Amount Of Intramuscular Fat Research Articles

Non-rigid registration of cervical spine MRI volumes.

Whiplash is the colloquial term for neck injuries caused by sudden extension of the cervical spine. Patients with chronic whiplash associated disorder (WAD) can experience neck pain for many years after the original injury. Researchers have found some evidence to suggest that chronic whiplash is related to the amount of intra-muscular fat in the cervical spine muscles. Hence, an important step towards developing a treatment for chronic WAD is a technique to accurately and efficiently measure the amount of intra-muscular fat in the muscles of the cervical spine. Our proposed technique for making this measurement is to automatically segment the cervical spine muscles using a fused volume created from multi-modal MRI volumes of the cervical spine. Multiple modes are required to enhance the boundaries between the different muscles to assist the following automatic segmentation process. However, before these multiple modes can be fused it is first necessary to accurately register these volumes. Hence, in this paper, we have proposed a new non-rigid multi-modal registration algorithm using the sum of conditional variance (SCV) with partial volume interpolation (PVI) similarity measure and Gauss-Newton (GN) optimization for the accurate registration of multi-modal cervical spine MRI volumes. The performance of the proposed approach is compared with the existing SCV based registration algorithm and the sum of the conditional squared deviation from the mode (SCSDM) method. The experimental results demonstrate that the proposed approach provides superior performance than the best existing approaches.

Genetic dissection of marbling trait through integration of mapping and expression profiling

Marbling traits, defined by the amount of intramuscular fat, has a heritable component and are quantitative in nature, being influenced by many genes of variable individual effects. The identification of the genetic variation associated with marbling is an important step toward the improvement of beef quality through breeding programs and the understanding of the biological network of marbling. A lot of genomic studies based on functional candidate gene approach and quantitative trait locus (QTL) mapping and many transcriptome studies based on expression profiling, respectively, provide information on variation in genomic regions and individual genes associated with marbling and of genes with marbling-associated expression changes. Further, the integrative approach combining mapping and expression profiling data is proving useful for identifying the causal genes for marbling QTLs. Application of this integrative approach to our marbling study using a rat model, Otsuka Long-Evans Tokushima Fatty (OLETF) rat and Japanese Black beef cattle is introduced finally in this review.

A Review of the Nutritive Value and Meat Quality Characteristics of the Dromedary (Camelus dromedaries) Camel Meats

The dromedary camel is a good source of milk and meatin harsh areas where the climate adversely affects the survivalof other livestock. The dromedary has unique physiological characters, including a great tolerance to various temperatures, solar radiation, water scarcity, rough topography and poor vegetation. Dromedaries are mostly raised under traditional systems on low feeding system and slaughtered at old ages. In general, dromedary camel carcasses contain about 57% muscle, 26% bone and 17% fat with fore-quarters significantly heavier than the hind halves. Camel lean meat contains about 78% water, 19% protein, 3% fat, and 1.2% ash with a small amount of intramuscular fat, which renders it a healthy food forgrowing human population. The amino acid and mineral contents of camel meat are often higher than other meat animals, probably due to lower intramuscular fat levels. Camel meat has been processed into burgers, patties, sausages and shawarma to add value. Future research efforts need to focus on exploiting the potential of the camel as a source of meat through multi-disciplinary research into efficient production systems, and improved meat technology and marketing.

Effect of two Spanish breeds and diet on beef quality including consumer preferences

Farmers in dry mountain areas are changing their management strategies to improve livestock farming efficiency, by using different forages or different breeds. The effect of breed (Parda de Montaña vs. Pirenaica) and finishing diet (grazing on meadows vs. a total mixed ration (50% alfalfa, 40% maize grain, 10% straw)) on carcass characteristics and meat quality of steers was studied. Parda de Montaña had a greater (P < 0.01) amount of intramuscular fat than Pirenaica. The finishing diet did not influence carcass fat color, but fatty acid composition was slightly affected. Finishing steers on a total mixed ration increased the percentage of fat of the 10th rib (P < 0.001). Supplementation with concentrates increased the diet energy concentration and also increased the dressing percentage. Both breeds had similar carcass characteristics. Consumers preferred beef from the Pirenaica breed because of its greater tenderness. Consumers did not differentiate between beef from animals fed different finishing diets. However, consumers who like meat very much preferred meat aged in a cooler at 4 °C for 15 days rather than 8 days.

