• Korean Journal of Food Science and Technology
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• v.41 no.3
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• pp.251-257
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• 2009

The effects of temperature variations during storage on the quality characteristics of muskmelons (Cucumis melo L.) were investigated. In samples stored at $4^{\circ}C$ and $10^{\circ}C$, weight losses were almost 2.9- and 3.4-fold higher, respectively, compared to samples stored at $0^{\circ}C$. Soluble solids slightly increased except in the samples stored at $10^{\circ}C$, but acidity decreased over the entire storage period. Firmness decreased with storage time, but the samples stored at $0^{\circ}C$ had a lesser decrease in firmness than the samples stored at other temperatures. Water loss from the muskmelon stalk was most inhibited, and vitamin C content was maintained for the longest period, with storage at $4^{\circ}C$. Mineral contents (Ca, Na, Fe, Mg, K) were best maintained in muskmelon samples stored at $10^{\circ}C$ for 15 days, but levels had decreased by 30 days. Microbiological quality was not appreciably different at any storage temperature at 18 days; however, samples stored at $4^{\circ}C$ and $10^{\circ}C$ had deteriorated by 25 days. The results of sensory evaluations indicated that taste was best retained in samples stored at $10^{\circ}C$ for 15 days, although changes in taste were evident at all storage temperatures. When the samples were stored over 22 days at $10^{\circ}C$, retention of texture and overall acceptability were more inferior compared to samples stored at $0^{\circ}C$ and $4^{\circ}C$. These results suggest that storage at $4^{\circ}C$ can be used to reduce deterioration in muskmelons without significant loss of their quality attributes.

• Korean Journal of Food Science and Technology
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• v.41 no.3
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• pp.302-306
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• 2009

The principal objective of this investigation was to identify adequate species for the harvest of Perilla frutescens leaves, which provide profound antioxidant activities, and harbor abundant caffeic acid and rosmarinic acid. Namchun, Donggeul-2, Bora, Sae-bora and Neul-bora variants of the plant were assessed herein. In this study, we evaluated the antioxidant effects of these plants, and utilized an HPLC system to verify their caffeic acid and rosmarinic acid contents. Dried Perilla frutescens leaves were boiled at a temperature of $100^{\circ}C$ for three hours, and were lyopholized in a freezedryer. The extracts were then processed in order to confirm their antioxidant activities via 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical-scavenging activity assay, ferric-reducing antioxidant power (FRAP) assay, total flavonoid content and total polyphenol content assays. According to the observed antioxidant results of the five tested species of Perilla frutescens leaves, Bora and Donggeul-2 were shown to have more potent antioxidant activities than the other tested variants. The scavenge 50% of DPPH radical ($SC_50$ of DPPH) values were 241 ${\mu}g$ DM/mL in Donggeul-2 and 261 ${\mu}g$ DM/mL in Bora. Based on the results of the FRAP assay, the Bora variant showed a value of 796 mM $FeSO_4$ $7H_2O/g$ DM, and Donggeul-2 exhibited a value of 748 mM $FeSO_4$ $7H_2O/g$ DM, of which the total polyphenol contents were measured as 69.4 g GAE/kg DM and 61.8 g GAE/kg DM, respectively. Moreover, the Bora variant had the highest level of caffeic acid, and Donggeul-2 showed the highest rosmarinic acid content among the tested samples (0.87 mg/100 g wet base and 121 mg/100 g wet base, respectively). According to the results of this experiment, we selected two species, Bora and Donggeul-2, which were both verified to contain adequate and favorable antioxidant activities.

