• Food Science of Animal Resources
• /
• v.31 no.1
• /
• pp.100-106
• /
• 2011

The physicochemical characteristics of chicken breast were determined to identify the optimal ratio of $CO_2$ and $N_2$ to maintain chicken breast quality during cold storage for 6 d. The mixing ratios of $CO_2$ and $N_2$ were 20:80, 40:60, 60:40, and 80:20, respectively. The pH of the chicken breast packed with 80% $CO_2$ and 20% $N_2$ was lower than that of the control on day 1 (p<0.05). The lightness ($L^*$) of the breast increased with increasing $CO_2$ during storage (p<0.05), whereas no difference was found for redness ($a^*$) and yellowness ($b^*$). A lower volatile basic nitrogen level was found for chicken breasts exposed to higher $CO_2$ levels. Furthermore, lipid oxidation of the chicken breast packed with $CO_2$ decreased with increasing $CO_2$ level, and 40% $CO_2$ significantly reduced 2-thiobarbituric acid reactive substances (TBARS) values on days 1 and 6. The total number of microbes was reduced in chicken breast exposed to more than 40% $CO_2$ during storage days 3 and 6 (p<0.05); however, Escherichia coli was not affected by $CO_2$ level. Coliforms of chicken breast were reduced in the 40% $CO_2$ level on storage day 3. Moreover, tray-packed chicken breast exposed to 40% $CO_2$ did not collapse. These results suggest that 40% $CO_2$ and 60% $N_2$ were the optimal conditions for packaging chicken breasts during cold storage.

• Food Science of Animal Resources
• /
• v.27 no.1
• /
• pp.87-94
• /
• 2007

This study was carried out to know the effect of the oriental medicinal plants byproduct containing vitamin E and 0.1% antibiotics (T1) and the oriental medicinal plants byproduct containing vitamin E and the replacing antibiotics by 0.03% herb extracts (T2) and 0.1% aminolevulinic acid (T3) on production performance of finishing hog and its meat qualities. There were no significant differences in the daily weight gain, feed intake, and feed conversion rate values between all treatment groups. However, the T2 group tends to have a higher daily weight gain (g/day) than the other groups (p>0.05). The T2 group showed lower total-cholesterol and LDL-cholesterol contents (114.71 and 68.09 mg/dl, respectively) than the control in the blood serum (p<0.001), and all the treated groups of oriental medicinal plants byproduct and vitamin E increased HDL-cholesterol and decreased LDL-cholesterol contents in the blood serum. Content of vitamin E in muscles from the group T1, T2 and T3 (2.11, 2.21 and 2.18 mg $kg^{-1}$, respectively) showed higher levels than those of control. The presence of antibiotics (chlortetracycline) in hog loin meat were detected (0.08 ppm) in control sample. However, there was no antibiotic in other treated hog loin meats (T1, T2 and T3, respectively). The thiobarbituric acid reactive substances and volatile basic nitrogen values of the groups T2 (0.06 mg MA $kg^{-1}$ and 11.21 mg%, respectively) and T3 (0.05 mg MA $kg^{-1}$ and 8.23 mg%, respectively) were significantly (p<0.05) lower than that of control in loin meat. However, there was no significant difference between treated samples (T1, T2 and T3, respectively) and control in cooking loss and drip loss.

• Food Science of Animal Resources
• /
• v.29 no.2
• /
• pp.194-202
• /
• 2009

This study was conducted to determine the effects of gamma and e-beam irradiation on the quality of minced pork and pork patties. Each sample was irradiated at 5 to 20kGy, and its quality characteristics were then evaluated during storage at 30. The results of the total bacterial populations in the minced-pork and pork patty samples showed that the antimicrobial effect of gamma irradiation was superior to that of e-beam irradiation. The 2-thiobarbituric acid reactive substances (TBARS) value of all the samples significantly increased (p<0.05) as the irradiation dose and storage period increased. In addition, the gamma-irradiated (GI) samples had higher (p<0.05) TBARS values than the e-beam-irradiated (EI) samples. The volatile basic nitrogen contents of the GI samples were lower (p<0.05) than those of the EI samples. The color values, such as the $L^*$(brightness), $a^*$(redness), and $b^*$(yellowness) of the minced pork and pork patties, were increased (p<0.05) by irradiation. The hardness and sensory properties, such as the color, chewiness, taste, and overall acceptability of the pork patties, were decreased when the irradiation dose increased, and the hardness and sensory scores of the GI samples were lower than those of the EI samples.

