• Journal of Life Science
• /
• v.23 no.10
• /
• pp.1223-1229
• /
• 2013

Ursolic acid (UA) a bio-active ingredient found in a variety of fruits and vegetables, and it has potent antioxidant activity. However, the role of UA in mouse embryonic stem (ES) cells is poorly understood. This study investigated the functional role of UA in regulating the development of mouse ES cells under hypoxia. Hypoxia did not exert a significant effect on the undifferentiated state of mouse ES cells. However, it induced reactive oxygen species (ROS) generation and increased the level of lactate dehydrogenase (LDH) production at 48 h of hypoxic exposure. Conversely, oxidative stress induced by hypoxia was significantly inhibited by UA ($30{\mu}M$) pretreatment. Hypoxia significantly decreased cell survival and the level of [$^3H$] thymidine incorporation, both of which recovered following pretreatment of UA. In addition, UA decreased the apoptotic effect of hypoxia by attenuating caspase-3 cleavage or by recovering cellular inhibition of the apoptotic protein (cIAP)-2 and Bcl-2 expression. We further found that UA decreased senescence-associated beta-galactosidase activity. We suggest that UA is a natural antioxidant and one of the functional modulators of hypoxia-induced survival, apoptosis, proliferation, and aging in mouse ES cells.

• The Korean Journal of Pesticide Science
• /
• v.18 no.3
• /
• pp.148-155
• /
• 2014

The transfer pattern of chlorpyrifos present in soil to cucumber plants were assessed and reported with plant growth, concentration dependency, and duration. Cucumber seedlings cultivated in a growth chamber for 30 days and a greenhouse for 120 days. Weight and length of cucumbers cultivated in the chamber increased with the increasing time, while the uptake of chlorpyrifos by cucumber increased a period from 0 to 15 days and decreased after 15 days. Uptake rates of chlorpyrifos into a cucumber plant were 1.0~1.3% to initial amounts treated with 20 and 40 mg/kg to soil. Most chlorpyrifos residues were detected in root, followed by stem and leaf. Results of the greenhouse test showed that chlorpyrifos amounts in cucumber fruits were present less than LOQ (0.02 mg/kg), and chlorpyrifos was mainly found in the root of the cucumber plant. Chlorpyrifos absorbed in a cucumber under greenhouse condition was smaller than that in chamber condition as 0.03~0.04%. Degradation patterns of chlorpyrifos in soils were similar during indoor and outdoor tests with half-lives of 25.8~73.0 days. These results may be useful for establishing the management strategy of residual pesticides in soil environment.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.28 no.4
• /
• pp.801-804
• /
• 1999

Quality characteristics of yakju prepared by different yeast strains such as Saccharomyces cerevisiae S 2, Saccharomyces cerevisiae S 6 and Saccharomyces cerevisiae IFO 1950 were investigated during fermentation. The pH in all kinds of yakju was gradually decreased until 6 days and then it was constant. In stage of fermentation, acidity of yakju made of Saccharomyces cerevisiae S 6 was higher than others. At the beginning stage of fermentation, ethanol contents were in the range of 0~2% increased to 9.5~11.5% after 10 days. Yakju made of Saccharomyces cerevisiae S-2 showed higher ethanol contents than others. Free sugars in yakju were found to be glucose and maltose. The contents of free sugars were decreased until 6 days and they were not detected. The content of ethanol in yakju showed the highest value at the 6th day and those of yakju A, B and C were 11.9, 9.5, 10.9%, respectively. Main organic acids in yakju were citric acid and lactic acid. The content of citric acid in yakju B was higher than others.

