• Korean Journal of Agricultural Science
• /
• v.42 no.1
• /
• pp.47-51
• /
• 2015

This study was conducted to make certain that the intramuscular fat score at 13th rib could represent the fat content of whole loin from Hanwoo in Korea beef grading system. A total 42 loins from 23 carcasses of grade $1^{{+}{+}}$, 16 carcasses of grade $1^+$, and 3 carcasses of grade 1 of Hanwoo were used for this study. The crude fat content and intramuscular fat score at the $1^{st}$, $6^{th}$, and $13^{th}$ rib, and the last lumbar position of loin were measured. The crude fat content was the highest at the $6^{th}$ rib of loin from the carcasses of grade $1^{{+}{+}}$ and $1^+$ (p<0.05). There were no significant difference of the intramuscular fat scores measured by image analysis and beef marbling score (BMS) between the 6th and $13^{th}$ rib of loin from the carcasses of $1^{{+}{+}}$ and $1^+$ and that were significantly higher than intramuscular fat scores at the $1^{st}$ rib and the last lumbar position of the loin. From the results, we conclude that the intramuscular fat score at the $13^{th}$ rib can represent the fat content of loin when meat graders decide the grade of Hanwoo carcass.

• Food Science of Animal Resources
• /
• v.36 no.5
• /
• pp.577-582
• /
• 2016

Despite several issues in relation to human health, beef is still a most popular meat product among large section of society due to the presence of high quality protein and other nutrients. The current paper reviews numerous studies that provide nutritional profiles and health implications of high marbled beef consumption. In relation to lipid content of beef, intramuscular fat contains high level of PUFA and MUFA compared to other beef fat. Level and composition of intramuscular fat varies depending on breed and feeding regime. Literature suggests that the marbling is more complex than the development of subcutaneous fat and marbling not only provides good fatty acids but also contributes to the higher eating quality of beef. Finally, the current work emphasize that meat plays a pivotal role in nutritious diets, high quality marbled beef is not only of excellent eating quality but also contain more beneficial fatty acids.

• Asian-Australasian Journal of Animal Sciences
• /
• v.20 no.10
• /
• pp.1587-1593
• /
• 2007

A single factorial experiment was conducted to test the effects of three dietary levels of energy on mRNA expression of fatty acid synthase (FAS-mRNA) and hormone-sensitive lipase (HSL-mRNA) and their association with intramuscular fat in finishing pigs. 72 crossbred (Large $White{\times}Rongchang$) barrows with an average initial body weight of 20.71 (s.e. 0.1) kg, were randomly allotted to three dietary treatments (11.75, 13.05 and 14.36 MJ DE/kg) and fed until slaughtered at 100 or 101 kg. The diets were iso-nitrogenous and iso-essential amino acids. The growth performances including the duration of finishing were changed linearly (p<0.05) or quadratically (p<0.05) with increased dietary energy levels. The effects of dietary energy content on the percentage of external fat, intramuscular backfat and the fat thickness were linear (p<0.05). The content of dietary energy increased FAS-mRNA linearly or quadratically, while HSL-mRNA decreased linearly or quadratically in backfat and Longissmus dorsi muscle. Meanwhile, significant positive correlations (p<0.05) were found between energy level and intramuscular fat, FAS-mRNA or the ratio of FAS-mRNA to HSL-mRNA, between the ratio of FAS-mRNA to HSL-mRNA and intramuscular fat. However, the correlations between HSL mRNA and dietary energy or intramuscular fat were negative (p<0.05). The results indicated that dietary energy level regulates lipid accumulation, especially intramuscular fat, possibly by modulating the mRNA of FAS and HSL together rather than individually.

