Acute exercise stress and electrical stimulation influence the consumer perception of sheep meat eating quality and objective quality traits

2005 ◽  
Vol 45 (5) ◽  
pp. 553 ◽  
Author(s):  
R. D. Warner ◽  
D. M. Ferguson ◽  
M. B. McDonagh ◽  
H. A. Channon ◽  
J. J. Cottrell ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Acute Exercise ◽  
Low Voltage ◽  
Gluteus Medius ◽  
Lower Surface ◽  
Exercise Stress ◽  
Eating Quality ◽  
General Exercise ◽  
Initial Ph ◽  
Negative Effect

The effects of acute exercise stress and electrical stimulation on lamb eating quality and objective measurements of quality were evaluated on the Longissimus thoracis et lumborum (LTL) and the Gluteus medius (GM) muscles. Meat quality attributes were also assessed on the LTL, Semimembranosus (SM) and the Semispinalis capitis (SC) muscles. Forty-eight Poll Dorset × Border Leicester–Merino ewes of about 6 months old were randomly allocated to treatments in a 2 × 2 factorial design, with the respective factors being exercise (Ex, 0 v. 15 min) and post-slaughter low voltage electrical stimulation (control v. ES). In general, exercise reduced the rate of pH fall and increased the ultimate pH of all 3 muscles (P<0.05). This effect was more pronounced in the SM than in the LTL and SC. Exercised LTL and SM muscles also had lower surface lightness (L*) values and higher muscle total water content, indicating an increased incidence of dark cutting meat. Exercised LTL steaks were rated higher for tenderness and juiciness by the taste panelists and had lower Warner-Bratzler shear force values, as is often observed with high ultimate pH meat. Electrical stimulation reduced initial pH (pH0.5) values, but resulted in a slower rate of pH fall in the LTL and SM thereafter. Electrical stimulation resulted in an elevation of temperature at rigor in the SM by 10°C (15 v. 25°C) and in the LTL by 3.1°C (7.4 v. 10.5°C). While no effect of electrical stimulation was observed with instrumental analysis, electrical stimulation reduced sensory tenderness scores and overall liking for the GM, and tended to reduce flavour and juiciness of both the GM and LTL. In conclusion, acute exercise pre-slaughter improved eating quality, but caused dark cutting meat. The negative effect of low voltage stimulation on the eating quality of the GM was probably due to a high rigor temperature and associated heat toughening.

COMPARISON OF THE EFFECTS OF LOW-VOLTAGE ELECTRICAL STIMULATION ON MATURE AND YOUNG COW CARCASSES

1985 ◽  
Vol 65 (3) ◽  
pp. 603-612 ◽  
Author(s):  
Z. J. HAWRYSH ◽  
F. H. WOLFE
Keyword(s):  
Electrical Stimulation ◽  
Low Voltage ◽  
Quality Characteristics ◽  
Eating Quality ◽  
Young Control ◽  
Ph Values ◽  
Consumer Panel ◽  
Cooking And Eating Quality ◽  
Water Holding

The quality characteristics of semitendinosus (ST) and longissimus dorsi (LD) roasts from 18 young and 6 mature cow carcasses subjected to low-voltage (110 V) electrical stimulation (ES) were determined. ES was applied for either 4 min or 5 min. Evaluations were conducted on meat obtained from young control sides (no ES) aged 48 h, from young and mature ES sides aged 48 h and from mature ES sides, aged 7 days. Data obtained from mature control sides (no ES), aged 48 h and 7 days, reported in a previous study, served as a reference point for mature ES meat. ES caused a reduction (P < 0.01) in pH values 1 and 4 h postmortem. At 24 h, the pH of ST and LD muscles from control and ES carcasses were similar. Cooking losses of roasts were not affected by ES, ES duration or increased aging. Trained panelists detected no significant effects of ES, ES duration or aging time on palatability. Consumer panel judgements of ST roasts were similar to those of the trained judges. Data from instrumental measurements of juiciness (water-holding capacity), tenderness (OTMS) and softness (penetrometer) for ST and LD roasts support sensory results. These studies show no differences in cooking and eating quality of ST and LD roasts attributable to low voltage ES. The palatability of meat from mature ES carcasses was judged to be similar to that of comparable meat from young control carcasses. For meat from young carcasses, there was no advantage in increasing ES duration. In addition, roasts from mature ES carcasses aged for either 48 h or 7 days were similar. Key words: Low voltage electrical stimulation, cow carcasses

Quantifying the rate of pH and temperature decline in lamb carcasses using medium voltage electrical stimulation in an Australian abattoir

2006 ◽  
Vol 46 (7) ◽  
pp. 869 ◽  
Author(s):  
K. L. Pearce ◽  
D. L. Hopkins ◽  
E. Toohey ◽  
D. W. Pethick ◽  
I. Richards
Keyword(s):  
Electrical Stimulation ◽  
Pulse Width ◽  
Eating Quality ◽  
Medium Voltage ◽  
Initial Ph ◽  
Australian Sheep ◽  
Temperature Window ◽  
Late Application ◽  
Rate Of Decline ◽  
The Individual

