• Korean Journal of Environmental Agriculture
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• v.32 no.1
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• pp.9-16
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• 2013

BACKGROUND: Eutrophication occurs occasionally in reservoirs around lake in summer and early autumn. Lakeside macrophyte which is one of internal pollutants effects on water quality when it is submerged during rainy season. To improve water quality of water supply source in Boknae reservoir around Juam lake, characteristics of nutrient(N, P) uptake and release by submerged plants were investigated. METHODS AND RESULTS: In order to establish the management plan of submerged plants in Boknae reservoir around Juam lake, water level, rainfall, flooding and non-flooding areas, biomass of dominant plants, contents of nitrogen and phosphorus were investigated during 7 months(August, 2010 through February, 2011). Dominant plants were Miscanthus sacchariflorus(MISSA) and Carex dimorpholepis(CRXDM) in Boknae reservoir. Total plant area of Boknae reservoir in August, 2010 was 987,872 $m^2$. In Boknae reservoir, flooding occurred from August until February caused by rainfall during rainy season. The total amounts of nitrogen and phosphorus uptakes by MISSA were 247 and 22 kg/total reservoir area, respectively. By CRXDM, the total amounts of nitrogen and phosphorus uptakes were 11,340 and 1,231 kg/total reservoir area, respectively. The total amounts of nitrogen and phosphorus residues by MISSA were 34 and 11 kg/total reservoir area, respectively. By CRXDM, the total amounts of nitrogen and phosphorus residues were 491 and 68 kg/total reservoir area, respectively. CONCLUSION(S): Total amounts of nitrogen and phosphorus releases in Boknae reservoir were 12,212 and 1,324 kg/total reservoir area, respectively. The results demonstrate that total nitrogen and total phosphorus in water were strongly influenced by submerged plants. Therefore, management plan for submerged plants during rainy season will be needed to improve water quality of water supply source in Boknae reservoir around Juam lake.

• Food Science of Animal Resources
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• v.26 no.3
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• pp.297-305
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• 2006

This study was conducted to evaluate the quality characteristics of low-fat emulsion type sausages containing 0% tomato powder (C), 5.0% ground raw tomato paste (T1) and 0.5% freeze dried tomato powder (T2) during storage at $5{\pm}1^{\circ}C$ for 30 days. The crude protein content of T2 was significantly lower (p<0.05) than that of the other sausage types. Moisture, crude fat and crude ash contents of the sausages during storage were not affected by the addition of tomato. The pH and shear force ($kg/cm^2$) values of C were significantly higher (p<0.05) than those of T1 and T2. There was no significant difference among the different sausages in cooking loss, ranging from $13.00{\sim}14.98%$. The WHC values of T1 and T2 were significantly higher (p<0.05) than that of C. The values of TBARS were significantly (p<0.05) increased for ail sausages following storage. The TBARS value (mg MA/kg) of C was significantly higher (p<0.05) than those of T1 and T2 at 15 days of storage, however T1 was significantly higher (p<0.05) than the other sausages after 30 days of storage. The meat color values tended to decrease with increased storage time. Microorganism analysis revealed that all sausage types did not reach $4.4log_{10}CFU/g$ until 30 days of storage. The texture, brittleness, Hardness, and springiness of each sausage type were not significantly different after 1 day of storage, while the cohesiveness, gumminess and chewiness of T1 and T2 were significantly higher (p<0.05) than that of C. T1 and T2 sausages had a slightly higher score regarding color, aroma, tenderness and overall acceptability, however the sensory evaluation score among the different sausage types was not significantly different (p>0.05). In conclusion, low-fat sausage with added tomato showed higher lipid oxidative stability during storage than sausage to which no tomato was added.

