• 농업과학연구
• /
• 제42권1호
• /
• 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.

• 한국축산식품학회지
• /
• 제29권6호
• /
• pp.726-735
• /
• 2009

본 연구는 국립축산과학원 한우시험장에서 사육된 한우 육질등급($1^{++}$, $1^+$, 1, 2, 3)과 5부위(chuck, strip loin, top round, brisket, loin) 간에 따른 전단력, 근절길이와 콜라겐 함량을 조사하고자 실시하였으며, 수소 및 거세우(24-30개월) 총 15두(5등급$\times$3두)를 공시 축으로 이용하였다. 전단력은 $1^{++}$, $1^+$, 1등급에서 목심은 각각 5.47 kg/0.5 $inch^2$, 5.46 kg/0.5 $inch^2$, 6.54 kg/0.5 $inch^2$로 3등급 목심(8.41 kg/0.5 $inch^2$)보다 유의적으로 낮았다(p<0.05). $1^{++}$, $1^+$, 1등급에서 양지는 등심 및 채끝부위보다 유의적으로 가장 높았으며(p<0.05) $1^+$등급에서 양지(3.24 kg/0.5 $inch^2$)는 등심(1.00 kg/0.5 $inch^2$)과 채끝(1.13 kg/0.5 $inch^2$)보다 전단력수치가 유의적으로 높게 나타났다. 또한 육질등급 간에 근절길이는 $1^{++}$등급 양지부위가 3.72um으로 유의적으로 가장 길었고 3등급에서는 1.62로 가장 짧았다. $1^{++}$등급과 2등급에서 양지부위의 근절길이가 채끝 및 우둔부위보다 유의적으로 길게 나타났다(p<0.05). 총 콜라겐함량은 $1^{++}$, $1^+$, 1등급에서 채끝부위가 각각 1.17, 1.18, 1.14로 유의적으로 낮았던 반면 3등급 채끝부위가 1.63으로 유의적으로 가장 높았다(p<0.05). 또한 3등급에서는 양지부위가 3.22로 등심 및 채끝, 목심, 우둔부위보다 콜라겐의 함량이 유의적으로 가장 높았다(p<0.05). 또한 한우고기를 육질등급에 따라 5부위를 탕, 구이와 스테이크의 3가지로 관능적인 특성을 조사한 결과 요리형태 탕, 구이와 스테이크의 관능평가에서 $1^{++}$등급이 다른 등급과 비교하였을 때 연도와 다즙성이 유의적으로 가장 높았던 반면에 3등급 한우고기는 연도와 다즙성이 유의적으로 낮은 것으로 평가되었다(p<0.05). 부위에 따라서는 등심부위가 탕, 구이와 스테이크의 관능평가에서 연도와 다즙성이 유의적으로 가장 높았으며 우둔부위가 유의적으로 가장 낮게 나타났다(p<0.05). 따라서 본 연구결과 한우고기는 전단력 및 관능 특성이 5부위 모두 육질등급 및 부위에 따라 유의적인 차이가 있는 것으로 나타났다(p<0.05). 한편 근절길이 및 콜라겐 함량은 부위에 따라 차이는 있었으나 목심, 우둔 및 등심부위의 경우 육질등급에 따른 유의적인 차이가 없는 것으로 나타났다.

• Asian-Australasian Journal of Animal Sciences
• /
• 제15권4호
• /
• pp.591-595
• /
• 2002

Three hundred thirty five progeny testing steers of Korean beef cattle were evaluated ultrasonically for back fat thickness (BFT), longissimus muscle area (LMA) and intramuscular fat (IF) before slaughter. Class measurements associated with the Korean yield grade and quality grade were also obtained. Residual standard deviation between ultrasonic estimates and carcass measurements of BFT, LMA were 1.49 mm and $0.96cm^2$. The linear correlation coefficients (p<0.01) between ultrasonic estimates and carcass measurements of BFT, LMA and IF were 0.75, 0.57 and 0.67, respectively. Results for improving predictions of yield grade by four methods-the Korean yield grade index equation, fat depth alone, regression and decision tree methods were 75.4%, 79.6%, 64.3% and 81.4%, respectively. We conclude that the decision tree method can easily predict yield grade and is also useful for increasing prediction accuracy rate.

• 한국식품영양과학회지
• /
• 제28권6호
• /
• pp.1288-1292
• /
• 1999

The physicochemical properties and palatability of Hanwoo(cow, steer, and bull) beef loin(1＋ carcass grade) were studied. pH(5.56~5.69), moisture content(67.6~69.0%), crude protein content(17.8~18.7%), and crude fat content(11.9~13.8%) of Hanwoo beef loin did not show significant difference between the types of Hanwoo. L(44.5~46.9), a(19.9~20.6), and b(10.3~11.6) color parameters, water holding capacity (69.4~70.5%), volatile basic nitrogen content(9.86~11.28mg%), thiobarbituric acid value(0.148~0.158 mg malonaldehyde/kg), and cooking loss(26.3~27.9%) of beef loin did not show significant difference between the types of Hanwoo either. Hardness, myofibrillar fragmentation index(MFI), and chewiness of beef loin were 6.1~6.9 dyne/cm2, 50.3~54.9, and 39.5~ 52.0g, respectively. No differences were found in hardness and MFI between the types of Hanwoo, while chewiness of cow was much lower than that of steer and bull(p<0.05). Cow was the best in palatability.