• Korean Journal of Food Science and Technology
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• v.45 no.3
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• pp.285-292
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• 2013

This study was carried out to validate the safety of ametoctradin residues in agricultural commodities by developing an official analysis method. An analytical method was developed and validated using HPLC-PDA detectors. The samples were extracted with methanol, subsequently partitioned with dichloromethane and purified with florisil column chromatograph using acetone/hexane (30/70, v/v) as solvent. The method was validated by using grape, hulled rice, mandarin, and potato spiked with ametoctradin at 0.05 and 5.0 mg/kg, and pepper at 0.05 and 2.0 mg/kg. Average recoveries were 76-114.8% with relative standard deviation less than 10%, and the limit of detection and limit of quantification were 0.0125 and 0.05 mg/kg, respectively. The result of recoveries and overall coefficient of variation of the laboratory results from Gwangju regional Food and Drug Administration (FDA) and Daejeon regional FDA was accorded with Codex Alimentarius Commission Guideline (CAC/GL 40). Based on these results, this method was found to be appropriate for ametoctradin residue determination and can be used as the official method of analysis.

• Korean Journal of Food Science and Technology
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• v.50 no.2
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• pp.216-224
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• 2018

To evaluate physiological effect of Aralia elata, in vitro antioxidant activity and hepatic protective effects were investigated. Ethyl acetate fraction from Aralia elata (EFAE) had higher total phenolic content than other fractions (n-hexane, chloroform, and distilled water layers). EFAE also showed significantly greater radical scavenging activity against 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) diammonium salt (ABTS) and 1,1-diphenyl-2-picrylhydrazyl (DPPH), than other fractions. Moreover, EFAE showed dose-dependent inhibitory effect of malondialdehyde (MDA). Hepatoprotective effects of EFAE against ethanol- and $H_2O_2$-induced oxidative stress and cytotoxicity in H4IIE and HepG2 hepatic cells were examined using 2',7'-dichlorofluorescein diacetate (DCF-DA) and 3-[4,5-dimethythiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) assay. The results showed that EFAE reduced cellular oxidative stress, and increased hepatic cell viability. In addition, EFAE inhibited ethanol-induced lipid accumulation in HepG2 cells. Finally, physiological substances of EFAE were analyzed using high performance liquid chromatography (HPLC), and the major bioactive compounds identified were 3,5-dicaffeoylquinic acid and chlorogenic acid.

• Horticultural Science & Technology
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• v.32 no.6
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• pp.872-878
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• 2014

This study aimed to enhance storage and freshness of strawberry fruits and foliage vegetables by spray treatment with Chlorella vulgaris as a bio-fertilizer. The tested strain, C. vulgaris CHK0008, was isolated from an organically cultivated rice paddy and identified as C. vulgaris by its morphology and 18S rDNA and 23S rDNA sequence homology. We successfully cultured C. vulgaris CHK0008 in BG11 modified medium (BG11MM) and adjusted $2.15{\times}10^6cell/mL$ C. vulgaris CHK0008 to one OD value by measuring the optical density at 680 nm using a UV-vis spectrophotometer. The soluble solid content of 'Seolhyang' and 'Yukbo' strawberry fruits treated by spray application with C. vulgaris CHK0008 was enhanced by 22.2% and 11.5% respectively, compared to untreated controls. Additionally, the decay rates of treated 'Seolhyang' and 'Yukbo' strawberry fruits decreased 63.8% and 74.4% respectively, compared to untreated control. Surface color changes and chlorosis of leaves in leaf vegetables such as lettuce, kale, red ornamental kale, white ornamental kale and beet were observed in samples treated with water spray for 10 days after cold storage. However, the decay rate of leafy vegetables treated with foliar application of 25% C. vulgaris CHK0008 liquid culture was significantly decreased compared to that of the untreated control during storage at $4^{\circ}C$.

• Horticultural Science & Technology
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• v.32 no.6
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• pp.834-844
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• 2014