• Journal of Mushroom
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• v.12 no.2
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• pp.138-143
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• 2014

This study was conducted to know the optimal supplementary level of spent mushroom substrates (Flammulina velutipes) as an energy source and fermentation period in manufacturing of rye silage. Whole crop rye was harvested at full bloom stage and ensiled with spent mushroom substrates of 20%(S-20), 40%(S-40) and 60%(S-60) as fresh matter basis. Each silage was prepared in plastic buckets included with vinyl bag by three replications and fermented for 3, 6 and 9 weeks, respectively. Moisture contents of whole crop rye at full bloom stage and spent mushroom substrates were 62.3% and 54.3%, respectively, and those of silages was ranged from 58% to 64%. Ether extracts content of silages was significantly (P<0.05) increased in 6 weeks of fermentation period. The pH of silages ranged from 4.46 to 5.05, and fluctuated in the changes by fermentation period beside of decreased with elapsing the period in the S-60. The organic acid content of silages was higher in the order of lactic acid, butyric acid, acetic acid and propionic acid. Lactic acid content was higher when fermented for 6 weeks compared to the other fermentation period. Flieg's score for estimation of silage quality ranged from 63 to 80, and was relatively high level in the S-20 and the S-40 fermented for 6 weeks, and was high level in S-20, and was relatively low level in the silages fermented for 3 week. Hence, we suggest that supplementation of 20% spent mushroom substrates in fresh matter basis and fermentation for 6 weeks are resonable for a good quality of rye silage.

• Journal of The Korean Society of Grassland and Forage Science
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• v.28 no.2
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• pp.81-88
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• 2008

The study was conducted to investigate the effects of DM (dry matter) content and split application of liquid swine manure (LSM) on productivity of rye and subsequent soil quality on the pasture of Livestock Policy Division, Jeju Special Self-Governing Province. The experiment was done between November, 2005 and June 2006, using split plot design. Treatments were 2 main plots (7.0 and 1.6% DM LSM) and 2 subplots (basal fertilizer 100% and basal fertilizer 50%+top dressing 50%). Application of 7.0% DM LSM resulted in significant increase in DM yield and plant length of rye compared with 1.6% DM LSM (p<0.05). Crude protein content of rye was significantly higher in split application(basal fertilizer 50%+ top dressing 50%) than in basal fertilizer 100% (p<0.05). No significant difference in macro and micro mineral contents of rye or in subsequent soil quality was found by application of LSM. Mean P content (0.16%) of rye appeared to be lower than proper P level $(0.2{\sim}0.4%)$ of grass crop. The pH (5.5), OM (13.3%), available $P_2O_5$ (47.6 mg/kg) and Ca (2.75cmole/kg) content of the pasture soil studied were lower, compared with those of cultivated soil. Results show that the application of a 7.5% DM liquid swine manure increases the productivity of rye compared with a 1.6% DM liquid swine manure, meanwhile the property of pasture soil was not influenced by application of LSM.

• Horticultural Science & Technology
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• v.29 no.3
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• pp.217-223
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• 2011

This study was conducted to examine the effect of several pretreatments and holding solutions on the vase life and quality of cut Polygonatum odoratum var. pluriflorum for. variegatum stems native to Korea. Postharvest foliar spray of 200 $mg{\cdot}L^{-1}$ $GA_3$ or 200 $mg{\cdot}L^{-1}$ BA + 200 $mg{\cdot}L^{-1}$ $GA_3$ markedly extended the vase life of cut stems of Polygonatum odoratum var. pluriflorum for. variegatum. These treatments maintained high chlorophyll contents as compared with the control (distilled water) during senescence of cut stems. Postharvest pretreatment (dipping) with 100 $mg{\cdot}L^{-1}$ $GA_3$ or 3% sucrose + 200 $mg{\cdot}L^{-1}$ 8-hydroxyquinoline sulfate (HQS) + 100 $mg{\cdot}L^{-1}$ $GA_3$ for 16 hours extended vase life of cut stems 2.5 times as long as nontreated control. Holding solution of 2% sucrose + 200 $mg{\cdot}L^{-1}$ HQS + 100 $mg{\cdot}L^{-1}$ $GA_3$ significantly extended vase life by 3.5 times and increased fresh weight as compared with control. $GA_3$ were very effective on preventing leaf yellowing of cut Polygonatum odoratum var. pluriflorum for. variegatum stems. Postharvest foliar spray of 200 $mg{\cdot}L^{-1}$ $GA_3$ or holding solution of 2% sucrose + 200 $mg{\cdot}L^{-1}$ HQS + 100 $mg{\cdot}L^{-1}$ $GA_3$ markedly extended vase life and improved quality of cut stems of Polygonatum odoratum var. pluriflorum for. variegatum.

