• Korean Journal of Food Science and Technology
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• v.5 no.2
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• pp.129-135
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• 1973

The accumulation of peroxides, acid values, and carbonyl values during irradiation and post-irradiation storage of the ricebran oil has been studied. The rice bran oils were irradiated two doses of 2 and 7 megarads (300 rads/sec) at $23^{\circ}C$ atmospheric circumstance. The acid values, peroxide values and carbonyl values were measured at regular intervals of one week during the storage at $5^{\circ}C$ and $25^{\circ}C$. 1) During the storage, the acid values of the irradiated rice bran oils increased or decreased insignificantly regardless of the addition of antioxidants and storage temperature. 2) The peroxide values were not increased continuously but increased zigzag. The result was indicated that the composition and decomposition of peroxides occurred continuously throughout the storage. 3) As the peroxide values increased, carbonyl values decreased and changed quite differently, but, especially in 7th week, they were constant or insignificant. 4) Dibutylhydroxytoluene is more effective than caffeic acid in retarding the formation of peroxides during irradiation of rice bran oils and post-irradiation storage. The effect of antioxidant is more efficient at 2 megarads than at 7 megarads irradiation. When we store the rice bran oil, the addition of antioxidants of post-irradiation is more desirable than that of preirradiation. 5) In spite of changing conditions such as storage temperature and addition of antioxidants, the peroxide values of rice bran oils irradiated at 2 megarads were always greater than those at 7 megarads during the storage. Peroxide values of samples at high temperature $(25^{\circ}C)$ storage increased as twice as those of low temperature $(5^{\circ}C)$ storage samples. At low temperature, peroxide values in the first week increased twice during the period of 8th weeks storage, but those did from three to four times at higher temperature in the same period Therefore, the low temperature storage is recommandable too.

• Nutrition Research and Practice
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• v.16 no.3
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• pp.285-297
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• 2022

BACKGROUND/OBJECTIVES: Korean pine nut oil (PNO) has been reported to suppress appetite by increasing satiety hormone release. However, previous studies have rendered inconsistent results and there is lack of information on whether dietary Korean PNO affects the expression of satiety hormone receptors and hypothalamic neuropeptides. Therefore, our study sought to evaluate the chronic effects of Korean PNO on the long-term regulation of energy balance. MATERIALS/METHODS: Five-week-old male C57BL/6 mice were fed with control diets containing 10% kcal fat from Korean PNO or soybean oil (SBO) (PC or SC) or high-fat diets (HFDs) containing 35% kcal fat from lard and 10% kcal fat from Korean PNO or SBO (PHFD or SHFD) for 12 weeks. The expression of gastrointestinal satiety hormone receptors, hypothalamic neuropeptides, and genes related to intestinal lipid absorption and adipose lipid metabolism was then measured. RESULTS: There was no difference in the daily food intake between PNO- and SBO-fed mice; however, the PC and PHFD groups accumulated 30% and 18% less fat compared to SC and SHFD, respectively. Korean PNO-fed mice exhibited higher messenger RNA (mRNA) expression of Ghsr (ghrelin receptor) and Agrp (agouti-related peptide) (P < 0.05), which are expressed when energy consumption is low to induce appetite as well as the appetitesuppressing neuropeptides Pomc and Cartpt (P = 0.079 and 0.056, respectively). Korean PNO downregulated jejunal Cd36 and epididymal Lpl mRNA expressions, which could suppress intestinal fatty acid absorption and fat storage in white adipose tissue. Consistent with these findings, Korean PNO-fed mice had higher levels of fecal non-esterified fatty acid excretion. Korean PNO also tended to downregulate jejunal Apoa4 and upregulate epididymal Adrb3 mRNA levels, suggesting that PNO may decrease chylomicron synthesis and induce lipolysis. CONCLUSIONS: In summary, Korean PNO attenuated body fat accumulation, and appeared to prevent HFD-induced dysregulation of the hypothalamic appetite-suppressing pathway.

