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.

Relationship between animal age, intramuscular fat, cooking loss, pH, shear force and eating quality of aged meat from sheep

2006 ◽  
Vol 46 (7) ◽  
pp. 879 ◽  
Author(s):  
D. L. Hopkins ◽  
R. S. Hegarty ◽  
P. J. Walker ◽  
D. W. Pethick
Keyword(s):  
Shear Force ◽  
Small Variation ◽  
Quality Measures ◽  
Intramuscular Fat ◽  
Cooking Loss ◽  
Objective Measures ◽  
Eating Quality ◽  
Fat Percentage ◽  
Rate Of Decline

The relationships between sensory traits (tenderness, juiciness, flavour and overall liking) and objective measures, such as shear force, intramuscular fat, cooking loss, pH and animal age, were derived for M. longissimus thoracis et lumborum (LL) from 471 lamb and sheep carcasses. Tenderness could be predicted with the most accuracy (R2 = 0.24) and flavour with the highest precision (r.s.d. = 7.5 units) when using the objective measures, which may be in part due to the small variation in the range of shear force values of the samples (all carcasses electrically stimulated and meat aged for 5 days) and the use of consumer panels for the assessment of sensory traits. The ultimate pH of the LL, the rate of decline in pH in the LL or the predicted temperature at pH 6.0 were not significant predictors of the sensory traits when tested on a subsample of the carcasses. The model coefficients indicated that all sensory traits (tenderness, flavour, juiciness and overall liking) declined as shear force and age increased, and as intramuscular fat percentage decreased. This translated into a decline of 16 points on average for tenderness and 13 points for overall liking when LL samples from 68.5-month-old sheep were compared with those from unweaned lambs, when adjusted to the same level of intramuscular fat and shear force. Predictions of the sensory traits at varying levels of shear force were made and show that at 49 Newtons (N), the overall liking score would be 51 and the tenderness score 48. Derived relationships between objective meat quality measures and sensory traits suggest that to achieve a failure rate of no more than 10% for loin meat when eaten, it must have a shear force of about 27 N or less.

Muscle glycogen concentrations in commercial consignments of Australian lamb measured on farm and post-slaughter after three different lairage periods

2005 ◽  
Vol 45 (5) ◽  
pp. 543 ◽  
Author(s):  
R. H. Jacob ◽  
D. W. Pethick ◽  
H. M. Chapman
Keyword(s):  
Western Australia ◽  
Muscle Glycogen ◽  
Glycogen Concentration ◽  
Age Class ◽  
Muscle Types ◽  
Carry Over ◽  
On Farm ◽  
Muscle Glycogen Concentration

The aim of this study was to gain an understanding of the distribution of glycogen concentrations and ultimate pH (pHu) in 2 different muscle types for lambs slaughtered under commercial conditions in Western Australia, and to compare muscle glycogen concentrations in lambs on farm and after slaughter. The study included 13 different consignments of prime lambs from a range of commercial scenarios. In each consignment, muscle glycogen concentration was measured in a group of lambs on farm and subsequently after slaughter in 3 different lairage groups. The lairage groups were: slaughter on arrival (no lairage), slaughter after 1 day, and slaughter after 2 days in lairage. Biopsies of M. semimembranosus and the M. semitendinosus were taken from live lambs on farm just before farm curfew before transport and from carcasses immediately after slaughter. There was a significant effect of consignment on muscle glycogen concentration. Muscle glycogen concentrations on farm were lower than 1 g/100 g in 4 consignments for the M. semimembranosus and 11 consignments for the M. semitendinosus. The cause of the differences between consignments was unclear as nutrition, genotype and age class were confounded between consignments. Glycogen concentrations were lower and meat pHu higher for sucker lamb compared with carry-over lamb consignments. However, lambs finished on grain-based feedlot rations had higher muscle glycogen concentrations than lambs finished on pasture and sucker lambs when finished on pastures only. Sucker lambs were only crossbred while carry-over lambs included crossbred and Merino genotypes. When data from different consignments were pooled and the effect of consignment was considered, there were no differences between muscle glycogen concentration measured on farm and muscle glycogen concentration measured after slaughter. However, there were differences between sample times within individual consignments. Glycogen concentration at slaughter was different from glycogen concentration on farm in more consignments for M. semitendinosus than M. semimembranosus, suggesting a difference between consignments for the effect caused by stress. Typically, the M. semimembranosus glycogen concentration at slaughter was lower than on farm in consignments consisting of Merino genotypes that had high muscle glycogen concentrations on farm. In the consignments in which lairage time had an effect on muscle glycogen concentration, the differences were small. In some consignments a difference occurred between lairage times for pHu without any difference occurring for muscle glycogen concentration.

