• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.27 no.3
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• pp.187-192
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• 2021

This study was conducted to compare the quality of baby leaves grown under several temperature conditions and the storage properties of MA storage for romaine lettuce. It was grown for 5 weeks under an artificial light source (200 µmol·m^-2·s^-1) in a chamber at 21℃, 28℃, and 35℃. The growth and quality of red romaine lettuce that grown in different temperatures were investigated at the end of cultivation, and the oxygen, carbon dioxide, and ethylene concentrations in the 20,000 cc OTR film and perforated film packed with lettuces were measured for 36 and 12 days, respectively. The red romaine lettuce baby leaf was examined for color, chlorophyll, and visual quality at the end of storage. The maximum quantum yield of baby leaf grown in different temperatures at 7days before the harvest was higher at 21℃ and 28℃ growth temperature treatments. On harvest day, the leaf length measured was longest at 28℃, and the leaf width was wider at 21℃ and 28℃, and the number of leaves was similar to 5-6 at all cultivation temperatures. Leaf weight, root weight, and dry weight were found to be higher at 21℃, and tended to decrease as the cultivation temperature increased. The concentration of ethylene in the film of the MA storage treatments was maintained at 1~2 µL·L^-1 until the end of storage in all treatments regardless of the cultivation temperature. Oxygen concentration in the MA treatment used 20,000 OTR film was maintained at around 19.5%, and carbon dioxide concentration around 1% that was satisfied the CA conditions. Both Hunter a^* and b^* values were generally higher in the MA storage treatment at the end of storage day. The chlorophyll content was decreased as the cultivation temperature increased, and was lower in the MA storage treatment than in the perforated film treatment. Visual quality was 3 points or higher in the MA storage treatment at 21℃ growth treatment, and it was maintained marketability. As the above results, the growth of baby leaves of romaine lettuce was the best at 21℃ treatment, and the lower the cultivation temperature, the longer the shelf life. And it was possible to extend the shelf life by 3 times by showing excellent visual quality at the MA storage treatment that satisfies the carbon dioxide concentration of CA condition until the end of storage day.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.6
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• pp.771-777
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• 2017

This study investigated the rheological properties of Calrose rice flour dispersions as well as the effects of different thawing methods (steamer, smart oven, and microwave oven) on quality characteristics of frozen turmeric rice. Apparent viscosity, consistency index, and yield stress significantly increased at higher rice flour concentrations. Magnitudes of storage modulus and loss modulus significantly increased with elevation of rice flour concentration. Frozen turmeric rice thawed using a steamer had the highest moisture content and largest size (length, width, and thickness) among all thawing methods. The L values of turmeric rice after thawing using a steamer was significantly higher than those of other thawing methods. The a value of turmeric rice after thawing using a steamer was significantly lower than those of other thawing methods. Textural properties (hardness, adhesiveness, springiness, cohesiveness, brittleness, and chewiness) of frozen turmeric rice after thawing using a steamer were significantly lower than those of other thawing methods. Therefore, it can be concluded that frozen turmeric rice after thawing using a steamer might be desirable for improvement of texture.

• Journal of Life Science
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• v.27 no.8
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• pp.951-957
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• 2017

To understand the cytotoxic activity of Machilus thunbergii, which has been used as a traditional oriental medicine, the mechanism underlying the cytotoxic effect of its extract on human acute Jurkat T cells was investigated. The methanol extract of roots (3 kg) of M. thunbergii was evaporated, dissolved in, and then extracted by water. The water-extracted active substance was designated MTWE. When Jurkat T cells were treated with MTWE at concentrations of 0, 25, 50, and $100{\mu}g/ml$, the apoptotic phenomenon of cells accompanying several subsequent biochemical reactions, such as mitochondrial cytochrome c release, activation of caspase-3, and ICAD degradation, was detected in the Jurkat T cells. Moverover. the expression of Bcl-xL, which is a suppressor for mitochondrial cytochrome c release pathway, was reduced in the Jurkat T cells. As DUSP6, a growth suppressor of cancer cells, ranged from 0, 25, 50, $100{\mu}g/ml$ of MTWE, the expression level was elevated in the Jurkat T cells. The apoptotic morphological change of the nuclei was observed by DAPI staining. Although the potential involvement of the other factors and DUSP6 is currently being investigated in more detail, these findings support the notion that MTWE is able to achieve the apoptosis of Jurkat T cells, and it seems that MTWE is useful as a method of evaluating a chemotherapeutic agent or tonic materials for human acute leukemia.