• Journal of Ecology and Environment
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• v.37 no.3
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• pp.131-137
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• 2014

To investigate the solute pattern of salt marsh plants in Suncheon Bay in Korea, plants and soil samples were collected at three sites from July to September 2011. The soil pH around the investigated species was weakly alkaline, 6.9-8.1. The total ion and Cl- content of site 1 gradually increased, while those of site 2 and site 3 were lowest in August and highest in September. The exchangeable $Ca^{2+}$, $Mg^{2+}$ and $K^+$ in the soil were relatively constant during the study period, but the soil exchangeable $Na^+$ content was variable. Carex scabrifolia and Phragmites communis had constant leaf water content and very high concentrations of soluble carbohydrates during the study period. However, Suaeda malacosperma and S. japonica had high leaf water content and constant very low soluble carbohydrate concentrations. Carex scabrifolia accumulated similar amounts of $Na^+$ and $K^+$ ions in its leaves. Phragmites communis contained a high concentration of $K^+$ ions. Suada japonica and S. malacosperma had more $Na^+$ and $Cl^-$ ions than $K^+$ ions in their leaves. Suaeda japonica had higher levels of glycine betaine in its leaves under saline conditions than C. scabrifolia and P. communis. Consequently, the physiological characteristics of salt marsh chenopodiaceous plants (S. japonica and S. malacosperma) were the high storage capacity for inorganic ions (especially alkali cations and chloride) and accumulation of glycine betaine, but monocotyledonous plant species (C. scabrifolia and P. communis) showed high $K^+$concentrations, efficient regulation of ionic uptake, and accumulation of soluble carbohydrates. These characteristics might enable salt marsh plants to grow in saline habitats.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.12 no.2
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• pp.1-9
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• 2009

Due to the increase of carbon dioxide in the atmosphere and global warming, the importance of forest ecosystems, as a place of carbon accumulation and emission, has received a great amount of recognition lately. This study was performed to help understand and provide the current status of carbon cycle in the pinus densiflora stand, Korea. The samples were collected from average 35-years-old Pinus densifiora rands in Gongju, Youngdong, Chungsan, Muju, Mupung, and Jangsu regions. Total thirty aboveground sample trees were cut, and ten roots were sampled, and soil samples were collected. Average carbon concentrations in foliage, branch, stem bark, stem wood, and root were 55.7%, 56.0%, 56.0%, 57.3%, and 56.5%, respectively. Carbon content was estimated by the model $Wt=aD^b$ where Wt is oven-dry weight in kg and D is DBH in cm. Total carbon content (aboveground and root) was 42.39tonC/ha in the Pinus densiflora stand. The proportion of each tree component to total carbon content was high in order of stemwood, root, branch, stem bark, and foliage. Total net primary production (aboveground and root) was estimated at 6.51tonC/ha/yr in Pinus densiflora stand. The proportion of each tree component to total net primary carbon content was high in order of sternwood, root, branch, foliage and stembark. Soil carbon contents in the study sites was 43.51tonC/ha at 0-50cm soil depth.

• Journal of Animal Reproduction and Biotechnology
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• v.35 no.4
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• pp.357-365
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• 2020