The current study evaluated the effectiveness of a medium voltage post-dressing electrical stimulation unit at different current and pulse width settings on pH decline. The objective was to optimise these settings to ensure that a high proportion of carcasses would reach pH 6.0 when the carcass was between 18–25°C according to the guidelines set by the Australian Sheep Meat Eating Quality (SMEQ) program. In the first experiment, 3 different current (400, 700 and 1000 mA) and pulse width (1, 2.5 and 5 ms) settings plus a control (0 mA and 0 ms) were applied to carcasses for 34 s at a frequency of 15 Hz with 7 sheep per treatment over 3 consignments (n = 210 carcasses). The pH–temperature decline was evaluated for all carcasses. Based on the SMEQ guidelines, 43% of stimulated carcasses reached a pH of 6.0 between a carcass temperature of 18–25°C, compared with 14% of unstimulated controls. Furthermore, 21% of carcasses reached a pH of 6.0 before the carcass temperature reached 25°C and 36% did not reach a pH of 6.0 by the time the carcass was 18°C. Alternatively, under the Meat Standards Australia (MSA) pH–temperature guidelines, carcasses should reach pH 6.0 between 12 and 35°C; 87% of stimulated carcasses reached a pH of 6.0 between 12–35°C, compared with 39% of unstimulated controls. One percent of carcasses reached a pH of 6.0 before the carcass temperature reached 35°C and 12% did not reach a pH of 6.0 by a carcass temperature by the time the carcass was 12°C. The abattoir in this study had a very fast chilling regime which resulted in carcasses reaching pH 6.0 at low temperatures and accounted for the low number of carcasses reaching a pH of 6.0 between 18–25°C. There was no effect of different current and pulse widths on the rate of decline, temperature at pH 6.0 or initial pH, which was attributed to the late application of electrical stimulation postmortem when muscle contraction is dependant on direct muscle stimulation. The combination of 2.5 ms and 1000 mA was the best performing treatment with respect to both SMEQ and MSA guidelines and the number of carcasses reaching the pH–temperature window. This treatment had the highest percentage of carcasses reaching the SMEQ window (60%) and MSA window (97%). Furthermore, it resulted in the lowest number of carcasses not reaching pH 6.0 by a carcass temperature of either 12 or 18°C, making it the most suitable to an abattoir with a fast chilling regime. Modulation and frequency manipulation of the segmented electrodes were assessed with the frequency manipulation resulting in the greatest stimulation response. Further work is needed to understand the effect of manipulating the frequency on the system overall or of the individual modules as well as changing the stimulation time.

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 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.

New electrical stimulation technologies for sheep carcasses New electrical stimulation technologies for sheep carcasses

2005 ◽  
Vol 45 (5) ◽  
pp. 575 ◽  
Author(s):  
F. D. Shaw ◽  
S. R. Baud ◽  
I. Richards ◽  
D. W. Pethick ◽  
P. J. Walker ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
High Voltage ◽  
Consumer Satisfaction ◽  
Electrode System ◽  
Constant Current ◽  
Eating Quality ◽  
Meat Eating ◽  
Medium Voltage ◽  
Sheep Meat ◽  
Maximum Voltage

High voltage electrical stimulation applied to the lamb carcass at the end of the dressing procedure often leads to an improvement in overall product quality by reducing the incidence of toughness. It would be advantageous if the same results could be consistently achieved with the use of lower, safer, voltages — medium voltage electrical stimulation. Experiments were conducted to determine the effect of medium voltage electrical stimulation applied to wool-on carcasses on meat quality as assessed using the Sheep Meat Eating Quality protocols. A further experiment examined the interaction of electrical stimulation and meat aging time on the consumer acceptance of lamb meat. In the first experiment, 3 treatments: control (non-stimulated), medium voltage electrical stimulation (applied to the wool-on carcass) and high voltage electrical stimulation (applied at the completion of dressing) were examined. Samples of the loin (LTL) and rump (GM) muscles were evaluated by consumers using Sheep Meat Eating Quality protocols. For both muscles, the consumers gave higher scores for tenderness, juiciness, flavour and overall acceptability to the stimulated product (P<0.001). There were no statistically significant differences between the 2 stimulation treatments. The second experiment was conducted at a commercial lamb-processing abattoir that had installed a prototype automated electrode system designed to work at chain speed. Lambs received either no stimulation (control), low current medium voltage electrical stimulation (constant current 300 mA peak, 15 Hz, maximum voltage 550 V peak) or high current medium voltage electrical stimulation (constant current 600 mA peak, 15 Hz, maximum voltage 550 V peak) immediately after sticking. Electrical stimulation improved both the objective and sensory (Sheep Meat Eating Quality) eating quality attributes of lamb loin muscle when assessed following 2 days of ageing. When expressed according to consumer satisfaction rating, 30, 37 and 70% of the loins receiving low, high or no electrical stimulation, respectively, were rated as unsatisfactory at 2 days of ageing. At 4 days of ageing no loins from carcasses in the low stimulation treatment were rated by consumers to be unsatisfactory (P<0.05) compared with either non-stimulated (40%) or high-stimulated loins (35%). With respect to the effects of aging meat, electrical stimulation improved the consumer score at 2 days post-stunning by 8.9 and 4.7 points for tenderness and overall liking, respectively. Further linear improvements due to aging were similar for both electrical stimulation and unstimulated products. Under conditions of no electrical stimulation used in this experiment, 10 days aging results in tenderness and overall liking scores greater than 60 and with ES similar scores are achieved in 5 days. Consumer scores over 60 greatly reduce the chance of meat being classified as unsatisfactory.

