• KOREAN JOURNAL OF CROP SCIENCE
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• v.56 no.4
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• pp.404-412
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• 2011

This experiment was conducted to clarify the effect of the temperature for grain filling duration on quality and taste of cooked rice cultivated in different region in Korea. In 2006 and 2007, 4 mid-late maturing group of rice varieties (Nampyeongbyeo, Ilpumbyeo, Junambyeo and Dongjin 1) were cultivated in 28 experimental plots of 27 different regions located in 8 provinces. The taste of cooked rice were positively correlated with 1,000 grain weight but negatively correlated with protein content of brown rice. Mean temperature for 30 days from heading was more closely correlated with grain filling and tastes of cooked rice than those for 40 days. Though, the optimum mean temperature for the best taste of cooked rice for 30 days after heading was 22.1 to $23.1^{\circ}C$ depending on varieties, in general, 1,000 grain weight and cooked rice taste were the highest in the mean temperature of $22.2^{\circ}C$ for 30 days from heading. But grains were poorly ripened in case of the mean temperature lower than $21.0^{\circ}C$ for 30 days after heading. Therefore, for the better taste of cooked rice in Korea, the developing new rice varieties and cultivation method should be focused to adjust the mean temperature within $22-23^{\circ}C$ during the period of 30 days after heading.

• Journal of Aquaculture
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• v.21 no.4
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• pp.226-233
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• 2008

This study investigated the effects of dietary moisture level and storage temperature on lipid oxidation and fatty acids composition of the extruded pellet feed. The diets containing the moisture levels of 5%, 15% and 25% were prepared by adding moisture (water) to the commercial extruded pellets and stored at $5^{\circ}C$, $20^{\circ}C$ (room temperature) and $35^{\circ}C$. The samples for analysis were collected at every 2 days for 10 days. Acid value (AV), peroxide value (POV), 2-thiobarbituric acid (TBA) value and fatty acid composition of the feeds were measured. No differences in the AV, POV and TBA value were observed in feed containing 5% moisture at all storage temperatures for 10 days. However, the AV, POV and TBA value of diets containing 15% and 25% moisture increased rapidly at $20^{\circ}C$ and $35^{\circ}C$ after 4 days. Fatty acids compositions of feeds containing 5% moisture did not change during the storage periods at $5^{\circ}C$ and $20^{\circ}C$. However, 5% moisture feed stored at $35^{\circ}C$ increased monoene fatty acid content and decreased the contents of polyene fatty acid, PUFA (polyunsaturated fatty acid)/SFA (saturated fatty acid) and $(C_{20:5}+C_{22:6})/C_{16:0}$ after 4 days. Also, 15% moisture feed stored at $35^{\circ}C$ showed increased monoene fatty acid content and decreased $(C_{20:5}+C_{22:6})/C_{16:0}$ after 2 days. The diet containing 25% moisture showed increased monoene fatty acid content and decreased contents of PUFA, PUFA/SFA and $(C_{20:5}+C_{22:6})/C_{16:0}$ at all temperatures after 2 days. In this study, lipid oxidation can occur in the extruded pellet feeds of 15% and 25% moisture at room temperature after 2 days.

• Journal of Bio-Environment Control
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• v.27 no.2
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• pp.125-131
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• 2018

The effect of 1-methylcyclopropene (1-MCP) in the storability of kimchi cabbage at cold storage condition was investigated. Kimchi cabbage (Brassica campestris L. cv Ryouckgwang) was divided four groups, forced air cooling (FAC), FAC + 0.03 mm linear low density polyethylene liner (Liner), $FAC+2{\mu}L{\cdot}L^{-1}$ 1-MCP (1-MCP), and FAC + 1-MCP + Liner. After each treatment kimchi cabbage was stored at $2^{\circ}C$, 95% RH. Quality parameters were weight loss, soluble solids content (SSC), firmness, and color ($CIE\;L^*$, $a^*$, $b^*$, chroma, hue angle). Weight loss during storage was showed significant difference by Liner treatment. In particular FAC + 1-MCP + Liner treatment showed 12.5% reduction after 6 weeks of storage period and minimized the weight loss rate compared to other treatments. SSC of kimchi cabbage was $2.5^{\circ}Brix$ at harvest and FAC + 1-MCP + Liner treatment maintained the SSC until 3 weeks, while in other treatments gradually were increased. The firmness of kimchi cabbage was 24.0 N immediately after harvest and the firmness at harvest time tended to be maintained at 22.6 N after 6 weeks of storage in FAC + 1-MCP + Liner treatment. During the storage period, the color change of the kimchi cabbage leaf can be confirmed by $CIE\;a^*$ and hue angle value. 1-MCP treatment alone did not affect the color change, however 1-MCP + Liner treatment was able to maintain the chromaticity at harvest time while minimizing the change of $CIE\;a^*$ and hue angle. These results suggest that 1-MCP treatment is not effective for the storage of kimchi cabbage but can be maintained for up to 6 weeks when treated with Liner.