• 한국축산식품학회지
• /
• 제42권2호
• /
• pp.240-251
• /
• 2022

Fat deposition in animal muscles differs according to the genetics and muscle anatomical locations. Moreover, different fat to lean muscle ratios (quality grade, QG) might contribute to aroma development in highly marbled beef. Scientific evidence is required to determine whether the abundance of aroma volatiles is positively correlated with the amount of fat in highly marbled beef. Therefore, this study aims to investigate the effect of QG on beef aroma profile using electronic nose data and a chemometric approach. An electronic nose with metal oxide semiconductors was used, and discrimination was performed using multivariate analysis, including principal component analysis and hierarchical clustering. The M. longissimus lumborum (striploin) of QG 1++, 1+, 1, and 2 of Hanwoo steers (n=6), finished under identical feeding systems on similar farms, were used. In contrast to the proportion of monounsaturated fatty acids (MUFAs), the abundance of volatile compounds and the proportion of polyunsaturated fatty acids (PUFAs) decreased as the QG increased. The aroma profile of striploin from carcasses of different QGs was well-discriminated. QG1++ was close to QG1+, while QG1 and QG2 were within a cluster. In conclusion, aroma development in beef is strongly influenced by fat deposition, particularly the fat-to-lean muscle ratio with regard to the proportion of PUFA. As MUFA slows down the oxidation and release of volatile compounds, leaner beef containing a higher proportion of PUFA produces more volatile compounds than beef with a higher amount of intramuscular fat.

• Journal of Animal Science and Technology
• /
• 제63권5호
• /
• pp.1064-1075
• /
• 2021

Recently, a high level of dietary crude protein (CP) has become of interest as a possible practice to improve the carcass quality of beef cattle, and its level has been increasing in the field. However, there is little scientific evidence that supports this. This study was conducted to test whether a high dietary CP level would improve growth performance, body metabolism, and carcass traits in Hanwoo beef cattle. A total of 32 Hanwoo finishing beef cattle (18 multiparous cows, six heifers, and eight steers) participated in a 12-weeks feeding trial. Two kinds of total mixed rations were prepared to contain two different CP; 156 g/kg for the control (CON) and 173 g/kg of CP for the treatment (HCP), while maintaining a similar level of metabolizable energy. The experiment was ended when more than half of the steers reached the target body weight (730 kg). Blood was collected at the end of the experiment. After harvesting, the carcass trait was evaluated at the slaughterhouse according to Korean standards. The carcass yield score and grade were also calculated based on revised criteria. Overall, dry matter intake, average daily gain, blood metabolites concentration, and the carcass traits, except for backfat thickness and the yield score, did not differ between the treatments. The HCP had lower backfat thickness than those of CON. There was no difference in the carcass yield grade, but the yield score was higher in the HCP treatment. According to the newly revised carcass grading criteria, both yield score and grade were higher in HCP than in CON. Increasing CP supply decreased the carcass's backfat thickness without altering growth performance and body metabolism, resulting in improved yield score and grade. Therefore, feeding a high CP diet may be beneficial in the farm income, although it may also increase feed cost and nitrogen excretion to the environment.

• 한국산학기술학회논문지
• /
• 제21권3호
• /
• pp.537-544
• /
• 2020

쇠고기 소비트랜드는 소비자 요구와 선호도 등에 따라 변화하고 있다. 본 연구는 한우고기 구매 소비자를 대상으로 구매성향 및 선호도 조사를 통해 쇠고기 등급제 보완방향에 대한 기초자료를 수집하였다. 조사대상자는 2017년 7월 24일부터 8월 14일에 걸쳐 서울, 경기도 및 5대 광역시에 거주하는 소비자를 대상으로 조사를 수행하였고, 무응답 등을 제외하고 최종 362명 데이터를 분석에 이용하였다. 위계적 회귀분석 결과 1등급 선호집단의 구매빈도 증가에는 마블링 형태가, 1⁺등급에서는 지방색이, 1⁺⁺등급에서는 소득, 등급제 개선 의견, 마블링 함량, 마블링 형태가 각각 정의 영향(⁺)을 미치는 것으로 분석되었다. 반면, 선호등급이 없는 집단에서는 구매빈도 증가에 영향을 미치는 변수는 없는 것으로 분석되었다. 종합적으로 살펴볼 때 구매빈도 증가에 영향을 미치는 변수들이 집단별로 다른 것으로 분석되었는데, 소도체 등급기준은 축산농가 및 산업체의 경제적 이익과 소비자 구매력에 직접적으로 연관되어 있어 매우 중요한 제도이기 때문에 생산자와 소비자 의견을 적절하게 반영하여 합리적이고 과학적인 방향으로 앞으로도 보완되어야 할 것으로 생각된다.

