic (11.20%), and linolenic (17.95%) acids. Degree of saturation was not affected by BCS (P = 0.212). Most saturated depots were AB and CD (P <= 0.049). In MS, IM, and SC, PUFA percentage was smallest (P < 0.001), but SFA and MUFA percentages were similar (P >= 0.505). In CD, SFA and PUFA percentages did not differ (P = 0.740), but MUFA percentage was less than both (P < 0.001). Percentages of SFA, MUFA, and PUFA in AB all differed (P <= 0.008) with SFA being greatest. Body condition score influenced FA composition of equine adipose tissues but to a lower extent than the type of fat depots.

The objective of the current study was to determine the effects of market type (super market - SM, indoor market - IM, open market - OM) and sampling time (at the opening - T0 and 4 h after the opening - T4) on antioxidant capacity, lipid oxidation, and descriptive sensory attributes of beef in Vietnam. Values of FC and TEAC were greater in OM beef than IM and SM (P < 0.001) and FC value was also greater at T4 than TO (P = 0.038). The beef from SM had 7% greater TBARS than IM and OM (P = 0.003). Livery odor was less intense in raw beef from OM when compared to SM and IM (P <= 0.047). Sour odor in raw beef, and livery flavor in cooked beef was increased from T0 to T4 (P <= 0.035). Principal component analysis of descriptive sensory attributes indicated that FC and TEAC could predict partial livery flavor in cooked beef, but not off-odors in raw beef.

ObjectivesThe objective of the study was to determine the effects of feeding endophyte-infected tall fescue seeds on mitochondrial fatty acid (FA) composition and phospholipid (PL) fractions and activity of superoxide dismutase (SOD) and metmyoglobin reductase (MRA) in beef longissimus muscle from Angus steers.Materials and MethodsTwelve Angus steers were blocked by initial BW and randomly assigned to be fed with either KY32 (E- or control) or KY31 (E+ or treatment; approximately 20 µg of ergovaline per kg of BW) within a block. Steers were fed individually using Calan gates in the first 70-d trial in the summer of 2015, followed by a 149-d withdrawal period and the second 64-d trial in the winter of 2016. After the second trial, steers were implanted with a dose of Ralgro, finished for 66 d on summer perennial pastures, and slaughtered at approximately 500 kg of BW. Immediately after carcass decontamination, longissimus thoracis muscle was collected at the 12th rib on the left side of the carcasses, cubed, snap-frozen in liquid nitrogen, wrapped in aluminum foil, vacuum-packaged, and stored at -80°C for FA, PL, and SOD analyses. Strip loins were collected at 72 h post-mortem, aged for 14 d, trimmed to 0.3-cm backfat thickness, cut into 2.54-cm steaks, placed on black Styrofoam trays, overwrapped with PVC film (O2 permeability of 1.21 mL/cm2/d and water vapor permeability of 0.022 g/cm2/d; LINPAC Packaging-Filmco Inc., Aurora, OH), and placed under simulated retail display conditions (2 to 4°C, 900-lux fluorescent intensity, and 80% relative humidity) for 0, 1, 3, 5, and 7 d. One steak per animal per time point was collected for MRA analysis. Mitochondria were separated by ultracentrifugation and their lipids were extracted in 1:2 chloroform:methanol (v/v) and converted to fatty acid methyl esters to be analyzed by gas chromatography (Hewlett-Packard 6890 FID GC System; Agilent Technologies, Santa Clara, CA). Phospholipid classes were determined by thin-layer chromatography. Activity of SOD was determined by a colorimetric assay kit applicable for muscle (ab65354; Abcam, Cambridge, MA). Metmyoglobin reducing activity (µM of MMb reduced/min/g of muscle) was determined by reacting extracted muscle reductases with equine skeletal metmyoglobin and measuring deoxymyoglobin at 580 nm (Spectra max plus 384; Molecular Devices, Sunnyvale, CA). One steer with a large abscess, yielding pH of 6.35 and dark cuts, was excluded. Statistical analysis was performed by the GLIMMIX procedure of SAS 9.4 (SAS Inst. Inc., Cary, NC) at 0.05 level of significance.ResultsFeeding endophyte-infected tall fescue seeds did not affect mitochondrial FA composition, PL fractions, and SOD activity (P ≥ 0.14). Metmyoglobin reducing activity of E+ steaks was 6.01 ± 0.37 µM/min/g, similar to that of E- steaks (6.92 ± 0.41 µM/min/g; P = 0.117). As expected, MRA was correlated with length of retail display (r = –0.74; P < 0.001) and decreased from 9.54 ± 0.49 µM/min/g on d 0 to 2.29 ± 0.93 µM/min/g on d 7 (P < 0.001).ConclusionEndophyte-infected tall fescue may not affect the integrity of mitochondria and MRA. A decrease in color stability was well correlated with decreased activity of metmyoglobin reductase.

