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

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.

2019 ◽  
Vol 3 (2) ◽  
Author(s):  
C. Fehrman ◽  
K. Grubbs ◽  
K. Underwood ◽  
A. Blair

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.


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 ◽  
...  

2020 ◽  
Vol 60 (7) ◽  
pp. 967
Author(s):  
E. C. Webb ◽  
B. Agbeniga

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.


1980 ◽  
Vol 45 (1) ◽  
pp. 144-145 ◽  
Author(s):  
D. G. TAYLOR ◽  
A. R. MARSHALL

Foods ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1587
Author(s):  
Archana Abhijith ◽  
Frank R. Dunshea ◽  
Robyn D. Warner ◽  
Brian J. Leury ◽  
Minh Ha ◽  
...  

The current study is a meta-analysis of the effects of electrical stimulation (ES, n = 28 papers) with different voltages combined with different ageing periods (0–3, 4–7, and 8–14 days) on the meat quality of small ruminants. A comprehensive search for published studies on meat quality of small ruminants investigating the application of low, medium, and high voltage electrical stimulation, was performed using Google Scholar, ScienceDirect, PubMed, and Scopus databases. Forest plots, funnel plots, and other statistical tools and tests were used in the study to analyze the results. Electrical stimulation significantly reduced ultimate pH (p < 0.001), Warner–Bratzler shear force (WBSF) (p < 0.001), cooking loss (p < 0.05), and purge loss (p < 0.001). In addition, sarcomere length (p < 0.01), myofibrillar-fragmentation index (MFI) (p < 0.001), and color (L*, a*, b*) (p < 0.001) showed higher values in meat subjected to ES as compared with the control group. In conclusion, the meta-analysis revealed statistical proof of beneficial effects of ES on meat quality of small ruminants in terms of ultimate pH, tenderness, enhanced proteolysis, and higher colorimetric values.


Author(s):  
Isam T. Kadim ◽  
Osman Mahgoub ◽  
Waleed Al-Marzooqi ◽  
Samera Khalaf

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. 


2005 ◽  
Vol 45 (5) ◽  
pp. 553 ◽  
Author(s):  
R. D. Warner ◽  
D. M. Ferguson ◽  
M. B. McDonagh ◽  
H. A. Channon ◽  
J. J. Cottrell ◽  
...  

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.


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