• Food Science of Animal Resources
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• v.42 no.5
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• pp.723-743
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• 2022

Beef muscles from mature cows and bulls, especially those originating from the extremities of the carcass, are considered as underutilized due to unsatisfactory palatability. However, beef from culled animals comprises a substantial proportion of the total slaughter in the US and globally. Modern consumers typically favor cuts suitable for fast, dry-heat cookery, thereby creating challenges for the industry to market inherently tough muscles. In general, cull cow beef would be categorized as having a lower extent of postmortem proteolysis compared to youthful carcasses, coupled with a high amount of background toughness. The extent of cross-linking and resulting insolubility of intramuscular connective tissues typically serves as the limiting factor for tenderness development of mature beef. Thus, numerous post-harvest strategies have been developed to improve the quality and palatability attributes, often aimed at overcoming deficiencies in tenderness through enhancing the degradation of myofibrillar and stromal proteins or physically disrupting the tissue structure. The aim of this review is to highlight existing and recent innovations in the field that have been demonstrated as effective to enhance the tenderness and palatability traits of mature beef during the chilling and postmortem aging processes, as well as the use of physical interventions and enhancement.

• Journal of Animal Science and Technology
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• v.48 no.6
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• pp.921-932
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• 2006

Management to improve beef tenderness is always been a historical idea, but during the recent past it has become an issue of prime importance to the meat scientists and the industries as well. Variation in tenderness is the prime explanation for consumer’s dissatisfaction for the concern meat. It has been well documented that both postmortem proteolysis and sarcomere length have significant effect on meat tenderness and its consistency. Electrical stimulation and tenderstretch techniques have been used by a number of countries to underpin carcass quality assurance schemes focused on eating quality. The mechanism(s) by which the postmortem interventions improve tenderness (or prevent toughness) has not been fully elucidated. However, it is evident that electrical stimulation accelerates the development of rigor mortis so that prevention of cold shortening is possible and ageing commences at higher temperatures. On the other hand, tendersretch appears to prevent meat toughness via placing tension of the myofibrils and connective matrix during rigor development. Previous findings indicated that electrical stimulation and tenderstretch improved beef tenderness even for fattened cattle under moderate chilling conditions. Recent studies demonstrate beef tenderness to be one of the most important factors determining satisfaction levels of Korean beef consumers. There are number of studies which reported that electrical stimulation and tenderstretch techniques improved Hanwoo tenderness and color. It is believed that the techniques are mostly useful wherein controls of carcass size, fatness and/or chilling regimes are not easy such as Korean beef industry. However, Korean beef industry is one such area where postmortem intervention techniques have not been adopted so far. Taking into consideration of the Korean beef industry, wherein carcass size and fatness varies the post-slaughter intervention technique could be the most feasible measurement to ensure eating quality. The manuscript attempts to highlight the current knowledge aiming primarily towards the assurance of beef tenderness.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.7
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• pp.1019-1025
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• 2014

This study was conducted to observe the effects of crossbreeding and gender on the carcass traits and meat quality of Korean Native Black Pig (KNP) and $KNP{\times}Duroc$ crossbred ($KNP{\times}D$). A total of 50 pigs comprising seven KNP barrows, eight KNP gilts, twenty $KNP{\times}D$ barrows and fifteen $KNP{\times}D$ gilts were used in this study. Animals were reared in the same housing condition with same feed diet for six months prior to slaughter. After an overnight chilling, the carcasses were graded, and samples of Musculus longissimus dorsi were obtained for meat quality analysis. The slaughter and carcass weights and dressing percentage of $KNP{\times}D$ were higher (p<0.001) than those of KNP. The slaughter and carcass weights and backfat thickness of barrows were higher (p<0.01) than those of gilts. There were no significant difference in carcass conformation and quality grade between KNP and $KNP{\times}D$ as well as barrow and gilt. Fat content of $KNP{\times}D$ was higher (p<0.001) than that of KNP. Fat content of barrow was higher (p<0.001) than that of gilt. There was interaction between crossbreeding and gender on the fat content. KNP gilt showed higher fat content than KNP barrow whereas $KNP{\times}D$ barrow showed higher fat content than $KNP{\times}D$ gilt. Lightness, redness, yellowness, chroma and hue angle values and color preference of meat of $KNP{\times}D$ were lower (p<0.001) than those of KNP. Redness, yellowness and chroma values of meat of barrow were lower (p<0.05) than those of gilt. It is concluded that crossbreeding KNP with Duroc increases carcass productivity and meat fat but decreases meat color values and preference. Crossbreeding of KNP with Duroc produces a better fat deposition in meat of barrows than in gilts.