Effect of dietary supplementation with Acacia karroo leaves on fatty acid profiles and consumer sensory attributes of Xhosa lop-eared goats under artificial haemonchosis

The effect of Acacia karroo supplementation on fatty acid profiles and sensory attributes of Xhosa lop-eared goats meat was evaluated in 18 4-month-old goats exposed to a single dose of 6000 L3 Haemonchus contortus larvae. The goats were allotted into two groups: non-supplemented (NSP) and supplemented (AK). The AK goats received 200 g of fresh A. karroo leaves. At the end of the experiment, all the goats were slaughtered to determine the fatty acid profiles and sensory perceptions. Faecal larval counts decreased significantly in the AK group as the infection progressed, while it increased in the NSP group. At necropsy, the NSP group had significantly higher worm counts than the AK group. The AK group contained significantly higher (P &lt; 0.05) amounts of intramuscular fat and had almost twice (P &lt; 0.05) the total polyunsaturated fatty acids and polyunsaturated fatty acid/monounsaturated fatty acid ratio. Furthermore, the AK goats also had higher amounts (P &lt; 0.05) of n-3. Mean sensory scores for juiciness and tenderness were superior in the AK goats (P &lt; 0.05). In conclusion, A. karroo supplementation positively influenced the fatty acid composition and sensory attributes of chevon from goats infected with H. contortus.

Muscle Gene Expression Associated with Increased Marbling in Beef Cattle

The objective of this study was to identify specific bovine genes expressed within skeletal muscle that are associated with intramuscular fat deposition. Twenty-eight Angus-Simmental cross steers and heifers were harvested at the University of Illinois Meat Science Laboratory. Four pairs of animals were identified based on similar adjusted backfat thickness but differing amounts of intramuscular fat within each pair. RNA was extracted from muscle samples devoid of visible fat and microarray analysis was performed. Based on this analysis, 9 genes were selected and expression was subsequently confirmed by qPCR. Expression levels of MYH3, HOXD10, MXRA8, and CASQ2 were increased in animals with high marbling, whereas levels of NPNT, MRC1, DNER, and CYPB4 were decreased in high marbled animals. The remaining gene, ACTN2 was determined to be a false positive and was, therefore, excluded from further study. Despite the positive results of the preliminary study, associations between gene expression and intramuscular fat content did not extend to the larger population of cattle. A significant negative association existed between expression of MRC1 and marbling level (P = 0.04). Therefore, this study was unable to identify a particular skeletal muscle gene set whose expression correlated well with marbling levels in the larger population of beef cattle.

Influence of the halothane gene (HAL) on pork quality in two commercial crossbreeds

We evaluated the effect of the halothane (HAL) gene on the quality of pork in domestic pigs. Half-carcasses from two different commercial pig (Sus domestica) crossbreeds were analyzed, 46 of which were homozygous dominant (HAL(NN)) and 69 of which were heterozygous (HAL(Nn)) for the halothane gene. The measures included backfat thickness, lean meat percentage, carcass weight, pH 24 h after slaughtering, color, and drip loss; DNA was extracted from the haunch muscle. Swine with the HAL(Nn) genotype had less backfat thickness and higher lean meat percentages than swine with the HAL(NN) genotype. Yet, swine with the HAL(Nn) genotype had lower quality meat than those with the HAL(NN) swine. The pH at 24 h was lower in HAL(Nn) swine. The meat color was paler in HAL(Nn) animals, the drip loss was greater in those animals bearing the n allele, and the amount of intramuscular fat was not related to the halothane genotype. We conclude that bearers of the recessive allele of the halothane gene produce more meat, but with quality parameters that are inferior to those sought by consumers and industry.

Annotation of novel transcripts putatively relevant for bovine fat metabolism

Two bovine transcripts encoded by the interleukin-1 receptor-associated kinase 1 (IRAK1) gene and the locus LOC618944 predicted as similar to human chromosome 6 open reading frame 52 (C6orf52) gene had indicated divergent expression in bovine skeletal muscle containing different amount of intramuscular fat in a pilot screening experiment. However, for both loci any role in the regulation of energy or fat metabolism is not yet described. In this study, we validated and refined gene structure, screened for mRNA splice variants and analyzed the tissue-specific gene expression patterns of both loci as a prerequisite to elucidate their potential physiological function. Based on comparative sequence analysis, a new full-length gene model for the bovine IRAK1 gene was developed and confirmed experimentally. Expression of IRAK1 mRNA was found in a variety of tissues, and a splice variant was identified in skeletal muscle caused by an in-frame deleted segment of 210 bp affecting regions of intrinsic disorder in the respective protein. For the locus LOC618944, our data contributed to a revised gene model and its assignment to BTA23 (bovine chromosome 23) on the current bovine genome assembly supported by comparative similarity analysis between the bovine and human genomes and experimental data. Furthermore, we identified several splice variants in mammary gland, fat and skeletal muscle tissue and detected a highly similar processed pseudogene on BTA26. All transcript variants of LOC618944 detected in the analyzed tissues represent noncoding RNAs. For both loci, our results suggest yet undetected physiological functions in tissues relevant for fat or energy metabolism in cattle.