• The Korean Journal of Ecology
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• v.24 no.5
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• pp.281-288
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• 2001

The relationships between the growths of Abies koreana W. and climatic factors were analyzed by the use of tree-ring analysis at the subalpine belt of Mt. Halla National Park. The four cores were extracted from each 21 trees at north-facing slope (1,900m a.s.1.). The site chronology was established on the periods from 1912 to 1999. The growth of A. koreana was very poor, in particular in the years of 1982, 1988 and 1996. Simple correlation was employed to analyze the relationship between the growth of A. koreana and climatic factors. The result of simple correlation indicates that the growth of A. koreana represent positive correlations both with the mean temperatures of April and previous November, and the precipitation of previous December and January. The presence of large number of frost-damaged scars in the individual trees of A. koreana implies that local freezing temperature conditions at Mt. Halla have occurred in 1964, 1965 and 1966. The correlations between the fir chronology SOI(Southern Oscillation Index) of previous January, February and November were significantly positive. The growth ratio of A. koreana demonstrates that this species is sensitive to seasonal variations. As the winter temperature rises, the growth ratio of A. koreana decreases, on the other hand, the increase of autumn temperature accelerates the growth ratio of A. koreana. The growth decline of A. koreana was observed from 51 cores out of the 54 cores, and the overall growth declines have initiated at 1978, 1982 and 1988. Distinct growth decline of A. koreana in the range of 70% is noticed at 34 cores out of the 51 cores. The decline of, A. koreana growth appears to be related to the winter temperature which has increased since mid-1970s.

• Journal of Bio-Environment Control
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• v.18 no.4
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• pp.385-392
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• 2009

This study was performed to evaluate the influence of temperature, relative humidity, and light conditions during healing and acclimatization on the graft-take and growth of grafted peppers (Capsicum annuum L.), in order to propose optimum environmental conditions for the healing and acclimatization of grafted peppers. The healing and acclimatization period was for six days and was divided into three stages (Stage I, II and III), of which each period was two days. Grafted peppers were healed under the condition of 30 and 95% relative humidity (RH) during Stage I. During Stage II and III, grafted peppers were healed and acclimatized under different temperatures ($20^{\circ}C$, $25^{\circ}C$, or $30^{\circ}C$) and RH conditions (75%, 85% or 95%). The growth of grafted peppers was greater under lower temperature and lower relative humidity conditions. The graft-take just after the end of healing and acclimatization was greater grafted peppers under high RH condition. However, the graft-take of peppers which were healed and acclimatized under $30^{\circ}C$ and RH 95%, dropped by about 10 percent on day seven after healing and acclimatization. And also, grafted peppers were healed and acclimatized under the different temperatures ($25^{\circ}C$ or $30^{\circ}C$), RH conditions (65%, 75% or 85%), and light condition (dark or light). Lower RH (to 65%) and light condition at $25^{\circ}C$ during healing and acclimatization promoted the graft-take and growth of grafted peppers.

• Korean Journal of Environment and Ecology
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• v.22 no.4
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• pp.409-419
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• 2008

The purpose of this study is to compare the differences in aboveground flora and underground flora between a forest road and a forest edge and to clarify each characteristic through ecological approach to a forest road. The study site was the forest planted with Pinus koraiensis and Abies holophylla, and located at an altitude of 45m($36^{\circ}36'23''N127^{\circ}21'45''E$). The width of the forest road is 3.2m. This research set the forest edge within the areas 5m away from the forest road and also conducted a survey on vegetation 5 times from september 2006 to August 2007. In addition, it installed thirty six quadrats to make an analysis of reclaimed soil seed bank. Soil amounting to 600$cm^3$ was collected from each quadrat using soil samplers(100$cm^3$),which was preserved in low temperature refrigeration for a month. Soil was thinly strewed evenly on trays and watered every four or five days; then, this research did experiment for six months until no more germination took place. Through this process, this research identified species and counted the number of germinating individuals by using emerging seedlings. The research result showed that on the whole, the similarity index between aboveground flora and underground flora was low. The correlation coefficient between the aboveground flora vegetations both on the forest road and on its edge was found to be 0.36, showing a correlation with each other(p<0.05). On the other hand, the correlation coefficient between underground flora vegetations through the analysis of reclaimed soil seed bank was 0.20, showing no correlation with each other(p>0.05). As the survey result of naturalized plants, there existed 7 species of naturalized plants on the forest road in case woody plants were included, showing 11.11% naturalization rate and 2.61% urbanization index(UI). On the other hand in case woody plants were not included among the naturalized plants, the naturalization rate on the forest road was 12.50% while the naturalization rate on the edge of the forest was 9.09%.

