Soo Kee Lee

Antioxidative Potential of Raw Breast Meat from Broiler Chicks Fed a Dietary Medicinal Herb Extract Mix

This study was performed to evaluate the antioxidative potential and quality of the breast meat of broiler chickens fed a dietary medicinal herb extract mix (MHEM, consisting of mulberry leaf, Japanese honeysuckle, and goldthread at a ratio of 48.5:48.5:3.0). A total of 480 one-day-old male Cobb broiler chicks were randomly allotted to 12 pens, with 40 birds per pen (replicate), and reared for 35 d. Dietary treatments consisted of a corn-soybean meal basal diet (control); a basal diet with 0.3% MHEM (T1); and a basal diet with 1% (T2) MHEM. At the end of the feeding trial, breast meat samples were excised and stored in a refrigerator at 4 degrees C to be analyzed at d 0, 3, and 7. The MHEM did not affect proximate composition of the breast meat. Total phenols content of the breast meats in the T1 and T2 diets was approximately 2 times greater than that of the control diet (P < 0.05). 1,1-Diphenyl-2-picrylhy-drazyl radical-scavenging activity and 2,2-azinobis-(3 ethylbenzothiazoline-6-sulfonic acid) cation-reduction activity were greater in the T2 diet at d 0 and in the T1 diet at d 3 compared with the control diet (P < 0.05). 2-Thiobarbituric acid-reactive substance values in the T1 and T2 diets were lower than in the control diet at d 3 and 7 and did not increase during storage, whereas the value in the control diet increased significantly. The pH of the T1 diet was significantly greater than that of the control diet at d 0 and 3. In a sensory test, panelists preferred the T1 breast meat throughout the 7-d storage period. This research indicates that dietary MHEM could increase the antioxidative potential and overall preference of breast meat during cold storage.

Changes in endogenous bioactive compounds of Korean native chicken meat at different ages and during cooking

This study aimed to examine the effect of bird age on the contents of endogenous bioactive compounds, including carnosine, anserine, creatine, betaine, and carnitine, in meat from a certified meat-type commercial Korean native chicken strain (KNC; Woorimatdag). Additionally, the effects of the meat type (breast or leg meat) and the state of the meat (raw or cooked) were examined. Cocks of KNC were raised under similar standard commercial conditions at a commercial chicken farm. At various ages (10, 11, 12, 13, and 14 wk), breast and leg meats from a total of 10 birds from each age group were obtained. Raw and cooked meat samples were then prepared separately and analyzed for bioactive compounds. The age of the KNC had a significant effect only on the betaine content. The breast meat of KNC had higher amounts of carnosine and anserine but had lower amounts of betaine and carnitine than the leg meat (P < 0.05). The KNC meat lost significant amounts of all bioactive compounds during cooking (P < 0.05). Leg meat had high retention percentages of carnosine and anserine after cooking, whereas breast meat showed almost complete retention of betaine and carnitine. The results of this study provide useful and rare information regarding the presence, amounts, and determinants of endogenous bioactive compounds in KNC meat, which can be useful for selection and breeding programs, and also for popularizing indigenous chicken meat.

Differentiation of Deboned Fresh Chicken Thigh Meat from the Frozen- Thawed One Processed with Different Deboning Conditions

This study was performed to evaluate the quality characteristics of three deboned categories of chicken thigh meat: one which was slaughtered and deboned in the same plant (fresh); one which was slaughtered, deboned, frozen, and thawed in the same plant (frozen-thawed); and the last which was slaughtered in a plant, deboned in a different plant, but then transferred to the original plant (fresh-outside). Surface color, drip loss, 2-thiobarbituric acid reactive substances (TBARS) value, sensory evaluation, and total aerobic bacterial counts of the chicken samples were determined. Moreover, the torrymeter was used to measure the differences in freshness of the chicken meat. The surface color and the TBARS values did not show significant differences among the three categories. However, the total aerobic bacterial counts of fresh-outside and frozen-thawed chicken meat were significantly higher than the fresh chicken meat on the first storage day, and the drip loss of frozen-thawed chicken meat was significantly higher than the fresh-outside and fresh chicken meat. In addition, the sensory evaluation of frozen-thawed chicken meat was significantly lower than the fresh-outside and fresh chicken meat. Torrymeter values were higher in fresh chicken meat than fresh-outside and frozen-thawed chicken meat during the storage period. These results indicate that the quality of frozen-thawed chicken meat is comparatively lower than the fresh chicken meat, and the torrymeter values can accurately differentiate the fresh-outside and frozen-thawed chicken meat from the fresh ones.