International perspective: characterisation of United States Department of Agriculture and Meat Standards Australia systems for assessing beef quality

The intent, in this manuscript, is to characterise the United States Department of Agriculture (USDA) and Meat Standards Australia (MSA) systems for assessing beef quality and to describe the research evidence that supports the principles involved in grade application. USDA beef quality grading standards rely on carcass-trait-only assessments of approximate age of the animal at harvest and amount of intramuscular fat (as marbling) inside the muscles. USDA beef quality grading started 82 years ago. Then, as now, because no traceability system was in place, each animal’s history (exact age, feeding regimen, management practices, etc.) was incomplete; those who assigned quality grades used indicators of age (physiological maturity) and plane of nutrition (amount of marbling), and they do so still. Since 1926, research studies have identified a multitude of palatability-determining live-animal factors (e.g. genetics, use of hormonal growth promotants, high-energy diet finishing) and carcass-treatment factors (e.g. electrical stimulation, tenderstretch carcass suspension, postmortem aging) that cannot be incorporated into a carcass-trait-only quality assessment system. The USA beef industry has depended on development of more than 100 beef brands – some using palatability assurance critical control point plans, total quality management (TQM) philosophies, USDA certification and process verification programs, or combinations of live-animal factors, carcass-treatment factors and carcass-trait constraints – to further differentiate fresh beef products. The MSA grading system is a TQM grading approach that incorporates animal-specific traits (e.g. genetics, sex, age), control of certain pre-harvest and post-harvest processes in the beef chain, cut-specific quality differences and consumer preferences, into a beef pricing system. A unique aspect of the MSA grading system is that the grades are assigned to cuts or muscles, not carcasses; cuts or muscles from the same carcass are assigned individual (and in many cases, different) grades that reflect differences in expected eating quality performance among the various cuts of beef further adjusted to reflect the influence of cut or muscle aging and alternative cooking methods. The MSA grading system is still being modified and refined (using results of an extensive, ongoing consumer testing program), but it represents the best existing example of a TQM grading approach for improving beef quality and palatability. Research studies have shown that the accuracy of palatability-level prediction by use of the two systems – USDA quality grades for US customers and consumers and MSA grades for Australian customers and consumers – is sufficient to justify their continued use for beef quality assessment.

Effect of a short duration feed withdrawal followed by full feeding on marbling fat in beef carcasses

The effect of feed withdrawal for 48 h, prior to initiation of the finishing (fattening) period (75 d) on carcass marbling fat was studied in 120 European × British cross-bred heifers with an average weight of 585 ± 39 kg. Heifers were randomized in a 2 × 2 factorial design experiment with two dietary management treatments, where half the heifers were provided the feed components of steam rolled barley and barley silage either free choice or as a total mixed ration (TMR) containing 87% steam rolled barley and 13% barley silage with ad libitum vitamins and minerals via salt blocks for all animals. Within each dietary management treatment, 30 heifers were denied feed (water was available) for 48 h prior to the two week adaptation to the high grain diet preceding the 75 d finishing period. At the end of the 48 h feed denial blood samples were collected from the jugular vein prior to feeding for determination of glucose and insulin concentrations, which indicated that 48 h feed withdrawal consistently decreased ( P = 0.0001) plasma concentrations of both glucose and insulin but the ratios of the concentrations of glucose to insulin were not affected. At slaughter samples of subcutaneous fat from the brisket (BF) and skirt muscle ( pars costalis diaphragmatis; PCD) were procured for determination of chemical fat content, fat dissected from the muscle and for enumeration of adipocytes, less than 35 μm in diameter and to determine the average cell size in the dissected fat and from the BF by flow-cytometry of adipocytes fixed in osmium tetroxide. The carcass characteristics were also obtained. Although no differences due feed withdrawal for 48 h were evident for carcass weight, percent lean (saleable) meat yield, rib eye area, average fat cover, fat content of PCD or BF, the US marbling score was increased ( P = 0.048) and the amount of dissected fat from the muscle tended to be higher ( P = 0.107), thus 81% of the carcasses graded “US Choice” or “Canada AAA,” or displayed at least a “small” amount of intramuscular fat as compared ( P = 0.0807) to 68% of the heifers not denied feed. Based on more than three years of weekly prices of carcasses that graded “Canada AAA” and “Canada AA,” these experimental results suggested that the expected price of a finished heifer could increase by $4.61 Canadian if a 48 h feed withdrawal was imposed prior to initiation of the finishing phase. Although significant differences in adipocyte numbers due to a single time 48 h feed withdrawal prior to initiation of the finishing phase were not detected, the carcass quality factors were affected leading to an odds ratio of 1.84 times in favour of cattle carcasses to grade “Canada AAA” than if fed continuously.

