scholarly journals Impact of Two Levels of Low Voltage Electrical Stimulation on Beef Quality

2019 ◽  
Vol 3 (2) ◽  
Author(s):  
C. Fehrman ◽  
K. Grubbs ◽  
K. Underwood ◽  
A. Blair
Keyword(s):  
Electrical Stimulation ◽  
Repeated Measures ◽  
Low Voltage ◽  
Random Effect ◽  
Temperature Data ◽  
Rigor Mortis ◽  
Aging Period ◽  
Time Interaction ◽  
Glycolytic Potential ◽  
Muscle Ph

ObjectivesElectrical stimulation (ES) prior to rigor mortis accelerates postmortem glycolysis, resulting in rapid postmortem depletion of glycogen and can partially simulate the physiological conditions created by stress. The objective of this study was to evaluate the influence of two levels of high voltage electrical stimulation on incidence of dark cutters, temperature decline, muscle pH, glycolytic potential, and meat quality.Materials and MethodsFifty beef carcasses were chosen at 3 collection times over 7 h; 14 at collection 1, 18 at collection 2, and 18 at collection 3. One side of each carcass received either 40 (E40) or 80 (E80) volts of ES. The paired side of each carcass served as a control and did not receive ES (C40 or C80). Temperature data loggers were placed into the sirloin of both sides of the first 4 carcasses from each collection period to monitor temperature decline. Muscle pH was measured on the longissimus muscle at 1, 12, 24, and 72 h postmortem. Steaks were fabricated from the longissimus lumborum for determination of WBSF, cook loss, glycolytic potential (GP), and objective color. Data were analyzed using PROC Mixed of SAS with fixed effect of treatment and random effect of carcass. Analysis of carcass temperature decline was conducted with control carcasses pooled to one treatment to better evaluate the effect of ES on temperature decline. Temperature data, WBSF, and pH were considered repeated measures. Significance was determined at P < 0.05.ResultsNo dark cutting carcasses were observed in this study. A time by treatment interaction was observed for carcass temperature decline (P < 0.001) where ES sides stayed warmer for longer than control sides. A treatment by time interaction was observed for pH decline (P < 0.001) with C40 sides having an increased pH at 1 h postmortem compared to E80 sides. Carcass characteristics did not differ among treatments (P > 0.05). A treatment effect was observed for WBSF values (P = 0.006) with ES sides being more tender than C40 sides. A day effect was observed (P = 0.009) with steaks aged for 7 d being less tender than steaks aged for 14 d (P = 0.007). Cook loss did not differ among treatments (P > 0.05). A difference in cook loss by aging period (P = 0.014) was observed. Steaks aged for 3 d had less cook loss than steaks aged for 7 d (17.3% vs. 18.8% respectively; (P = 0.017) and tended to have less cook loss than steaks aged for 14 d (18.3%; P = 0.065). Glucose, lactate, and overall GP measurements did not differ among treatments (P > 0.05). Objective L* values for E80 sides were greater than C40 (P = 0.0009) and C80 (P < 0.0001), and E40 values were greater than C40 (P < 0.0001). Objective a* values for E80 sides were greater than C40 (P = 0.002) and C80 (P = 0.035), and E40 values were greater than C40 (P < 0.0001). Objective b* values were greater for E80 than C80 (P = 0.005) and C40 (P = 0.001), and E40 was greater than C40 (P < 0.0001).ConclusionThese data suggest ES does not influence the incidence of dark cutters. However, utilization of an ES system can improve tenderness of steaks in addition to producing brighter, more red beef products. The results of this study indicate that similar quality characteristics can be obtained using 40 or 80 V of ES. Therefore, beef packing plants applying ES to carcasses may be able to reduce voltage without sacrificing quality.

scholarly journals Low-Voltage Electrical Stimulation of Beef Carcasses Slows Carcass Chilling Rate and Improves Steak Color

Foods ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1065
Author(s):  
Christina Bakker ◽  
Keith Underwood ◽  
Judson Kyle Grubbs ◽  
Amanda Blair
Keyword(s):  
Electrical Stimulation ◽  
Meat Quality ◽  
Low Voltage ◽  
Instrumental Color ◽  
Time Interaction ◽  
Beef Carcasses ◽  
Glycolytic Potential ◽  
Muscle Ph ◽  
Initial Ph