• Korean journal of applied entomology
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• v.46 no.1 s.145
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• pp.37-42
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• 2007

To construct a life table and development model Schizaphis graminum (Rondani), its adult longevity and fecundity were studied at various constant temperatures ranging from 15 to $32.5^{\circ}C$, with $65{\pm}5%$ RH, and a photoperiod of 16L:8D. Adult longevity of the greenbug gradually increased with decreasing temperature below $32.5^{\circ}C$. Total fecundity was not significantly different at all temperatures except at $32.5^{\circ}C$. Daily fecundity gradually increased from $25.0^{\circ}C$. It was 3.6 at $27.5^{\circ}C$ and as temperatures either went down or up, it decreased to 1.4 at $15.0^{\circ}C$ and 0.4 at $32.5^{\circ}C$ Net reproduction rate (Ro) was highest with 47.6 at $25.0^{\circ}C$. The intrinsic rate of increase per day $(r_m)$ and the finite rate of increase per day $({\lambda})$ were highest with 0.4 and 1.5 at $30.0^{\circ}C$, respectively and the doubling time (Dt) was shortest with 0.98 at $32.5^{\circ}C$. The mean generation time (T) was 8.41 at $30.0^{\circ}C$.

• Applied Biological Chemistry
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• v.48 no.2
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• pp.132-139
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• 2005

The major obstacle in the popularization of Chungkookjang is the short shelf-life of $2{\sim}3$ months and some problems concerning storage including the growth of molds even in the products even within shelf-life. To solve these problems we conducted a research to improve its storage by using the vacuumed packaging and sanitary method through seed culture, innoculation and sterilization. For the optimization of storage time, temperature and sterilization temperature, we measured viable cell numbers of bacteria and fungi, amount of gas outbreak and contents of amino type nitrogen and monitored these experimental results by response surface methodology of SAS program, so that we could observe the quality changes of Chungkookjang during shelf-life. Especially fungi, which are the biggest troublemaker in Chungkookjang shelf-life, couldn't be detected from the generally and vacuum-packed samples; also, viable cell numbers were highly influenced by sterilization temperature and in vacuum-packed samples. In the case of vacuum-packed samples, amount of gas outbreak was highly influenced by sterilization temperature of its storage conditions and it was higher in generally packed samples as compared to vacuum-packed samples even at any storage conditions. The changes of pH in generally and vacuum-packed samples were highly influenced by the storage temperature. As the temperatures of storage and sterilization were higher and the storage time was longer, so the amount of gas outbreak was accordingly lower. These results showed that amino type nitrogen contents in generally and vacuum-packed samples were systematically influenced by the temperature, storage time and sterilization temperature. Also the result showed that the change of amino type nitrogen contents during storage was less in vacuum-packed samples than in general ones. Based on the above results, we can produce Chungkookjang products with extended shelf-life of as far as 6 months without any quality change using sanitary manufacturing method, vacuumed packaging condition, sterilization in $70^{\circ}C$ for 60 minutes and storage under $10^{\circ}C$ during shelf-life. According to this research, we have the possibility to greatly increase the goods value of Chungkookjang by developing the manufacture processing and packaging.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.12
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• pp.1808-1815
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• 2016

In this study, quality characteristics of three different kinds of Gat Kimchi, added with Cheonnyuncho fruit (C-fruit) water extract, Cheonnyuncho cladodes (C-cladodes) water extract, and without Cheonnyuncho water extract (control group), were investigated during storage for 80 days at $5{\pm}1^{\circ}C$. In terms of mineral content of Gat Kimchi, C-fruit group showed higher calcium and zinc contents than the control group, whereas Cheonnyuncho groups showed higher iron content, and C-cladodes showed higher potassium content than the control group. The pH was mostly higher in Cheonnyuncho groups than in the control group until 40 days of storage, whereas the pH of the C-cladodes group significantly decreased after 60 days. On the other hand, titratable acidity showed the reverse tendency during storage. Hunter's color L, a, and b values all increased during the storage period. The hardness value was significantly higher in Cheonnyuncho groups than in the control group after 40 days of storage, and hardness value of the C-fruit group was significantly higher than those of the other groups after 80 days of storage. In terms of sensory evaluation, there was no significant difference between the control group and Cheonnyuncho group during fermentation. As a result, the study suggests that addition of C-fruit extracts increase nutrition and function of Gat Kimchi during storage.

• Journal of Dairy Science and Biotechnology
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• v.16 no.2
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• pp.90-97
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• 1998

This study was carried out to investigate changes of microbiological and sensory properties in various heat-treated market milks (LTLT, HTST, and UHT milks) stored at 10$^{\circ}C$ during 15d. Titratable acidity (TA) increased with storage, while pH tended to decrease. During the initial 9d, no difference was found in TA, however, after 9d, it was slightly higher in HTST and UHT milks than that in LTLT milk. In LTLT and HTST milks, total viable cells and psychrotrophs were dramatically increased during storage, In addition coliform and pathogenic bacteria were found at 12 and 15d. In UHT milk, total viable cells were found only at 15d. In sensory evaluation, LTLT and HTST milks developed a negligible off-flavor until 9d. At 12d, it became stronger in HTST milk than that in LTLT milk. In UHT milk, off-flavor was detected at 9d and increased rapidly there-after. The degree of off-flavor was little higher in HTST and UHT milks, compared with that of LTLT milk after 9d storage. These observations indicated that LTLT and HTST milks may not be microbiologically acceptable after 5d, while off-flavor was not detectable until 9d, In comparison, UHT milk keeps a good quality in microorganism until 15d, however, it may not be accepted in sensory aspect after 9d storage.