• Food Science of Animal Resources
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• v.41 no.1
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• pp.34-44
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• 2021

Buffalo animals are slaughtered at their early age and carcasses are chilled rapidly which deteriorates its meat quality and decreases the consumer likeliness of buffalo meat. This study investigated the appropriate methods to prevent the quality deterioration of buffalo meat during chilling. Twenty four 18-mon-old buffalo bulls were slaughtered, electrically stimulated and suspended either by hip or achilles tendon. After 24 h postmortem, meat quality characteristics were recorded. Results showed that electrical stimulation (ES) led to rapid decline of carcass pH compared to non-ES method (p<0.05). Furthermore, electrically stimulated meat presented lower shear force accompanied with the higher CIE L⁎, a⁎, and b⁎ values (p<0.05). Suspension methods only affect the meat shear values and were lowered in hip suspended samples. It can be concluded that ES combined with hip suspension can be adopted to prevent the meat quality deterioration of young buffalo bulls during postmortem storage.

• Korean Journal of Agricultural Science
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• v.42 no.1
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• pp.29-35
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• 2015

This study was performed to analyze the distribution and antimicrobial resistance of pathogenic microorganisms isolated from the carcass and environments of chicken processing plant located in Gyeonggi province from October to November in 2010. Chicken slaughterhouse was visited 3 times and totally 40 samples were collected from chicken carcass before and after washing (n=14), chicken cuts (n=7), cooling water (n=8), brine (n=2), cutting knives (n=7) and working plate (n=2). Whole-chicken rinsing technique (for chicken carcasses) and swab technique (for working plate and knives) were used to analyze the distribution of pathogenic microorganisms. In addition, brine and chilling water from storage tanks were gathered using sterilized tubes and used as samples. The matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS) for whole cell fingerprinting in combination with a dedicated bioinformatic software tool was used to identify the isolated microorganisms. The pathogenic microorganisms, such as Bacillus cereus (n=8) and Staphylococcus aureus (n=9), were isolated form the chicken processing process (chicken carcasses of before and after chilling, chicken cuts, and working plate). The antimicrobial susceptibility of those isolated microorganisms was analyzed using 21 antimicrobial agents. In the case of B. cereus, it showed 100% of resistance to subclasses of penicillins and peptides, and it also resistant to cephalothin, a member of critically important antimicrobials (CIA), however there was no resistance (100% susceptible) to vancomycin and chloramphenicol. S. aureus showed 100% resistance to subclasses of peptides and some of penicillins (penicillin and oxacillin), however, it showed 100% susceptibility to cephalosporins (cefazolin and cephalothin). All of the tested pathogens showed multi drug resistance (MDR) more than 4 subclasses and one of B. cereus and S. aureus showed resistance to 9 subclasses. After the ban on using the antimicrobials in animal feed in July 2011, there would be some change in microbial distribution and antimicrobial resistance, and it still has a need to be analyzed.

• Food Science of Animal Resources
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• v.25 no.1
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• pp.1-6
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• 2005

To evaluate the microbiological quality of pork carcasses at different slaughtering process in large and small scale slaughtering houses, swabbing method was used to analyze microorganisms on the surface of pork belly in each process of before evisceration, after evisceration, before final wash, after final wash and in chilling. In autumn time, large scale slaughterhouse showed lower incidence of aerobic microorganisms (10²∼10³ CFU/㎠) than those of small scale slaughterhouse (10⁴∼10/sup 5/ CFU/㎠) during all processing lines. Samples from cold room of large scale slaughterhouse showed lower incidence of aerobic cells (10² CFU/㎠) than small scale slaughterhouse (10⁴ CFU/㎠). In winter and spring time, large scale slaughterhouse showed lower incidence of aerobic microorganisms than those of small scale slaughterhouse during the slaughtering process of before evisceration, after evisceration and before final wash, except spring samples from before final wash and chilling at cold room storage in spring time. After final wash, different sampling place of carcass such as belly, ham, jowl showed the different washing effect depending on the small and large scale slaughterhouse. After final wash, ham and belly had lower aerobic cell counts, but jowl had higher aerobic cell counts than each site before final wash.

• Journal of Environmental Health Sciences
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• v.22 no.1
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• pp.45-50
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• 1996

