EFFECT OF LOW VOLTAGE STIMULATION OF BEEF CARCASSES ON MUSCLE TENDERNESS AND pH

The objective of the current study was to evaluate the effect of differing electrical stimulation (ES) voltage levels on beef longissimus muscle (LM) tenderness, postmortem temperature, and pH decline, and carcass quality. Beef carcasses from three commercial beef processing plants (A, B, C) were exposed to three varying voltage levels: 1) control (no ES) 2) high ES (60-Hz for 17s each at 25, 35, 45, and 55 V) 3) low-ES (60-Hz for 17s each at 16, 20, 24, and 28 V). Ninety beef carcasses were selected from the three plants, and within a carcass, paired sides were randomly assigned to one of three ES treatments. The results indicated that ES affected (P < 0.05) muscle pH at 3 h postmortem in two of the three plants. However, ES did not affect (P > 0.05) pH at the time of grading (post rigor). Although the slice shear force (SSF) values were lower (P < 0.05) for ES steaks compared to controls, it was not (P < 0.05) influenced by the voltage levels. Variation in tenderness was observed among the plants (P < 0.05), with Plant C having the toughest steaks, whereas Plant A and B exhibited similar (P > 0.05) tenderness. Overall, the lack of difference in postmortem tenderness between high- and low-voltage settings indicated the ES-voltage minimally influenced tenderness. 

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Studies of extra low voltage electrical stimulation of mature beef carcasses

Meat Science ◽

10.1016/0309-1740(87)90025-8 ◽

1987 ◽

Vol 21 (2) ◽

pp. 121-135 ◽

Cited By ~ 4

Author(s):

Z.J. Hawrysh ◽

P.J. Shand ◽

F.H. Wolfe ◽

M.A. Price

Keyword(s):

Electrical Stimulation ◽

Low Voltage ◽

Beef Carcasses ◽

Stimulation Of

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Effects of Electrical Stimulation and Early Postmortem Muscle Excision on pH Decline, Sarcomere Length and Color in Beef Muscles

Journal of Food Protection ◽

10.4315/0362-028x-43.7.514 ◽

1980 ◽

Vol 43 (7) ◽

pp. 514-519 ◽

Cited By ~ 18

Author(s):

J. E. NICHOLS ◽

H. R. CROSS

Keyword(s):

Electrical Stimulation ◽

Sarcomere Length ◽

Storage Temperature ◽

Sampling Period ◽

Initial Time ◽

C Storage ◽

Beef Carcasses ◽

Color Uniformity ◽

Initial Drop ◽

Stimulation Of

Electrical stimulation of prerigor beef carcasses produced a rapid initial drop in pH of longissimus muscles excised and vacuum-packaged at 1, 2 or 4 h postmortem. This initial drop was further increased by delayed excision and was severe enough that even −30-C storage did not retard the overall decline. Through the first 10 h of the 30-h sampling period at −30 C, pH was higher for nonstimulated than for stimulated muscle and was substantially affected by the time of muscle excision. Compared to −30-C storage, a 3-C storage temperature resulted in an even faster decline of pH in electrically stimulated muscle but still hindered the decline in nonstimulated muscle. Although the decline in pH was affected by electrical stimulation, excision time and storage method, initial (time of excision) and final (5 days postmortem) sarcomere length were not. Electrical stimulation of prerigor beef carcasses did not affect the appearance of hot-boned or cold-boned longissimus or semimembranosus muscles. Excision time, however, did affect the color and color uniformity of semimembranosus muscles, apparently because of alteration of the temperature and pH relationship. Excision times of 1 or 2 h appear preferable to 4 or 48 h because combinations of high temperature and low pH within deeper areas of the carcass could cause severe non-uniformity of color in muscles set deep within the carcass.

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Electrical responses to limbic and thalamic stimulation in the unrestrained hooded rat

American Journal of Physiology-Legacy Content ◽

10.1152/ajplegacy.1962.203.5.796 ◽

1962 ◽

Vol 203 (5) ◽

pp. 796-798

Author(s):

Lucy Birzis

Keyword(s):

Limbic System ◽

Thalamic Nucleus ◽

Low Voltage ◽

Electrical Response ◽

Active Growth ◽

Thalamic Stimulation ◽

Fast Activity ◽

Mediodorsal Thalamic Nucleus ◽

Slow Activity ◽

Stimulation Of

A procedure for implanting cortical and subcortical brain electrodes in young hooded rats is described. In unrestrained rats, cortical activity showed patterns of high voltage slow activity or low voltage fast activity correlated with quiet or alert states, respectively. Typical recruiting responses were elicited by stimulation of the mediodorsal thalamic nucleus. Low intensity stimulation of the limbic system produced an electrical response similar to thalamocortical recruiting, and higher intensity stimulation induced a seizure discharge in the limbic circuit with accompanying behavioral signs of excitement and hypermotility. Neither ongoing electrical activity, nor thresholds or amplitudes of response to stimulation of thalamus or limbic system were observably different after a period of 8 weeks of active growth of the rats.

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Central angiotensin II stimulation of ovine fetal swallowing

Journal of Applied Physiology ◽

10.1152/jappl.1994.76.3.1340 ◽

1994 ◽

Vol 76 (3) ◽

pp. 1340-1345 ◽

Cited By ~ 22

Author(s):

M. G. Ross ◽

L. K. Kullama ◽

A. Ogundipe ◽

K. Chan ◽

M. G. Ervin

Keyword(s):

Angiotensin Ii ◽

Arginine Vasopressin ◽

Low Voltage ◽

Control Period ◽

Late Gestation ◽

Ang Ii ◽

Fetal Plasma ◽

Plasma Arginine ◽

Ovine Fetal ◽

Stimulation Of

In the late-gestation ovine fetus, spontaneous swallowing occurs primarily during fetal low-voltage electrocortical (ECoG) activity in association with fetal breathing movements. Fetal swallowing activity may be stimulated in response to systemic or carotid plasma hyperosmolality, although not to increased plasma angiotensin II (ANG II) levels. In view of the potent dipsogenic effects of central, but not peripheral, ANG II in adult sheep, the present study investigated the effect of intracerebroventricular (ICV) ANG II on fetal swallowing activity. Six ovine fetuses (127 +/- 1 days) were chronically prepared with electromyogram and cortical electrodes and with vascular and lateral ventricle catheters. After a 2-h control period, fetuses received ICV injections of artificial cerebrospinal fluid and increasing concentrations of ANG II (0.1, 1.0, 10, 100, and 500 ng/kg). Fetal ECoG activity did not change, although fetal swallowing activity significantly increased in response to the 100- and 500- ng/kg ANG II doses (1.20 +/- 0.14 to 3.34 +/- 0.59 and 3.46 +/- 0.81 swallows/min of low-voltage ECoG, respectively). In response to the highest ANG II dose, fetal plasma arginine vasopressin levels significantly increased (5.7 +/- 1.2 to 17.2 +/- 4.6 pg/ml). ICV ANG II stimulation of fetal swallowing and arginine vasopressin secretion demonstrates that central ANG II dipsogenic mechanisms are intact by 0.9 of ovine gestation.

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