• 한국동물위생학회지
• /
• 제28권3호
• /
• pp.215-223
• /
• 2005

The bacteria on the surface of slaughtered meat was monitored to investigate the relationships between microbiological quality and sanitation management in slaughter process of cattle and pig. It was conducted to evaluate the microbiological quality on the surface of slaughtered beef and pork in Seoul from January to December 2004. Two hundred and thirty three beef and 233 pork carcasses were surveyed on generic E coli counts and standard plate count for microbiological quality and Salmonella spp, Listeria monocytogenes, Staphylococcus aureus, Clostridium perfringens and E coli O157: H7 as pathogenic microorganisms. The prevalence of the excellent or good grade $(10^4\;CFU/cm^2)$ in beef and pork carcasses were $100\%\; and\;99.2\%$, respectively. The frequency of beef carcasses with less than $10^2\;CFU/cm^2$ of generic I coli counts was $100\%$, while that of pork carcasses was $99.6\%$. Of 233 beef carcasses, $1(0.42\%)$ was contaminated with L monocytogenes and $6(2.58\%)$ with C perfringens. Of 233 pork carcasses, $11(4.72\%),\;2(0.86\%),\;and\;2(0.86\%)$ were contaminated with L monocytogenes, C perfringens, and S aureus, respectively, Salmonella spp and E coli O157:H7 were not detected with all of the beef and pork carcasses. In conclusion, this study emphasized the Importance of relationship between microbiological quality and sanitation management in slaughter process of cattle and pig, in abattoirs.

• Asian-Australasian Journal of Animal Sciences
• /
• 제33권1호
• /
• pp.157-165
• /
• 2020

Objective: The objective of this study was to compare the quality of dry-aged beef from cull Hanwoo cows slaughtered at 60 or 80 months old. Methods: A total of eight cull Hanwoo carcasses with a quality grade of 3 (low-grade) were selected and divided into two age groups: 63.5±2.5 months old (n = 4) and 87.8±4.5 months old (n = 4). Whole longissimus thoracis et lumborum from the 11th rib to the last lumbar vertebrae, including the back fat, was removed from the carcass at 24 h postmortem and aged for 50 days in darkness at a temperature of 2℃±1℃, a relative humidity of 85% and an air flow of 2 m/s. The sampling was performed aseptically after 0, 20, 24, 40, and 50 days of aging. Results: Regardless of the aging period, aging increased the lightness (p<0.05), redness (p<0.05) and yellowness (p<0.05) at initial blooming (90 min after slicing) and the overall acceptance (p<0.05). No further tenderization effect was found after 20 days of aging, but aging for 50 days significantly increased the lipid oxidation (p<0.05). The generation of aroma volatiles in the roast steak from aged samples was higher (p<0.05) than that of non-aged samples. No significant effect of age at slaughter was found on the color, pH, water-holding capacity, cooking loss, shear force value, bacterial counts, volatile basic nitrogen, consumer acceptance, lipid oxidation, fatty acid composition or aroma volatiles. Conclusion: The quality of dry-aged beef obtained from cull Hanwoo cows slaughtered at either 60 or 80 months old with similar quality grade was comparable and extending dry aging for more than 40 days is not recommended considering the costs and further lipid oxidation.

• 한국축산식품학회지
• /
• 제30권2호
• /
• pp.321-327
• /
• 2010

성별 한우쇠고기의 품질 특성을 조사하기 위하여 육질등급이 5개로 개전된 후 첫 해인 2005년도에 전국에 출하된 42,113두의 육질등급 요인을 조사하였으며, 2005년부터 2008년도 상반기까지 국립축산과학원에서 도축된 257두의 쇠고기 품질을 분석하였다. 성별 한우의 육질등급요인(근내지방도, 육색, 지방색, 조직감, 성숙도)은 유의적인 차이가 있었으며 한우 거세우가 가장 우수하였다(p<0.05). 근내지방도, 성숙도 및 조직감은 거세우가 각각 5.02, 2.17 및 1.31로 가장 우수하였으며 이에 따라 육질등급 지수도 2.75($1^{++}$ 등급 =1, 3등급= 5)로 가장 높았다(p<0.05). 수분함량은 수소가 73.23%로 가장 높았으며, 조지방 함량은 거세우가 17.27% 가장 높았다(p<0.05). 거세우의 명도($L^*$), 전단력 및 보수력은 각각 39.01, 4.03 kg 및 57.08%로 가장 높았으나(p<0.05), 암소와 수소 간의 차이가 없었다. 전단력에 있어서 암소 및 수소가 각각 7.73 kg 및 8.35 kg으로 비교적 높게 나타난 것은 연도 증진에 관련된 연구가 필요한 것으로 판단된다. 관능검사 결과 연도, 다즙성, 향미 및 총 점수에서 거세우가 가장 좋았다(p<0.05). 이와 같은 연구는 시대적으로 변화하는 한우산업의 여건에 따라 단계 별로 수행할 필요가 있으며, 암소의 경우 경산우 비육이 대부분인 우리나라의 실정에 비추어 볼 때 산차별 또는 연령별 품질관련 연구가 더욱 필요하다고 생각된다.