Electrical stimulation (ES) is used in beef slaughter plants to improve tenderness; however, varying levels of low-voltage ES have not been well characterized. The objective was to evaluate the influence of two levels of low-voltage ES on temperature decline, pH, glycolytic potential, and meat quality. Forty-two beef carcasses were chosen from a commercial packing facility. One side of each carcass received either 40 or 80 volts of ES for 60 s at 45 min postmortem. The paired side of each carcass did not receive ES (Control). Temperature loggers were placed in the sirloin of 12 carcasses to record temperature decline. Longissimus muscle pH was measured at 1, 12, and 24 h, and 3 d postmortem. Strip steaks were fabricated for determination of meat quality. A treatment by time interaction was observed for carcass temperature decline (p < 0.001) where ES sides stayed warmer longer than Control sides. A treatment by time interaction was observed for pH decline with Control sides exhibiting an increased pH at 1 h postmortem (p < 0.001). Instrumental color values were increased for ES compared to Control sides (p < 0.001). These results indicate ES slows carcass temperature decline, hastens initial pH decline, and improves instrumental color. Similar results were observed between the ES treatments indicating either ES level may be used to achieve similar quality characteristics.

scholarly journals Modified Atmospheric Packaging and Antioxidant Enhancement Improves Redness of Atypical Dark-Cutting Beef

2019 ◽  
Vol 3 (2) ◽  
Author(s):  
L. Yoder ◽  
A. Cassens ◽  
G. Mafi ◽  
D. VanOverbeke ◽  
R. Ramanathan
Keyword(s):  
Oxygen Consumption ◽  
Modified Atmosphere Packaging ◽  
Processing Plant ◽  
Glycogen Depletion ◽  
Display Time ◽  
Rigor Mortis ◽  
Biochemical Basis ◽  
Time Interaction ◽  
Modified Atmospheric Packaging ◽  
Muscle Ph

ObjectivesDark-cutting carcasses occur when muscle pH does not decrease sufficiently during rigor mortis because of antemortem glycogen depletion. Typical dark-cutting beef have a pH > 6.0, however, atypical dark-cutting (ADC) beef have a pH around 5.7- 5.9 but have a darker lean color similar to dark-cutting beef. Previous studies noted that greater muscle pH in dark-cutting beef increase oxygen consumption and decrease myoglobin oxygenation. However, limited research has determined the biochemical basis of ADC. Therefore, the objectives of this study were to characterize the biochemical basis of ADC beef carcasses and to utilize modified atmosphere packaging (MAP) and rosemary enhancement to improve appearance during retail display.Materials and MethodsStrip loins from ADC and USDA Low Choice (C) carcasses were selected from a commercial beef processing plant and transported to the Food and Agricultural Products Center in Stillwater, OK. Control (C) and ADC steaks (prior to enhancement and packaging) were utilized to measure pH, color, oxygen consumption, and proximate compositions. Loin sections were cut into halves and randomly assigned to combinations of packaging types and enhancement treatment. Packaging included high-oxygen MAP (HiOx-MAP; 80% oxygen and 20% carbon dioxide), carbon monoxide MAP (CO-MAP; 0.4% CO, 69.6% N, and 30% CO2), and PVC. Enhancement includes 0.1% rosemary oleoresin pumped to 10% of loin green weights. Following enhancement and packaging, steaks were displayed under retail conditions for 6 d to measure color changes using a HunterLab spectrophotometer. The data were analyzed using the Mixed Procedure of SAS, and the experiment was replicated 13 times (n = 13).ResultsThere were no differences for initial pH or proximate compositions (P < 0.05) between C and ADC. However, ADC had lower initial lightness (L* values), redness (a* values), and red intensity (chroma) compared with C. Further, ADC had greater (P < 0.05) oxygen consumption than C. There was a significant packaging × enhancement × display time interaction resulted for L*, a*, and chroma. CO-MAP and HiOx-MAP in combination with rosemary enhancement improved (P < 0.05) redness of ADC by 61.7% and 42.3%, respectively, compared with ADC in PVC packaging. Similarly, MAP and enhancement improved lightness (L* values) and chroma compared with ADC in PVC. By Day 6 of display, enhanced ADC steaks packaged in both HiOx-MAP and CO-MAP had similar color parameters to control choice steaks; however, non-enhanced ADC steaks had significantly lower a* (P < 0.0001) and chroma (P < 0.01) values when packaged in HiOx-MAP when compared to both C and enhanced ADC.ConclusionThe results suggest that ADC beef has greater oxygen consumption than C steaks even at similar muscle pH. Use of modified atmospheric packaging in combination with enhancement has the potential to improve surface color of ADC beef.