Postharvest browning of mushroom (Agaricus bisporus) reduces the shelf life of harvested mushrooms. Here, mushrooms were dipped in various solutions (distilled water; DW, 0.25% rice bran extract; RB, 0.1% ascorbic acid; AA, RB + AA) for 3 min. After air-drying at room temperature, the dipped mushrooms were packaged in a polypropylene (PP) films and stored at 4 or $15^{\circ}C$. The quality changes of mushrooms were measured in terms of color, gas composition, firmness, and sensory evaluation during storage. Rice bran extract was measured for total polyphenol content, total flavonoid content, DPPH, ABTS radical scavenging, chelating activity and PPO inhibition activity. No difference in firmness were found in the mushroom samples regardless of dipping solution or storage temperature. At both 4 and $15^{\circ}C$ storage temperatures, RB + AA solution-dipped samples showed the highest L value and lowest delta E value. During the storage period, sensory evaluation showed that overall acceptability of mushrooms treated with RB and RB + AA solution was higher than that of the untreated mushrooms. Total polyphenol and flavonoid contents of 0.25% rice bran extract were $36.42mg\;GAE{\cdot}g^{-1}$ and $4.85mg\;QE{\cdot}g^{-1}$, respectively. The DPPH and ABTS radical scavenging activity of 0.1% ascorbic acid was higher than that of 0.25% rice bran extract. The highest copper ($Cu^{2+}$) chelating activity was found in the 0.25% rice bran extract. The PPO inhibition activity of 0.1% ascorbic acid was higher than that of 0.25% rice bran extract. Our results suggest that 0.25% rice bran extract with 0.1% ascorbic acid is effective anti-browning agent for maintaining quality of Agaricus bisporus during storage.

• Horticultural Science & Technology
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• v.32 no.6
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• pp.819-826
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• 2014

This study was carried out to investigate the effects of night-time far-infrared irradiance quality of red pepper dried in greenhouses. This study involved 4 treatments: sunlight alone (control), or sunlight plus nightly far-infrared irradiation at $250W{\cdot}6.6m^{-2}$ ($250W{\cdot}6.6m^{-2}$), far-infrared irradiation at $250W{\cdot}3.3m^{-2}$ ($250W{\cdot}3.3m^{-2}$), or far-infrared irradiation $500W{\cdot}3.3m^{-2}$ ($500W{\cdot}3.3m^{-2}$). The drying periods were 12 days in $500W{\cdot}3.3m^{-2}$ and $250W{\cdot}3.3m^{-2}$, and 14 days in $250W{\cdot}6.6m^{-2}$, and 15 days in the control. The daytime temperature was same among the treatments. The lowest temperature was at $23.8^{\circ}C$ in control, and $29.5-37.2^{\circ}C$ in far-infrared irradiation treatments. The marketable yield was 7-14% higher in far-infrared irradiation treatments compared to the control. The rate of marketability was higher in far-infrared irradiation treatments (93.6-96.3%) than in the control (87.0-87.5%). The American Spice Trade Association (ASTA) value was greatest in the $250W{\cdot}3.3m^{-2}$ treatment, followed by $250W{\cdot}6.6m^{-2}$, then $500W{\cdot}3.3m^{-2}$, and finally the control. Capsaicinoid content showed no regular trend among the treatments. Our results provide an optimized method for reducing drying time of red pepper under sunlight, and improving the quality of dried red pepper.

• Journal of Life Science
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• v.17 no.4 s.84
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• pp.540-545
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• 2007

The purpose of this research is to study the effects of feeding dietary citrus byproducts TMR (total mixed ration) on physicochemical properties and sensory characteristics of Korean native beef loin (KNBL). The samples for experiment consist of the KNBL not fed with citrus byproducts (TMR-0) and the KNBL fed with citrus byproducts during fattening period (TMR-1). The control (TMR-0) KNBL was fed by general practical feeding (roughages and concentrates were fed separately), while the TMR-1 KNBL was fed by the same as TMR-0 until 17 months yearling but was fed by citrus byproducts feeding for 10 months after that. The $L^*(lightness),\;a^*(redness)\;and\;b^*(yellowness)$ value were not significantly different between TMR-0 and TMR-1. The pH of TMR-1 was lower than that of TMR-0 (p<0.05), the VBN content, TBARS value and EDA were not significantly different between TMR-0 and TMR-1. The water holding capacity, frozen loss and cooking loss were not significantly different between TMR-0 and TMR-1, but thawing loss of TMR-0 was higher than that of TMR-1 (p<0.05). The hardness of TMR-0 was higher than that of TMR-1, and the springiness of TMR-1 was higher than that of TMR-0 (p<0.05), but the cohesiveness, gumminess, chewiness and shear force were not significantly different between TMR-0 and TMR-1. The pH and VBN content during storage were not significantly different between TMR-0 and TMR-1, but the TBARS value of TMR-1 stored during 4 weeks was lower than that of TMR-0 (p<0.05). In case of sensory score, the color and aroma of raw meat, and the taste, juiciness and palatability of cooked meat were not significantly different between TMR-0 and TMR-1. But the flavor and tenderness of TMR-1 were superior than those of TMR-0 (p<0.05)

