• Korean Journal of Veterinary Service
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• v.27 no.1
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• pp.1-6
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• 2004

It was conducted to evaluate the microbiological quality on the surface of slaughtered beef and pork products in Seoul from January 2003 to December 2003. Two hundreds four beefs and 284 pork carcasses were surveyed on generic E coli, total bacterial count for microbiological quality, and Salmonella spp as food-borne pathogen. The prevalence of the excellent or good grade(10$^4$ CFU/$\textrm{cm}^2$ in SPC) of beef and pork carcasses were 99.7% and 97.9%, respectively. The frequency of beef carcasses with less than 10$^2$ CFU/$\textrm{cm}^2$ of E coli was 100%, while that of pork carcasses was 98.2%. Salmonella spp was not recovered from all of beef and pork carcasses.

• Food Science of Animal Resources
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• v.39 no.1
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• pp.139-150
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• 2019

This study aimed to determine the suitable point of sale and consumption of different quality grade (QG) Hanwoo short loin during aging period, based on physicochemical, sensory, and microbiological quality. Short loins obtained from the carcasses of 13 Hanwoo steers and 2 bulls with 5 different QGs (1++, 1+, 1, 2, and 3) were analyzed over 28 d. QG and aging time had significant effect on water holding capacity, color, shear force, total volatile basic nitrogen (TVBN) content, and sensory traits. Higher QG groups generally exhibited a lower shear force, nucleotide content, and water holding capacity, and higher $L^*$, $a^*$, and $b^*$ values. Acceptable tenderness (shear force <5.4 kg) in QG 1++, 1+, 1, and 2 was achieved on days 7, 14, 16, and 18, respectively, and QG 3 showed a shear force of 6.8 kg, even after 28 d. Regardless of QG, TVBN content below threshold levels (20-30 mg%) was observed throughout the 28 d aging period, while total plate counts above 7 Log CFU/g were seen at 21 d. In conclusion, it is recommended that Hanwoo beef with QG 1++, 1+, and intermediate QG (1 and 2) should be sold or consumed between 7 and 21, 14 and 21, 16 and 21 d, respectively. Beef with QG 3 should be sold or consumed within 21 d, based on microbial growth, even though it has not achieved desirable tenderness. For this reason, an additional tenderizing process is recommended before this beef is ready for consumption.

• Food Science of Animal Resources
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• v.40 no.6
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• pp.908-923
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• 2020

The objective of this study was to compare tastes-related components and eating quality properties between Hanwoo steer and cow meats. Longissimus thoracis (LT) muscles with same quality grade (1⁺ grade) collected from left sides of the steer and cow carcasses were used for analyses of technological quality traits, free amino acids (FAAs), metabolites, nucleotides, fatty acids and sensory attributes. there were no differences occurring in the chemical composition (fat, protein, moisture and collagen) and technological quality traits (cooking loss, water holding capacity, shear force and color) between the two beef types (p>0.05). The cow meat exhibited significantly higher amounts of some FAAs associated with umami (e.g., glutamic acid and lysine), sweetness (e.g., proline and glutamic acid) and saltiness (e.g., histidine and glutamic acid) compared to the steer meat (p<0.05). Regarding the nucleotides, no differences occurred in all the identified nucleotides between the two beef types (p>0.05). A total of 27 metabolites were identified, however, only some compounds (e.g., acetate, creatine, creatinine, glucose and inosine, etc.) showed their significantly higher amounts in the cow meat compared with those in the steer meat (p<0.05). In terms of sensory aspects, the panelists found no differences in scores of all the eating quality traits between the two sex types of beef (p>0.05). Overall, excepts some variations in tastes-active compounds, there were no differences in the quality characteristics in general and eating quality in particular between the cow and steer meats when they were in the same quality grade.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.1
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• pp.123-135
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• 2001

Application of growth promoters by means of implantation or supplementation to the diets has been routine in the beef cattle industry of many countries for the better performance in growth and improvement of feed efficiency. Anabolic implants (zeranol, trenbolone acetate, and estradiol with testosterone or progesterone) have generated various positive effects. Zeranol implantation, in general, improved average daily gain (ADG), feed conversion (FC), dressing percentage (DP) and yield grade (YG) of cattle, and increased dry matter intake (DMI). Trenbolone acetate with or without estradiol also increased mean values of ADG and loin eye area (LEA) but reduced DMI and improved FC of cattle. Estradiol with testosterone or progesterone increased ADG and DMI. Anabolic implants, however, had minimal or negative effects on marbling or quality grade. The magnitude of the response to these anabolic implants in performance of beef cattle has varied depending on the type of implants, amount and duration of exposure, age of animals and combination of implants. Administration of bovine somatotropin improved ADG and FC, and decreased fat deposition. Ionophores improved FC in cattle from reduced DMI without great response to ADG. Supplementation of monensin and lasalocid reduced molar proportion of propionate. Monensin and lysocellin increased apparent absorption and retention of some minerals in cattle. Despite the improved cattle performance in growth and FC, results in beef quality from the application of the growth promoters appeared to vary or in conflict under a variety of environmental conditions.