Melatonin supplementation during mid to late gestation increases uterine blood flow, thereby altering the flux of nutrients delivered to the developing fetus by the dam. Changes in the amount and composition of fatty acids available to the fetus can alter the long-term growth and developmental potential of the offspring in postnatal life. The objective of this study was to determine the effect of supplementing melatonin to beef heifers during mid to late gestation on fatty acid composition of maternal, umbilical, and fetal plasma as well as fetal perirenal adipose tissue. A total of 32 pregnant heifers were treated with (MEL) or without (CON) two 24-mg melatonin implants every 30 d starting on d 180 and ending on d 240 of gestation. On d 240 of gestation (approximately 85% of gestation), 6 CON and 6 MEL heifers were randomly selected to undergo Cesarean sections to collect fetal blood and tissues. Maternal blood (MB) was collected from the tail vein of the dams immediately prior to the surgery. Before excising the fetus, the umbilical cord was clamped on the fetal and maternal ends to collect blood from the umbilical artery (UA) and umbilical vein (UV). Fetal peripheral blood (FB) was collected during exsanguination, and perirenal (PR) adipose tissue was dissected from the fetal kidney following evisceration. Plasma and PR adipose tissue samples were directly derivatized for fatty acid quantification on a gas chromatography system to determine fatty acid concentration and percentage by internal calibration. Data were analyzed using the GLIMMIX procedure of SAS 9.4 (SAS Inst. Inc., Cary, NC), and statistical significance was determined at P ≤ 0.05. There was no difference in total plasma fatty acid concentrations between the CON and MEL groups in MB, UA, UV, FB or PR (P > 0.324). Total SFA, MUFA, and PUFA in UA, UV, MB, FB, or PR also did not differ between treatments (P ≥ 0.11). However, MEL tended to increase C22:6 fatty acid concentration in MB (P = 0.065), UV (P = 0.079), and FB (P = 0.068). Additionally, there was a tendency for increased (P = 0.080) C20:5n-3 fatty acid in PR adipose tissue in fetuses from MEL-treated dams. Both C22:6 and C20:5n-3 fatty acids improve fetal development and immune function. Therefore, additional research is warranted to determine the specific effect of MEL on these fatty acids and their long-term impacts on offspring growth and physiology.