• Korean Journal of Soil Science and Fertilizer
• /
• v.18 no.3
• /
• pp.247-253
• /
• 1985

In order to investigate the effects of water temperature on chemical properties of soil and nutrient uptake of rice plant, four varieties of rice were cultivated in a field where water temperature range was $17.3-23.0^{\circ}C$ and plant samples were taken at three growing stages and were analyzed in detail. The results were summarized as follows: 1. Organic matter content and pH of surface soil were showed no differences while the contents of $P_2O_5$ and $SiO_2$ were increased and potassium was decreased as the water temperature increased. 2. The amounts of nutrient uptake were related to the water temperature and the total nutrient contents of rice plants at harvesting stage were in order of $SiO_2$ > $K_2O$ > T-N > $P_2O_5$ > MgO. The rate of $SiO_2$/N and $K_2O$/N of rice plants grown at water temperature $23.0^{\circ}C$ were over two times to those of the water temperature $17.3^{\circ}C$. 3. Nutrient contents of rice plants showed a increasing tendency as increasing the water temperature. However, nutrient contents such as T-N at whole period, $P_2O_5$ at heading and harvesting stage, and $K_2O$ at heading stage were higher at low water temperature than those of high water temperature. 4. Most of nitrogen was translocated and accumulated in grain, potassium in straw respectively. All nutrients translocated to grain more easily as the water temperature increased.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.4 no.1
• /
• pp.33-39
• /
• 1999

In order to understand the importance of tidal action and $NH_4{^+}$ -nitrification in the removal of dissolved oxygen (DO) and $NH_4{^+}$, concentrations of DO, $NH_4{^+}$, $NO_2{^-}$ and $NO_3{^-}$ were measured with time for water samples collected at different tidal state in the eutrophic macrotidal Han River estuary. Field measurements indicated that most environmental parameters, except for the water temperature and DO concentration, were tightly controlled by the eutrophic freshwater runoff and large-scale tidal action. Dark incubation of the water sample at $25^{\circ}C$ showed that the removal rates of DO and $NH_4{^+}$ in high tide sample were 2.76 ${\mu}M\;O_2\;d^{-1}$ and 1.76 ${\mu}M\;N\;d^{-1}$ respectively, and increased to 5.66 ${\mu}M\;O_2\;d^{-1}$ and 3.36 ${\mu}M\;N\;d^{-1}$ respectively, in low tide sample. These changes indicated that microbial degradation and uptake of organic matter and inorganic nutrients were more active during low tide. $NH_4{^+}$-nitrification responsible for total DO removal in low tide (23.81%) and $NH_4{^+}$ turnover rates due to $NH_4{^+}$-nitrification in low tide (0.18 $d^{-1}$) were approximately 3.7 times and 3 times, respectively, higher than those in high tide. These results indicated that $NH_4{^+}$ -nitrifying bacteria introduced into the Han River estuary during low tide played a significant role in the removal of DO and $NH_4{^+}$. The decreasing removal rates in DO and $NH_4{^+}$ with the increasing tidal level seemed to be associated with the salinity impact on the halophobic freshwater $NH_4{^+}$-nitrifying bacteria. The results implied that anthropogenic $NH_4{^+}$ sources should be treated prior to the freshwater runoff into the estuary for the effective control of $NH_4{^+}$ in the Han River estuary. These results also suggest that parallel ecological studies on the chemoautotrophic nitrifying bacteria are essential for the elucidation of nitrogen cycles in the eutrophic Han River estuary.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.19 no.1
• /
• pp.53-65
• /
• 2014

