The aim of this study was to compare the effects of different thawing methods including; refrigerated at 4℃ for 6 hr, soaked in 15℃ water for 40 min, exposed to room temperature (25℃) for 4 hr, and microwaved (600 W) for 2 min on the water-soluble nutritional component and meat quality trait of Hanwoo beef. The thawing beef by the refrigerated method resulted in significantly lower cooking loss, drip loss and loss of water-soluble vitamin B group, whereas the water-soaked method had higher loss of vitamin B group (p<0.05). Furthermore, total aerobic counts and coliforms were significantly lower in the meat samples thawed by the refrigerated method than that in the samples thawed by the other methods when stored for 6 days at 4℃. However, the thiobarbituric acid reactive substance (TBARS) content was found significantly (p<0.05) higher in the microwaved method than that in the other thawing methods. Based on the results obtained in the present study, it is concluded that the thawing methods had remarkable impact on the water-soluble nutritional components, quality properties and storage stability of meat. Therefore, the present study recommends that the thawed meat needs to be consumed and should not be stored for long time due to the acceleration of its quality deterioration

This research was conducted to estimate the effect of packaging methods on the color and taste-related precursors in Hanwoo (Korean cattle) beef during aging. Following packaging with vacuum (VACP), low oxygen-modified atmosphere (LOMAP; 0% O2/20% CO2/80% N2) or vacuum skin+LOMAP (VSP+LOMAP), the loins and top rounds were aged at 2℃ for 14 days and lipid oxidation (TBARS content), surface color, glucose and lactate contents were measured. TBARS and glucose contents were not different by packaging methods in both loins and top rounds. The a* (redness), b* (yellowness) and C* (chroma) values were higher (p<0.05) in VACP-aged beef as compared to the other beef. Lactate content was significantly higher (p<0.05) in both LOMAP- and VSP+LOMAP-aged beef than in VACP-aged beef at day 14 of aging. These findings suggested that VACP was the most effective in maintaining color stability but LOMAP was more effective in maintenance of some taste-related precursor compared to VACP.

The objective of this study was to investigate meat quality and nutritional composition of 10 cuts (loin, striploin, chuck roll, chuck tender, short plate, brisket, bottom round, top sirloin, eye of round, and top round) from quality grade 1 beef from 11 Hanwoo steers at Hanwoo Experimental Station of National Institute of Animal Science. The protein contents were higher in top round (Udoon) and eye of round (Hongduke) and lower in loin (Dngsim) and short plate (Abjin) when compared to the other cuts (p<0.05). Whereas the intramuscular fat contents were highest in loin (12.51%), those were lowest in top round (4.14%) (p<0.05). The calories were higher in loin and short plate and lower in top round, chuck tender (Guri), top sirloin (Bosup), eye of round, chuck roll (Moksim), and bottom round (Sulgit) (p<0.05). The cooking loss (%) was 24.38% in loin and it was lower than the other cuts (p<0.05). The bottom round had higher water holding capacity (WHC) and chuck tender had lower WHC than those in the other cuts (p<0.05). In meat color, L* values were higher in loin and lower in top round than the other cuts (p<0.05). Total saturated fatty acid contents were higher in loin and lower in bottom round than the other cuts (p<0.05). In amino acid compositions, top round had significantly higher than those in the other cuts (p<0.05). The iron contents were higher in chuck tender and chuck roll contained higher iron contents than those of the other cuts (p<0.05). In conclusion, the meat quality and nutritional properties were significantly different among 10 cuts in the same quality grade of Hanwoo beef. Therefore, the provision of the meat quality and nutritional information of 10 cuts to consumers could be important for utilization and balanced consumption of different cuts.