scholarly journals Low voltage electrical stimulation of lamb: Its effect on muscle pH and tenderness

1984 ◽  
Vol 27 (4) ◽  
pp. 513-523 ◽  
Author(s):  
B. B. Chrystall ◽  
G. E. Devine ◽  
S. Ellery ◽  
L. Wade
Keyword(s):  
Electrical Stimulation ◽  
Low Voltage ◽  
Muscle Ph ◽  
Stimulation Of

EFFECTS OF A LOW-VOLTAGE RECTAL ELECTRODE SYSTEM ON BEEF QUALITY FROM YOUNG AND MATURE COWS

1987 ◽  
Vol 67 (3) ◽  
pp. 689-704 ◽  
Author(s):  
Z. J. HAWRYSH ◽  
F. H. WOLFE
Keyword(s):  
Electrical Stimulation ◽  
Low Voltage ◽  
Biceps Femoris ◽  
Electrode System ◽  
Eating Quality ◽  
Beef Quality ◽  
Young Control ◽  
Muscle Ph ◽  
Postmortem Aging

The quality characteristics of biceps femoris (BF), longissimus (L) and pectoralis profundis (PP) roasts obtained from young and mature cow carcasses subjected to low voltage (110 V) electrical stimulation (ES) were determined. ES was applied with a steel busbar rectal probe for 2 min. Evaluations were conducted on meat obtained from young control sides (no ES) aged 48 h, from young and mature sides (no ES) aged 6 d and from young and mature ES sides aged 48 h. ES caused a reduction (P < 0.001) in BF muscle pH at 1 and 4 h postmortem. Except for the pH differences in L muscle of young cows at 24 h, there were no differences in L muscle pH values due to ES for either young or mature cows. At 24 h, the pH of muscles from all carcasses was about 5.6. Cooking losses did not appear to be affected by either ES or increased aging in young control roasts. For both young and mature BF and L roasts, trained panelists generally did not detect significant effects due to ES. Except for differences in OTMS-Warner Bratzler shear values for mature PP samples, objective measurements for all roasts show no significant effects due to ES. Thus, no differences in cooking and eating quality of BF, L and PP roasts were found due to the application of low-voltage ES via the busbar rectal probe. Increasing postmortem aging time from 48 h to 6 d for young control carcasses did not influence roast quality. Animal maturity had some significant effects on the quality of all roasts. Key words: Low-voltage electrical stimulation, beef quality

scholarly journals Effect of Electrical Stimulation on Qualitative Characteristics of Aged Chicken Carcasses: A Comprehensive Review

2020 ◽  
Vol 33 (1) ◽  
pp. 135-158
Author(s):  
Asaad R. Al-Hilphy ◽  
Majid H. Al-Asadi ◽  
Hong Zhuang
Keyword(s):  
Electrical Stimulation ◽  
Meat Quality ◽  
High Voltage ◽  
Low Voltage ◽  
Poultry Meat ◽  
Limited Information ◽  
Breast Meat ◽  
Rigor Mortis ◽  
Experimental Conditions ◽  
Commercial Applications

The aim of this review was to summarize the histological, physical, chemical and microbial aspects and ways to stop the fluctuation in meat quality in addition to enhance its sensory quality using electrical stimulation. The low-voltage electrical stimulation and high-voltage electrical stimulation were employed. Electrical stimulation improves quality of poultry meat by reducing shear, increasing Sarcomere length, and reducing the diameter of muscle fibers. Low-voltage electrical stimulation affects voltages (120 volts directly in the nervous system, while high voltages were more than enough) to remove the polarization of the cover and produce a dense physio-chemical response in the muscles that had a direct effect. Electrical stimulation and injection with salts of sodium chloride and calcium chloride in the carcasses of female goats improved the tenderness of the meat. It was found that electrical stimulation accelerated the development of rigor mortis. Although electrical stimulation reduces breast meat shear, there was limited information about the effects of electrical stimulation on the other quality attributes of poultry meat and the results vary with quality attribute and differ from experimental conditions High voltage (higher than 120 volts) electrical stimulation improved meat quality and decreased the pH. Low voltages (below 120 volts) are used to ensure the safety of workers and give the desired results when used in commercial applications.