Combat and Blast Exposure Blunt Sympathetic Response to Acute Exercise Stress in Specialized Military Men

2021 ◽  
Author(s):  
Marcus K. Taylor ◽  
Nikki E. Barczak‐Scarboro ◽  
D. Christine Laver ◽  
Lisa M. Hernández
Keyword(s):  
Acute Exercise ◽  
Exercise Stress ◽  
Sympathetic Response ◽  
Blast Exposure

scholarly journals Effect of Functional Electrical Stimulation of the Gluteus Medius during Gait in Patients following a Stroke

2020 ◽  
Vol 2020 ◽  
pp. 1-6
Author(s):  
Sota Araki ◽  
Masayuki Kawada ◽  
Takasuke Miyazaki ◽  
Yuki Nakai ◽  
Yasufumi Takeshita ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Lower Limb ◽  
Stride Length ◽  
Gluteus Medius ◽  
Gait Velocity ◽  
Inertial Measurement Units ◽  
Stroke Patients ◽  
Inertial Measurement ◽  
Motion Range ◽  
Measurement Units

Many stroke patients rely on cane or ankle-foot orthosis during gait rehabilitation. The purpose of this study was to investigate the immediate effect of functional electrical stimulation (FES) to the gluteus medius (GMed) and tibialis anterior (TA) on gait performance in stroke patients, including those who needed assistive devices. Fourteen stroke patients were enrolled in this study (mean poststroke duration: 194.9 ± 189.6   d ; mean age: 72.8 ± 10.7   y ). Participants walked 14 m at a comfortable velocity with and without FES to the GMed and TA. After an adaptation period, lower-limb motion was measured using magnetic inertial measurement units attached to the pelvis and the lower limb of the affected side. Motion range of angle of the affected thigh and shank segments in the sagittal plane, motion range of the affected hip and knee extension-flexion angle, step time, and stride time were calculated from inertial measurement units during the middle ten walking strides. Gait velocity, cadence, and stride length were also calculated. These gait indicators, both with and without FES, were compared. Gait velocity was significantly faster with FES ( p = 0.035 ). Similarly, stride length and motion range of the shank of the affected side were significantly greater with FES (stride length: p = 0.018 ; motion range of the shank: p = 0.02 6). Meanwhile, cadence showed no significant difference ( p = 0.238 ) in gait with or without FES. Similarly, range of motion of the affected hip joint, knee joint, and thigh did not differ significantly depending on FES condition ( p = 0.115 ‐ 0.529 ). FES to the GMed and TA during gait produced an improvement in gait velocity, stride length, and motion range of the shank. Our results will allow therapists to use FES on stroke patients with varying conditions.

Variation in the response to manipulation of post-mortem glycolysis in beef muscles by low-voltage electrical stimulation and conditioning temperature

Meat Science ◽  
2007 ◽  
Vol 77 (3) ◽  
pp. 372-383 ◽  
Author(s):  
Kristin Hollung ◽  
Eva Veiseth ◽  
Terje Frøystein ◽  
Laila Aass ◽  
Øyvind Langsrud ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Low Voltage ◽  
Post Mortem ◽  
Conditioning Temperature ◽  
Beef Muscles

scholarly journals Effects of low voltage electrical stimulation during bleeding on characteristics of beef loin eye top round muscles

1984 ◽  
pp. 6-9
Author(s):  
Donald H. Kropf ◽  
Melvin C. Hunt ◽  
John A. Unruh ◽  
Curtis L. Kastner ◽  
Michael E. Dikeman
Keyword(s):  
Electrical Stimulation ◽  
Low Voltage

Effects of low-voltage electrical stimulation and rapid chilling on meat quality characteristics of Chinese Yellow crossbred bulls

Meat Science ◽  
2006 ◽  
Vol 72 (1) ◽  
pp. 9-17 ◽  
Author(s):  
C.B. Li ◽  
Y.J. Chen ◽  
X.L. Xu ◽  
M. Huang ◽  
T.J. Hu ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Meat Quality ◽  
Low Voltage ◽  
Quality Characteristics
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