• Food Science and Preservation
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• v.23 no.7
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• pp.931-938
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• 2016

To evaluate the effect of freezing temperature on quality characteristics of dried persimmons, dried persimmons were frozen at $-50^{\circ}C$ (quick frozen, QF) and $-20^{\circ}C$ (slow frozen, SF) for 24 hr. Frozen persimmons were then stored at -20, -10, 0 and $10^{\circ}C$ for 80 days. Total free sugar content of SF persimmons was higher than those of QF in the $+10^{\circ}C$ and $-20^{\circ}C$ stored samples. Except for samples stored at $10^{\circ}C$, the CIE $L^*$ values for QF persimmons were higher than those for SF persimmons. For samples stored at $10^{\circ}C$ and $0^{\circ}C$, the CIE $a^*$ and $b^*$ values of SF samples were higher than those for QF samples. The texture of frozen dried persimmons was investigated to determine springiness, chewiness and hardness. Chewiness and hardness of samples held at $0^{\circ}C$ were higher in SF than in QF persimmons. However, when stored at $-10^{\circ}C$, chewiness and hardness were higher in QF than in SF samples. Springiness results were similar among the QF and SF persimmons held at different storage temperatures. For all storage temperatures, QF persimmons had a high soluble tannin content. All of the sample, the average soluble tannin contents of QF is 236.09 mg%. On the other hands, those of SF is 226.87 mg%. The results indicate that freezing rate and holding temperatures have significant effects on dried persimmon texture, soluble tannin level, and free sugar content. Further studies that include sensory evaluations are needed to determine the optimum freezing rate and holding temperature for dried persimmons.

• FLOWER RESEARCH JOURNAL
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• v.18 no.4
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• pp.238-243
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• 2010

This study was conducted to investigate effects of nutrient solution pH control agent and foliar spray of ethephon on the reduction of stem inside-cavity and improvement of flower quality in chrysanthemum 'Baekma'. Changes of pH in nutrient solution as affected by the kind of pH control agent showed more settled pattern in the plot of KOH treatment than in others. Plant growth and development such as cut flower length, leaf numbers, cut flower weight and petal number were the greatest in the plot of KOH. However, the size and area of stem cavity was large in KOH rather than $KHCO_3$. As changes in the absorbing patterns of mineral elements as affected by nutrient solution pH control agent in closed system, contents of total nitrate, phosphorus, potassium and calcium by $KHCO_3$ was absorbed into the plant less than KOH, so that it remained a lot of mineral element residues rather than KOH in closed system. Plant growth as affected by the foliar spray of ethephon showed growth retardation effect in the plot of solution diluted to 1 : 500 and growth promotion effect in the plot of solution diluted to 1 : 1,000 or 1 : 2,000. The number of petals was the best in the plot of foliar spray of ethephon solution diluted to 1 : 1,000 before flowering at 45 days showing 331 petals compared to control showing 302 petals. The size and area of stem cavity as affected the foliar spray of ethephon was smaller 1 mm and 7%, respectively, in the plot of solution diluted to 1 : 2,000 before flowering at 30 days than in control. Therefore, treating pH stabilization using KOH after floral initiation stage with the foliar spray of ethephon solution diluted to 1 : 2,000 before flowering at 30 days would help to reduce stem cavity size and improve flower quality in hydroponically grown chrysanthemum 'Baekma'.

• Food Science of Animal Resources
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• v.32 no.6
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• pp.820-827
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• 2012