The aim of present study was to investigate regulatory mechanism of alpha-linolenic acid (ALA) during in vitro maturation (IVM) on nuclear and cytoplasmic maturation of porcine oocytes. Basically, immature cumulus-oocyte complexes (COCs) were incubated for 22 h in IVM-I to which hormone was added, and then further incubated for 22 h in IVM-II without hormone. As a result, relative cumulus expansion was increased at 22 h after IVM and it was enhanced by treatment of ALA compared with control group (p < 0.05). During IVM process within 22 h, cAMP level in oocytes was decreased at 6 h (p < 0.05) and it was recovered at 12 h in ALA-treated group, while oocytes in control group recovered cAMP level at 22 h. In cumulus cells, it was reduced in all time point (p < 0.05) and ALA did not affect. Treatment of ALA enhanced metaphase-I (MI) and MII population of oocytes compared with oocytes in control group at 22 and 44 h, respectively (p < 0.05). Intracellular GSH levels in ALA group was increased at 22 and 44 h after IVM (p < 0.05), whereas it was increased in control group at 44 h after IVM (p < 0.05). In particular, the GSH in ALA-treated oocytes during 22 h of IVM was higher than control group at 22 h (p < 0.05). Lipid amount in oocytes from ALA group was higher than control group (p < 0.05). Treatment of ALA did not influence to absorption of glucose from medium. Cleavage and blastocyst formation of ALA-treated oocytes were enhanced compared with control group (p < 0.05). These findings suggest that supplementation of ALA could improve oocyte maturation and development competence through increasing GSH synthesis, lipid storage, and regulation of cAMP accumulation during early 22 h of IVM, and these might be mediated by cumulus expansion.

• Journal of Nutrition and Health
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• v.10 no.4
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• pp.10-18
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• 1977

Activities of lipoprotein lipase (LPL) and hormone-sensitive lipase (HSL) in adipose tissue, accumulation of carcass fat, and serum triglyceride have been determined in meal-fed (MF) and ad libitum-fed (AD) rats. At each feeding frequency, the animals received diets providing total fat as 15% or 30% of calories and polyunsaturated fatty acids (PUFA) as 2.5% or 11% of calories. The food intake of the MF rats was 75% of that consumed by the AD rats but MF rat utilized their food more efficiently, as evidenced by weight gain per 100 Kcal consumed. Meal feeding, as contrasted to ad libitum feeding, resulted in greater activities of both LPL and HSL. This suggested a higher turnover of fat in the adipose tissue of MF rats. In AD rats, body fat was significantly correlated with LPL and the ratio of LPL/HSL. Meal feeding significantly increased the ratio of LPL/HSL, indicating a greater capacity for energy storage and fat deposition in the MF rat. However, at the limited caloric intake, MF rats failed to realize this potential; there was no significant difference in percentage of body fat at the two feeding frequencies. Body fat deposition was greater in rats fed the 30% fat diet, as compared with the 15% diet, regardless of the rate of food ingestion. This was coupled with a higher ratio of LPL/HSL. The significant correlation of serum triglycerides with body fat and with the ratio of LPL/HSL in AD rats suggests that LPL activity and fat deposition may be controlled by the concentration of circulating triglycerides. Both serum triglycerides and adipose LPL activity were significantly reduced when the diet contained high levels of PUFA. The percentage of body fat was also lower in animals whose intake of PUFA was high.

• Journal of The Korean Society of Grassland and Forage Science
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• v.4 no.3
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• pp.220-225
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• 1984

In the grassland ecosystem dominated by Phragmites longivalvis in the delta of Nak Dong River, the production, decomposition, and accumulation of organic were estimated by the theoretical analysis. The amounts of organic carbon and organic matter of litter are $1020.43g/m^2\;and\;591.90g/m^2$, respectively. The amounts of organic matter and organic carbon on the grassland floor is $1154.96g/m^2\;and\;669.93g/m^2$, the ratio of annual litter production 'L' to the amount of accumulation on the top mineral soil (F, H and $A_2$ horizons) provided estimates of decay constant k. Constant k is 0.884 in the Phragmites longivalvis community. The vertical levels of organic matter and organic carbon is the highest in 120-140 cm of photosythetic system and in 0-20 cm of non-photosyntic system.