Exploration of genes showing intramuscular fat deposition‐associated expression changes in musculus longissimus muscle

Marbling, as defined by the amount of intramuscular fat, is an economically important trait in beef cattle. Intramuscular fat deposition is postulated to arise mainly from a series of adipogenic events in intramuscular adipocyte-lineage cells and in the physiological or anatomical milieux surrounding them. This study was designed to investigate gene-expression patterns associated with fat deposition in musculus longissimus muscle, including adipocyte-lineage cells and part of the milieux. Differential-display PCR (ddPCR) was used to examine expression differences between low-marbled and high-marbled steer groups at 8, 10, 12 and 14 months of age, encompassing the time that marbling starts to appear. Seventy-four of 2114 total bands on ddPCR gel-bands were significant (P < 0.05) for the group effect, the interaction effect between group and age, or both the group and the interaction effects. Sequence analysis of 72 of these bands revealed 77 genes, including 35 annotated genes and 42 novel sequences. Among the 35 annotated genes, 6 (BTG2, PDHB, SORBS1, TRDN, TTN and MGP) have been related to changes in intramuscular fat deposition, possibly by exerting effects on adipocyte-lineage cells or on the milieux surrounding them.

Carcass traits, blood serum and meat lipid fractions in Polish Landrace pigs differing in RYR1 genotype

The aim of study was to investigate the effect of RYR1 genotypes on carcass traits and lipid fractions in blood serum and musculus longissimus dorsi of Polish Landrace pigs. The fatteners with RYR1CRYR1 genotype had lower level of triglycerides, total cholesterol, HDL- and LDL cholesterol in blood serum than individuals from RYR1CRYR1C group. The same group of animals had lower amount of intramuscular fat and cholesterol in comparison to homozygotes RYR1CRYR1C. The intramuscular fat of heterozygotes contained less saturated fatty acids, but more unsaturated fatty acids including polyunsaturated acids. The RYR1 genotype had no significant effect on all studied traits in Polish Landrace fatteners.

Multivariate mixed inheritance models for QTL detection on porcine chromosome 6.

A series of multivariate mixed-inheritance models is fitted to the data from an outbred-line pig cross commercially used in Norway. Each model accommodates information on polygenic (co)variances between F2 individuals and their F1 parents across the five traits through incorporation of a random animal effect. Considered traits relate to meat quality and are chosen following up the results from a previous evaluation, in which a putative quantitative trait locus (QTL) was identified on chromosome six that affects the amount of intramuscular fat (IMF), meat percentage, meat tenderness and smell intensity (Grindflek et al., 2001). An additional trait included in the model, based on results of other studies, is the backfat thickness. The analysed material comprises data scored for 305 F2 individuals, whereas marker information is available for F1 and F2 generations. Based on the results of the multivariate analysis with the mixed-inheritance model, it was possible to conclude that the evidence for QTLs for meat percentage, meat tenderness and smell intensity in the study of Grindflek et al. (2001) do not represent separate QTLs, but is caused by the fact that the applied pre-adjustment of trait values for polygenic effects failed properly to remove the polygenic variation. The QTL effect on IMF on chromosome six was confirmed.