Comparison of eating quality of bull and steer beef

1984 ◽  
Vol 39 (1) ◽  
pp. 37-50 ◽  
Author(s):  
E. Dransfield ◽  
G. R. Nute ◽  
M. A. Francombe
Keyword(s):  
Connective Tissue ◽  
Intramuscular Fat ◽  
Eating Quality ◽  
Longissimus Dorsi ◽  
Castrate Male ◽  
Consumer Panel ◽  
Chemical Measurements ◽  
Significant Difference ◽  
Psoas Major

ABSTRACTEating qualities of beef from entire and castrate male animals were compared using taste panel, objective texture and chemical measurements and a consumer panel. The eating quality of roast m. longissimus dorsi, casseroled m. supraspinatus, minced m. gastrocnemius and grilled m. psoas major from bull beef, slaughtered at 400 days was different (by triangular tests) from that of twin steer beef. The differences (attributed to flavour, texture and juiciness) were not substantiated using descriptive scaling tests when the only significant difference was that roast m. longissimus dorsi from bulls was slightly drier than that from steers. Tenderness, juiciness and flavour of roast m. longissimus dorsi from 71 bulls and 84 steers raised semi-intensively to 390 to 510 kg and slaughtered commercially were assessed using descriptive category scales and the instrumental toughness values. There was no significant difference in organoleptic qualities and the distributions of tenderness and juiciness within these populations were similar. Bull beef contained more connective tissue and had less intramuscular fat. Fatness was poorly related to tenderness (r = 0·3) and unrelated to juiciness or flavour. A consumer panel of 606 assessors showed that bull beef was not as pale as steer beef and found no difference in fatness of the cuts, flavour or juiciness. Fore-rib roasts of bull beef were marginally less tender than steer fore rib.

The eating quality of Canadian pork and its relationship with intramuscular fat

Meat Science ◽  
2005 ◽  
Vol 69 (2) ◽  
pp. 297-305 ◽  
Author(s):  
A. Fortin ◽  
W.M. Robertson ◽  
A.K.W. Tong
Keyword(s):  
Intramuscular Fat ◽  
Eating Quality

Intramuscular fat levels in sheep muscle during growth

2008 ◽  
Vol 48 (7) ◽  
pp. 904 ◽  
Author(s):  
M. J. McPhee ◽  
D. L. Hopkins ◽  
D. W. Pethick
Keyword(s):  
Near Infrared ◽  
Accretion Rate ◽  
Intramuscular Fat ◽  
Dual Energy ◽  
Carcass Composition ◽  
Eating Quality ◽  
Fat Percentage ◽  
X Ray ◽  
Slaughter Age ◽  
Sheep Muscle

