scholarly journals Comparing Heat Shock Proteins in Angus and Brahman Cattle and their Effect On Tenderness

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.

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.


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 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.


Foods ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 208 ◽  
Author(s):  
Andrea Garmyn ◽  
Nicholas Hardcastle ◽  
Rod Polkinghorne ◽  
Loni Lucherk ◽  
Mark Miller

Our objective was to determine the effect of extending postmortem aging from 21 to 84 days on consumer eating quality of beef longissimus lumborum. Strip loins were collected from 108 carcasses. The longissimus lumborum muscle was isolated from strip loins and assigned to one of ten postmortem aging periods from 21 to 84 days (7-day increments) and balanced within four anatomical positions within the muscle. Consumer evaluations for tenderness, juiciness, flavor, and overall liking were conducted using untrained consumer sensory panels consisting of 1080 individual consumers, in accordance with the Meat Standards Australia protocols. These scores were then used to calculate an overall eating quality (MQ4) score. Postmortem aging had no effect (P > 0.05) on tenderness, but juiciness, flavor liking, overall liking, and MQ4 declined (P < 0.05) as aging period increased. Samples aged 21 to 42 days were most preferred having greater (P < 0.05) overall liking and greater (P < 0.05) MQ4 scores than samples aged 70 to 84 days postmortem. These results suggest that longissimus lumborum samples should not be wet-aged longer than 63 days to prevent potential negative eating experiences for consumers; however, altering storage conditions, specifically reducing temperature, could potentially allow for longer chilled storage without such negative effects on flavor and overall liking.


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

2019 ◽  
Vol 3 (2) ◽  
Author(s):  
B. I. Mills ◽  
N. C. Hardcastle ◽  
A. J. Garmyn ◽  
M. F. Miller

ObjectivesConsumers are increasingly searching for more natural and healthier foods that avoid ingredients like phosphates (“clean label”). The objective of this study was to determine the effects of enhancement ingredients and quality grade on the eating quality of longissimus lumborum and semitendinosus.Materials and MethodsStrip loins (n = 36) and eye of rounds (n = 31) were collected from beef carcasses to equally represent USDA Prime, Average Choice, and Select quality grades at a commercial packing facility in Omaha, NE. Subprimals were shipped under refrigeration (0 to 2°C) to the Texas Tech University for processing. Subprimals were trimmed of all accessory muscles, external fat, and connective tissue, leaving longissimus lumborum (LL) and semitendinosus (ST). Each subprimal was equally portioned into 6 sections. One section served as a non-enhanced control (CON), while the remaining 5 sections were injected with 112% of green weight with water, salt, and either sodium tripolyphosphate (STP), native potato starch (NPS), sodium carbonate (SC), sodium bicarbonate (SB), or beef flavoring (BF). Sections were cut into steak pieces (5 × 5 × 2.5-cm thick) and frozen at 40 d postmortem. Steak pieces were cooked to a targeted medium degree of doneness on a clamshell grill using a fixed time cooking schedule. Each sample was portioned and served warm to 2 consumer panelists. Panelists (n = 1380) rated each sample for tenderness, juiciness, flavor, and overall liking on an anchored 100-mm line scale. During a session, panelists evaluated 6 samples representing each treatment combination, arranged in a predetermined, balanced order. Data were analyzed using PROC GLIMMIX (SAS) with fixed effects of muscle, enhancement, quality grade, and their interactions (α = 0.05).ResultsNo two-way or three-way interactions were detected for any palatability trait (P > 0.05). Enhancement ingredients influenced tenderness, juiciness, flavor, and overall liking (P < 0.01), regardless of muscle or quality grade. Samples from SC and SB had greater (P < 0.05) tenderness scores than samples enhanced with any other ingredient, except PS. Meanwhile, CON samples were the least tender, and STP was scored lowest for tenderness of the enhanced treatments (P < 0.05). Samples enhanced with BF, SC, and SB were rated juicier than STP and all enhanced samples were rated juicier than CON (P < 0.05). Samples enhanced with BF, SC, SB, and NPS were all similarly rated with greater flavor and overall liking than STP (P < 0.05), which was intermediate, and CON had the lowest flavor and overall liking compared to all other treatments (P < 0.05). Quality grade also affected tenderness, juiciness, flavor and overall liking (P < 0.05). Prime samples received the greatest ratings for all traits, over Average Choice, which was intermediate, and Select samples were scored lowest for all palatability traits. Lastly, muscle influenced all palatability traits (P < 0.01). Longissimus lumborum samples were more tender, juicier, more flavorful, and liked more than semitendinosus samples (P < 0.01).ConclusionResults showed consumers liked alternative functional ingredients over enhancement with phosphate and non-enhanced beef. This shows clean label ingredients are not only effective in increasing palatability but had superior eating quality over enhancement with phosphate.


2019 ◽  
Vol 59 (7) ◽  
pp. 1349 ◽  
Author(s):  
L. Pannier ◽  
G. E. Gardner ◽  
D. W. Pethick

Slower growing Merino sheep often miss the lamb category and become yearlings. Yet, they may still produce meat of acceptable eating quality, thus opening the opportunity to develop high quality yearling products. Consumer sensory differences (tenderness, overall liking, juiciness, liking of flavour and liking of odour) of grilled wet-aged (5 days) steaks from the M. longissimus lumborum (LL) and M. semimembranosus (SM) derived from wether lamb (n = 185; average age 355 days) and wether yearling (n = 206; average age 685 days) Merinos were tested. Additionally, the age effect on carcass and instrumental meat quality traits was analysed. Lambs were born in 2009 and 2010 at two research sites (Kirby, Katanning), and yearlings were born in 2009 at five research sites (Kirby, Cowra, Rutherglen, Struan, Katanning). On average within each muscle, yearlings had lower scores for all sensory attributes (P &lt; 0.01) compared to lambs. Lambs versus yearlings born in the same year and reared at the same research site had greater sensory differences within the SM (P &lt; 0.01), up to 10.0 eating quality scores more for tenderness. In contrast, the LL samples had almost no significant differences between the two age groups. A portion of the differences in overall liking and liking of flavour scores was explained by intramuscular fat. Yearlings were slightly heavier (P &lt; 0.01) but leaner (P &lt; 0.01), compared to lambs, and yearling meat colour was darker (P &lt; 0.01). While the results generally supported the better eating quality of lamb, they demonstrated a very acceptable yearling LL eating quality, and showed the smaller impact of age on the LL muscle in Merinos. Hence, the development of a high quality yearling product for the LL muscle is possible.


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