근내지방도(IMF)가 한우육의 품질 및 기능성분에 미치는 영향을 조사하기 위하여, 250두의 한우를 근내지방 함량 에 따라 Low(<14%, n=96), Medium(14～17%, n=83), High(>17%; n=71) 세 그룹으로 분류하고, 7일간 숙성 후 등심육의 품질 및 기능성분을 분석하였다. 한우 등심육의 수분 함량은 IMF와 반비례하였으며, High IMF 그룹은 Low IMP 그룹 에 비하여 낮은 드립 감량을 나타내었다. 기능성 didpeptide 함량은 IMF에 따라 유의적 차이가 없었으나, High IMF 그룹은 다른 그룹보다 낮은 inosine monophosphate, 높은 hypoxanthine, 낮은 histidine 함량은 나타내었다. 불포화지방산 의 비율은 IMF에 따라 유의적 차이가 없었다. 저지방육의 건강지향적 가치를 고려할 때 지나친 IMF를 목표로 하는 육종 및 사양은 지양되어야 할 것으로 판단되었다.

This study was conducted to investigate the effect of age on the oxidative stability of Hanwoo (Korean cattle) cow beef. The samples of M. longissimus dorsi from 65 and 133 months-old-Hanwoo cows (4 and 3 heads, respectively) were stored at 4±0.2℃ for 9 days. The proximate composition, total myoglobin content, pH value, water-holding capacity and drip loss were not significantly affected by age. At day 9 of storage, the lipid oxidation (2-thiobarbituric acid reactive substances) was significantly (p<0.05) higher in beef from 133 months-old-cows than 65 months-old-cows. Lower (p<0.05) oxymyoglobin concentration and R630-R580 value and higher (p<0.05) metmyoglobin concentration were observed in beef from 133 months-old-cows at day 9 of storage than 65 months-old-cows. The CIE a*, b* and C* values were significantly (p<0.05) lowered in beef from 133 months-old-cows at day 9 of storage than 65 months-old-cows. It could be concluded that old age decreased the lipid oxidation stability and myoglobin oxidation stability in Hanwoo cow beef.

This study was carried out to investigate the effect of muscle part and aging period on free amino acids and aroma compounds of Hanwoo (Korean cattle) cow beef. The M. longissimus (ML) and M. semitendinosus (MS) from 101 mon-old-cows were aged at 2℃ for 14 d. The free amino acids concentration increased in both ML and MS on 14 d of aging. In ML, asparagine, glutamine, histidine, glycine, threonine, arginine, tyrosine, phenylalanine, isoleucine, leucine and lysine were significantly (p<0.05) higher than those in MS. Varieties of aldehydes, ketones, alcohols, hydrocarbons, nitrogen and sulfur compounds were detected in both ML and MS and majority of these compounds showed increasing trend on aging. The ML had higher 14 aldehydes (acetaldehyde, 2-methylpropanal, 3-methylbutanal, 2- methylbutanal, pentanal, hexanal, heptanal, E-2-heptanal, octanal, 2-octenal, 2-nonenal, E-2-decenal, E,E-2,4-decadienal and 2-undecenal), 5 ketones (2-propanone, 2,3-butanedione, 2-butanone, 2-heptanone and 2,3-octanedione), 4 alcohols (ethanol, 1-pentanol, 1-hexanol and 1-octanol), 3 hydrocarbons (3-ethyl-2-methyl-1,3-hexadiene, 3- methyldecane and 2,2-dimethyloctane) significantly (p<0.05) compared with MS. However, the MS had higher 5 nitrogen and sulfur compounds (methanethiol, dimethyldisulfide, fufural, 2,5-dimethylpyrazine and 2-octylfuran) significantly (p<0.05) compared with ML.