A 5 × 4 factorial experiment was designed in which lambs representing five genotypes were slaughtered at four ages (110, 236, 412 and 662 days of age). The genotypes represented were Poll Dorsetgrowth × Border Leicester Merino, Poll Dorsetgrowth × Merino, Poll Dorsetmuscling × Merino, Merino × Merino and Border Leicester × Merino. Both sexes (ewes and wethers) were represented for each genotype and slaughter age combination. In total, 595 animals were slaughtered and the carcass composition and intramuscular fat were measured. Carcass composition [fat, ash and protein (lean)] was determined by dual energy X-ray absorptiometry, with the intramuscular fat percentage determined using near-infrared spectroscopy following removal and weighing of the entire longissimus thoracis et lumborum (LL) muscle. Analysis revealed that the proportion of intramusular fat in the loin relative to total carcass fat decreases as animals mature, thus indicating that intramusular fat deposition occurs early in the maturation of sheep. Furthermore, as animals became heavier and older the accretion rate of intramuscular fat in the LL muscle slowed down. Both genotype (P < 0.05) and sex (P < 0.001) were found to impact on this pattern, with Border Leicester × Merino animals exhibiting the largest increase in intramuscular fat proportion in the LL muscle (4.92 and 5.50% at 22 months of age for ewes and wethers, respectively). The Poll Dorsetgrowth × Border Leicester Merino animals were found to have the greatest absolute levels of intramuscular fat in the whole LL muscle (80.95 and 97.60 g at maturity for ewes and wethers, respectively). The amount of intramuscular fat significantly increased as the sheep became older and fatter; however, these differences were quantitatively small. As such, finishing prime lambs to high levels of total carcass fatness would have little effect on any eating quality benefits associated with increased intramuscular fat proportion.

Unravelling the complex interactions between genetics, animal age and nutrition as they impact on tissue deposition, muscle characteristics and quality of Australian sheep meat

2007 ◽  
Vol 47 (10) ◽  
pp. 1229 ◽  
Author(s):  
R. D. Warner ◽  
D. W. Pethick ◽  
P. L. Greenwood ◽  
E. N. Ponnampalam ◽  
R. G. Banks ◽  
...  
Keyword(s):  
Meat Quality ◽  
Subcutaneous Fat ◽  
Intramuscular Fat ◽  
Carcass Composition ◽  
Early Weaning ◽  
Fat Percentage ◽  
Complex Interactions ◽  
Sheep Meat ◽  
Australian Sheep

The combined effects of age and genetics and Poll Dorset sire and growth path were studied in two separate experiments (n = 595 and 627, respectively). In the first experiment, containing genotype crosses typically used in Australia (Merino, Poll Dorset, Border Leicester) and sires selected for growth or muscling, sheep were slaughtered at 4, 8, 14 and 22 months. The second experiment used Poll Dorset sires selected for high muscling, fat or growth with progeny having two levels of nutrition postweaning. Border Leicesters expressed higher levels of carcass fat percentage and intramuscular fat and produced the heaviest carcass. Merinos had the lowest subcutaneous fat depth and highest carcass lean percentage when compared at the same age. The progeny of Poll Dorset sires selected for high muscling (PDm) expressed a shift toward glycolytic fibres relative to those from Merino sires, and PDm sires produced progeny with reduced spine and limb length and higher carcass muscle : mineral ratios, suggesting skeletal stunting. Genotype meat quality differences were minimal except that PDm sire topsides were tougher and Merinos produced higher pH meat. With age (4–22 months), lambs became heavier and fatter, fibres shifted towards oxidative and away from glycolytic, muscle myoglobin increased, the meat became darker and redder and tenderness declined. Early weaning had no effect on the time to reach slaughter weight, provided nutrition was not restricted. The sire genetics influence on the carcass composition far outweighed the effect of nutrition postweaning. Lambs on a restricted diet tended to have less acceptable meat quality but this was not evident in lambs from sires selected for high fatness. Sensory tenderness was improved and intramuscular fat was higher in lamb progeny from sires selected for high fatness.

scholarly journals Eating Quality and Other Characteristics of New Mexico Pecan Cultivars Harvested over Three Years

