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

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.

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

Canadian Journal of Animal Science ◽

10.4141/cjas87-072 ◽

1987 ◽

Vol 67 (3) ◽

pp. 689-704 ◽

Cited By ~ 2

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

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Electrophysiological evidence for an L-shaped interhemispheric connection in the cat

Arquivos de Neuro-Psiquiatria ◽

10.1590/s0004-282x1989000400001 ◽

1989 ◽

Vol 47 (4) ◽

pp. 381-384 ◽

Cited By ~ 1

Author(s):

A Cukiert ◽

C. Timo-Iaria

Keyword(s):

Electrical Stimulation ◽

Low Voltage ◽

Cortical Surface ◽

Variable Intensity ◽

Anterior Cortex ◽

Ketamine Hydrochloride ◽

Interhemispheric Connection ◽

Projection Pattern ◽

Posterior Area ◽

Stimulation Of

Transcallosal potentials evoked by electrical stimulation with rectangular pulses of 1 ms, 5 c/s and variable intensity were recorded from the cortical surface in cats anesthetized with ketamine hydrochloride. Sites of stimulation and recording were selected by means of a cartesian map of most of the neocortex. In addition to the well known transcallosal projection pattern it was found that stimulation of a restricted posterior area evokes low voltage potentials over the contralateral symmetric area while high voltage potentials are recorded from a few sites located at the ipsilateral anterior cortex and from the area symmetric as to the latter. This L-shaped transcallosal connection may be involved in complex cortical processes and is compatible with effective results of partial anterior callosotomies in patients with multifocal epilepsy and frontal bisynchronism.

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

Foods ◽

10.3390/foods10051065 ◽

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.

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