Effect of electrical stimulation and hot boning on the eating quality of Gannan yak longissimus lumborum

Meat Science ◽  
2016 ◽  
Vol 112 ◽  
pp. 3-8 ◽  
Author(s):  
Yumiao Lang ◽  
Kun Sha ◽  
Rui Zhang ◽  
Peng Xie ◽  
Xin Luo ◽  
...  
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

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


2005 ◽  
Vol 45 (5) ◽  
pp. 499 ◽  
Author(s):  
D. L. Hopkins ◽  
P. J. Walker ◽  
J. M. Thompson ◽  
D. W. Pethick

The effect of type of lambs and hoggets on eating quality was evaluated using the M. longissimus lumborum (LL) and the M. biceps femoris (BF) from 210 animals. The animals comprised 7 types as follows: Poll Dorset or White Suffolk × (Border Leicester × Merino) (second cross unweaned lambs, mixed sex, 3–5 months of age); Poll Dorset × (Border Leicester × Merino) (second cross weaned lambs, mixed sex, 9–12 months of age); Border Leicester × Merino (BLM; first cross weaned lambs, mixed sex, 9 months of age); Poll Dorset or White Suffolk × Merino (PDM; first cross weaned lambs, wethers, 12 months of age); Merino × Merino (weaned wether lambs, 9–12 months of age); Border Leicester × Merino (BLM; first cross hoggets, mixed sex, 20 months of age); and Poll Dorset or White Suffolk × Merino (PDM; first cross hoggets, wethers, 16 months of age). The animals were sourced from a number of different properties in New South Wales (NSW) (n = 120) and Victoria (n = 90). Each carcass was subjected to high voltage stimulation (700 V) within 1 h of slaughter. All meat was aged for 5 days before freezing and was subsequently tested by consumers on a 0–100 scale for a number of attributes after cooking using a grilling procedure. The LL from sucker lambs had the lightest colour (highest L* values) with the hoggets having the darkest colour in the NSW group with differences less apparent in the Victorian group. Muscle from first cross and Merino weaned lambs had consistently higher pH levels across the 3 muscles tested (LL; M. semimembranosus; M. semitendinosus) for the NSW group with no differences detected in the Victorian group. LL meat from second cross sucker and first cross (BLM and PDM) weaned lambs had the highest overall liking score, with that from second cross weaned lambs, BLM hoggets and Merino lambs scored as intermediate, while meat from the PDM hogget group had the lowest overall liking score. A similar outcome was found for the other sensory attributes with differences between types being lower for juiciness compared with overall liking scores but they were of a similar ranking. For the BF there was some re-ranking of the overall liking scores compared with the LL, with meat from suckers and first cross PDM lambs and hoggets being intermediate in score while second cross weaned lambs and first cross BLM lambs had the highest scores. The BF from hoggets (BLM) and Merino lambs were given the lowest scores. The lower juiciness score for sucker BF contributed to this change in ranking compared with the LL.


1985 ◽  
Vol 65 (3) ◽  
pp. 603-612 ◽  
Author(s):  
Z. J. HAWRYSH ◽  
F. H. WOLFE

The quality characteristics of semitendinosus (ST) and longissimus dorsi (LD) roasts from 18 young and 6 mature cow carcasses subjected to low-voltage (110 V) electrical stimulation (ES) were determined. ES was applied for either 4 min or 5 min. Evaluations were conducted on meat obtained from young control sides (no ES) aged 48 h, from young and mature ES sides aged 48 h and from mature ES sides, aged 7 days. Data obtained from mature control sides (no ES), aged 48 h and 7 days, reported in a previous study, served as a reference point for mature ES meat. ES caused a reduction (P < 0.01) in pH values 1 and 4 h postmortem. At 24 h, the pH of ST and LD muscles from control and ES carcasses were similar. Cooking losses of roasts were not affected by ES, ES duration or increased aging. Trained panelists detected no significant effects of ES, ES duration or aging time on palatability. Consumer panel judgements of ST roasts were similar to those of the trained judges. Data from instrumental measurements of juiciness (water-holding capacity), tenderness (OTMS) and softness (penetrometer) for ST and LD roasts support sensory results. These studies show no differences in cooking and eating quality of ST and LD roasts attributable to low voltage ES. The palatability of meat from mature ES carcasses was judged to be similar to that of comparable meat from young control carcasses. For meat from young carcasses, there was no advantage in increasing ES duration. In addition, roasts from mature ES carcasses aged for either 48 h or 7 days were similar. Key words: Low voltage electrical stimulation, cow carcasses