In order to estimate the effect of nutrients addition for phytoplankton growth and community compositons in spring and summer season, we investigated the abiotic and biotic factors of surface and bottom waters at 20 stations of inner and offshore areas in Gwangyang Bay, Korea. Nutrient additional experiments were also conducted to identify any additional nutrient effects on phytoplankton assemblage using the surface water for the assay. Bacillariophyceae occupied more than 90% of total phytoplankton assembleges. Of these, diatom Eucampia zodiacus and Skeletonema costatum-like species was mainly dominated in spring and summer, respectively. Here, we can offer the season why the two diatom population densities were maintained at high levels in both seasons. First, light transparency of spring season in the euphotic zone was greatly improved in the bay. This improvement is one of important factor as tigger of increase in E. zodiacus population. Second, low salinity and high nutrient sources supplied by Seomjin River discharge are a main cue for strong bottom-up effects on S. costatum-like species during the summer rainy season. Based on the algal bio-assays, although maximum growth rate of phytoplankton communities at inner bay (St.8) were similar to those of outer bay (St.20), half-saturation constant ($K_s$) for phosphate at outer bay was slightly lower than those of inner bay. This implied that adapted cells in low nutrient condition of outer bay may have enough grown even the low phosphate and they also have a competitive advantage against other algal species under low nutrient condition. In particular, efficiency of N (+) addition in summer season was higher compared to control and P added experiments. In the bay, silicon was not a major limiting factor for phytoplankton growth, whereas nitrogen (N) was considered as a limiting factor during spring and summer. Therefore, a sufficient silicate supply form water mixing Si recycled from diatom decomposition and river water is favorable form maintaining diatom ecosystems in Gwangyang Bay.

• Korean Journal of Medicinal Crop Science
• /
• v.9 no.2
• /
• pp.91-98
• /
• 2001

Scutellaria baicalensis G. was cultivated in plots of different soil textures which were sand loam(SL), loam(L) and clay loam(CL). Also three fertilizer conditions were used; non application (NA)treatment, rice straw manure(RSM) treatment and N-P-K, chemical fertilization(CF) treatment. The chemical-physical properties, such as organic matter, available phosphate, $K_2O$, CaO, clay contents and porosity ratio in CL plot with RSM application were the most proper in CL plot and RSM application for the culture of S. baicalensis plants. RSM had very high contents of total nitrogen, 2.25% and C/N ratios, 21.4. Thus the growth of shoot and root in loam plot with RSM treatment were greater compared to that of CL plot with NA treatment. Whereas, The highest baicalin, baicalein and wogonin contents in roots were found in CL plot with RSM treatment. There was significantly positive correlation between aerial and underground parts of plant, yield and contents of T-N, $K_2O$ but negatively correlated with the contents of baicalin, baicalein and wogonin in S. baicalensis roots.

• The Korean Journal of Mycology
• /
• v.16 no.3
• /
• pp.135-143
• /
• 1988

The treatments of $H_2O_2$ were more effective on the degradation of difficult digestible materials by increasing the treatment concentration and adjusting the pH to alkaline. The smaller particle size of rice straw was, the more these effect. $2N_2CO_3{\cdot}3H_2O_2$, didn't need to adjust on pH, but the effect of treatment was lower than $H_2O_2$(pH 11.5) treatment. Lignin and hemicellulose content were decreased by the alkaline peroxide treatments. The fermentation of rice straw which pretreated with alkaline peroxide, the content of total nitrogen and ash increased. And NDF, hemicellulose and lignin were decreased, and ADF and cellulose decreased as the lower concentra­tion of treatment. The digestibility of rice straw which treated alkaline peroxide was increased with increasing the treatment concentration. The treatment of 12% $H_2O_2$(pH 11.5) and 12% $2Na_2^-CO_3{\cdot}3H_2O_2$ increased the digestibility from 31.1% to 89.4% and 76.8% compared with nontreated rice straw, respectively. The digestibility of fermented rice straw which pretreated with alkaline peroxide was effectively increased as the pretreatment concentration was low. Semi-dry treat­ment of $H_2O_2$ decreased the ADF and cellulose, and exhibited the 57.5% of digestjbility. Fer­mentation of rice straw which semi-dry treated with 4% $H_2O_2$, increased the digestibility from 33.4% to 63.4% compared with control.

