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.

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.

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 &lt; 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.

scholarly journals Carcass characteristics and meat quality of once-calved heifers

1991 ◽  
Vol 71 (2) ◽  
pp. 311-319 ◽  
Author(s):  
B. C. Vincent ◽  
S. D. M. Jones ◽  
L. E. Jeremiah ◽  
J. A. Newman ◽  
M. A. Price
Keyword(s):  
Electrical Stimulation ◽  
Connective Tissue ◽  
Meat Quality ◽  
Quality Parameters ◽  
Eating Quality ◽  
Consumer Acceptability ◽  
Meat Tenderness ◽  
Aging Period ◽  
Trained Panel

Three groups of once-calved (OCH) heifers were slaughtered following the weaning of their calves at 3 (OCH3, n = 32), 5 (OCH5, n = 33) and 7 (OCH7, n = 31) months postcalving. A fourth group of heifers was fed a silage/grain diet and slaughtered at 15 mo of age (C, n = 32). Alternate sides of each carcass were electrically stimulated (ES) at 475 volts for 1 min (20 pulses m−1, 60 Hz) at 45 min post-stunning. All left sides were dissected into fat, lean and bone and meat quality parameters recorded. Rib eye steaks were evaluated for palatability by a trained panel and for consumer acceptability after an aging period of 6 d. All OCH groups produced heavier carcasses with a higher level of marbling than the C group after adjustment of the data to a constant proportion of carcass fatness, but the proportional yields of lean and bone tissue were similar for all heifer groups. OCH groups produced meat that was darker with a lower drip loss and higher 45 min and 6 d pH than the C group. Consumer acceptability of rib eye steaks was similar for all heifer groups, but the OCH7 (oldest) group had a higher amount of connective tissue when evaluated by a trained panel than other heifer groups. Taste panel evaluations showed that ES increased meat tenderness and overall palatability and reduced the amount of connective tissue when compared to meat from unstimulated carcasses. ES also increased the consumer acceptability of tenderness by 14.3%, flavor by 5.6%, juiciness by 5.2% and overall palatability by 6.7% over meat from unstimulated carcasses. It was concluded that once-calved heifers could produce heavier carcasses of similar composition and meat with similar eating quality to conventionally managed nonpregnant feedlot heifers. Electrical stimulation improved the consumer acceptability of meat primarily through an improvement in meat tenderness. Key words: Beef, carcass, electrical stimulation, meat quality, once-calved heifers

Case studies demonstrating the benefits on pH and temperature decline of optimising medium-voltage electrical stimulation of lamb carcasses

2010 ◽  
Vol 50 (12) ◽  
pp. 1107 ◽  
Author(s):  
K. L. Pearce ◽  
R. van de Ven ◽  
C. Mudford ◽  
R. D. Warner ◽  
J. Hocking-Edwards ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Current Approach ◽  
Random Regression ◽  
Eating Quality ◽  
Medium Voltage ◽  
Sheep Meat ◽  
Random Regression Model ◽  
Optimum Ph ◽  
Temperature Window ◽  
Stimulation System

The efficacies of electrical stimulation practices at Australian abattoirs that process significant proportions of Australian lamb and sheep meat were assessed. Several abattoirs used medium-voltage electrical stimulation system (MVS) units suboptimally and many carcasses at these abattoirs exhibited a poor rate of pH decline and, consequently, a low proportion of carcasses attained pH 6 at a carcass temperature of 18−35°C, according to Sheep Meat Eating Quality pH–temperature guidelines as adopted by Meat Standards Australia. In the present communication, we describe the causes of suboptimal results with electrical stimulation and discuss procedures for optimising the stimulation dose delivered by MVS units. Carcass pH responses to various levels of current and pulse width were assessed to determine the best MVS settings for individual abattoirs. The MVS units at the abattoirs involved in the present study have now been programmed for optimal efficacy and carcass quality will be monitored on an ongoing basis. Evaluation of methods for assessing the proportion of carcasses that fall within the optimum pH–temperature window showed that a random regression model is more accurate than the current approach.

The effect of lairage time on consumer sensory scores of the M. longissimus thoracis et lumborum from lambs and lactating ewes

2005 ◽  
Vol 45 (5) ◽  
pp. 535 ◽  
Author(s):  
R. H. Jacob ◽  
P. J. Walker ◽  
J. W. Skerritt ◽  
R. H. Davidson ◽  
D. L. Hopkins ◽  
...  
Keyword(s):  
Western Australia ◽  
Sarcomere Length ◽  
Intramuscular Fat ◽  
Primary Effect ◽  
Eating Quality ◽  
Fat Percentage ◽  
Age Class ◽  
Hue Angle ◽  
Carry Over

The aim of this study was to determine whether lairage time influenced consumer sensory scores of the eating quality of lamb and mutton. Commercial consignments of lambs and ewes were subjected to 3 different lairage periods (slaughter on arrival, slaughter after 1 day or slaughter after 2 days in lairage) at one site in Victoria (experiment 1) and another site in Western Australia (experiment 2). In experiment 1, 3 sucker and 3 carry-over lamb consignments, each consisting of 36 lambs, were sourced from a public saleyard. In experiment 2, 3 ewe and 3 lamb consignments, each consisting of 150 animals were sourced directly from the farm of origin. There was no primary effect of lairage time on consumer sensory scores of the M. longissimus et lumborum from either lambs or ewes at the 2 locations. Sucker lambs were tenderer than carry-over lambs in experiment 1. There was an interaction between age class and lairage time for tenderness in experiment 2, such that lamb meat was tenderer than ewe meat when slaughtered after 1 day in lairage. Ewes produced loins with shorter (0.6 µm, P<0.05) sarcomere length, higher (4.9%, P<0.05) intramuscular fat percentage and darker (P<0.05) meat colour compared with those from sucker lambs. Hue angle was higher (2°, P<0.01) for meat from sheep killed after 1 day in lairage compared with meat from sheep killed on arrival or after 2 days in lairage in both experiments.

