• Journal of the East Asian Society of Dietary Life
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• v.26 no.1
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• pp.80-87
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• 2016

This study was conducted to investigate the physicochemical properties and antioxidant activities of strawberries from different cultivars and ripening stages grown in Korea. Fragaria ananassa 'Seolhyang' and 'Janghee' in unripe and ripe stages were used in this study. Overall, firmness of unripe fruits was harder than that of ripe fruits, whereas firmness of 'Seolhyang' was harder than that of 'Janghee'. There was no significant difference in soluble solid content (SSC) between the two cultivars, whereas SSC increased when fruits matured. Total phenolic and flavonoid concentrations of 'Seolhyang' were greater than those of 'Janghee' cultivar. However, there was no ripening effect on total phenolic concentration in both cultivars. Total anthocyanin concentrations of the two cultivars were higher in ripe stage while that of 'Janghee' was greater than that of 'Seolhyang' statistically. Total antioxidant activities of 'Seolhyang' were greater than those of 'Janghee'. Total phenolic and flavonoid concentrations were highly correlated with antioxidant activities but there was no correlation between total anthocyanins and total antioxidant activities.

• Food Science and Preservation
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• v.20 no.4
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• pp.475-481
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• 2013

This study was performed in order to compare the changes in fruit quality and antioxidant activity depending on the ripeness degree of the banana flesh and peel (unripe, ripe, and over ripe) when stored at room temperature for 6 days. The moisture contents showed differences such as the significantly lower maturity in the over ripe fruit peel and the moisture content increase in the fruit flesh during ripening. During the maturity stage, the L and b values decreased, while the a value increased. During ripening, the titratable acidity (TA) decreased, while the soluble solids contents (SS), sugar acid ratio (SS/TA), total sugar, and reducing sugar contents increased, respectively. Also during ripening, the glucose and the fructose contents increased considerably, thus resulting in the decrease of the sucrose content. In addition, this study revealed that the phenolic substance, which was part of the fruit skin, showed more favorable reaction to radical ability than the fruit flesh. Furthermore, the DPPH, ABTS radical scavenging ability, and reducing power showed better reaction for the fruit skin than for the fruit flesh, and there was a significant increase in the antioxidative activity as a result of the higher levels of phenolic substance. Therefore, maturity played an important role in changing the chemical composition and physiological activity of a banana. The unripe peels could be used as antioxidant ingredients and they could also enhance the biological activity in the utilization of by-products.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.10a
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• pp.281-281
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• 2017

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.10a
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• pp.717-720
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• 2007

With the convergence of mobile devices and the Internet ubiquitous computing promises to revolutionalize the way that we access services and run application. However, ubiquitous computing environments, in particular, mobile and wireless environments interfaced with the Internet, currently possess security vulnerabilities that are ripe for attack from cyber-threats. Thus, this paper discusses the Limitation of current security mechanisms in ubiquitous computing environments

• 한국약용작물학회:학술대회논문집
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• 2008.05a
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• pp.202-203
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• 2008

• 한국약용작물학회:학술대회논문집
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• 2009.05a
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• pp.353-354
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• 2009

• The Korean Journal of Malacology
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• v.30 no.2
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• pp.127-134
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• 2014

Gonad maturation of Manila clam, Ruditapes philippinarum was induced in this study using a recirculation system over 8 weeks in early spring. Clams used in the experiment were collected in $15^{th}$ April 2010 from the west coast of Korea, as the surface water temperature remained $11^{\circ}C$. To induce gametogenesis and subsequent maturation seawater temperature was elevated $1^{\circ}C$ per day over 10 days to reach $20^{\circ}C$. For the experiment, clams were raised in 120 L quadrangle tank maintained with re-circulated seawater system over 57 days. Water quality parameters including the water temperature, salinity dissolved oxygen, ammonium ion and nitrate levels in the tanks were monitored daily. Mixture of concentrated microalgae including Tetraselmis, Isochrysis, Pavlova and Thalassiosira weissflogii was supplied to clams twice a day, and quantity of the daily ration was adjusted as 3% of clam body dry weight. Histology was applied to examine gonad maturation. Daily monitoring of the water quality parameters indicated that the recirculation system supplied suitable environment to Manila clam; the nitrogenous components stayed below toxic levels (< 0.2 mg/L). At the beginning of the study, clams were mostly in early developing stage. As the seawater temperature reached $20^{\circ}C$, 10 days after the experiment, 20% of clams reached late development at 12 days. First ripe clams were observed at 42 days and 40% of clams were in ripe and ready for spawning at the end of study, 57 days after the experiment. In this study, gametogenesis of Manila clam was successfully induced by elevating water temperature and supplying commercially produced microalgae in a recirculation tank system.

