Electrical stimulation extends the time limits for very fast chilling of lamb loins

2020 ◽  
Vol 60 (15) ◽  
pp. 1861
Author(s):  
Robin H. Jacob ◽  
Katja Rosenvold ◽  
Michael North ◽  
Robert Kemp ◽  
Robyn D. Warner
Keyword(s):  
Electrical Stimulation ◽  
Shear Force ◽  
Sarcomere Length ◽  
Post Mortem ◽  
Inventory Costs ◽  
Commercial Scale ◽  
Lamb Meat ◽  
Muscle Ph ◽  
Potential Benefits ◽  
Low Shear

Context Very fast chilling (VFC) involves cooling meat to approximately –1°C before the onset of rigor, and offers potential benefits compared with conventional chilling that include accelerated tenderisation, improved shelf life and reduced inventory costs. However, the practical difficulties of achieving the required temperature profile prevents adoption of VFC commercially. Aims The objective of this study was to determine if electrical stimulation could be a way of making VFC easier to achieve for lamb meat. The hypothesis tested was that electrical stimulation would reduce the rate of chilling required with very fast chilling by accelerating the rate of pH decline post-mortem. Methods The experiment was a 2 × 3 factorial design whereby 54 loins from 27 lambs were allocated to one of six different treatments: no electrical stimulation and electrical stimulation, and chilling rates to reach −1°C at 1 h (Fast), 1.5 h (Moderate) and 2.5 h (Slow) post-mortem respectively. Key results Without electrical stimulation, shear forces were lowest for the Moderate chilling rate; but with electrical stimulation, consistently low shear force values were obtained with all chilling rates. Muscle pH depended on treatment, although this effect also depended on the time post-mortem. Shear force depended on chilling rate only when there was no electrical stimulation. Without electrical stimulation, the optimal chilling rate was the Moderate treatment. Effects on sarcomere length accounted for some, but not all, of the effects of treatment on shear force. Conclusions Electrical stimulation therefore reduced the chilling rate required to optimise tenderness with VFC, and could be a component of a practical VFC regime for lamb meat. Implications VFC could become a practical chilling method, but only when sensory evaluation supports the favourable shear force findings established in this study. This would require evaluation of VFC at a commercial scale.

Timing and duration of low voltage electrical stimulation on selected meat quality characteristics of light and heavy cattle carcasses

2020 ◽  
Vol 60 (7) ◽  
pp. 967
Author(s):  
E. C. Webb ◽  
B. Agbeniga
Keyword(s):  
Electrical Stimulation ◽  
Meat Quality ◽  
Shear Force ◽  
Sarcomere Length ◽  
Low Voltage ◽  
Carcass Weight ◽  
Drip Loss ◽  
Early Application ◽  
Early Stimulation ◽  
Stimulation Parameters

Context The present study investigated the effects of several electrical-stimulation parameters with conventional chilling of heavy- and light-grade carcasses from commercial feedlot cattle on selected meat-quality attributes. Aims The aim was to determine the combination of electrical-stimulation parameters that produced the most desirable results in terms of meat quality, which will serve as a guide to processors seeking to enact best processes in the meat industry. Methods Low-voltage electrical stimulation (110 V peak, 17 pulses/s, 5-ms pulse width) was applied either early post-mortem (PM) at 7 min or late PM at 45 min, for either 30 or 60 s on steer carcasses (n = 98) divided into two weight categories (light (≤260 kg) and heavy (≥290 kg) grades). The Longissimus lumborum muscle was evaluated for sarcomere length, myofibril fragment length (MFL), calpain-1, calpastatin, shear force and drip loss (3 and 14 days PM). Key results There were no significant differences in sarcomere length and no sarcomere shortening was observed. There were minor inconsistencies where early stimulation coincided with marginally longer MFL at 3 and 14 days PM, while late stimulation produced the shortest MFL at 14 days PM. Higher decline in calpain-1 concentration (mean 36.2%) was recorded in the early stimulated carcasses compared with the late stimulated carcasses (mean 29.7%) from 1 to 24 h PM, while calpastatin concentration decreased at a similar rate (mean 24%). Early stimulation resulted in lower shear force (P < 0.05) at 3 days PM, especially in the heavier carcasses, indicating that higher initial temperature did accelerate tenderisation. At 14 days PM, there were no significant differences in shear force as regards stimulation time or carcass weight. Higher drip loss was however recorded in the early stimulated carcasses. Conclusions Early application of low-voltage electrical stimulation produced faster tenderisation early PM, due to higher rigor temperature, but, after aging for 14 days, all meat was acceptably tender with a lower variability, regardless of the stimulation time and carcass weight. Higher drip loss was associated with higher tenderness, which is normal and not a defect. Implications The use of low-voltage electrical stimulation should be encouraged for its ability to reduce variability in meat quality due to carcass-weight differences, especially in the current feedlot systems.