Growth, carcass and meat quality characteristics of beef cattle with 0, 50 and 75 percent Wagyu genetic influence

Feeding trials were conducted in two years to compare growth performance, carcass characteristics and quality of meat from beef cattle with 0, 50 or 75% Wagyu genetic influence. The cattle types used in the two years of the study were Continental crossbred steers (0% Wagyu), cattle with 50% Wagyu influence (Wagyu/Angus crossbreds) and 75% Wagyu influence (containing 25% from other European breeds). Cattle were housed in individual pens in the first year and in group pens in the second year. Cattle were fed a backgrounding diet containing 35% barley grain and 65% barley silage with protein, mineral and vitamin supplements until they weighed more than 380 kg, after which they were adapted to a finishing diet consisting of 80% barley and 20% barley silage with mineral and vitamin supplements. Cattle were weighed every 4 wk and at the end of the finishing period they were processed and carcass information was obtained. A three-rib section (10–12) was removed from 41 (year 1) and 44 (year 2) carcasses selected randomly from each group, and Warner–Bratzler shear force was determined. The year-by-cattle type interaction was significant for most parameters; thus all the data were also analysed by year using weight of cattle at initiation of the feeding trial as a covariate for the backgrounding and finishing phases of growth and using carcass weight and back fat depth as covariates for carcass and meat-quality parameters. Weight at the start of the trial influenced most growth parameters and age at slaughter. Continental crossbred steers had higher (P &lt; 0.05) ADG than Wagyu crossbred cattle during the finishing phase (1.47 vs. 0.82 kg d−1) in year 1, but not in year 2. Carcass weights of 75% Wagyu crossbred cattle were lower (P &lt; 0.05) than those of Continental crossbred steers in both years. Warner–Bratzler shear force values were less than 5.3 kg to shear cores of 19 mm diameter. However, 92% in year 1 and 71% in year 2 of the carcasses from Wagyu crossbred cattle graded Canada AAA, and contained more than a "small" amount of intramuscular fat. Thirty percent of the carcasses from Wagyu crossbred cattle in year 1 graded Canada Prime. Only 30% of Continental crossbred steers in year 1 and 10% in year 2 graded Canada AAA. Wagyu genetic influence enhanced marbling in beef cattle without loss in carcass size for the 50% Wagyu steers. Key words: Wagyu, Carcass characteristics, Warner–Bratzler shear force

Variability in marbling in Angus steers and an evaluation of subjective marbling assessment

Currently there are no marbling grades within the New Zealand beef classification system, yet within some of our major markets (e.g., the United States and Japan) marbling is an important component of the grading system. This paper aims to examine the extent of marbling within Angus steers in New Zealand and relate these data to US and Japanese marbling grades. The amount of intramuscular fat (marbling) in the M. longissimus thoracis at the 12th rib site was estimated for samples from 259 Angus steers using NIRS. Carcass weight ranged from 220 to 540 kg and explained 66% of the variability in chemical fat. For carcasses in the 300 to 400 kg range, intramuscular fat content increased at average rate of 3.5 g kg−1 fresh weight of muscle for each 10 kg increase in carcass weight. Marbling was assessed in 118 ribeye steaks by 11 novice panellists using both the Japanese (JMGA) and United States (USDA) marbling grading standards and the scores obtained were compared against the predicted chemical fat content for each sample as estimated by NIR spectroscopy. Panellists assessed 8 to 13 steaks per session to determine between‐grader variability. Immediately after each session, steaks were re‐randomised and reassessed to determine within‐grader variability. There was sufficient between‐operator variability to indicate that graders should be trained or screened if carcasses are to be graded on the basis of marbling scores. The regression equations of mean panel scores on chemical fat content accounted for approximately 87% of the variation in panel means. Each unit increase in Japanese marbling score was equivalent to an increase in intramuscular fat content of 27 (±1.0) g kg−1. Each unit increase in USDA marbling score was associated with an increase in intramuscular fat of 30 (±1.1) g kg−1. Our results using novice graders differed substantially from earlier calibrations of intramuscular fat on marbling score using trained graders. The longissimus thoracis muscle of heavyweight Angus steers was estimated to contain intramuscular fat contents equivalent to JMGA marbling scores of up to 8 and USDA scores of 6, suggesting that New Zealand has cattle genotypes capable of producing well marbled beef.