• Korean Journal of Plant Tissue Culture
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• v.27 no.4
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• pp.339-343
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• 2000

When plants are exposed to subfreezing temperatures ice crystals are forming within extracelluar space in leaves. The growth of ice crystal is closely related to the degree of freezing injury. It was shown that an antifreeze protein binds to an ice nucleator through hydrogen bonds to prevent growth of ice crystal and also reduces freezing damage. The antifreeze proteins in plants are similar to PR proteins but only the PR proteins induced upon cold acclimation were shown to have dual functions in antifreezing as well as antifungal activities. Three of the genes encoded for CLP, GLP, and TLP were isolated from barley and Kentucky bluegrass based on amino acid sequence revealed after purification and low temperature-inducibility as shown in analysis of the protein. The deduced amino acid of the genes cloned showed a signal for secretion into extracellular space where the antifreezing activity sup-posed to work. The western analysis using the antisera raised against the antifreeze proteins showed a positive correlation between the amount of the protein and the level of freeze tolerance among different cultivars of barely. Besides it was revealed that TLP is responsible for a freeze tolerance induced by a treatment of trinexapac ethyl in Kentucky bluegrass. Analysis of an overwintering wild rice, Oryza rufipogon also showed that an acquisition of freeze tolerance relied on accumulation of the protein similar to CLP. The more direct evidence for the role of CLP in freeze tolerance was made with the analysis of the transgenic tobacco showing extracellular accumulation of CLP and enhanced freeze tolerance measured by amount of ion leakage and rate of photosynthetic electron transport upon freezing. These antifreeze proteins genes will be good candidates for transformation into crops such as lettuce and strawberry to develop into the new crops capable of freeze-storage and such as rose and grape to enhance a freeze tolerance for a safe survival during winter.

• Journal of Soil and Groundwater Environment
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• v.27 no.5
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• pp.1-9
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• 2022

A correlation analysis was performed to investigate differences in the response of surface water and groundwater to drought using the Standardized Precipitation Index (SPI). Water level data of 20 agricultural reservoirs, 4 dams, 2 rivers, and 8 groundwater observation wells were used for the analysis. SPI was calculated using precipitation data measured at a nearby meteorological station. The water storage of reservoirs and dams decreased significantly as they responded sensitively to the drought from 2014 to 2016, showing high correlation with SPI of the relatively long accumulation period (AP). The responses of rivers varied greatly depending on the presence of an upstream dam. The water level in rivers connected to an upstream dam was predominantly influenced by the dam discharge, resulting in very weak correlation with SPI. On the contrary, the rivers without dam exhibited a sharp water level rise in response to precipitation, showing higher correlation with SPI of a short-term AP. Unlike dams and reservoirs, the responses of groundwater levels to precipitation were very short-lived, and they did not show high correlation with SPI during the long-term drought. In drought years, the rise of groundwater level in the rainy season was small, and the lowered water level in the dry season did not proceed any further and was maintained at almost the same as that of other normal years. Conclusively, it is confirmed that groundwater is likely to persist longer than surface water even in the long-term drought years.

• Journal of Hydrogen and New Energy
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• v.8 no.2
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• pp.79-90
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• 1997

Extensive work has been done on investigating the inner cell pressure characteristics of sealed type Ni-MH battery in which Zr-Ti-Mn-V-Ni alloy is used as anode. The inner cell pressure of this type Ni-MH battery much more increases with the charge/discharge cycling than that of the other type Ni-MH battery where commercialized $AB_5$ type alloy is used as anode. The increase of inner cell pressure in the sealed type Ni/MH battery using Zr-Ti-Mn-V-Ni alloy system is mainly due to the accumulation of oxygen gas during charge/discharge cycling. The accumulation of oxygen gas arises mainly due to the low rate of oxygen recombination on the MH electrode surface during charge/discharge cycling. The difference of oxygen recombination rate between $AB_5$ type electrode and Zr-Ti-Mn-V-Ni electrode is caused by the difference of electrode reaction surface area resulting from different particle size after their activation and the difference of surface catalytic activity for oxygen recombination reaction, respectively. After EIS analysis, it is identified that the surface catalytic activity affects much more dominantly on the oxygen recombination reaction than the reaction surface area does. In order to suppress the inner cell pressure of Ni-MH battery where Zr-Ti-Mn-V-Ni is used as anode, it is suggested that the surface catalytic activity for oxygen recombination should be improved.