Explaining the variation in the shear force of lamb meat using sarcomere length, the rate of rigor onset and pH

Meat Science ◽  
2011 ◽  
Vol 88 (4) ◽  
pp. 794-796 ◽  
Author(s):  
D.L. Hopkins ◽  
E.S. Toohey ◽  
T.A. Lamb ◽  
M.J. Kerr ◽  
R. van de Ven ◽  
...  
Keyword(s):  
Shear Force ◽  
Sarcomere Length ◽  
Lamb Meat

A note on the effects of pre-slaughter housing, diet and sex on responses to post-mortem electrical stimulation in cattle

1984 ◽  
Vol 39 (2) ◽  
pp. 301-304
Author(s):  
J. Jedlička ◽  
J. Mojto ◽  
V. Foltys ◽  
J. Lichtner ◽  
D. Szakáczová ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Good Condition ◽  
Normal Diet ◽  
Processing Plant ◽  
Post Mortem ◽  
Meat Processing ◽  
Basic Requirement ◽  
Ph Values ◽  
Muscle Ph

ABSTRACTEffects of the period of pre-slaughter lairage and diet on responses to post-mortem electrical stimulation (ES) were observed in 113 bulls and 18 cows. The efficiency of ES was assessed by the rate of the decrease of muscle pH. Stimulation was made at 80 V for 45 s. ES significantly decreased pH values at 1 h after slaughter. The effect was greater for animals on a normal diet than for those on a reduced diet. ES was also more effective for animals killed within 2 h after transportation to the meat processing plant than for animals slaughtered 24 h after transportation. There were no significant differences in the effect of ES between sexes. The basic requirement for effective ES is a good condition of animals at slaughter.

scholarly journals Effect of Transportation and Low Voltage Electrical Stimulation on Meat Quality Characteristics of Omani Sheep

2010 ◽  
Vol 15 ◽  
pp. 1
Author(s):  
Isam T. Kadim ◽  
Osman Mahgoub ◽  
Waleed Al-Marzooqi ◽  
Samera Khalaf
Keyword(s):  
Electrical Stimulation ◽  
Meat Quality ◽  
Shear Force ◽  
Sarcomere Length ◽  
Low Voltage ◽  
Quality Characteristics ◽  
Cooking Loss ◽  
Longissimus Dorsi ◽  
Road Transportation ◽  
Fragmentation Index

