• Food Science of Animal Resources
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• v.32 no.5
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• pp.659-668
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• 2012

The objective of this research was to investigate the effect of marbling scores on carcass grade factors, physico-chemical and sensory traits of Hanwoo. Data used in this study were collected from 73,316 carcasses obtained at the Nonghyup Seoul slaughterhouse in 2009 and 271 cuts of M. longissimusdorsi were analyzed to estimate beef qualities. As the marbling scores increased, backfat thickness was linearly increased (p<0.05) in cows (9.51 mm-14.69 mm) and steers (8.71 mm-14.23 mm). As the marbling scores increased, maturity of cows was increased and meat color, texture and quality grade improved for all genders. With increase of the marbling scores, crude fat contents (3.07%-26.70%), water holding capacity (52.09%-58.66%), $L^*$ value (34.08-41.97) were significantly increased (p<0.05) and Warner-Bratzler shear force was linearly decreased (p<0.05) from 8.58 kg to 2.60 kg. The increase of crude fat contents had the similar interval with the increase of marbling scores from 1 to 6 but it is sharply increased from marbling score 7. There was no difference observed on $pH_{24}$ (5.50-5.66), protein contents (19.57%-21.15%) among the marbling scores. Marbling score was significantly correlated with live weight (r=0.29) in cows, loineye area (r=0.35) in steer, and overall acceptability of panel scores (r=0.67) (p<0.01).

• Journal of Animal Science and Technology
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• v.48 no.2
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• pp.255-268
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• 2006

Twenty four Hanwoo cull cows were assigned to 2 groups, control and melengerol acetate(MGA)+selenium supplement containing vitamin E(SeE), based on the parity(6.5±1.7 birth) and body weight (493.17±55.61kg), and the experiment was conducted to establish the reasonable fattening method of cull cows for 240 days. Average daily body gains during 240 days were 0.51kg and 0.63kg in control and MGA+SeE, respectively(P<0.10). DDMI/ADG of MGA+SeE group improved compared to control group(P<0.05). Therefore, supplementation of MGA+SeE in concentrates may accelerate both of the growth rate and feed efficiency in Hanwoo cull cows. MQI from MGA+SeE was more developed based on the larger rib-eye area and thinner backfat thickness in carcass than that from control. Marbling score for MGA+SeE tended to increase compared to control. Dietary Se supplementation significantly affected muscle Se concentration in longissimus dorsi meat of MGA+SeE group(P<0.05). Similar results to Se were obtained from α-Tocoperol concentration. During 7 days of simulated retail display, accumulations of thiobarbituric acid reactive substances(TBARS) concentration in beef was greater(P<0.05) in control than in supplemented cows. These results supported the hypothesis that supplementation of MGA+SeE improve the growth performance and carcass grade both by the growth stimulating effect of MGA+SeE and by preventing the oxidation of the longissimus dorsi muscle in Hanwoo cull cows.

• Journal of Food Hygiene and Safety
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• v.27 no.1
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• pp.68-73
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• 2012

In this study, a method was developed using molecular biological technique to distinguish an authenticity of meats for processed meat products. The genes for distinction of species about meats targeted at 12S or 16S genes in mitochondrial DNA and the species-specific primers were designed by that PCR products' size was around 200bp for applying to processed products. The target materials were 10 species of livestock products and it checked whether expected PCR products were created or not by electrophoresis after PCR using species-specific primers. The results of PCR for beef, pork, goat meat, mutton, venison, and horse meat were 131, 138, 168, 144, 191, and 142 bp each. The expected PCR products were confirmed at 281, 186, 174, and 238 bp for chicken, duck, turkeymeat, and ostrich. Also, non-specific PCR products were not detected in similar species by species-specific primers. The method using primers developed in this study confirm to be applicable for composite seasoning including beefs and processed meat products including pork and chicken. Therefore, this method may apply to distinguish an authenticity of meats for various processed products.

• Journal of Animal Science and Technology
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• v.53 no.4
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• pp.357-365
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• 2011

This study was carried out to investigate the effects of the feeding level of cracked whole barley (CWB) on fatty acid composition, free amino acid content, organic acid content, pH, HDL cholesterol, total phenol and DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity of finishing Hanwoo steers. The dietary treatments were consisted of five types (C: base feed + 0% CWB, T1: base feed + 10% CWB, T2: base feed + 20% CWB, T3: base feed + 30% CWB, T4: base feed + 40% CWB). A total 30 Hanwoo steers(588.6${\pm}$11.8kg) were allocated into 5 feeding groups, and a total of thirty Hanwoo steers raised from 24 to 30 months. Linoleic acid of fatty acid composition was significantly higher for cracked CWB treatments (T1, T2, T3, and T4) than C, and T3 of CWB treatments was the highest than the other treatments (P<0.01). SFA, USFA, MUFA and USFA/SFA did not differ among the treatments. On the contrary, PUFA was significantly higher for CWB treatments(T1, T2, T3, and T4) than C, and T3 was the highest (P<0.05). EAA was higher in the order of T1 > T2 > C > T3 > T4 (P<0.05). NEAA was higher in the order of T2 >T3 >T1 >C >T4, although a statistical significance was not detected. The total organic acid content was the highest for T3 (20.15 mg/100g) and the lowest for T2 (13.19mg/100g). pH and total phenol of all treatments were did not differ. HDL cholesterol was higher in the order of T1 > C > T4 > T2 > T3 (P<0.01). DPPH radical scavenging activity was in order of T1 > T2 >T4 > C > T3 (P<0.01). Based on the above results, T1 treatment compared to other treatments have been shown to improve EAA, DHL, and DPPH radical scavenging activity.