1990 ◽  
Vol 50 (2) ◽  
pp. 291-299 ◽  
Author(s):  
E. Dransfield ◽  
G. R. Nute ◽  
B. W. Hogg ◽  
B. R. Walters

ABSTRACTCarcass and meat composition and eating quality of m. longissimus lumborum (LI) and leg joints were compared in entire male (ram), castrated male (wether) and female (ewe) Dorset Down-cross and Suffolk-cross lambs at about 20 weeks old. Rams grew faster than wethers and ewes particularly in the earlier maturing Suffolk crosses. Carcass weights ranged from 13 to 24 kg and at the mean carcass weight of 17·7 kg ram carcasses yielded larger shoulder joints. Ram carcasses were assessed visually leaner than those from the other sexes with similar conformation scores. Dorset Down carcasses tended to be fatter than Suffolk carcasses and the leanest carcasses were from Suffolk rams. Intramuscular fatness in LI was similar in all sexes. Intramuscular collagen contents were higher in ram LI than in other sexes. There were no differences in protein content, pH or colour of raw or roast LI. In assessments of eating quality of LI by triangle tests, male and female assessors differentiated twin rams and wethers equally. Category scaling showed LI from ewes to be slightly tougher than those from rams and wethers. Consumer evaluation of leg joints did not detect any differences in odour due to sex and ram meat was assessed better than that from wethers or ewes.


Author(s):  
Z Pietrasik ◽  
Phyllis J Shand

Abstract Several muscles from mature beef carcasses have been identified as failing to provide adequate tenderness required for a satisfactory consumer eating experience. Postmortem processing strategies can help improve the tenderness and subsequent eating quality of mature beef muscles. The current study was undertaken to investigate the impact of processing strategies (blade tenderization [BT], pre-tumbling [PT], and moisture enhancement [ME]), alone and in combination, on processing yield and eating quality-related parameters of selected loin and hip muscles (gluteus medius [GM], longissimus lumborum [LL], semimembranosus [SM], and biceps femoris [BF]) from youthful and mature beef cattle. Results indicate that muscles from mature beef were inherently less tender (P &lt; 0.05), but some tenderization procedures produced meat that was similar in tenderness to that of youthful cattle. Of the different tenderization strategies evaluated, BT followed by ME (injection of a salt/phosphate solution) was the most effective strategy for improving (P &lt; 0.05) tenderness of tougher muscle cuts such as BF and SM. Moisture enhancement alone improved tenderness (P &lt; 0.05) and juiciness (P &lt; 0.01) of SM, GM and LL, but with the exception of samples tenderized prior to injection, was not effective (P &gt; 0.05) in BF muscles. No additional tenderization of GM and LL samples was observed (P &gt; 0.05) by combining PT or BT with ME. Combining PT or BT with ME; however, was effective (P &lt; 0.05) to control the increased purge loss observed following ME treatment in SM and LL muscles. Pre-tumbling as a single treatment was ineffective (P &gt; 0.05) in all of the muscles, and only treatments that included BT were sufficient to affect an increase (P &lt; 0.05) in tenderness of BF.


2019 ◽  
Vol 3 (2) ◽  
Author(s):  
B. Hawryluk ◽  
P. Ramos ◽  
D. Johnson ◽  
M. Elzo ◽  
C. Carr ◽  
...  