This study was performed to evaluate the effect of yam (Diocorea japonica) extract by methanol on sausage quality during cold storage. Yam extracts were prepared by 70% methanol and concentrated using rotary evaporation. The total phenol contents of the extracts were 123.03 mg/g. 1,1'-diphenyl-2-picrylhydrazyl (DPPH) scavenging activity and super oxide dismutase (SOD) activity of the extracts were increased with dose dependently. Nitrite scavenging activity was also increased with the increase of concentration of yam extracts; in particular, 70 ${\mu}g/mL$ of the extracts showed 57.12% of nitrite scavenging activity. Sausages containing yam extracts showed lower pH than that of the control. In color, the lightness ($L^*$) of sausages with 1.0% of the yam extracts was lower than that of the control. Redness and yellowness of the sausages with 1.0% of the yam extracts were higher than those of the control. Thiobarbituric acid reactive substances (TBARS) value of the sausage with 1.0% of the extracts was lower than those of the control on days 9 and 12. However, the hardness of the sausage was increased with an increase in yam extracts. From these results, the yam extracts showed high antioxidant activity; moreover, it also retards the lipid oxidation of the sausages during cold storage. The yam extracts could be used as additives to prevent lipid oxidation of the sausage. Further study should be conducted in order to identify the optimum concentration of the extracts in meat products.

• Journal of the Korean Society of Food Science and Nutrition
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• v.13 no.2
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• pp.215-221
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• 1984

To investigate stability for the quality of selected ginseng products, their sorption properties were clarified in red ginseng extract(RGEP), and red ginseng extract powder(RGEP), and red ginseng extract tea(RGET). Simultaneously, the BET monolayer value of each product was determined in order to inquire out the possibility of establishment as a criterion for the optimum moisture content of the ginseng products. Based on the BET monolayer moisture level of spray dried RGEP which ranged from 4.08 to 4.65%, it would be desirable to establish the optimum moisture content of the products at 4.4${\pm}$0.3%. This is 1.3 to 1.9% lower than the criter on, "less than 6.0%". The optimum moisture level for RGET of which monolayer value ranged 0.93 to 1.37% would be 1.2${\pm}$0.17%. In this case, the maximum permissible limit of moisture content could presumably be raised up to 1.37% in place of current criterion, "less than l.2%". From the results of a study on the growth of molds, the optimum moisture content for RGE assumed to be extended up to 40.0${\pm}$1.07 despite 36.0${\pm}$1.0% of the present criterion. On the other hand, a storage study under the maltreated condition, $48{\pm}2^{\circ}C$ 75%RH, was also carried out in order to make it clear whether the BET monolayer values were able to be used as indices for optimum moisture level of the products. In all samples tested adsorption occurred at even higher levels of moisture than the monolayer values. However, since there are many other possible factors affecting the quality of products the optimum moisture content is preferable to be reduced to the monolayer value. As a result, it was proved that the optimum level of moisture for both RGEP and RGET could be established by the monolayer values.

• Journal of Korean Society of Forest Science
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• v.90 no.4
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• pp.513-523
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• 2001

This study was conducted to investigate influences of solifluction and sediment runoff on the stream water qualities during the spring season. The study sites were four points in the northeastern area of the Bukhansan National Park. And, field surveys were carried out in the spring of 1999, 2000 and 2001. The results of this study were summarized as follows; During the investigation period, the amounts of sediment caused by solifluction on stream side slopes in the downstream were 1.3~1.7 times as large as those in the upstream. The pH of sediment caused by solifluction was a potential influence on the pH of stream water. Amounts of dissolved $Cl^-$, $NO_3{^-}$ and $SO{_4}^{2-}$ in stream water were proportion to the average amounts of $Cl^-$, $NO_3{^-}$ and $SO{_4}^{2-}$ in the sediment caused by solifluction. In the spring, the average pH of stream water was lower than the first class of the river water quality standard because of increasing chemical concentration as well as the contents of anions($Cl^-$, $NO_3{^-}$ and $SO{_4}^{2-}$) in the spring season. Also, the average electrical conductivity of water in downstream was about 2.3-3.3 times higher than that in upstream. The amounts of anions($Cl^-$, $NO_3{^-}$ and $SO{_4}^{2-}$) of water in downstream were about 1.2~7.4, 1.1~3.9, 1.1~1.4 times higher than those in upstream, respectively. Therefore, these results showed that the water quality of downstream was worse than that of upstream. As a result of regression analyses, the linear and exponential equation of pH and water quantity was pH = 1.7926 ${\times}$ stream water quantity + 5.9577($R^2=0.46$), and those of electrical conductivity and water quantity was $EC=34.417e^{3.6334{\times}\text{stream water quantity}(m^3/sec)}$ ($R^2=0.44$).