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.

Use of electrical stimulation and chilling to enhance meat tenderness of heavy lambs

2014 ◽  
Vol 94 (4) ◽  
pp. 627-637 ◽  
Author(s):  
E. Pouliot ◽  
C. Gariépy ◽  
M. Thériault ◽  
F. W. Castonguay
Keyword(s):  
Body Weight ◽  
Electrical Stimulation ◽  
Factorial Design ◽  
Shear Force ◽  
Meat Tenderness ◽  
Fragmentation Index ◽  
Individual Variations ◽  
Temperature Dynamics ◽  
Temperature Window ◽  
Optimal Window

Pouliot, E., Gariépy, C., Thériault, M. and Castonguay, F. W. 2014. Use of electrical stimulation and chilling to enhance meat tenderness of heavy lambs. Can. J. Anim. Sci. 94: 627–637. The aim of this study was to determine if electrical stimulation and chilling can modulate pre-rigor pH–temperature dynamics in order to enhance meat tenderness of heavy lambs produced in Quebec and determine if there is an optimum carcass temperature window to reach pH 6.0. A total of 128 heavy lambs (fasted body weight between 38 and 52 kg) were selected at the abattoir over 8 slaughter days (16 lambs d–1) and assigned to four processing treatments in a 2×2 factorial design: electrical stimulation (ES) or not (NES) and normal (NC) or slow (SC) chilling. Slow-chilled carcasses stayed warmer during the first 12 h postmortem (P<0.001), but reached the same temperature as NC ones thereafter. They also had a lower pH between 2 and 12 h (P<0.05). Stimulated carcasses had a lower pH than NES throughout the first 24 h postmortem (P<0.001), while ultimate pH was similar (P=0.738). Shear force values were improved (P<0.001) by both ES and aging as expected, although chilling had no effect (P=0.400). Stimulation×aging interactions for shear force values (P=0.019) and myofibrillar fragmentation index (P=0.097) indicate that aging began earlier following ES. Sarcomeres were longer for ES compared with NES carcasses (P<0.001) indicating that the latter were subject to cold shortening. Meat from NES carcasses was more prone to be tough, although an important part of NES carcasses provided tender meat. This illustrates the importance of individual variations on tenderness and the multiplicity of factors involved in its development. No optimal window was observed for temperature at pH 6.0.

scholarly journals Influence of ultrasound and proteolytic enzyme inhibitors on muscle degradation, tenderness, and cooking loss of hens during aging

2012 ◽  
Vol 30 (No. 3) ◽  
pp. 195-205 ◽  
Author(s):  
G.-Y. Xiong ◽  
L.-L. Zhang ◽  
W. Zhang ◽  
J. Wu
Keyword(s):  
Group Treatment ◽  
Proteolytic Enzyme ◽  
Shear Force ◽  
Enzyme Inhibitors ◽  
Proteolytic Enzymes ◽  
Treated Group ◽  
Cooking Loss ◽  
Potential Contribution ◽  
Meat Tenderness ◽  
Endogenous Proteases

The potential contribution of mechanical disruption by ultrasonics and endogenous proteolytic enzymes on the tenderisation of hen muscle were investigated. The importance of endogenous enzymes was evaluated using various specific inhibitors. Freshly obtained breast muscles of culled hens, from the 6 groups investigated were treated with different proteolytic enzyme inhibitors and/or ultrasonics, group was treated with different methods, and then stored at 4&deg;C for 0, 1, 3, and 7 days. Shear force decreased by 1.19 kg, and shear force and cooking loss were reduced by 0.69&nbsp;kg and 4.27%, respectively, in the incorporated group treatment. The calpastatin activity was affected by all treatments except in the Z-DEVD-fmk-treated group, caspase-3 activity decreased in Z-DEVD-fmk-treated group. Therefore, the results suggest that ultrasonics and endogenous proteases contributed to muscle degradation, thereby improving hen meat tenderness and decreasing the cooking loss. Thus muscle degradation, tenderness, and water-retaining properties of hens were improved by a combination of ultrasound and exogenous proteolytic enzyme inhibitors. &nbsp;