Effect of medium voltage electrical stimulation and prior ageing on beef shear force during superchilled storage

Meat Science ◽  
2021 ◽  
Vol 172 ◽  
pp. 108320
Author(s):  
Xianqiu Ji ◽  
Xin Luo ◽  
Lixian Zhu ◽  
Yanwei Mao ◽  
Xiao Lu ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Shear Force ◽  
Medium Voltage

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. 

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.

Sire and growth path effects on sheep meat production. 2. Meat and eating quality

2007 ◽  
Vol 47 (10) ◽  
pp. 1219 ◽  
Author(s):  
D. L. Hopkins ◽  
D. F. Stanley ◽  
E. S. Toohey ◽  
G. E. Gardner ◽  
D. W. Pethick ◽  
...  
Keyword(s):  
Shear Force ◽  
Sarcomere Length ◽  
Subcutaneous Fat ◽  
Eating Quality ◽  
Meat Production ◽  
Growth Path ◽  
Treatment Groups ◽  
Sheep Meat ◽  
Australian Sheep ◽  
The Impact

The meat and eating quality characteristics of 627 crossbred lamb progeny from 20 Poll Dorset sires were studied. The sires were selected on the basis of Australian sheep breeding values (ASBVs) for postweaning growth (PWWT), depth of loin muscle (PEMD) and subcutaneous fat (PFAT). Lambs were either weaned at 20- or 30-kg liveweight and then within each of these groups held at their weaning weight for 55 days or fully fed, giving four treatment groups. Restricted lambs were realimentated subsequent to the period of feed restriction and the lambs within each treatment group were slaughtered when their mean liveweight reached 45 kg.Shear force of the M. longissimus thoracis et lumborum (LL) decreased with temperature at pH 6.0, increased with LL ultimate pH and decreased as sarcomere length increased. Within LL aged for 5 days there was no difference between (P > 0.05) between treatments for shear force. There was a treatment effect on M. semimembranosus (SM) shear force, such that for a sire having an average ASBV PWWT of 9.34, topsides from lambs early weaned and restricted had significantly (P < 0.05) lower values. Further within these same lambs, i.e. early weaned and restricted, as the sire ASBV PWWT increased there was a significant (P < 0.001) reduction in shear force. There was a significant (P < 0.05) increase in sensory tenderness as the sire ASBV PFAT increased and across the range of ASBV PFAT this represented a change in sensory tenderness of four points. Overall liking increased with an increase in the temperature at pH 6.0 (P < 0.05) with a coefficient of 0.43 ± 0.19. There was a significant (P < 0.05) interaction between feeding level and the sire ASBV PFAT, such that for restricted fed lambs overall liking increased as the ASBV PFAT increased (coefficient 2.80 ± 0.89) after adjusting for temperature at pH 6.0, but this is not the case for fully feed lambs (coefficient –0.01 ± 0.89). Subtle interactions between sire ASBVs and growth path suggest that the impact of a period of restriction and refeeding on meat and eating quality will be meditated by the sire genetics.

scholarly journals Effects of additional electrical stimulation and pre-rigor conditioning temperature on the ageing potential of hot-boned bovine muscles

2020 ◽  
Vol 33 (10) ◽  
pp. 1642-1655
Author(s):  
Prabhu Balan ◽  
Mustafa M. Farouk ◽  
Maryann Staincliffe ◽  
Adam D Stuart ◽  
Robert Kemp ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Meat Quality ◽  
Shear Force ◽  
Quality Parameters ◽  
Conditioning Temperature ◽  
Longissimus Lumborum ◽  
The Impact ◽  
Water Holding ◽  
Holding Temperature

Objective: The aim of this study is to characterize the impact of additional electrical stimulation (AES) and various pre-rigor holding temperatures (for 3 h) on the ageing-potential of hot boned bovine M. longissimus lumborum (LL).Methods: Paired LL loins from 12 bulls were hot-boned within 40 min of slaughter, immediate AES applied and subjected to various holding temperatures (5°C, 15°C, 25°C, and 35°C) for 3 h.Results: AES did not accelerate the rate of rigor attainment, but the 3 h pre-rigor holding temperature did. Shear force values decreased as the pre-rigor holding temperatures increased. AES and holding for 3 h (at 25°C) resulted in higher water-holding capacity.Conclusion: Data confirmed that AES did not influence the various meat quality parameters in the present study, but pre-rigor holding temperature (25°C) alone or in combination with AES resulted in superior meat quality.

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