Combined Effects of High Pressure Processing and Addition of Soy Sauce and Olive Oil on Safety and Quality Characteristics of Chicken Breast Meat

This study was conducted to evaluate the combined effect of high pressure (HP) with the addition of soy sauce and/or olive oil on the quality and safety of chicken breast meats. Samples were cut into 100 g pieces and 10% (w/w) of soy sauce (SS), 10% (w/w) of olive oil (OO), and a mixture of both 5% of soy sauce and 5% olive oil (w/w) (SO) were pressurized into meat with high pressure at 300 or 600 MPa. Cooking loss was lower in OO samples than SS samples. With increased pressure to 600 MPa, the oleic acid content of OO samples increased. The total unsaturated fatty acids were the highest in SO and OO 600 MPa samples. Lipid oxidation was retarded by addition of olive oil combined with HP. The addition of olive oil and soy sauce followed by HP decreased the amount of volatile basic nitrogen during storage and reduced the population of pathogens. Sensory evaluation indicated that the addition of olive oil enhanced the overall acceptance and willingness to buy. In conclusion, the combination of HP with the addition of soy sauce and/or olive oil is an effective technology that can improve chemical, health, sensory qualities and safety of chicken breast.

The Effect of Washing of Carcasses with Sodium Hypochlorite Solution and Vacuum Packaging on the Microbiological and Physiochemical Quality of the Breast Meat from Old Hen during Storage at 4

Department of Agricultural Biotechnology, Seoul National University, 151-921, KoreaABSTRACT This study was conducted to examine the effect of spray-washing old hens (old laying hens, old molting hens and old breeder hens) carcasses with sodium hypochlorite (50 ppm) solution and vacuum packaging on the microbiological and physiochemical quality of breast meat during storage at 4. There were no significant differences of cooking loss and texture among breast meats from different birds with spray-washing by water or sodium hypochlorite solution before storage. The numbers of total aerobic bacteria of aerobically packaged and only water-washed breast meat were higher than 7 Log CFU/g (the limitation population for spoilage of meat) after 7 days of storage. However, the numbers of total aerobic bacteria of vacuum packaged breast meat washed by sodium hypochlorite solution were lower than 7 Log CFU/g even after 14 days of storage. The volatile basic nitrogen content of vacuum packaged breast meat were lower than 20 mg% (the limitation value for spoilage of meat) regardless of the washing method, while those of aerobically packaged breast meat washed by tap water and sodium hypochlorite solution were 41.1 and 20.1 mg%, respectively. In addition, lipid oxidation and change of pH in breast meat was inhibited by vacuum packaging when compared with that of aerobic packaged breast meat during storage. Therefore, the results indicated that the washing old hen’s carcasses with sodium hypochlorite (50 ppm) solution and vacuum packaging could improve the shelf-life of meat from old birds. This result can provide the basic information for industry, which are seeking for export market.(Key words : old hen, sodium hypochlorite, vacuum packaging, shelf-life)Authors, Jae Cheon Na and Sun Hyo Kim contributed equally as co-first authorship.