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.14 no.4
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• pp.343-356
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• 2016

The Korea Radioactive Waste Agency (KORAD) has developed a dual-purpose metal cask for the dry storage of spent nuclear fuel that has been generated by domestic light-water reactors. The metal cask was designed in compliance with international and domestic technology standards, and safety was the most important consideration in developing the design. It was designed to maintain its integrity for 50 years in terms of major safety factors. The metal cask ensures the minimization of waste generated by maintenance activities during the storage period as well as the safe management of the waste. An activation evaluation of the main body, which includes internal and external components of metal casks whose design lifetime has expired, provides quantitative data on their radioactive inventory. The radioactive inventory of the main body and the components of the metal cask were calculated by applying the MCNP5 ORIGEN-2 evaluation system and by considering each component's chemical composition, neutron flux distribution, and reaction rate, as well as the duration of neutron irradiation during the storage period. The evaluation results revealed that 10 years after the end of the cask's design life, $^{60}Co$ had greater radioactivity than other nuclides among the metal materials. In the case of the neutron shield, nuclides that emit high-energy gamma rays such as $^{28}Al$ and $^{24}Na$ had greater radioactivity immediately after the design lifetime. However, their radioactivity level became negligible after six months due to their short half-life. The surface exposure dose rates of the canister and the main body of the metal cask from which the spent nuclear fuel had been removed with expiration of the design lifetime were determined to be at very low levels, and the radiation exposure doses to which radiation workers were subjected during the decommissioning process appeared to be at insignificant levels. The evaluations of this study strongly suggest that the nuclide inventory of a spent nuclear fuel metal cask can be utilized as basic data when decommissioning of a metal cask is planned, for example, for the development of a decommissioning plan, the determination of a decommissioning method, the estimation of radiation exposure to workers engaged in decommissioning operations, the management/reuse of radioactive wastes, etc.

• Korean Journal of Agricultural and Forest Meteorology
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• v.2 no.1
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• pp.1-8
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• 2000

The objectives of this study were to investigate weather conditions which induced discolored grains and viviparous germination, and to evaluate yield responses following viviparous germination during mid- and late- ripening stage, the submergence during reproductive growth stage, and lodging in the yellow ripe stage. Weather conditions which caused glume discoloration at heading stage were 21.3-26.4$^{\circ}C$ in average temperature, 75.2-98.4% in relative humidity, 19.3 in transpiration coefficient and 10.8-13.8 m/sec. in wind speed. Yield reduction was 26-27% and 10~17%, respectively, when the glume discoloration rates were 63.2-65.7% and 38.3-45.2%, obviously due to the decrease in percent of fertile grain and ripening ratio. Weather conditions during continuous rain for 7 days were 96% in relative humidity, 18.9$^{\circ}C$ in average temperature, 21.9$^{\circ}C$ in maximum temperature, and 16.8$^{\circ}C$ in minimum temperature, causing the most viviparous germination in Juanbyeo(45.5%), followed by Jinbubyeo(14.5%), Bongkwangbyeo(14.2%), and Obongbyeo(12.6%). Lateral tillers started to occur when the submergence at the depth of 1.5-2 m lasted one day during the reproductive growth stage. The submergence for 2-3 days at 3-4 m of water depth induced 269-571 lateral tillers/m$^2$, supporting 32-52% of the total yield. The rice yield in the paddy fields which were left under the lodging conditions until harvesting was not different compared to that of the paddy fields which were kept upright by tieing them together after lodging, but perfect grain ratio decreased about 9.1% in the transplanting culture and 12.5% in the direct seeding culture on dry paddy field because of the increase in immature grains.