This study was carried out to investigate the effect of amino acids complex and choline supplementation on the antioxidant enzyme activities and oxidative stability of Hanwoo (Korean cattle) beef. Fifteen months-old-Hanwoo steers were assigned into two groups and fed on a basal diets with or without amino acids complex (≥25% L-lysine monohydrochloride+≥8% DL- methionine)+choline (≥25% choline chloride) for 12 months. After slaughter, the M. longissimus from carcasses were stored at 4℃ for 7 days. Catalase, glutathione peroxidase and total superoxide dismutase activities were found to be unaffected by supplementation of amino acids+choline. After 2 days of storage, significant decline (p<0.05) in lipid oxidation (2-thiobarbituric acid reactive substances, TBARS) was observed when supplemented with amino acids+choline. However, supplementation of amino acids+choline maintained meat color as indicated by higher CIE L* (Lightness), a* (Redness), b* (Yellowness) and C* (Chroma) values during storage. It was therefore concluded that supplemental amino acids+choline could stabilize the lipid oxidation stability and meat color in Hanwoo beef.

The current study was carried out to investigate the effect of addition of Rhus veniciflua Stokes oil (RVSO) and black garlic extract (BGE) on the lipid oxidation in Hanwoo (Korean cattle) beef model systems. The RVSO at 0.2% inhibited the TBARS (2-thiobarbituric acid reactive substances) formation when tested in liposome model system. The antioxidant effect of RVSO was further found to be similar to 0.2% butylated hydroxy toluene (BHT) and 0.01% vitamin E. On the other hand, BGE at 0.1% also showed the inhibition of TBARS formation in 4% NaCl-added Hanwoo beef patty and found to have slightly lower (p<0.05) effect than 0.1% vitamin E but higher (p<0.05) effect than 0.1% BHT. Results of this study indicated that both RVSO and BGE possess strong antioxidant effects and help to increase the oxidative stability in Hanwoo beef products.

The present study was performed to determine beneficial effects of donkey meat extract supplementation (15 and 30 mg/kg B.W.) on streptozotocin (STZ) induced diabetic rat. Rump muscle of donkey was extracted by boiling in water for 3 hrs and supplemented to STZ induced diabetic rats for 6 weeks. Feed and water intake of STZ induced diabetic rats were higher than those of normal rats, while no significant difference was found in DME treated rats as compared to the rats in control group. STZ-induced diabetic rats did not improved their body weight as compared to that of rats in the control group. However, blood glucose level of 30 mg DME supplemented rats was found to be significantly reduced after 4 weeks of supplementation (p<0.05) when compared to the control animals. Administration of DME did not show any improving effect on serum lipids (HDL-cholesterol, total cholesterol, and triglyceride). No significant changes were noticed in terms of weight of all the visceral organs of animals fed on DME except liver. It is therefore, concluded that supplementation of DME with dose of 30 mg/B.W. resulted in decreased blood glucose levels, however, blood lipid profile of diabetic rats, having more than 400 mg/dl glucose level, did not change.

This study was carried out to investigate the effect of market weight on the sensory attributes of Korean native black pork. The M. longissimus from Korean native black pigs (KNP) with market weight of 56 kg and 70 kg were utilized as experimental materials. The intramuscular fat content, a* (redness) and b* yellowness) values were higher in KNP with market weight of 70 kg than in KNP with market weight of 56 kg (p<0.05). In TPA, hardness, adhesiveness, guminess and chewiness were lower in KNP with market weight of 70 kg than in KNP with market weight of 56 kg (p<0.05). The marbling score, meat color and overall liking among sensory evaluation of raw pork and taste, texture and overall liking among sensory evaluation of cooked pork were higher in KNP with market weight of 70 kg than in KNP with market weight of 56 kg (p<0.05). Therefore, higher market weight of KNP increased the sensory attributes of pork.