Validating Four Standard Scales in Spiritually Practicing and Nonpracticing Samples Using Propensity Score Matching

2008 ◽  
Vol 24 (3) ◽  
pp. 165-173 ◽  
Author(s):  
Niko Kohls ◽  
Harald Walach
Keyword(s):  
Propensity Score ◽  
Propensity Score Matching ◽  
Repeated Measures ◽  
Propensity Scores ◽  
Total Sample ◽  
Experimental Manipulation ◽  
Brief Symptom Inventory ◽  
Time Interaction ◽  
Social Support Scale ◽  
Lower Test

Validation studies of standard scales in the particular sample that one is studying are essential for accurate conclusions. We investigated the differences in answering patterns of the Brief-Symptom-Inventory (BSI), Transpersonal Trust Scale (TPV), Sense of Coherence Questionnaire (SOC), and a Social Support Scale (F-SoZu) for a matched sample of spiritually practicing (SP) and nonpracticing (NSP) individuals at two measurement points (t1, t2). Applying a sample matching procedure based on propensity scores, we selected two sociodemographically balanced subsamples of N = 120 out of a total sample of N = 431. Employing repeated measures ANOVAs, we found an intersample difference in means only for TPV and an intrasample difference for F-SoZu. Additionally, a group × time interaction effect was found for TPV. While Cronbach’s α was acceptable and comparable for both samples, a significantly lower test-rest-reliability for the BSI was found in the SP sample (rSP = .62; rNSP = .78). Thus, when researching the effects of spiritual practice, one should not only look at differences in means but also consider time stability. We recommend propensity score matching as an alternative for randomization in variables that defy experimental manipulation such as spirituality.

Social isolation of goats: significance of visual contact with conspecifics on behavioral and physiological responses

2021 ◽  
Author(s):  
Govind Kannan ◽  
Zaira M Estrada-Reyes ◽  
Phaneendra Batchu ◽  
Brou Kouakou ◽  
Thomas H Terrill ◽  
...  
Keyword(s):  
Social Isolation ◽  
Stress Responses ◽  
Repeated Measures ◽  
Physiological Stress ◽  
Physiological Responses ◽  
Average Weight ◽  
Median Frequency ◽  
Visual Contact ◽  
Time Interaction ◽  
Rank Score

Abstract Social isolation can increase distress in goats, particularly when they cannot maintain visual contact with conspecifics. This experiment was conducted to determine the behavioral and physiological responses in goats during isolation with or without visual contact with conspecifics. Male Spanish goats (uncastrated, 8-mo old, average weight 29.4 ± 0.59 kg) were randomly assigned to a control (CO) group with no isolation or to one of four isolation treatment (TRT) pens (1.5 × 1.5 m) with: (1) open grill panels but with no visual contact with conspecifics (IO), (2) covered grill to prevent visual contact (IC), (3) open grill with visual contact (IV), or (3) covered grill with a 30 × 30 cm window to allow visual contact (IW) for 90 min of social isolation (n = 12 goats/TRT). Blood samples were collected at 0, 30, 60, and 90 min (Time) from isolated and control goats. The experiment was repeated one week later using the same animals, with each goat being subjected to the same isolation treatment the second time to study the effect of prior exposure to isolation. Friedman’s Two-Way ANOVA by Ranks Test in SAS showed that the median frequency of vocalization (rank score) in goats was high in IO group, low in IV and IW groups, and intermediate in IC group (P &lt; 0.01). Vocalization rank score was also higher (P &lt; 0.01) during the first 30 min of isolation in goats. Median frequency of visual contact was higher in the IW group than in the IV group (P &lt; 0.01). Frequency of climbing behavior was high in IC and IO groups, low in IV group, and intermediate in IW group (P &lt; 0.01). Repeated Measures Analysis using GLM procedures in SAS revealed that plasma cortisol and glucose concentrations tended (P &lt; 0.1) to be the highest in IO group than in CO, IC, IV, and IW groups. Cortisol levels were also higher (Time; P &lt; 0.05) at 0 and 90 min compared to 30 and 60 min. Norepinephrine concentrations decreased (P &lt; 0.05) with Time, and plasma non-esterified fatty acid (NEFA) levels were affected by TRT × Time interaction (P &lt; 0.01). Overall, epinephrine, norepinephrine, glucose, and NEFA concentrations were lower (P &lt; 0.01) and cortisol concentrations and lymphocyte counts higher (P &lt; 0.01) when goats were exposed to isolation the second time. The results showed that goats with no visual contact with conspecifics during social isolation had greater physiological stress responses and spent more time vocalizing or trying to escape the pen, which may indicate distress.