The aim of this study was to determine the effects of road transportation during the hot season (36 oC) and low voltage electrical stimulation on meat quality characteristics of Omani sheep. Twenty intact male sheep (1-year old) were divided into two equal groups: 3 hrs transported or non-transported. The transported group was transferred to the slaughterhouse the day of slaughter in an open truck covering a distance of approximately 300 km. The non-transported group was kept in a lairage of a commercial slaughterhouse with ad libitum feed and water for 3 days prior to slaughter. Blood samples were collected from the animals before loading and prior to slaughter in order to assess their physiological response to stress in terms of hormonal levels. Fifty percent of the carcasses from each group were randomly assigned to low voltage (90 V) at 20 min postmortem. Muscle ultimate pH, expressed juice, cooking loss percentage, WB-shear force value, sarcomere length, myofibrillar fragmentation index and colour L*, a*, b* were measured on samples from Longissimus dorsi muscles collected 24 hrs postmortem at 2-4 oC. The transported sheep had significantly (P<0.05) higher cortisol adrenaline, nor-adrenaline, and dopamine levels than the non-transported group. Muscles from electrically-stimulated carcasses had significantly (P<0.05) lower pH values, longer sarcomere length, lower shear force value, higher expressed juice, myofibrillar fragmentation index and L* values than those from non-stimulated ones. Transportation significantly influenced meat quality characteristics of the Longissimus dorsi muscle. Muscle ultimate pH and shear force values were significantly higher, while CIE L*, a*, b*, expressed juice and cooking loss were lower in transported than non-transported sheep. This study indicated that pre-slaughter transportation at high ambient temperatures can cause noticeable changes in muscle physiology in sheep. Nevertheless, meat quality of transported sheep can be improved by electrical stimulation post-slaughter. 

Validating the benefits of a medium voltage electrical stimulation unit at an abattoir in Western Australia

2008 ◽  
Vol 48 (7) ◽  
pp. 898 ◽  
Author(s):  
R. H. Jacob ◽  
K. L. Pearce ◽  
N. Smith
Keyword(s):  
Electrical Stimulation ◽  
Western Australia ◽  
Shear Force ◽  
Sarcomere Length ◽  
Quality Parameters ◽  
Eating Quality ◽  
Colour Stability ◽  
Visual Appearance ◽  
Medium Voltage ◽  
Optimal Setting

Two experiments were done following installation of a new generation medium voltage electrical stimulation unit at a commercial lamb abattoir in Western Australia. The first experiment was designed to optimise settings in relation to rate of pH decline post mortem. The second experiment was designed to investigate the eating quality and visual appearance effects of the optimal setting. In the first experiment, nine different settings were compared with a control using 60 lamb carcasses from each of 10 different consignments. The rate of pH × temperature decline was optimal with a pulse width of 2.5 ms and a current of 1.2 A. In the second experiment, 80 lamb carcasses consisting of four carcasses from each of 20 consignments were examined for various eating quality parameters including sarcomere length, shear force, bloom colour and colour stability. Two of the lambs from each consignment were stimulated and two were not stimulated. Stimulation improved compliance with the Sheep Meat Eating Quality (SMEQ) pH × temperature ‘window’ for domestic and frozen product but not for long ship product. Colour was improved by electrical stimulation without changing colour stability. There was a small effect on sarcomere length and no effect of stimulation on shear force measured at day 1 and day 10 after slaughter.

EFFECTS OF POSTMORTEM GLYCOLYSIS ON THE QUALITY OF HOT-DEBONED BOVINE MUSCLE

1990 ◽  
Vol 70 (2) ◽  
pp. 431-439
Author(s):  
H. L. BRUCE ◽  
R. O. BALL
Keyword(s):  
Electrical Stimulation ◽  
Shear Force ◽  
Sarcomere Length ◽  
Low Voltage ◽  
Protein Solubility ◽  
Lactate Concentration ◽  
Muscle Metabolism ◽  
Meat Tenderness ◽  
Sarcoplasmic Protein

Meat tenderness may be improved by accelerating muscle metabolism or by damaging muscle structure and increasing the solubility of muscle proteins. Pre- and postrigor protein and collagen solubilities were measured in semitendinosus muscles, removed pre-rigor from 24 Charolais crossbred steer carcasses, that were either unstimulated or electrically stimulated (115 V, 0.25 amp, 60 Hz) within 1 h postexsanguination to accelerate muscle metabolism. Temperature, pH, Hunterlab color reflectance, sarcomere length and lactate concentration were measured during ageing. Shear force was measured on aged (7 d) muscle only. Low voltage electrical stimulation increased glycolytic rate as indicated by significantly (P < 0.05) lower pH and higher L-lactate concentrations of stimulated muscles as compared to control muscles. Total and sarcoplasmic protein solubilities decreased due to ageing, and myofibrillar protein solubility increased; however, collagen solubilities were unchanged. Low voltage electrical stimulation did not affect color reflectance, sarcomere length or shear force, indicating that an increased rate of glycolysis alone was not sufficient to effect increases in meat tenderness. Key words: Beef, electrical stimulation, meat quality, muscle

scholarly journals Effects of stimulation on tenderness of lamb with a focus on protein degradation