• Asian-Australasian Journal of Animal Sciences
• /
• v.20 no.5
• /
• pp.622-626
• /
• 2007

Using multi-trait animal model BLUP, selection was conducted over seven generations for growth rate (DG), real-time ultrasound loin-eye muscle area (LEA), backfat thickness (BF), and intramuscular fat content (IMF) to develop a new line of purebred Duroc pigs with enhanced meat production and meat quality. This study was intended to investigate the relationship between restriction fragment length polymorphism (RFLP) of a heart fatty acid-binding protein (H-FABP) gene and intramuscular fat content (IMF) of this Duroc purebred population. The present experiment examined the RFLP of 499 slaughtered pigs. The DNA was separated from the blood or ear tissue of the pigs, which were slaughtered at 105 kg of body weight. Intramuscular fat content of the longissimus muscle was measured using chemical analysis. A significant difference was detected in the breeding value of IMF among the H-FABP PCR RFLP genotypes. The AA genotype has a significantly larger positive effect on the IMF breeding value than do the Aa and aa genotypes for the MspI RFLP. In addition, the DD genotype has a significantly greater positive effect on IMF breeding value than the Dd and dd genotypes for the HaeIII RFLP. For the HinfI RFLP, the hh genotype has a significantly larger positive effect on IMF breeding value than the HH genotype. Multiple regression analysis was performed using the IMF breeding values as the dependent variable and the three H-FABP genotypes as independent variables. Results revealed that the contribution of the genotypes to variation in IMF breeding values was approximately 40%. These results demonstrated that H-FABP RFLPs affect IMF in this Duroc population.

• Journal of Life Science
• /
• v.22 no.1
• /
• pp.31-35
• /
• 2012

In a previous study, succinate dehydrogenase (SDH) and triose phosphate isomerase (TPI) were detected by 2D gel electrophoresis as differentially expressed proteins in the longissimus thoracis muscles of cattle aged between 12 and 27 months old. In the present study, we investigated the association of SDH and TPI gene expression with intramuscular fat content in 50 Hanwoo steers. The SDH gene was expressed at a 4 times higher level in the 12 month old group than in the 27 month old group (p<0.01). A regression analysis between gene expression value and intramuscular fat content showed a negative correlation between expression of the SDH gene and intramuscular fat content (p<0.001). In contrast, the expression of the TPI gene showed no significant association with intramuscular fat content. This result suggests that the SDH gene may be a candidate marker gene for intramuscular fat content in the longissimus thoracis of Korean cattle.

• Asian-Australasian Journal of Animal Sciences
• /
• v.5 no.4
• /
• pp.629-634
• /
• 1992

Seventeen Japanese Black steers were used to evaluate the influence of slaughter weight (550 kg, 600 kg or 650 kg), sire (two sires), concentrate feeding (barley or corn) and muscle (six muscles) on the following characteristics: pH value, cooking loss, shear value, moisture and crude fat contents. Crude fat contents were higher, and moisture content and shear values were lower in muscles from the large slaughter weight group 650 kg than those from other slaughter weight groups. Cooking loss, shear value, moisture and crude fat contents differed between sires. Corn feeding increased crude fat content in muscle compared to barley feeding. Muscles containing a large amount of intramuscular fat showed lower shear values and less cooking loss than those containing a small amount of intramuscular fat.

• Asian-Australasian Journal of Animal Sciences
• /
• v.32 no.5
• /
• pp.607-613
• /
• 2019

Objective: Intramuscular fat (IMF) content plays an important role in meat quality. Identification of single nucleotide polymorphisms (SNPs) and genes related to pig IMF, especially using pig populations with high IMF content variation, can help to establish novel molecular breeding tools for optimizing IMF in pork and unveil the mechanisms that underlie fat metabolism. Methods: We collected muscle samples of 453 Chinese Lulai black pigs, measured IMF content by Soxhlet petroleum-ether extraction method, and genotyped genome-wide SNPs using GeneSeek Genomic Profiler Porcine HD BeadChip. Then a genome-wide association study was performed using a linear mixed model implemented in the GEMMA software. Results: A total of 43 SNPs were identified to be significantly associated with IMF content by the cutoff p<0.001. Among these significant SNPs, the greatest number of SNPs (n = 19) were detected on Chr.9, and two linkage disequilibrium blocks were formed among them. Additionally, 17 significant SNPs are mapped to previously reported quantitative trait loci (QTLs) of IMF and confirmed previous QTLs studies. Forty-two annotated genes centering these significant SNPs were obtained from Ensembl database. Overrepresentation test of pathways and gene ontology (GO) terms revealed some enriched reactome pathways and GO terms, which mainly involved regulation of basic material transport, energy metabolic process and signaling pathway. Conclusion: These findings improve our understanding of the genetic architecture of IMF content in pork and facilitate the follow-up study of fine-mapping genes that influence fat deposition in muscle.