ObjectivesHeat shock proteins (HSP) are biomarkers of stress and perform chaperoning functions to fold, unfold, and refold proteins after heat stress. Brahman are more heat tolerant than Angus, while Angus beef has been associated with greater palatability than Brahman. The objectives were to determine if HSP content in the longissimus lumborum differs between Angus and Brahman and examine how HSP content relates to the eating quality of beef.Materials and MethodsAngus and Brahman steers (n = 12 per breed) were finished during summer in Florida and harvested at approximately 17 mo of age. Samples of longissimus lumborum were collected at 1 h after exsanguination and were immediately immersed in liquid nitrogen. Samples were then pulverized, diluted in extraction buffer, and homogenized. The protein samples were assayed to assess protein concentration and subsequently diluted to equal concentrations for loading into acrylamide gels. Proteins were separated by gel electrophoresis, and western blotting was used to evaluate content of aβ-crystallin, HSP27, HSP60, HSP70, and HSP90. Target bands were detected and quantified using LI-COR Odyssey and target signal was normalized to total protein stain. Tenderness was evaluated in 14d-aged steaks using Warner-Bratzler shear force (WBSF) and a trained sensory panel. Data were analyzed using one-way ANOVA and Pearson correlations were conducted for content of HSPs and objective and subjective tenderness.ResultsHSP27, HSP60, and HSP70 did not differ between breeds (P > 0.05); however, HSP90 and aβ-crystallin were greater (P = 0.005) in the longissimus lumborum of Angus compared to Brahman. Even though WBSF did not differ (P = 0.29) between breeds, breed affected (P < 0.0001) sensory tenderness. Content of aβ-crystallin was associated with sensory tenderness (r2 = 0.52, P = 0.0098).ConclusionLongissimus dorsi from the Angus were contained more aβ-crystallin and HSP90 than Brahman. Elevated concentrations of both aβ-crystallin and HSP90 could be breed related or may have been influenced by the season they were harvested. While WBSF was not affected by breed, panelists rated Angus steaks as more tender after aging for 14d. Content of aβ-crystallin is associated with tenderness; however further work is necessary to determine if this small HSP affects proteolysis.


2019 ◽  
Vol 59 (2) ◽  
pp. 384 ◽  
Author(s):  
D. T. Packer ◽  
G. H. Geesink ◽  
R. Polkinghorne ◽  
J. M. Thompson ◽  
A. J. Ball

The Meat Standards Australia beef-grading model applies a variable adjustment for different cuts of hormonal growth promotant (HGP)-treated carcasses, but does not differentiate between different HGP types. Using 300 non-implanted Bos indicus–Bos taurus composite steers, an experiment was conducted to compare the effects of an oestradiol only (OES) and a combination trenbolone acetate and oestradiol (TBA+OES) implant with non-implanted animals (CON) fed a concentrate ration for 73 days before slaughter, on eating quality of the mm. longissimus lumborum (LL) and gluteus medius (GM) muscles. Sensory and objective LL and GM samples were aged for either 5 or 35 days before freezing at −20°C. Carcass weights from each group were significantly (P &lt; 0.05) different. Corrected for carcass weight, HGP treatment had a significant effect on hump height, ossification score, marble score, P8 fat depth and eye-muscle area. The TBA+OES treatment resulted in significantly (P &lt; 0.05) tougher meat than the OES and CON treatments as assessed by shear force, although this difference was reduced with aging. Sensory scores (tenderness, juiciness, like flavour, overall liking and a composite MQ4 score) confirmed a negative HGP treatment effect, whereby TBA+OES was significantly lower than the CON and OES treatments after 5 days of aging, and these differences were reduced through aging. TBA+OES had a greater impact on sensory scores in the LL when compared to the GM. Both HGP treatments increased calpastatin activity, and the TBA+OES treatment was significantly (P &lt; 0.05) different from the CON and OES treatments. It was concluded that OES and TBA+OES implants have different impacts on meat eating-quality measurements, which could have important implications for the Australian and international beef industry.


2017 ◽  
Vol 8 (s1) ◽  
pp. s2-s5 ◽  
Author(s):  
D. J. Devlin ◽  
N. F. S. Gault ◽  
B. W. Moss ◽  
E. Tolland ◽  
J. Tollerton ◽  
...  

The most important factors known to influence the eating quality of beef are well established and include both pre- and post-slaughter events with many of the determinants interacting with each other. A substantial programme of work has been conducted by the Agri-Food and Biosciences Institute in Northern Ireland aimed at quantifying those factors of most importance to the local beef industry. Post-slaughter effects such as carcase chilling and electrical stimulation, ageing, carcase hanging and cooking method have been shown to have a significant impact on eating quality when compared with pre-slaughter activities such as animal handling and lairage time in the Northern Ireland studies. However, the effect of animal breed, particularly the use of dairy breed animals, was shown to significantly improve eating quality. Many of these factors were found to interact with each other.


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