• Journal of Animal Science and Technology
• /
• v.47 no.5
• /
• pp.825-836
• /
• 2005

This study was carried out to evaluate the quality characteristics of the fermented pork with soy sauce, red pepper paste and soybean paste. The ham of pork were cut to cube (7 × 10 × 2 cm³) and Korea traditional seasonings such as soy sauce (T1), red pepper paste (T2), soybean paste (T3) were seasoned by the proportions of meat to seasonings (1:1), respectively. The pH of fermented pork with soybean paste seasoning were significantly higher compared to those for fermented pork with soy sauce and red pepper paste seasoning at 1 and 28 days of storage, but were significantly lower at 14 days of storage. The water-holding capacity of fermented pork with soy sauce seasoning were significantly higher compared to those for fermented pork with red pepper and soybean paste seasoning at 28 days of storage. The surface meat L* values of fermented pork with soybean paste seasoning were significantly higher compared to those for fermented pork with soy sauce and red pepper paste seasoning, but a* and b* values of fermented pork with red pepper paste seasoning significantly higher. The volatile basic nitrogen (VBN) of fermented pork with soybean paste seasoning were significantly lower compared to those for fermented pork with soy sauce seasoning at 1 and 28 days of storage. The shear force and thiobarbituric acid reactive substances (TBARS) of fermented pork with soybean paste seasoning were significantly lower compared to those for fermented pork with soy sauce and red pepper paste seasoning. The total plate counts of fermented pork with soybean paste seasoning were significantly higher compared to those for fermented pork with soy sauce and red pepper paste seasoning at 14 days of storage, but were significantly lower at 28 days of storage. The Escherichia coli of fermented pork with soy sauce and soybean paste seasoning were significantly lower compared to those for fermented pork with red pepper paste seasoning at 1 day of storage. The Lactobacilli spp. of fermented pork with red pepper paste seasoning were significantly lower compared to those for fermented pork with soy sauce and soybean paste seasoning.

• Journal of Animal Science and Technology
• /
• v.47 no.5
• /
• pp.837-850
• /
• 2005

This study was conducted to investigate the changes of quality characteristics on seasoned pork with Korean traditional 4 types seasoning such as soybean sauce(T1); Kimchi sauce(T2); pickled shrimps sauce(T3); onion sauce(T4). The seasoned samples were aged at 10±1℃ for 13 days. The results obtained were as follows; Except for T2, pH of treatments were significantly decreased(P<0.05) as aging period increased. Salinity(%) and saccharinity(%) of seasoned meat were tended to increased during aging period. Thiobarbituric acid reactive substances(TBARS) were increased significantly during storage in all treatment(P<0.05). T4 showed the highest TBARS among the all treatment groups. Volatile basic nitrogen(VBN) values of all treatments were significantly increased(P<0.05) as storage period increased. There were no significant differences in water holding capacity(WHC) among the all treatments, and those values were not changed by the passage of storage days. Shear force values of all treatments were tended to decreased by the passage of storage days. In surface color, the values of L*, a* and b* showed a tendency of increasing value along the storage days. The values of a* and b* of T2 were significantly higher than other treatments during aging period(P<0.05). In inner color, a* and b* values of T2 were significantly higher than those of other treatments during aging period(P<0.05). In the sensory evaluation of cooked meat, T3 treatment resulted in lower score in aroma, flavor, tenderness, juiciness and overall acceptability. The number of total plate counts and Lactobacilli spp. tended to increase with storage in all treatments group. The numbers of Escherichia coli were not changed by the passage of storage time.