2006 ◽  
Vol 46 (7) ◽  
pp. 891 ◽  
Author(s):  
K. M. Martin ◽  
D. L. Hopkins ◽  
G. E. Gardner ◽  
J. M. Thompson
Keyword(s):  
Electrical Stimulation ◽  
Protein Degradation ◽  
Proteolytic Enzyme ◽  
Shear Force ◽  
Meat Tenderness ◽  
Protein Breakdown ◽  
Structural Protein ◽  
Complete Understanding ◽  
Muscle Ph ◽  
Optimal Ph

Past studies have identified that electrical stimulation systems not only affect the pH–temperature decline of lamb carcasses, but also affect the tenderness of the product. It is unknown whether these differences are due to the effects of an optimal pH–temperature decline path by which the occurrence of shortening is decreased and proteolytic enzyme activity is increased, or by another mechanism, such as disruption of the muscle myofibres. This study attempted to elucidate this by placing control and mid-voltage electrically stimulated samples of the M. longissimus thoracis et lumborum in a water bath to prevent shortening by imposing an even pH–temperature decline on all samples. In order to obtain a complete understanding of the effects of stimulation on the muscle, samples were taken for indicators of tenderness, myofibre degradation and protein breakdown. No effect of stimulation was seen on tenderness and structural degradation measures aside from the expected rapid lowering of muscle pH. Interesting relationships were observed, however, between the different methods of meat tenderness assessment, with muscle structural protein degradation, shear force and muscle fibre and myofibre breakdown comparisons. These results suggest that the effects of electrical stimulation seen in mid-voltage systems as applied in this study are due only to the prevention of shortening conditions.

Effects of low-voltage electrical stimulation and aging on lamb meat quality

2012 ◽  
Vol 92 (1) ◽  
pp. 59-66 ◽  
Author(s):  
E. Pouliot ◽  
C. Gariépy ◽  
M. Thériault ◽  
C. Avezard ◽  
J. Fortin ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Aging Time ◽  
Meat Quality ◽  
Shear Force ◽  
Low Voltage ◽  
Ph Value ◽  
Target Weight ◽  
Lamb Meat ◽  
Fragmentation Index

Pouliot, E., Gariépy, C., Thériault, M., Avezard, C., Fortin, J., Simmons, N. J. and Castonguay, F. W. 2012. Effects of low-voltage electrical stimulation and aging on lamb meat quality. Can. J. Anim. Sci. 92: 59–66. The aim of this study was to evaluate the effect of electrical stimulation (ES) and aging time on meat quality of heavy lamb as produced in Quebec. Seventy-six Suffolk-sired crossbred male lambs were slaughtered at a target weight of 50±2 kg. Half of them were electrically stimulated (ES vs. control) at 5–10 min postmortem (21 V; 0.25 A; 60 s). Postmortem pH decline and temperature were monitored. After carcass cutting, longissimus dorsi sections were assigned to aging periods of 1, 3 or 8 d. Temperature decline was the same for both treatments (P=0.749). However, ES carcasses always had a lower pH value than controls during the first 24 h (P<0.001) while the ultimate pH was equivalent (P=0.803). Tenderness, as assessed by either Warner-Bratzler shear force (39 carcasses) or sensory evaluation (35 carcasses) was enhanced by both ES (P<0.001) and aging (P<0.001). At each aging time, tenderness was greater for ES meat. In addition, only 3 d of aging were necessary for ES meat to achieve the tenderness level attained by the controls after 8 d. Sarcomeres were longer (P<0.001) in ES meat than in controls while myofibrillar fragmentation index was not affected by ES treatment (P=0.743). Electrical stimulation also had small effects on color parameters (a*, b* and L*; P<0.01) and flavor (P=0.04). These results provide the first evidence that tenderness of the meat from heavy lambs produced and processed in Quebec could be enhanced by ES, mostly through cold shortening reduction.