• Journal of the Korean Dietetic Association
• /
• v.10 no.1
• /
• pp.13-24
• /
• 2004

This study was designed to examine fast food consumption, nutritional knowledge, food behavior and dietary intake of university students and to investigate if there were differences in these variables by fast food consumption. The questionnaire was administered to university students in Daejeon. Data(n=269) was analyzed using $x^2$-test and analysis of variance. Subjects were mostly female(62%) and freshmen or sophomores(86%). Based on the frequency of fast food consumption, subjects were categorized into non-users(27.9%), users(<2 times/week, 42%) and frequent users($\geq$2 times/week, 30.1%). Those who used fast foods(n=194) consumed the foods 7.5 times per month, on the average. Subjects scored 15.6 out of 20 on a nutritional knowledge scale, showing the moderate level of knowledge. When examined by fast food use, the nutritional knowledge score was 15.5 for non-users, 16.1 for users, and 15.0 for frequent-users(p<0.05). Only two items, regarding 'fat type(animal, plant) and health' and 'importance of having breakfast', were significantly different by fast food consumption, with user group and non-users scoring higher than frequent-users(p<0.05). Food behaviors, measured by 20 items, were not desirable, with mean scores of 51.5(possible score: 20-100). Subjects showed problems in eating meals regularly, eating a variety of foods, eating breakfast, and consumption of some food groups(vegetables, fruits, and proteins). Fast food non-users showed more desirable food behaviors than users or frequent-users, such as having processed foods (p<0.001) and eating-out less frequently(p<0.01). Dietary intake data showed that some nutrient intakes, including energy, calcium, iron, zinc and folic acid were less than 75% of the RDA. Index of nutritional quality(INQ) was adequate except for calcium and zinc. Compared to non-users or user group, frequent-users of fast foods consumed higher amounts of lipids(p<0.05), and had lower INQ for calcium(p<0.01). This study described the status of fast food consumption, nutritional knowledge, food behavior of university students, and provided some baseline data for planning nutrition education for university students.

• Culinary science and hospitality research
• /
• v.21 no.1
• /
• pp.250-266
• /
• 2015

This study concentrated on the dining out consumption behaviors, dining out selection attributes, and changes in eating habits of silver generation. Total 216 residents in metropolitan area were employed for statistical analysing. The results are as follows. First, as the result of t-test and ANOVA showed that female and higher academic background tended to regularly take high level of fruits, vegetables, meat, and fish eating habits. These results identified that dining out culture and dietary lifestyle are closely linked. Second, as the result of difference in dining out consumption attitudes on eating habit of silver generation, consumers who have better eating behaviors tended to consider the physical environment, variety of menu, and service quality when they choose a restaurant. Third, as the result of analysis on changes in dining out consumption behavior based on eating behavior of silver consumers, groups differences were found from only the source for information on dining out business and standard variable in selection of dining out business. Fourth, physical environment, variety of menu, business quality, and service were indicated as significant selection attributes of dining out among silver peoples. Fifth, dining out consumption behaviors of silver consumers were developed through newspapers, magazines, and previous visiting experiences. In conclusion, the results of present study showed that silver consumers tend to select a restaurant based on word-of-mouth and various factors related to experiences. Hence, various promotional activities are necessary for the business succession.

• Korean Journal of Food Science and Technology
• /
• v.44 no.1
• /
• pp.106-113
• /
• 2012

The present study was conducted to assess the dietary exposure to mercury and the associated risks for Koreans resulting from their food intake. The probabilistic approach in the Monte Carlo simulation was used to estimate dietary exposures. Based on several reports regarding heavy metals published by KFDA in the 2000s, 178 types of representative foods were selected and data were collected on the occurrence of mercury. The contents of mercury in foods ranged: agricultural products 0.1 (fruits)-45.4 ${\mu}g/kg$ (mushrooms), 3.7 ${\mu}g/kg$ (meat), and 9.3 (Echinodermata, chordata)-194.9 ${\mu}g/kg$ (fish). Others categories investigated were alcoholic beverages (0.7 ${\mu}g/kg$) and processed food (4.4 ${\mu}g/kg$). The mean and 95th percentile for exposure to dietary mercury were 4.29 and 12.48 ${\mu}g/day$, corresponding to 13.6% and 39.7% of PTWI (Provisional Tolerable Weekly Intake), respectively. Therefore, overall level of mercury exposure for Koreans through food intake is below levels recommended by JECFA, indicating the least possibility of risk, and is less than or similar to levels reported in other countries.