ObjectivesThe objective of this study was to evaluate the effects of extended retail display on metmyoglobin reducing activity in ground beef model.Materials and MethodsTwo retail display trials were conducted using 2 ground beef batches with 91 and 93% lean. Thirty-six 454-g ground beef loaves per trial were produced, placed on black Styrofoam trays, overwrapped with PVC film (O2 permeability of 1.21 mL/cm2/d and water vapor permeability of 0.022 g/cm2/d; LINPAC Packaging-Filmco Inc., Aurora, OH), and displayed at 2°C under fluorescent light (900 lux) for up to 0, 4, 8, 12, 24, 36, 48, 72, 96, 120, 144, 168, 192, 216, 240, 264, 288, and 312 h (n = 4 per time point). Two randomly selected loaves per time point per trial were withdrawn for further analysis. The pH value was determined by placing 1 g of meat in 10 mL of D-water (Accumet AE150 pH Benchtop Meter; Fisher Scientific, Waltham, MA). Aerobic Plate Count (APC, log CFU/g) was determined using 3M APC Petrifilm (3M Corporation, St. Paul, MN). Lean redness and reflectance spectra (400 to 700 nm) were recorded with illuminant A at 10° angle (MiniScan EZ 4500L, Hunter Associates Laboratory, Inc., Reston, VA). Metmyoglobin reducing activity (MRA) was measured by reacting extracted reductases with horse skeletal metmyoglobin and measuring absorbance by deoxymyoglobin at 580 nm (Spectramax Plus 384; Molecular Devices, Sunnyvale, CA). Statistical analysis was performed by using the GLIMMIX procedure of SAS (SAS Inst. Inc., Cary, NC) at 0.05 level of significance.ResultsThe APC was increased by 0.7 log CFU/g from 0 to 168 h (P = 0.022), which coincided with an increase in pH from 5.61 to 5.88 (P < 0.001). As expected, redness was decreased from 30.83 (0 h) to 13.48 (96 h; P < 0.001), which coincided with 10.56% decrease in surface oxymyoglobin (P = 0.001). However, lean redness and surface oxymyoglobin was increased after 120 h up to 216 h (P < 0.001). Although MRA remained constant from 0 to 120 h of retail display (7.03 to 8.58 µM/min/g; P ≥ 0.220), it was increased up to 16.01 µM/min/g by 288 h (P ≤ 0.004), following a quadratic relationship that could be fit as MRA = 7.68 + 0.0001 × time2 (R2 = 0.67; P < 0.001).ConclusionThese findings were in contrast with the conventional wisdom that beef color continues to deteriorate as retail display progresses. The current study indicated that microorganisms in meat might contribute to the increase in metmyoglobin reducing activity, which may be used as novel technology to maintain meat color stability.

The objective of this study was to investigate the effects of feeding endophyte-infected tall fescue seeds on carcass characteristics including dressing percentage, ribeye area, backfat thickness, percentage of KPH fat, pH, objective lean color, marbling score, and intramuscular fat content. Twelve Angus steers of the same preconditioning operation entering the stocker phase at Mississippi State University H. H. Leveck Animal Research Center were selected and blocked by BW into 3 groups: light (4 animals, 205.5 ± 7.4 kg), medium (5 animals, 231.3 ± 8.2 kg), and heavy (3 animals, 272.7 ± 8.4 kg). A control (KY32 or E–; 0.9 kg) and a treatment (KY31 or E+; 0.8, 0.9, or 1.0 kg for light, medium, or heavy steers, respectively, to provide 20 µg of ergovaline per kg of BW) were randomly assigned to animals within blocks (n = 6) by using Calan® gates. Seeds were mixed with soybean, corn gluten pellets at 2% of BW in the Calan® gates during two trials of 70 d (Summer 2015) and 56 d (Winter 2016). Upon the completion of the second trial, steers were implanted with one dose of Ralgro® and finished to a slaughter weight of approximately 499 kg. During the entire study, steers had ad libitum access to the same annual and perennial summer grass pasture, alfalfa hay supplementation, minerals, and water. Hot carcass weight and dressing percentage were recorded at slaughter, whereas all other data were collected at 72 h post mortem on the right side of the carcasses. Statistical analysis was performed by the GLIMMIX procedure of SAS with significance level of 0.05. There was no difference in carcass characteristics between the E- and E+ treatments (P > 0.199). Carcasses from steers fed KY31 and KY32 seeds had dressing percentage of 48.7 to 49.8%, ribeye area of 62.9 to 64.4 cm2, backfat thickness of 0.41 to 0.46 cm, KPH fat of 1.2 to 1.3%, lean pH of 5.6 to 5.7, L* value of 39.35 to 39.75, a* value of 35.43 to 36.04, b* value of 31.75 to 32.74, and a marbling score of 226.7 to 236.7. Ultrasound prediction of steers before slaughter indicated an intramuscular fat content of 4.1 to 4.2%, agreeing with marbling score evaluation. Results suggested that ingestion of endophyte-infected tall fescue seeds followed by a withdrawal period might not have residual effects on carcass characteristics of grass-finished beef cattle.