• The Korean Journal of Malacology
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• v.16 no.1_2
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• pp.35-41
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• 2000

We investigated the gonad index (GI), gonadal development, the reprodutive cycle and first sexual maturity of the venus clam, Cyclina sinensis by histological observation. Samples were collected from the intertidal zone of Komso Bay, Chollabuk-do, west coast of Korea, from April 1998 to March 1999. This clam is dioecious and oviparous. Monthly changes in the gonad index (GI) showed a similar pattern to the reproductive cycle. Ripe oocytes are about 90-100 ㎛ in diameter. The spawning period was between early July to September, and the main spawning occurred between July and August when the sea water temperature was over 20$\^{C}$ The reproductive cycle of this species can be divided into five successive stages: early active stage (February to April), late active stage (March to June), ripe stage (April to August), partially spawned stage (July to October), and spent / inactive stage (September to February). Percentages of first sexual maturity of female and male clams measuring 26.1-30.0 ㎜ in shell length were 53.3% and 62.5%, respectively, and 100% for the clams > 41.0 ㎜. It is assumed that both sexes begin reproduction at about two years age.

• Development and Reproduction
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• v.21 no.3
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• pp.297-305
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• 2017

An experiment was conducted to investigate the annual reproductive cycle of a Korean endemic species, Acheilognathus majusculus, from Jeokseong-myeon located in Seomjin River. The reproductive cycle is examined histologically regarding water temperature and day length of the habitat, the gonadosomatic index (GSI), the female ovipositor length index (OLI), monthly variation in egg diameter distribution, and developmental characteristics of female and male gonads. The maximum GSI was found in $19.21{\pm}2.32$ and $6.90{\pm}0.53$ for female and male respectively when water temperature ($14^{\circ}C$) and day length (11.1hr) began to rise. On the other hand, the minimum level was reached during August ($1.87{\pm}0.67$ for female and $0.88{\pm}0.50$ for male). No samples represent with measurable ovipositor between September and November, while the longest ovipositor length index was in April ($79.68{\pm}4.69%$). We compared and calculated the stages of testis and ovary development process in order to determine the germ cell development characteristics and the reproductive cycle. According to the result, we classified the female Acheilognathus majusculus reproductive cycle into four stages: Ripe (April) and spawning phase (May to June), degenerative phase (July), growing phase (August to December), and mature phase (January to March). The annual reproductive cycle of male Acheilognathus majusculus was categorized into five stages viz. Ripe and spawning phase (May to June), degenerative phase (July to August), resting phase (September to November), growing phase (December to February), and mature phase (March to April).

• The Plant Pathology Journal
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• v.26 no.1
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• pp.49-56
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• 2010

Thirty-six isolates of Colletotrichum spp. were obtained from infected grapes in two different locations of Korea; 18 isolates from Cheonahn, where carbendazim (MBC) and the mixture of MBC and diethofencarb (NPC) had been applied to control grape ripe rot, and 18 isolates from Cheongju, where no fungicides had been used. Sequences analysis of the internal transcribed spacer (ITS) and the $\beta$-tubulin gene identified 34 of the 36 isolates as Colletotrichum gloeosporioides. The remaining two isolates from Cheongju were identified as C. acutatum. Of the 18 isolates from Cheonahn, 12 were resistant to both MBC and the mixture (MBC+NPC), and six were sensitive to them. All C. gloeosporioides isolates from Cheongju, but not the two C. acutatum isolates, were sensitive to these fungicides. Sequence analysis of the $\beta$-tubulin gene in all isolates revealed that C. gloeosporioides resistant to MBC and MBC+NPC had a tyrosine instead of phenylalanine at the amino acid position 200. The appearance of resistance to MBC and the mixture in C. gloeosporioides correlated with the history of fungicide application in Korea.