• Applied Biological Chemistry
• /
• v.41 no.7
• /
• pp.527-532
• /
• 1998

This study was aimed at the development of the rice product by fermentation of saccharified rice solution with Bifidobacterium. To optimize the preparation of saccharified rice solution for Bifidobacterium fermentation, various pretreatment conditions were established. Grinding for 30seconds by an impact mill was more efficient than any other grinding schemes tested. The preheating before gelatinization showed a positive effect for efficient saccharification, and its optimal conditions were at $60^{\circ}C$ for 45 min. The optimum gelatinization conditions were at $100^{\circ}C$ for 40 min. The optimum levels of enzymes for saccharification of rice were 0.135 unit/g rice powder for ${\alpha}-amylase$ and 3.375 unit/g rice powder for glucoamylase, respectively. The physico-chemical properties of the fermented product by a fastidious Bifidobacterium showed a great potential for a functional rice product. However, an improvement on its flavor was required, which might be achieved by the addition of various fruits and vegetables.

• Korean Journal of Organic Agriculture
• /
• v.18 no.2
• /
• pp.221-232
• /
• 2010

During 2005~2009, current status on the occurrence and the management of the major disease, insect and mite pests were investigated in the non-chemical or organic cultured apple orchards in Korea. Numbers of certified organic or non-chemical apple orchards increased from 14 in 2005 to 78 in 2008. Severe damages on leaves and fruits were caused by the several diseases such as marssonina blotch, bitter rot, white rot, sooty blotch and flyspeck, and the several insect pests such as apple leaf-curling aphid, woolly apple aphid, oriental fruit moth and peach fruit moth on the almost certified organic or non-chemical pest control orchards. About 10 and 18 environmental-friendly materials were used to control diseases and insect or mite pests, respectively. But, lime sulfur and bordeaux mixture to diseases and machine oil, plant oil mixed with egg yolk, and pheromone mating disruptions to insect pests were effective under the adequate conditions.

• Food Science and Preservation
• /
• v.15 no.5
• /
• pp.648-655
• /
• 2008

A gamma irradiation process was applied to prolong the shelf-life of grapes and changes in microbiological, physicochemical, nutritional, and sensory characteristics were investigated during 6 weeks of post-irradiation storage at $4^{\circ}C$ and $25^{\circ}C$. Physiochemical characteristics of grapes such as total sugar content, pH, titratable acidity, and anthocyanine content, were stable after 1 kGy of irradiation, a dose recommended by CODEX for fruits and vegetables. The viable cell counts of contaminating microorganisms were reduced 1-2 logs by this radiation dose. After 6 weeks of storage at $4^{\circ}C$ the microbiological quality of irradiated grapes was stable, but all non-irradiated grapes had deteriorated. Whether or not grapes were irradiated, weight loss rapidly increased after 2 weeks of storage at $25^{\circ}C$, whereas weight loss was delayed by storage at $4^{\circ}C$. Immediately after gamma irradiation, the sensory evaluation results did not differ between samples, and the sensory quality of the irradiated grapes remained acceptable for over 6 weeks of storage at $4^{\circ}C$. The results suggest that 1 kGy of gamma irradiation does not detrimentally affect the nutritional or physical characteristics of grapes, especially when cold storage follows radiation treatment. In conclusion, a combination of gamma irradiation and cold storage prolonged the shelf-life of grapes by 6 weeks.

• Journal of Bio-Environment Control
• /
• v.30 no.4
• /
• pp.342-350
• /
• 2021

This study was conducted to investigate the effect of time of hand-thinning on vegetative growth, bitter pit incidence, fruit quality, and return bloom in 'Gamhong'/M.9 apple trees. The time of hand-thinning were 3, 5, 7 and 9 weeks after full bloom, and the primary thinning (leaving only the king fruit on cluster) and secondary thinning (adjusting crop load) were conducted at the same time. The time of hand-thinning was correlated to the vegetative growth, average fruit wight, yield, soluble solids content, bitter pit incidence, and return bloom, negatively, and to the yield of middle grade fruits (fruit weight was 250-299g and none pit on fruit surface) per tree, calcium contents of leaves, and fruit red color, positively. There was no significant effect of time of hand-thinning on fruit firmness, titratable acidity, and total incomes per tree. In conclusion, if the time of hand-thinning of 'Gamhong'/M.9 apple tree was completed at 9 weeks after full bloom, it could produce about 300g of high-quality fruit without bitter pit.