scholarly journals Comparison of different meat tenderization methods: a review

Food Research ◽  
2019 ◽  
Vol 4 (3) ◽  
pp. 571-577 ◽  
Author(s):  
Y. Woinue ◽  
A. Ayele ◽  
M. Hailu ◽  
R.S. Chaurasiya
Keyword(s):  
Electrical Stimulation ◽  
Proteolytic Enzyme ◽  
Economic Value ◽  
Meat Products ◽  
Quality Parameters ◽  
Meat Industry ◽  
Meat Tenderness ◽  
Mechanical Method ◽  
Meat Tenderization ◽  
Cooking Times

Meat tenderness is one of the quality parameters that affect the tough muscle and changes into soft meat, which is characterized by, increased the palatability, juiciness, and flavor of the meat, the process is known as meat tenderization. According to literature reports, meat can be tenderized by using different methods. The tenderize meat gives rise to customer satisfaction and repeated buyers that improve the value of the meat industry as well as the restaurants. The most widely used methods for tenderization of meat are mechanical, electrical stimulation, application of exogenous proteolytic enzyme, and thermal treatment methods. All these methods result in tenderization of meat that reduces the cooking times, hardness of meat and chewiness of meat products, that can increase meatiness, flavor, and overall palatability. Therefore, an attempt has been made to review the different meat tenderization methods concerning their effectiveness, economic value, and mode of action. The toughness of the meat is reduced during mechanical method by disrupting the structure of the meat and weakening the protein network in muscles. Whereas, in case of enzymatic treatment tenderization is achieved by hydrolyzing the meat protein, which reduces the bonding between muscles and results in softening of the meat.

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

The influence of chilling rate and fat cover on beef quality

2001 ◽  
Vol 81 (3) ◽  
pp. 321-330 ◽  
Author(s):  
J. L. Aalhus ◽  
J. A. M. Janz ◽  
A. K. W. Tong ◽  
S. D. M. Jones ◽  
W. M. Robertson
Keyword(s):  
Electrical Stimulation ◽  
Meat Quality ◽  
Shear Force ◽  
Backfat Thickness ◽  
Meat Tenderness ◽  
Beef Quality ◽  
Wide Range ◽  
Average Shear ◽  
Longissimus Lumborum

The economic advantages of rapid carcass chilling include reduced cooling time, increased carcass processing rate, and decreased shrink and drip losses; however, it may also reduce subsequent meat tenderness, especially in lean carcasses. The present study examined the effects of blast chilling and electrical stimulation on quality of longissimus lumborum (LL) and semimembranosus muscles from carcasses with a wide range in backfat thickness (0 to 69 mm). Despite promoting a wide range in postmortem pH and temperature decline, backfat thickness had a limited effect on meat quality. There was a decrease in the proportion of carcasses with very high (>35 N cm–2) shear values and a tendency (P = 0.12) for the average shear force to decrease in the LL as backfat depth increased. Unexpectedly, leaner carcasses had less shrink loss than fatter carcasses under blast chill conditions. While blast chilling resulted in slightly darker, tougher meat, electrical stimulation was able to reduce these effects. Neither early postmortem pH nor temperature at 10 h was clearly associated with a pattern in shear force, although high pH10 was associated with tough steaks. Blast chilling in combination with electrical stimulation can be recommended to industry as a means to reduce chilling times and shrink losses while producing meat quality that is as good as, or slightly superior to conventionally cooled carcasses. Key words: Beef quality, blast chilling, electrical stimulation, fat thickness