scholarly journals Effect of Post-Mortem Electrical Stimulation on Ovine Sarcoplasmic Reticulum Vesicies

1980 ◽  
Vol 33 (1) ◽  
pp. 43 ◽  
Author(s):  
RK Tume
Keyword(s):  
Electrical Stimulation ◽  
Sarcoplasmic Reticulum ◽  
White Muscle ◽  
Post Mortem ◽  
Steady State Concentration ◽  
High Affinity ◽  
Muscle Ph ◽  
Membrane Phosphorylation ◽  
State Concentration ◽  
Reduced Activity

Sarcoplasmic reticulum (SR) vesicles from ovine skeletal muscle were iodinated with the use of immobilized lactoperoxidase to determine the location of proteins in the membrane and to observe any changes resulting from post-mortem electrical stimulation. The labelling pattern of the nonstimulated SR preparations was essentially the same as that observed previously for white muscle SR of rabbit. Most of the membrane proteins were labelled, except for the high-affinity calciumbinding protein. Electrical stimulation, however, resulted in an increased labelling of calsequestrin suggesting that this protein is more exposed as a result of such treatment. Certain activities of the adenosinetriphosphatase were affected by electrical stimulation. Both the steady-state concentration of phosphoenzyme and the ATP~PI exchange reaction were significantly reduced by electrical stimulation. It is not known if this alteration in the membrane is responsible for the reduced activity of the SR and thus the greater rate of post-mortem pH fall in electrically stimulated muscle. [Other keywords: Membrane phosphorylation, muscle pH, cold-shortening.]

scholarly journals Effects of Early Post-Mortem Rate of pH fall and aging on Tenderness and Water Holding Capacity of Meat from Cull Dairy Holstein-Friesian Cows

2016 ◽  
Vol 5 (2) ◽  
pp. 1 ◽  
Author(s):  
Carlos Santos ◽  
Carlos Moniz ◽  
Cristina Roseiro ◽  
Marina Tavares ◽  
Vera Medeiros ◽  
...  
Keyword(s):  
Aging Time ◽  
Shear Force ◽  
Gluteus Medius ◽  
Meat Industry ◽  
Post Mortem ◽  
Lower Shear ◽  
Holstein Friesian ◽  
Muscle Ph ◽  
Water Holding ◽  
Friesian Cows

Fast or slow muscle pH fall may give unacceptable purge losses or tough meat, depending much on concomitant evolution of muscle temperature early post-mortem, costing millions of euros to the meat industry. Tenderness and purge losses of <em>Longissimus thoracis/lumborum</em> (<em>LTL</em>) and <em>Gluteus medius</em> (<em>Gm</em>) sampled from cull dairy cows differing in production status (10 lactating vs. 22 dried off) and aging time, were evaluated regarding different rates of pH<sub>2</sub> fall. Shear force related to pH<sub>2</sub> was dependent on muscle and aging time. The intermediate glycolysis led to lower shear force in <em>LTL</em>, while the faster produced best quality in <em>Gm</em>. Purge was influenced by pH<sub>2</sub> (P=0.0077), aging (P&lt;0.0001) and muscle*pH<sub>2</sub> interaction (P&lt;0.0001). Aging affected thawing (P&lt;0.0001), grilling (P=0.0004) and overall losses (P&lt;0.0001). Under the ruled chilling regime, the fast pH fall in <em>Gm</em> and the slow pH fall in <em>LTL</em> approached out of the ideal pH6/temperature limits, being compatible with heat and cold shortening, respectively.

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