scholarly journals PSVIII-17 Assessment of conformational changes across three parities in sows

2020 ◽  
Vol 98 (Supplement_3) ◽  
pp. 221-222
Author(s):  
Melanie D Trenhaile-Grannemann ◽  
Ronald M Lewis ◽  
Stephen D Kachman ◽  
Kenneth J Stalder ◽  
Benny E Mote
Keyword(s):  
Body Size ◽  
Body Length ◽  
Conformational Changes ◽  
Repeated Measures ◽  
Fixed Effects ◽  
Random Effect ◽  
Joint Angles ◽  
Body Depth ◽  
Conformation Changes ◽  
Over Time

Abstract Conformation-based sow selection is performed prior to reaching mature size, yet little is known about how conformation changes as growth continues. To assess conformation changes, 9 conformational traits were objectively measured at 12 discrete time points between 112 d of age and parity 3 weaning on 622 sows in 5 cohorts. The 9 traits included 5 body size traits (body length, body depth at the shoulder and flank, and height at the shoulder and flank) and 4 joint angles (knee, hock, and front and rear pastern). Data were analyzed with a repeated measures model (SAS V 9.4) including cohort and time point as fixed effects, sire as a random effect, and heterogeneous compound symmetry as the covariance structure. Sire variance ranged from 0.16 (body depth shoulder) to 2.00 (body length) cm2 for body size traits and 2.28 (rear pastern) to 4.22 (front pastern) degrees2 for joint angles. Cohort had an effect on all traits (P &lt; 0.05). All traits displayed changes over time (P &lt; 0.001). Size traits increased between 112 d of age and parity 3 weaning (64.16 vs. 107.57 cm, 26.62 vs. 44.14 cm, 23.32 vs. 36.92 cm, 46.10 vs. 73.55 cm, 49.36 vs. 77.47 cm for body length, body depth shoulder and flank, and height shoulder and flank, respectively); however, they fluctuated within parity by increasing during gestation and decreasing at weaning. Knee angle decreased (164.12 vs. 150.72 degrees) while fluctuating within parity by decreasing in the second half of gestation and increasing after weaning. Front and rear pastern angles decreased over time (60.89 vs. 53.74 degrees and 64.64 vs. 55.50 degrees for front and rear pastern, respectively), while biologically negligible change was observed in hock angle (148.63 vs. 147.48 degrees). Sow conformation changes throughout life, and these changes may require consideration when making selection decisions.

The combined effects of time on feed, electrical stimulation and aging on beef quality

1992 ◽  
Vol 72 (3) ◽  
pp. 525-535 ◽  
Author(s):  
J. L. Aalhus ◽  
S. D. M. Jones ◽  
A. K. W. Tong ◽  
L. E. Jeremiah ◽  
W. M. Robertson ◽  
...  
Keyword(s):  
Quality Control ◽  
Electrical Stimulation ◽  
Combined Effects ◽  
Consumer Survey ◽  
Beef Quality ◽  
Muscle Ph ◽  
Consumer Ratings ◽  
Postmortem Aging ◽  
Fat Thickness ◽  
Production Practices

Two experiments were conducted to determine the combined effects of time on feed, high-voltage electrical stimulation (HVES) and postmortem aging on beef quality and palatability. Increasing time on feed resulted in an increase in carcass fat thickness, dressed carcass weight and marbling and a decrease in carcass lean content, carcass shrinkage and shear values in both experiments. Steaks from longer-fed animals were rated more highly for juiciness, tenderness and overall palatability by the consumers polled. HVES lowered muscle pH (3, 24 and 144 h), increased subjectively appraised marbling fat, gave brighter, redder muscle colour up to 6 d postmortem, and improved consumer ratings for flavour, juiciness, tenderness and overall palatability. HVES also resulted in a significant improvement in shear values (shear values were decreased by 27 and 35% in experiments 1 and 2, respectively). Aging for 6 d improved meat colour, decreased the amount of expressible juice and lowered the shear value of steaks by 11 and 9% respectively, in experiments 1 and 2. A consumer survey indicated that more than 20% of steaks were rated as unacceptable for tenderness when time on feed and postmortem aging were similar to Canadian beef-production practices. Incorporation of HVES as a means of quality control would reduce the proportion of unacceptable steaks to approximately 10%. Key words: Beef quality, time on feed, electrical stimulation, aging

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