In this study, dietary Rhus verniciflua Stockes were feeded on the porks and Hanwoo beef to determinate sanitation effects. this experiment was performed to measure oxygen contents and total flavor compounds of pork and beef inoculated Pseudomonas aeruginosa in headspace with SPME-GC. The headspace oxygen contents in Hanwoo beef were no difference on the diet supplementation ratio of Rhus verniciflua Stokes during storage at 5℃. Headspace oxygen contents of teratment dieted for 5 and 6months were higher than that of treatment dieted for 3 and 4months. No remarkable difference was observed in headspace oxygen contents in pork between control and treatment during storage at 0℃. Oxygen contents in pork of treatment diet containing 4% Rhus verniciflua Stokes was higher than that of treatment were lower than that of control on Hanwoo beef. Flavor compounds were the lowest in diet supplemented 6% of Rhus verniciflua Stokes during 4 months. Flavor compounds of pork is no change at 0℃. The longer storage periods It had the more increasing total flavor compounds and Rhus verniciflua Stokes supplement ratio had no effects on change of total flavor compounds. Such as this experiment, Flavor compounds and oxygen contents in headspace could be analyzed by SPME-GC method promptly and easily in accordance with, it is expected to apply SPME-GC method to evaluation of food quality.

This study was carried out to investigate the comparison of meat quality of Korean native black porks and modern genotype pork fed high and low lysine levels of diets at growing and finishing stages during refrigerated storage after thawing. M. longissimus from Korean native black pigs (gilts) with a live weight of 65 kg and modern genotype pork (gilts) with a live weight of 110 kg were frozen at -80 ℃ for 1 month and placed in the dark room at 1℃ for 7 days after thawing. The moisture content was significantly lower in modern genotype pork fed high lysine level of diets than to the other treatments (p<0.05), but crude fat content was significantly higher in modern genotype pork fed high lysine level of diets (p<0.05). The pH value and sensory evaluation were significantly higher in Korean native black pork than to modern genotype pork (p<0.05), and the drip loss was significantly lower in Korean native black pork (p<0.05). CIE L*, ho and hunter L were significantly lower in modern genotype pork fed high lysine level of diets than to modern genotype pork fed low lysine level of diets (p<0.05). Myristate, palmitate and saturated fatty acid content were significantly lower in Korean native black pork fed high lysine level of diets than to Korean native black pork fed low lysine level of diet (p<0.05), but unsaturated fatty acid content and UFA/SFA ratio were higher in Korean native black pork fed high lysine level of diets (p<0.05). Consequently, as Korean native black pigs were fed high lysine level of diets at growing and finishing stages, saturated fatty acid content of pork increased but unsaturated fatty acid content and UFA/SFA ratio of pork decreased. And the water-holding capacity, color stability and sensory evaluation of Korean native black porks were better than those of modern genotype pork.

This study was carried out to investigate the comparison of quality characteristics of Korean native black porks fed high, medium and low levels of lysine diets at growing and finishing stages during refrigerated storage. M. longissimus from Korean native black pigs (gilts) with a live weight of 65 kg were placed in the dark room at 4℃ for 7 days and utilized for the quality measurements. The proximate composition, drip loss, TBARS value and sensory evaluation of raw and cooked meat were not affected by dietary lysine level. Korean native black pork fed low lysine diets showed the highest redness (a*) at day 7. Consequently, as Korean native black pigs were fed low lysine diets at growing and finishing stages, it was effective in color stability of porks.

This study was carried out to investigate the effect of feeding level of dietary lysine on the quality of Korean native black pork during cold storage (4℃). After 54 Korean native black pigs was fed by the high, medium, low lysine dietaries at 25 kg live weight, the M. longissimus from 6 carcasses (3 gilts, 3 barrows) slaughtered at 65 kg live weight stored at 4℃ for 7 days. The proximate composition, drip loss, cooking loss, sensory evaluation was affected by feeding level of dietary lysine. The pH value was significantly higher in high lysine treatment than in the other treatments until 5 days (p<0.05) and significantly lower in medium lysine treatment (p<0.05). The CIE L* value was significantly higher in gilts among high lysine treatment (p<0.05) and increased significantly in all treatments until 5 days (p<0.05). The CIE a*, b*, C* values were higher in low lysine treatment. The hardness, adhesiveness, springiness, cohesineness, guminess, chewiness were lower in low lysine treatment and those in 7 days were lower than in 0 day.