Effect of Irradiation on the Mixture of Egg White Proteins Responsible for Foaming Property

Xian De Liu, Rong Xiu Han, Dong Il Jin, Soo Kee Lee and Cheorun JoDepartment of Animal Science and Biotechnology, Chungnam National UniversityABSTRACTIrradiation of egg white increased foaming ability significantly. To investigate the protein modification by irradiation responsible for the increase of foaming ability, 3 major egg white proteins were purchased and mixed(7.7g/L ovalbumin, 1.8g/L ovotransferrin, 0.5g/L lysozyme) as a model system and irradiated at 0, 2.5, and 5kGy. The different protein expressions were evaluated using 2-D electrophoresis and it was found that ovotransferrin was cleaved by irradiation and molecular weight and isoelectric point were changed. In addition, many uncharacterized proteins were found and it indicated that irradiation modified proteins randomly but mainly fragmentation was observed. Therefore, it can be concluded that protein fragmentation of 3 major egg white proteins responsible for foaming ability may be the main reason for the improvement of foaming ability.(Key words : Irradiation, Egg white protein mixture, Foaming ability, 2-D electrophoresis)

Quality Prediction of Eggs Treated in Combination with Gamma Irradiation and Chitosan Coating Using Response Surface Methodology

The aim of this work was to determine the method and predict the optimum conditions for egg quality stored for 7 days when combination treatments of irradiation and chitosan coating were applied using response surface methodology (RSM). A central composite design was chosen for the RSM in this study and the factors were irradiation dose (0~2 kGy) and concentration of chitosan coating material (0~2%). Performance of the irradiation and chitosan coating were evaluated by analyzing the egg quality and functional property factors. The predicted maximum level of Haugh units and foaming ability calculated by a developed model were 74.19 at 0 kGy of irradiation with coating by 0.96% chitosan solution and 50.83 mm at 2.0 kGy with 1.01%, respectively. The predicted minimum value of foam stability and 2-thiobarbituric acid reactive substances (TBARS) value were 2.97 mm at 0.39 kGy with 0.21% and 0.54 mg malonaldehyde/kg egg yolk at 0 kGy with 0.90% of chitosan solution, respectively. Results clearly showed that gamma irradiation negatively affected the Haugh unit and TBARS but positively affected the foaming capacity. The estimated value from the developed model by RSM was verified by no statistical difference with observed value. Therefore, RSM can be a good tool for optimization and prediction of egg quality when 2 or more treatments are combined. However, one should decide the target quality first to achieve a successful implementation of this technology. (Key words : Egg, Irradiation, Chitosan, Response surface methodology)

Effects of Molasses Addition on the Feeding Value of Socheongryongtang(Herbal Medicine) Meal Silage

ABSTRACT Two experiments were conducted to investigate effects of molasses addition to silage materials in ensiling Socheongryongtang meal on the nutritive quality of silage, palatability and various ruminal parameters in Korean native goats. In Experiment 1, Socheongryongtang meal silage was produced by the addition of 0, 0.5, or 1.0% molasses and stored for 40 days at room temperature. There were three replicates per treatment. Lactic acid contents of Socheongryongtang meal silage containing molasses (0.5 and 1.0%) were significantly (p<0.05) higher than that of the control (0%). However, the pH and butyric acid contents of Socheongryongtang meal silage containing molasses (0.5 and 1.0%) were lower than those of the control (0%). In addition, molasses (0.5 and 1.0%) increased the number of lactobacillus , but decreased the number of fungi in Socheongryongtang meal silage. In vitro dry matter disappearance tended to increase by molasses addition. In Experiment 2, three 1.5-yr-old Korean native female goats were employed in cross-over design to measure the palatability and various ruminal parameters of Socheongryongtang meal silage. Feed intake of Socheongryongtang meal silage containing molasses (0.5 and 1.0%) for 30 min significantly higher than that of control (0%). Silmilar trend was found when the feed intake was measured for 6 hr. In various ruminal parameters, molasses addition to silage materials increased propionic acid (P) and total volatile fatty acid contents, but decreased pH, acetic acid (A), and butyric acid. The A/P ratio was the lowest in 1.0% molasses treatment group. It is concluded that molasses addition in ensiling Socheongryongtang meal could enhance its nutritional quality and lengthen storage period. Also the palatability of silage was improved by the addition of molasses. (