Meat quality of heifers fattened to heavy weights to enhance marbling

Marbling is the primary factor affecting quality grades of youthful grain-fed cattle in the Canadian, American and Japanese grading systems. Cattle were fed for an extended period of time and to extreme slaughter weights to enhance marbling. The effects of slaughter weight, breed, nutrition, and grading site (12/13th rib-Canadian or 6/7th rib-Japanese) on meat quality were evaluated using 221 weaned heifer calves (exp. 1) and 216 yearling heifers (exp. 2) raised on high (HP) or moderate-high (MHP) planes of nutrition. Mean intramuscular fat concentration in longissimus muscle was 6.93, 8.94, and 9.86% at mean slaughter weights of 500, 590, and 680 kg, respectively (exp 1) and 6.84% and 9.02% at 590 and 680 kg (exp. 2). HP carcasses had more intramuscular fat and lower shear values and drip losses than MHP carcasses (P ≤ 0.05). Angus carcasses had more intramuscular fat and lower shear values than the other breeds studied. Holsteins on the HP diet produced tender meat with a high amount of intramuscular fat whereas Holsteins on the MHP diet produced tougher meat with less intramuscular fat (P &lt; 0.05). The 6/7th rib site had lower marbling scores, lighter meat, higher drip losses and lower shear values (P ≤ 0.001) than the 12/13th rib site. Intramuscular fat accounted for only 3 to 7% of the variation in shear force. Breed, nutrition, and slaughter weight had little effect on most measurements of meat quality except intramuscular fat and shear force. Key words: Beef cattle, meat quality, intramuscular fat, tenderness

Age-related changes of growth hormone secretion and somatotroph function in Japanese Black Steers

Growth hormone (GH) is a vital component for the regulation of animal growth. The circulating levels of GH decrease with age in bull calves (McAndrews et al., 1993) and in steers (Verde and Trenkle, 1987), and are higher in large Simmental steers than in small Angus steers (Grigsby and Trenkle, 1986). Japanese Black cattle, known as Wagyu, is early-matured and small frame size, and has an ability to deposit the high amount of intramuscular fat. The present study was conducted to clarify the age-related changes of GH secretion and somatotroph function in Japanese Black steers, since the information about endocrine profiles of Japanese Black cattle has been scantly.

Determination of α-tocopherol in pork with high intramuscular fat content

Extraction of α-tocopherol from pork samples with low (3%) (LF) or high (9%) (HF) amount of intramuscular fat have been carried out by three different methods, two of them based in saponification plus extraction of α-tocopherol and the other one without saponification. All samples were spiked with five different amount of α-tocopherol prior to analysis. In LF samples, recovery was in the range 85-95% in all cases, with not significant differences between methods. Recovery was much lower in HF samples when using methods which involve prior saponification of muscle samples (50-60%). Changes in KOH concentration did not improve markedly the recovery. The method based on direct extraction provided much better recovery in HF samples (85- 92%) and consequently is recommended for samples high in fat.

Repeatability of taste panel tenderness scores and their relationships to objective pig meat quality traits.

Repeatabilities of 12 meat quality measurements were calculated as a value for the accuracy of those measurements. Sixty-four Duroc and Dutch Yorkshire boars and gilts were slaughtered during 8 wk. The repeatabilities between carcass halves within animals were .53 for repeated taste panel tenderness scores based on 12.4 observations of different panelists per mean, .08 for two repeated tenderness scores of different panelists within one animal, .50 for two repeated tenderness scores of one panelist within one animal, and 41 for repeated measurements of maximum shear force. Repeatabilities of other meat quality traits ranged from .29 for cooking loss to .76 for the Minolta L* color coordinate. The phenotypic correlation between tenderness assessed by a panel and maximum shear force was -.50. The phenotypic correlation between those traits corrected for measurement errors was -.74. A correlation of zero was found between the total amount of collagen and meat tenderness, between amount of intramuscular fat and tenderness, and between ultimate pH and tenderness. The other correlations with meat tenderness ranged from -.00 for Minolta b* color coordinate to -.44 for drip loss. It was concluded that the measurement of maximum shear force can be used as an effective indicator of pig meat tenderness.

VARIATIONS IN THE SENSORY PROPERTIES OF BEEF AS AFFECTED BY SEX CONDITION, MUSCLE AND POSTMORTEM AGING

ABSTRACTThe longissimus (LD), biceps femoris (BF), psoas major (PM), semitendinosus (ST) and semimembranosus (SM) muscles from 8 bulls and 8 steers were removed from sides at 1 day postmortem and 7 days postmortem. The sensory and textural properties were evaluated and related to meat composition, meat characteristics and mineral content. Muscles were ranked in order of increasing sensory tenderness ratings: PM&gt;ST&gt;LD&gt;BF&gt;SM. The amount of intramuscular fat was found to be positively correlated to sensory panel tenderness ratings. The amount of intramuscular collagen was found to be negatively correlated to sensory panel tenderness ratings. Muscle concentrations of copper, iron and manganese were found to be positively correlated to tenderness ratings.