• Food Science of Animal Resources
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• v.39 no.1
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• pp.54-64
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• 2019

Wet and dry aging methods were applied to improve the quality of three different beef cuts (butt, rump, and sirloin) from Hanwoo cows (quality grade 2, approximately 50-mon-old). After 28 d of wet aging (vacuum packaged; temperature, $2{\pm}1^{\circ}C$) and dry aging (air velocity, 2-7 m/s; temperature, $1{\pm}1^{\circ}C$; humidity, $85{\pm}10%$), proximate composition, cooking loss, water holding capacity, shear force, color, nucleotides content, and sensory properties were compared with a non-aged control (2 d postmortem). Both wet and dry aging significantly increased the water holding capacity of the butt cuts. Dry aging in all beef cuts induced lower cooking loss than that in wet-aged cuts. Shear force of all beef cuts was decreased after both wet and dry aging and CIE $L^*$, $a^*$, and $b^*$ color values in butt and sirloin cuts were higher in both wet and dry aging (p<0.05) groups than those in the non-aged control. Regardless of the aging method used, inosine-5'-monophosphate content among beef cuts was the same. The sensory panel scored significantly higher values in tenderness, flavor, and overall acceptability for dry-aged beef regardless of the beef cuts tested compared to non- and wet-aged cuts. In addition, dry-aged beef resulted in similar overall acceptability among the different beef cuts, whereas that in wet-aged meat was significantly different by different beef cuts. In conclusion, both wet and dry aging improved the quality of different beef cuts; however, dry aging was more suitable for improving the quality of less preferred beef cuts.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.9
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• pp.1500-1506
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• 2018

Objective: Although Hanwoo has been selected as the superior commercial beef cattle breed in Korea, Chikso (Korean brindle cattle) is still recognized as a valuable breed for beef production. The aim of this study was to compare the meat quality, fatty acid composition and aroma volatiles of beef from Chikso and Hanwoo steers maintained under identical feed management, as information regarding these characteristics is still limited. Methods: A total of 19 carcasses with a quality grade of 1 were selected, and strip loin (longissimus lumborum) cuts were collected from 11 Hanwoo carcasses and 8 Chikso carcasses. Meat quality and aroma analyses were performed at day four postmortem. Results: Though Hanwoo strip loin tended to have higher fat content (15.37%) than Chikso (12.01%), no significant differences were observed. Meat pH, water-holding capacity, cooking loss, shear force value, instrumental surface color (Commission International De L'eclairage $L^{\star}$, $a^{\star}$, $b^{\star}$, chroma, and hue angle) and fatty acid composition were not significantly different. Roasted Chikso beef released more intense aroma than roasted Hanwoo beef based on the total area units of identified volatiles. Among identified volatiles, the amounts of toluene, heptanal, octanal, and nonanal were higher in roasted Chikso beef than in roasted Hanwoo beef. In addition, the aroma pattern of the roasted beef from these breeds was well-discriminated by electronic nose. Conclusion: No distinct differences were found in terms of meat quality between Hanwoo and Chikso beef in this study. However, the aroma pattern and volatiles of roasted Hanwoo and Chikso beef were different according to instrumental analysis.

• Food Science of Animal Resources
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• v.36 no.3
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• pp.291-299
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• 2016

Interaction between carcass quality grade and end-point cooking temperature on eating quality of Hanwoo m. longissimus was investigated. Ten (10) of steers were sampled from a commercial population; carcasses with QG 1⁺⁺ (n=5) and QG 1 (n=5) were chosen. Samples were cooked by electric oven at 60 or 82℃ and compared with uncooked control samples. The pH was not affected by cooking temperature but decreased the redness after cooking and steaks cooked at 60℃ were more reddish than steaks cooked at 82℃ in both QG groups. Higher cooking temperature greatly (p<0.05) increased the cooking loss, but there was no significant interaction between cooking temperature and QG on the cooking loss. Moisture is negatively correlated with temperature in both QG while the proportionate relationship between crude fat and end-point temperature found in QG 1⁺⁺. WBSF values were significantly (p<0.05) high for QG 1, while that was significantly (p<0.05) increased when the temperature continues to increase. The increasing quality grade of beef resulted in significant higher (p<0.01) level of TBARS and cooking temperature increased TBARS content. Fatty acid composition was not altered by cooking at both temperatures and also the amount of fat intake was not changed. The current study indicates that eating quality of beef m. longissimus was greatly influenced by end-point temperature being interacted with QG. However, the amount and composition of fat were stable regardless of end-point temperatures. These results will provide a consumer reference to determine cooking conditions and intramuscular fat content.