• Journal of Food Hygiene and Safety
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• v.33 no.3
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• pp.176-184
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• 2018

The aim of the present work was to develop simultaneous methods of quantification of carazolol, azaperone, and azaperol residues in livestock and fishery products using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Samples were extracted from beef, pork, chicken, egg, milk and shrimp using acetonitrile (ACN); while flat fish and eel were extracted using 80% ACN. For purification, ACN saturated n-hexane was used to remove fat composition. The standard calibration curves showed good linearity as correlation coefficients; $r^2$ was > 0.99. Average recoveries expressed were within the range of 67.9-105% for samples fortified at three different levels ($0.5{\times}MRL$, $1{\times}MRL$ and $2{\times}MRL$). The correlation coefficient expressed as precision was within the range of 0.55-7.93%. The limit of quantification (LOQ) was 0.0002-0.002 mg/kg. The proposed analytical method showed high accuracy and acceptable sensitivity based on Codex guideline requirements (CAC/GL71-2009). This method can be used to analyze the residue of carazolol, azaperone, and azaperol in livestock and fishery products.

• Journal of Life Science
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• v.27 no.2
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• pp.202-210
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• 2017

As an effort to find a potential biopreservative, we isolated bacterial strains producing bacteriocin from fermented foods. A strain was finally selected and characteristics of the bacteriocin were investigated. The selected strain was identified as Bacillus subtilis E9-1 based on the 16S rRNA gene analysis. The culture supernatant of B. subtilis E9-1 showed antimicrobial activity against Gram-positive bacteria. Subtilisin A, ${\alpha}$-chymotrypsin, trypsin and proteinase K inactivated the antimicrobial activity, which means its proteinaceous nature, a bacteriocin. The bacteriocin activity was fully retained at the pH range from 2.0 to 8.0 and stable at up to $100^{\circ}C$ for 60 min. Solvents such as ethanol, isopropanol and methanol had no effect on the antimicrobial activity at the concentration of 100% but acetone and acetonitrile reduced the activity at up to 100% concentration. Cell growth of four indicator strains was dramatically decreased in dose-dependent manner. Listeria monocytogenes was the most sensitive, but Enterococcus faecium was the most resistant. Bacillus cereus and Staphylococcus aureus showed the medium sensitivity. The bacteriocin showed its antimicrobial activity against B. cereus and L. monocytogenes via bactericidal action. The number of viable cells of L. monocytogenes started to reduce after addition of bacteriocin to the minced beef. The bacteriocin was purified through acetone concentration, gel filtration chromatography and RP-HPLC. The whole purification step led to a 6.82 fold increase in the specific activity and 6% yield of bacteriocin activity. The molecular weight of the purified bacteriocin was determined to be 3.3 kDa by MALDI-TOF/TOF mass spectrometry.

• Korean Journal of Microbiology
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• v.46 no.2
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• pp.192-199
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• 2010

The alone and combined effects of bacteriocin produced from Enterococcus faecalis MJ-213 and potassium sorbate against the food-borne pathogenic bacteria were studied. Bacteriocin minimal inhibitory concentration (MIC) values for Staphylococcus aureus ATCC 6538 and Salmonella enteritidis ATCC 13076 were 50 and 100 ${\mu}g$/ml, respectively. Bacteriocin (100 ${\mu}g$/ml) alone was active against S. aureus and S. enteritidis, but it was lower in antimicrobial effectiveness than the combination of bacteriocin (100 ${\mu}g$/ml) with potassium sorbate (100 ${\mu}g$/ml), which reduced initial counts (6 log cycle) of S. aureus and S. enteritidis by 1 and 3 log cycle, respectively. The bactericidal activity of bacteriocin of E. faecalis MJ-213 heated at $100^{\circ}C$ for 30 min or $121^{\circ}C$ for 15 min was markedly decreased as compared with the control. Moreover, the activity of bacteriocin was completely abolished by pepsin or protease II, but not affected by ${\alpha}$-amylase or lipase. The activity of bacteriocin adjusted to pH 6.0-8.0 showed almost the same inhibition ratio compared with the bacteriocin unadjusted pH, and though the inhibition ratio against pathogenic bacteria was reduced than the control, the bacteriocin was stable at pH 4.0 or 10.0, relatively. Furthermore, the combined treatment of bacteriocin and potassium sorbate than the alone treatment of bacteriocin significantly decreased (p<0.05) the viable cell counts of S. aureus or S. enteritidis inoculated on grind beef during storage at $4^{\circ}C$.