1995 ◽  
Vol 5 (3) ◽  
pp. 206-208 ◽  
Author(s):  
Juan L. Silva ◽  
Estuardo Marroquin ◽  
Frank B. Matta ◽  
Esteban A. Herrera
Keyword(s):  
New Mexico ◽  
Sensory Evaluation ◽  
Collaborative Research ◽  
Carya Illinoinensis ◽  
Eating Quality ◽  
Physical Chemical ◽  
Hue Angle ◽  
Harvest Year ◽  
Light Color

This work is the result of 3 years of collaborative research between Mississippi State Univ. and New Mexico State Univ. Physical, chemical, and sensory characteristics were studied to assess eating quality of popular New Mexico pecan (Carya illinoinensis) cultivars. The force and energy necessary to break (shear) pecan nuts, and Hunter `a' and hue angle values varied with harvest year and cultivar. All other traits, including sensory evaluation results, varied only with cultivar. `Ideal' was of light color, small size, and not as firm as the others, while `Burkett' was soft and slightly rancid. `Wichita' was the cultivar rated best by panelists, despite its slightly darker color. `Western Schley' and `Salopek' were also acceptable, although not as acceptable as `Wichita'.

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.

Relationship between sire estimated breeding values and the meat and eating quality of meat from their progeny grown on two planes of nutrition

2005 ◽  
Vol 45 (5) ◽  
pp. 525 ◽  
Author(s):  
D. L. Hopkins ◽  
R. S. Hegarty ◽  
T. C. Farrell
Keyword(s):  
Meat Quality ◽  
Shear Force ◽  
Best Practice ◽  
Intramuscular Fat ◽  
Eating Quality ◽  
Quality Traits ◽  
Breeding Values ◽  
Meat Quality Traits ◽  
Estimated Breeding Values

The meat of 140 female lambs was examined. These lambs were sired by 9 Poll Dorset sires (3 selected for growth, 3 for muscling and 3 control) and fed either a low or high plane of nutrition from birth to slaughter. All carcasses were electrically stimulated and portions of M. longissimus thoracis et lumborum (loin) aged for 5 days before freezing. Subsequently, 10 consumers tested each portion for eating quality traits. A portion of the same muscle from the opposing side of the carcass was divided into 3 sections and aged for either 1, 3 or 5 days and then used to measure shear force (objective tenderness). Portions of the M. semimembranosus (topside) were also aged for 3 or 5 days and subjected to shear testing. Low plane animals produced tougher loins (based on shear force). As ultimate pH increased, shear force of the loin increased for low plane animals, while for high plane animals there was no such effect. This latter group had significantly lower ultimate pH values in all 3 muscles tested. Plane of nutrition had the greatest effect on topside shear force with low plane lambs producing tougher topsides. As ultimate pH increased, the topsides became tougher and as expected ageing improved the tenderness. There was no effect of sire EBVs (estimated breeding values) on shear force or objective meat quality traits apart from loin lightness which increased as the EBV for post-weaning weight (PWWT) increased and intramuscular fat in the loin which decreased as sire EBV for post-weaning muscle depth (PEMD) increased. Plane of nutrition did not have a significant effect on eating quality attributes as assessed by consumers. There was, however, an effect of sire EBV for muscling (PEMD) on tenderness, juiciness, flavour and overall liking, such that increased EBV led to decreased scores for the sensory traits. The findings suggest selection of sires for increasing PEMD will have a detrimental affect on the eating quality of their progeny, but this will not be reflected in shear force values or other objective meat quality traits apart from intramuscular fat. The effects of a low plane of nutrition on eating quality were minimal and largely controlled by the use of best practice processing, but were evident for a number of meat quality traits.

Intramuscular fat content has little influence on the eating quality of fresh pork loin chops1

2008 ◽  
Vol 86 (3) ◽  
pp. 730-737 ◽  
Author(s):  
P. J. Rincker ◽  
J. Killefer ◽  
M. Ellis ◽  
M. S. Brewer ◽  
F. K. McKeith
Keyword(s):  
Intramuscular Fat ◽  
Fat Content ◽  
Eating Quality ◽  
Pork Loin ◽  
Intramuscular Fat Content
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