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.

The study was conducted to investigate the differences in the compounds responsible for volatile flavors in Hanwoo and imported fresh beef from Australia, United States and New Zealand. Different imported beef samples were prepared as Angus beef from Australia, United States and New Zealand and the cross beef from the United States. Significant differences (p<0.05) in hexanal, benzaldehyde, octanal, nonanal, nonenal, decanal, E-2-decenal, hexadecyloxirane, tetradecanal, 2,2-dideutero octadecanal, octadecanal, pentadecane, 2,5-dimethyl pyrazine, 4-methyl-2-propyl-furan, 2-hexylfuran, 2-butylfuran, 2- pentylfuran, 2-heptyl furan were observed between loin and eye of round from Hanwoo and imported beef (p<0.05). In loin muscles, various volatile compounds such as hexanal, heptanal, octanal, E-2-octenal, nonenal, E-2-decenal, E,E,2,4-decadienal, 2-undecenal, heptane, 2-butyl furan were found to be significantly higher in Hanwoo beef as compared to imported beef. However, in the round muscles of Hawnoo eye compounds that were observed to be significantly higher were pentanal, hexanal, heptanal, benzaldehyde, octanal, nonanal, E-2 -decenal, octadecanal, 2-furan methanol and 2-pentyl furan. Further study need to be determined if those volatile compounds can be used as a bio-marker to identify origins of beef.

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.

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 aroma patterns of Hanwoo (Korean cattle) beef by using an Electronic nose. The M. longissimus muscle and Semimembranosus muscle after 24 hours postmortem was obtained, and half muscles cooked in water batch until internal temperature arrived at 70℃ or microwave for 30 sec. The raw and cooked beef samples stored at 1℃ for 11 days. Sensitivity values (dR/RO) among electronic nose data were changed differently by muscle parts, heat treatments and storage days. The dR/RO values from SY/LG, T30/1, P10/1, P10/2 were decreased at 11th storage compared with those at 1th storage. Mapping these data by using PCA (principal component analysis) showed that raw and cooked beef data were presented on the right and left side of board, respectively. The data of 1st storage were presented on the right side, and flock together. Otherwise, the data of 11th storage were spreaded out more widely on the left side. Consequently, the dR/RO value and PCA mapping by Electronic nose data showed difference by sample treatments and storage days. Therefore it will be possible to able to detect separated aroma patterns of Hanwoo beef by using an Electronic nose.

Recently there has been an increasing amount of foreign livestock products distributed in the domestic market due to the market opening. Some vicious dealers sell the foreign beef in the trade name of the native beef during the final distribution step to arouse the social criticism frequently. In this report, we investigated a method to distinguish the native beef from the foreign one scientifically using the PCR-RAPD, a recent gene technique. Hygienical safety was also examined using a microbiological test for toxicity of Escherichia coli O157:H7 and the food poisoning bacteria. The conditions of DNA amplification for the PCR analysis were 1 × Taq polymerise buffer, 1.5 mM MgCl₂, 50 uM dNTP, 100 ng primers, 2.5 unit Taq polymerise and 5-20 ng template DNA, with the final volume of 50 Etl. The size of the amplified product was detected mostly in the range of 0.5-2.0 kbp. The size of DNA, gene marking factor, which could be a criterion distinguishing the native beef from the foreign one, appeared approximately 1.2 kbp. The native beef was distinguished from the foreign beef with more than 90% of confidence by the gene marking factor. This method was expected to be useful in the breed discrimination between the native beef and the foreign one. The hygienical test results showed that, fortunately, neither Salmonella spp. and Listeria monocytogenes which form a principal cause of the food poisoning nor Enterohemorrhagic Escherichia coli : EHEC which have provoked a recent social disturbance, were detected at all.

The objective of this research was to investigate the effect of immersion in Rhus verniciflua Stokes extract (RVSE) on the total reducing ability (TRA), protein oxidation and myoglobin oxidation of beef steak (Hanwoo longissimus muscle) stored with high oxygen-modified-atmosphere packaging (MAP) (HOMAP, 75% O2+20% CO2+5% N2) and low oxygen-MAP (LOMAP, 0% O2+20% CO2+80% N2) at 4℃ for nine days. RVSE induced TRA (p<0.05), metmyoglobin (MetMb) formation, and the CIE Ho value but reduced the carbonyl content and R630-R580, as an index of the intensity of redness by oxymyoglobin, and the CIE L*, a*, and C* values. HOMAP maintained a lower TRA, MetMb concentration, and CIE H° value but had higher R630-R580 and CIE L*, a*, and C* values compared to LOMAP. Therefore, RVSE induced TRA and protein oxidation stability but reduced myoglobin stability in Hanwoo beef steak. In addition, the effects of HOMAP were opposite those of RVSE.