• Food Science of Animal Resources
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• v.40 no.1
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• pp.34-43
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• 2020

The objectives of this study was to compare palatability changes of the longissimus thoracis (LT) and vastus lateralis (VL) muscles of Hanwoo steers from different beef quality grades (1⁺ and 1) during 28 d of wet-aging in order to improve the utilization of the VL muscle as a steak. The VL muscle showed a higher collagen content and a lower intramuscular fat content than the LT muscle (p<0.05). As expected, the Warner-Bratzler shear force value was greater in the LT 1 grade (LT-1) muscle than the LT-1⁺ muscle (p<0.05); whereas no difference was observed between the grades in the VL muscle at 24 h postmortem. Compared to 0 d of aging, tenderness scores significantly increased after 14 and 21 d of aging in the LT and VL muscles, respectively (p<0.05). Additionally, there was no difference in tenderness score between the VL-1⁺ aged for 21 d and the LT-1 at 24 h postmortem, although tenderness score was greater in the LT than the VL at each period (p<0.05). Moreover, the VL-1⁺ steak exhibited a higher tenderness score than the VL-1 steak at 21 and 28 d of aging (p<0.05). On the other hand, the effect of aging time on juiciness and flavor in the VL muscle was somewhat limited unlike the LT muscle. Taken together, the VL muscle requires a longer aging time than the LT muscle to improve consumer preference. Considering the tenderness, using a higher quality grade for aging is more useful in the VL muscle.

• Food Science of Animal Resources
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• v.39 no.6
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• pp.934-942
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• 2019

Previous studies on dry aged beef, which substantially increases the value of low-grade raw beef and non-preferred cuts, are currently limited to the observation of aged beef changes in laboratory settings or under particular aging conditions, whereas the factors influencing aging have so far been underexplored. Herein, we attempt to establish a technique for distinguishing between fresh and aged beef by observing changes in quality during beef aging. Specifically, we analyzed the effect of time on the quality of aged beef sourced from three Korean manufacturers and identified quality indicators that can be used to distinguish between fresh and aged beef, regardless of supplier. Storage/trimming/aging/cooking losses, moisture/fat/protein/collagen contents, and water holding capacity were tested as potential indicators, among other parameters. As a result, the quality of dry aged beef was shown to be supplier-dependent, which made the identification of factors for the above origin-independent discrimination difficult. Nevertheless, as storage loss, water holding capacity, and cooking loss significantly changed with dry aging time in all cases, these parameters were concluded to be potentially suited for discrimination purposes. The insights gained in this work may help promoting further research in this field and contribute to the development of a standard for consistent aged beef production.

• Food Science of Animal Resources
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• v.30 no.3
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• pp.495-503
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• 2010

Analyses were conducted to estimate the effect of quality grade on the carcass characteristics, physico-chemical and sensory traits of Longissimus dorsi in Hanwoo. A total of 42,113 carcasses were selected on the basis of five quality grades (grade $1^{++}$, $1^+$, 1, 2, and 3) and an additional 258 samples of Longissimus dorsi were used to evaluate the beef quality. The increase in quality grade from grade 3 to grade $1^{++}$ was significant (p<0.05) for carcass weight (from 338.7 kg to 387.2 kg), backfat thickness (from 7.45 mm to 12.23 mm) and marbling score (from 1.09 to 8.31). In contrast, significantly decreased levels of meat color, fat color, texture and maturity were apparent with increasing quality grade (p<0.05). Increasing quality grade was also correlated with significant increases (p<0.05) in crude fat contents (from 3.57% to 25.68%) and water holding capacity (from 52.41% to 58.03), and a decrease of the Warner-Bratzler shear force from 8.29 kg to 2.83 kg. The highest $L^*$ value (41.53) and highest cooking loss (22.11%) were observed with grade $1^{++}$ and 3 beef, respectively. There was no difference observed on $pH_{24}$ (5.53 to 5.66) among the quality grades, which were within the normal range. Sensory evaluation experiments revealed that quality grades were associated with significantly altered (all p<0.05) tenderness, juiciness, flavor, and overall acceptability. The crude fat contents showed significant correlation with juiciness (r=0.59), tenderness (r=0.71), flavor (r=0.55), and overall acceptability (r=0.69). The lower sensory trait scores were related to higher WBs. Grade $1^+$ Hanwoo beef had a significantly higher WBs and lower fat contents when compared to grade $1^{++}$ Hanwoo beef (p<0.05).