Meat tenderness and palatability of Swamp buffalo and four breeds of cattle

1982 ◽  
Vol 34 (1) ◽  
pp. 79-84 ◽  
Author(s):  
D. D. Charles
Keyword(s):  
Shear Force ◽  
Intramuscular Fat ◽  
Taste Panel ◽  
Carcass Weight ◽  
Quality Traits ◽  
Meat Tenderness ◽  
Feeding Regime ◽  
Muscle Ph ◽  
Swamp Buffalo

ABSTRACTSamples of cooked muscle of Swamp buffalo, Hereford, Angus, Friesian and Charolais cross steers were sheared and scored by a taste panel for tenderness, flavour, juiciness and palatability. The cattle were given commercial pellets from 9 months of age to slaughter at 12,15 and 18 months. The buffaloes were fed one of four regimens: all pellets, all hay, 3/4 pellets and 1/4 hay or 1/4 pellets and 3/4 hay from 13 to 22 months of age to slaughter at 20 to 34 months.There was little difference between the buffaloes and the cattle in shear-force or taste panel scores. Age at slaughter had no significant effect on the quality traits measured in either the buffaloes or the cattle. The feeding regime did not influence the tenderness, flavour or palatability of buffalo muscle but the high pellet diets increased juiciness.Shear-force was not influenced by rectal or muscle temperatures, muscle pH, carcass weight or fatness in the buffaloes but fatness reduced shear-force in cattle m. longissimus.Buffalo intramuscular fat increased with age and carcass fatness but had no effect on shear-force or taste panel score.

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.

scholarly journals The beef tenderness model

1970 ◽  
Vol 45 (3) ◽  
pp. 234-248 ◽  
Author(s):  
L Frylinck ◽  
A O'Neil ◽  
E Du Toit ◽  
PE Strydom ◽  
EC Webb
Keyword(s):  
Electrical Stimulation ◽  
Connective Tissue ◽  
Shear Force ◽  
Production Systems ◽  
Drip Loss ◽  
Meat Tenderness ◽  
Phase 2 ◽  
Proteolytic System ◽  
Beef Tenderness ◽  
Feed Withdrawal

In Phase1 of this study, three breed types (Simmentaler-, Brahman- and Nguni bulls; n = 60 each) were grain-fed and slaughtered at 12 months of age (A-age, fat-class 2). Feed was withdrawn for either three hours or 24 hours pre-slaughter. Within each feed withdrawal group, three electrical stimulation (ES) treatments were applied, viz. ES for 15 seconds, 120 seconds or no stimulation. In Phase 2, the effects of animal age and feeding regime were investigated using of A-age (feedlot and pasture), AB-age (feedlot and pasture) and B-age (pasture) animals. All carcasses were electrically stimulated for 15 seconds. Longer feed withdrawal increased dark-firm-dry (DFD) meat occurrence (pHu >6) in the Nguni and Simmentaler-cross. Brahman-cross longissimus (LL) tended to be more tender with paler colour and higher drip loss when 120 ES was applied. Longer feed withdrawal recorded higher Warner Bratzler shear force (WBSF) than three hour feed withdrawal. However, ES neutralized the effect of stress on tenderness. On average the AB-age feedlot animals produced the most tender LL followed by the B-age pasture and A-age feedlot which was similar to the AB-age pasture. A-age pasture animals produced the least tender LL steaks. The calpain proteolytic system played a pivotal role in determining the ultimate meat tenderness and although connective tissue becomes less soluble in older animals it did not play the determinant role in tenderness in this study. The intramuscular fat (< 3%) played an important role in the tenderness outcome of Nguni LL which marbled well at AB-age.Keywords: Meat tenderness, pH and temperature decline profile, pre- and post-slaughter conditions, production systems

scholarly journals Sources of variation in mechanical shear force measures of tenderness in beef from tropically adapted genotypes, effects of data editing and their implications for genetic parameter estimation