Body condition score serves as a proxy indicator of the health and metabolic disposition of horses; however, this subjective assessment does not take into account the fatty acid composition of adipose tissue (AT) depots. The objective of this study was to investigate the relationship between BCS and fatty acid composition of subcutaneous AT. Fourteen horses with BCS of 4 (n = 4), 5 (n = 6), and 6 (n = 4) were euthanized, and the subcutaneous fat was collected at the junction of the last rib and the vertebral column. Samples were frozen in liquid nitrogen, pulverized, and stored at −80°C. Fat samples were directly derivatized for fatty acid identification and quantification on a gas chromatography system (Agilent Technologies, Santa Clara, CA) using an internal standard for calibration. Fatty acid methyl ester concentrations were used to calculate fatty acid percentages. Statistical analysis was performed by the GLIMMIX procedure of SAS 9.4 (SAS Inst. Inc., Cary, NC), and statistical significance was determined at P ≤ 0.05. Overall, there was no effect of BCS on fatty acid percentages composition (P ≥ 0.129), except that capric acid was greater in horses with BCS of 4 than in those with BCS of 6 (P = 0.008). In terms of overall composition, equine subcutaneous AT was composed of approximately 35.36 to 37.77% SFA, 35.80 to 36.90% MUFA, and 25.33 to 28.84% PUFA, which were markedly distinguishable from the relative percentages reported in ruminants and other monogastric species. Palmitic, oleic, and linolenic acids were the predominant SFA, MUFA, and PUFA with respective relative percentages of approximately 24.68, 28.96, and 16.41%, respectively. Linoleic acid, the predominant PUFA found in most ruminant and monogastric species, was the second most predominant PUFA in equine, at 6.78%. Vaccenic acid, a typical trans fatty acid found in ruminants, was not detected in horse subcutaneous adipose tissues. These data indicate that BCS did not have a marked impact on the fatty acid composition of the subcutaneous AT depot in the equine animal for the range of BCS investigated in the current study.

Deoiled distillers dried grains with solubles (D-DDGS), a by-product of the fuel ethanol industry, have increasingly been used as ingredients in livestock feed. These D-DDGSs have a reduced fat content and increased protein content making them attractive ingredients, however, feeding D-DDGS can affect carcass composition. The objective of this study was to investigate the effect of D-DDGS on fatty acid (FA) composition of subcutaneous (s.c.) adipose tissues in goats. Four experimental diets containing 50% Bermuda grass hay plus 50% concentrate mix containing 0 (CON), 10, 20, or 30% D-DDGS (D-DDGS10, D-DDGS20, or D-DDGS30, respectively) in the diet were randomly assigned to twenty-four castrated male Kiko goats (n = 6 per treatment). The goats were slaughtered at 84 d and s.c. fat was collected from directly over the sternum of the carcass, and were then pulverized, and stored at −80°C. The fat samples were directly derivatized for fatty acid identification and quantification on a gas chromatography system (Agilent Technologies, Santa Clara, CA) using internal standard calibration. Fatty acid methyl ester concentrations were used to calculate fatty acid concentrations and percentages. Statistical analysis was performed using the GLIMMIX procedure of SAS 9.4 (SAS Institute Inc., Cary, NC.) and statistical significance was determined at P ≤ 0.05. D-DDGS did not affect total FA content (P ≤ 0.395) of adipose tissues, however, their inclusion changed concentrations and percentages of important FA (P < 0.038). Concentrations of 18:1 t, 18:2 n6c, 20:1 n9c, and polyunsaturated (PUFA) of s.c. fat from D-DDGS30 goat were 16.26, 16.29, 9.35, and 19.74 mg/g, respectively, which were greater than those from D-DDGS10 and CON goats (P < 0.026). Because of the similar total FA content, the percentages of 18:1 t, 18:2 n6c, 20:1 n9c, and PUFA (2.12, 2.11, 1.25, and 2.56%, respectively) were also greater in s.c. fat of D-DDGS30 goats than those of D-DDGS10 and CON goats. Although concentration of 20:4 n6c was similar among CON and D-DDGS treatments (P = 0.408), its percentage was greater in s.c. fat of D-DDGS30 goats than that of CON goats (P = 0.018). These data indicate that feeding D-DDGS30 increased the percentages of unsaturated fatty acids in the s.c. depot of the meat goats in the current study and may be used to alter carcass fat composition.