The application of HACCP system, which was adopted by Codex Alimentarius Committee for the safe meat and poultry production, is one of the urgent task for competing in the world trade markets. But there have been no useful analytical studies to identify the causes of contamination in the poultry meat processing plants in Korea. This study was conducted to investigate the potential hazards during the operations by the microbiological examination for the poultry meat processing plant (20,000 birds capacity a day) located in Kangwon province. In spite of air contamination of work places, it may not directly affect the surface contamination of poultry meats. But the risk of Campylobacter jejuni/coli contamination was high. The number of total count was decreased about ten times, but remarkable changes of microbial contamination could not be recognized in each procedure during the operations. The washing water was already contaminated as much as $10^{3-6}CFU/ml$ in SPC before the operations. It means that to keep water tanks hygienic is a primary step to prevent the occurrences of microbial contamination. The overflow and recirculation of water in scalding, washing, and chilling was aslo an important factor for a hygienic control. Based on this study, the followings could be regarded as an important factors for hygenic control in the poultry slaughtering plants on a small scale. The temperature of water used for scalding should be constantly maintained on a required temperature, and the overflow rate of 1~1.5 liter per bird. The carcass surface and the body cavity should be washed thoroughly and the cross-contamination due to facilities, workers, and tools should be prevented. The chilling water sholud be maintained under 5$\circ$C of temperature with ice and overflow, and residual chlorine level of 50 ppm.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.12
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• pp.1645-1656
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• 2010

This study was conducted to investigate the effects of strain on broiler performance, and age at slaughter and postchilling (PC) aging time on meat quality traits. A total of 500 one-day-old chicks (250 Hubbard classic and 250 Lohman) were reared under commercial conditions. Half of the broiler birds from each strain were slaughtered at 32 days and the other half at 42 days old. At each processing day, 168 carcasses were randomly selected (84 Hubbard and 84 Lohman) and divided into groups of 28 carcasses within each strain, and aged for 0, 4 and 24 h after chilling. Average weekly body weight was comparable between strains. Feed conversion ratio was higher (p<0.05) for the Hubbard strain during the second and third week of age. Initial carcass pH was significantly (p<0.05) affected by age where younger birds (32-d-old) had lower pH values than older (41-d-old) birds. Breast temperature was higher (p<0.001) for Lohman than Hubbard at 0, 2 and 4 h of PC. Younger birds had a lower breast temperature (p<0.001) at all measured times of PC. Thaw loss, cook loss and water holding capacity were not significantly affected by strain, age or aging time. Lohman strain had more tender meat (p<0.05) than Hubbard strain, and tenderness was improved with the increase of broiler age and aging time. Meats from Hubbard were lighter and less red than those from Lohman strain where younger birds had darker color. In conclusion, strain, age at slaughter and PC aging duration are critical to breast meat quality characteristics, and 4 h of aging are required before deboning in order to obtain more tender fillets.

• Journal of Animal Environmental Science
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• v.17 no.2
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• pp.101-106
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• 2011

One hundred and forty-four cross-bred market pigs weighing approximately 110 kg were randomly divided into four groups in a 2 (handling stress; minimal vs stimulated) ${\times}$ 2 (transport vehicle type; enclosed box vs conventional open) factorial arrangement of treatments. The stimulated handling stress group received overally rough handling including electric prod stimulation during loading, transport and lairage at least once at each step. All the animals received 3-h lairage prior to slaughter. Blood and longissimus dorsi muscle (LM) samples were taken at slaughter and after overnight chilling of the carcass, respectively. Plasma concentrations of stress indicators glucose, cortisol, creatine kinase and lactate dehydrogenase were greater in the stimulated vs minimal handling stress group. There were no interactions between the handling stress and transport vehicle type in their effects on these blood variables. The incidence of pale, soft and exudative (PSE) carcass and drip loss of LM, 24-h postmortem LM pH and color including the lightness and redness were not affected by the handling stress and transport vehicle type. In conclusion, results suggest that rough handling inflicts a stimulated stress on the animal, which is manifested by increased blood concentrations of stress indicators, and therefore should be avoided for animal welfare.

• Food Science of Animal Resources
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• v.18 no.4
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• pp.322-331
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• 1998

Good temperature control in the chill chain is imperative for maintaining safety and quality of the fresh meat. Therefore, the actual state of temperature or relative humidity histories of fresh meat product from carcass chill room to retail shop and the temperatures of chill and freezing rooms at local butcher shops were monitored by means of data loggers. The relative humidity and air temperature in carcass chill room were between 86 and 98%, and -3 and 0$^{\circ}C$, respectively. The surface temperatures of boxed beef measured in winter, when the outside air temperature was measured between -2 and -5$^{\circ}C$, were recorded between 1 and 3$^{\circ}C$, although transport vehicle switched off the chilling unit during transportation, However, the inside temperatures of chill transport vehicle measured in summer, when the transport time was prolonged to maximum 8 hrs, were raised to 10 to 15$^{\circ}C$, in worst case up to 25$^{\circ}C$. In that case, however, the inside temperature of boxed beef was maintained generally lower than 5$^{circ}C$ as the loading and unloading were finished within 30 min. The storage temperatures for meat in the subfreezing room, at which the butcher shops in local market are used to set to facilitate the thin slicing of meat, were measured between -2 and -8$^{\circ}C$. Furthermore, the temperatures of storage room for vacuum packaged meat in the chilled meat retail shops were maintained generally between 0 and +2$^{\circ}C$.