• Food Science of Animal Resources
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• v.33 no.2
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• pp.244-250
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• 2013

The objective of this study was to investigate the effects of marinade condition (injection and tumbling process) on the physicochemical and sensory characteristics of marinade steak. The pH of marinade steaks was in the range of 5.26-5.51, with the highest level in the injection/tumbling (IT) treatment, while injection processes tended to result in higher pH levels (p<0.05). Salinity and sweetness contents were determined to be the highest in the IT treatment. Cooking loss was highest in the control (Immersion, 6 hr), but there were no significant differences between control and injection/tumbling, injection/ vacuum/tumbling (IVT), and vacuum/tumbling treatments. Hardness was in the range of 8.01-13.99 kg, with the lowest level observed for the IVT treatment, and the highest level observed for the control. However, there were no significant differences in hardness between injection process treatments and non-injection process treatments. Therefore, injection and tumbling processes have a similar effect on meat tenderness. In the sensory evaluation, there was a significant difference between the control, injection and tumbling process treatments in terms of tenderness, texture preference and taste. These results suggest that injection and tumbling processes improved tenderness, product yield and sensory preference in meat products.

• Journal of Animal Science and Technology
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• v.46 no.5
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• pp.799-810
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• 2004

This study was conducted to determine effects of spent composts of Se-enriched mushrooms (Se-SMC) as the dietary selenium source on carcass characteristics, plasma glutathione peroxidase(GSH-Px) activity and Se deposition in finishing Hanwoo steers. In combination with both Se-SMC and normal SMC, experimental treatment diets were formulated to contain 0.1, 0.3, 0.6 and 0.9 ppm of Se on a dry matter basis. A total of 20 finishing Hanwoo steers (average BW = 613 kg, average age = 20 to 24 mo) were allotted to treatments in four groups of five steers per pen for 12 wk preceding slaughter. While the experiment is employed, blood samples were taken to analyze Se concentration and GSH-Px activity, and muscle and liver samples were collected for analyses of Se contents in their tissues after slaughter. DMl and BW gain were not affected by dietary Se level and any toxic symptoms in treatments with a higher level of Se were not observed. No differences were noted for carcass characteristics. Se concentration in whole blood and plasma GSH-Px activity were linearly increased with the increasing level of dietary Se (P < 0.01). Se content in the hind leg for Se-SMC supplemented groups significantly increased (P < 0.05) upon dietary Se level, with 0.27, 0.37, 0.40 and 0.46 !1g1g dry, respectively. However, Se content in the loin was not affected by dietary Se levels. Se content in the liver was significantly increased(P < 0.05) as dietary Se increased, with 0.79, 1.40, 2.39 and 3.10 !1g1g dry, respectively. These results suggested that Se in the Se-SMC was highly bioavailable, and Se-SMC might be used not only as an inexpensive way of providing Se for ruminants but also as another way of producing Se-fortified beef.

• Food Science of Animal Resources
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• v.27 no.4
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• pp.531-537
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• 2007

Small amounts of trans fatty acids exist naturally in beef and dairy foods. Also, they can be produced in the process of partial hydrogenation to manufacture shortning or margarine. They can provide a better palatability and shelf life. According to the recently studies, trans fatty acids can raise health risk such as heart diseases and coronary artery diseases. They can also increase low-density lipoprotein (LDL) cholesterol and decrease high-density lipoprotein (HDL) cholesterol in the blood plasma, therefore increasing the risk of atherosclerosis and diabetes. The aim of this study was to determine total lipids and trans fatty acids (TFAs) content in processed foods and meat products. The analysis of trans fatty acids was performed in 28 samples of donuts, 18 samples of bakeries, 4 samples of frozen doughs, 2 samples of popcorns, and 4 samples of meat products (ham, sausage, nuget, and bacon). Total lipids in processed foods and meat products were extracted by chloroform-Methanol method and acid digestion, respectively. They were analyzed by gas chromatography using a SP-2560 column and flame ionization detector. The amounts of TFAs per 100 g of foods were 0-3.3% (0.74% on average) in donuts, 0.2-5.8% (1.18% on average) in bakeries, 0.2-6.3% (1.93% on average) in frozen doughs, and 0-5.8% in popcorns. Meat products such as ham, sausage, and nuget analyzed 0.1% of TFAs, respectively and trans fatty acids in bacon were not detected. As a result, the distribution of TFAs in processed foods was widely ranged from O% to 6.3% according to manufacturers and types of products, whereas the content of TFAs in meat products ranged from 0% to 0.1%.