2001 ◽  
Vol 41 (7) ◽  
pp. 991 ◽  
Author(s):  
D. J. Johnston ◽  
A. Reverter ◽  
D. L. Robinson ◽  
D. M. Ferguson
Keyword(s):  
Electrical Stimulation ◽  
High Voltage ◽  
Shear Force ◽  
Low Voltage ◽  
Genetic Parameter ◽  
Residual Variance ◽  
Meat Tenderness ◽  
Beef Tenderness ◽  
Sources Of Variation ◽  
Stimulation Method

Warner-Bratzler shear force measures of tenderness were taken on 2 muscles from 2661 carcasses from 3 tropically adapted breeds: Belmont Red, Brahman and Santa Gertrudis. The data were used to determine suitable methods of editing the raw data and to partition sources of variation for meat tenderness measured in 2 different muscles. The effect of different methods of electrical stimulation was examined: non-stimulated, extra low voltage or high voltage. The results showed stimulation method had a large effect on the mean and variance of the shear force. Non-stimulated slaughter groups were more variable than high voltage treated groups, which were more variable than low voltage treated groups. The effect of stimulation method was greater for shear force measured in M. longissimus dorsi than in M. semitendinosus. The variability in tenderness associated with different methods of electrical stimulation and the larger effect seen for the M. longissimus muscle suggest cold shortening, a processing effect, may have occurred in some of the slaughter groups. Several methods of editing outlier records were used and the effects of removing these records on the partitioning of variances among the independent variables of tenderness were examined. Removal of non-stimulated slaughter groups and other outliers resulted in a large reduction in slaughter group variance and residual variance, with the estimate of heritability for shear force of the M. longissimus increasing from 19 to 39%. Beef tenderness, as measured mechanically, could be improved by selection. However, the fluctuating heritability estimates reflect differences in handling pre- and post-slaughter and thus highlight difficulties in measuring tenderness consistently. The low genetic correlation between the 2 muscles (r g = 0.34) suggests improving overall tenderness of the carcass may be difficult. The large variance of the slaughter date effect within an abattoir (15% of the total variance) presents a problem in achieving consistently tender meat.

The combined effects of time on feed, electrical stimulation and aging on beef quality

1992 ◽  
Vol 72 (3) ◽  
pp. 525-535 ◽  
Author(s):  
J. L. Aalhus ◽  
S. D. M. Jones ◽  
A. K. W. Tong ◽  
L. E. Jeremiah ◽  
W. M. Robertson ◽  
...  
Keyword(s):  
Quality Control ◽  
Electrical Stimulation ◽  
Combined Effects ◽  
Consumer Survey ◽  
Beef Quality ◽  
Muscle Ph ◽  
Consumer Ratings ◽  
Postmortem Aging ◽  
Fat Thickness ◽  
Production Practices

Two experiments were conducted to determine the combined effects of time on feed, high-voltage electrical stimulation (HVES) and postmortem aging on beef quality and palatability. Increasing time on feed resulted in an increase in carcass fat thickness, dressed carcass weight and marbling and a decrease in carcass lean content, carcass shrinkage and shear values in both experiments. Steaks from longer-fed animals were rated more highly for juiciness, tenderness and overall palatability by the consumers polled. HVES lowered muscle pH (3, 24 and 144 h), increased subjectively appraised marbling fat, gave brighter, redder muscle colour up to 6 d postmortem, and improved consumer ratings for flavour, juiciness, tenderness and overall palatability. HVES also resulted in a significant improvement in shear values (shear values were decreased by 27 and 35% in experiments 1 and 2, respectively). Aging for 6 d improved meat colour, decreased the amount of expressible juice and lowered the shear value of steaks by 11 and 9% respectively, in experiments 1 and 2. A consumer survey indicated that more than 20% of steaks were rated as unacceptable for tenderness when time on feed and postmortem aging were similar to Canadian beef-production practices. Incorporation of HVES as a means of quality control would reduce the proportion of unacceptable steaks to approximately 10%. Key words: Beef quality, time on feed, electrical stimulation, aging

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