• Food Science of Animal Resources
• /
• v.37 no.5
• /
• pp.780-786
• /
• 2017

The objective of this study was to investigate the relationship between muscle fiber characteristics, intramuscular fat (IMF) content, and fatty acids composition in longissimus lumborum (LL) muscle from Hanwoo steers. The LL muscles were obtained from four quality grades (QG) carcasses and subjected to histochemical analysis. There were significant (p<0.05) differences in fiber number percentage (FNP) and fiber area percentage (FAP) of muscle fiber types among muscles from four QGs. Both FNP and FAP of type I increased while those of type IIB decreased with increasing QG from QG 2 to QG $1^{{+}{+}}$ (p<0.05). Also, with increasing QG, the saturated fatty acid (SFA) proportion decreased while monounsaturated fatty acid (MUFA) increased significantly (p<0.05). IMF content was positively correlated with both FNP and FAP of type I, but negatively correlated with those of type IIB. The proportions of SFA and MUFA were significantly (p<0.001) correlated with both type I and IIB composition. These results implied that muscle fiber type composition is an important factor influencing fatty acid composition in LL muscle of Hanwoo steer.

• Food Science of Animal Resources
• /
• v.39 no.2
• /
• pp.197-208
• /
• 2019

The aim of this study was to investigate the relation of sensory quality traits of cooked beef to fresh meat quality and histochemical characteristics, especially muscle bundle traits, in the longissimus thoracis muscle of Hanwoo steers. Cooking loss negatively correlated with softness, initial tenderness, chewiness, rate of breakdown (RB), and amount of perceptible residue (AR) after chewing (p<0.05), and drip loss showed negative correlation with RB and AR (p<0.05). All the attributes of tenderness exhibited negative correlation with the Warner-Bratzler shear force value (p<0.05). Marbling score and the intramuscular fat (IMF) content showed positive correlation with all the organoleptic characteristics, including tenderness attributes, juiciness, and flavor (p<0.05). Regarding histochemical characteristics, muscle fiber size did not have a significant correlation with all the sensory quality traits, although the area percentage of type I fiber was related with softness, initial tenderness, and chewiness (p<0.05). On the contrary, the characteristics of muscle bundle were related to all the sensory tenderness attributes (p<0.05), and the sensory tenderness increased with smaller muscle bundle size (p<0.05). These results suggest that the IMF content and bundle characteristics can be used as indicators for explaining the variations in sensory tenderness in well-marbled beef.

• Korean Journal of Food Science and Technology
• /
• v.21 no.4
• /
• pp.505-510
• /
• 1989

Red muscle and white muscle were separated from bovine, porcine and poultry skeletal muscles, respectively. Intramuscular lipids were extracted and fractionated to neutral-, glyco- and phospho-lipid by silica gel chromagraphy and then fatty acid composition were analyzed with gas chromatography. The results obtained were as follows; Total lipid content of red muscle was higher than that of white muscle in case of beef and chicken. In pork, however, total lipid content of white muscle was higher than red muscle The content ratio of neutral lipid to phospholipid revealed a number of distinctions between red and white muscle among animals. There were noteworthy differences in respect of polyunsaturated fatty acid. The intramuscular fat of pork had the higher content of highly polyunsaturated fatty acid such as arachidonic acid in contrast to beef.