• Korean Journal of Agricultural Science
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• v.48 no.2
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• pp.299-310
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• 2021

Glycerol is a non-volatile compound with no aromatic properties that contributes significantly to the quality of wine by providing sweetness and richness of taste. In addition, it is also the third most significant byproduct of alcoholic fermentation in terms of quantity after ethanol and carbon dioxide. In this study, Fourier transform infrared (FT-IR) spectroscopy was employed as a fast non-destructive method in conjugation with multivariate regression analysis to build a model for the quantitative analysis of glycerol concentration in wine samples. The samples were prepared by using three varieties of red wine samples (i.e., Shiraz, Merlot, and Barbaresco) that were adulterated with glycerol in concentration ranges from 0.1 to 15% (v·v^-1), and subjected to analysis together with pure wine samples. A net analyte signal (NAS)-based methodology, called hybrid linear analysis in the literature (HLA/GO), was applied for predicting glycerol concentrations in the collected FT-IR spectral data. Calibration and validation sets were designed to evaluate the performance of the multivariate method. The obtained results exhibited a high coefficient of determination (R²) of 0.987 and a low root mean square error (RMSE) of 0.563% for the calibration set, and a R² of 0.984 and a RMSE of 0.626% for the validation set. Further, the model was validated in terms of sensitivity, selectivity, and limits of detection and quantification, and the results confirmed that this model can be used in most applications, as well as for quality assurance.

• Journal of Life Science
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• v.32 no.7
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• pp.523-531
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• 2022

The purpose of this study was to evaluate the effect of antioxidant and anti-adipogenic activities in ethanol extracts from herb mixture (Ephedra sinica, Atractylodes lance, Gypsum fibrosum, and Theobroma cacao). DPPH, ABTS⁺ radical and xanthine oxidase scavenging activities were measured for antioxidant activity. Extracts of the herb mixture had 75.0, 100.8, and 79.5% scavenging activities at 1,000 ㎍/ml concentration, respectively. We investigated the inhibition of adipogenesis and adipocyte differentiation with an extract of an herb mixture in 3T3-L1 preadipocytes. An extract from the herb mixture at concentrations between 0 and 50 ㎍/ml did not affect 3T3-L1 cell viability. Treatment with herb mixture extracts of 25, 50, and 75 ㎍/ml in 3T3-L1 preadipocytes inhibited lipid accumulation in a dose-dependent manner. As a result of a Western blot experiment, it was shown that the herb mixture inhibited the differentiation transcription factors, PPARγ and C/EBPa, by 44.2 and 77.6%, respectively, at a concentration of 75 ㎍/ml in MDI-induced differentiated 3T3-L1 cells. As a result of RT-PCR, the gene expression of C/EBPa, SREBP-1c, and PPARγ was significantly inhibited by 43.4%, 59.6%, and 55.3%, respectively, at the concentration of 75 ㎍/ml of the herb mixture compared with the MDI-treated group. In addition, the expression of fatty acid synthase (FAS), a fatty acid synthesis regulator, was suppressed. These results can be applied to develop a functional food for anti-obesity with a herb mixture.

• Korean Journal of Agricultural and Forest Meteorology
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• v.25 no.4
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• pp.436-445
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• 2023

Methane (CH₄) emissions from rice paddies are mainly observed using the closed chamber method or the eddy covariance method. In this study, a new observation technique combining a portable gas analyzer (Model LI-7810, LI-COR, Inc., USA) and an automatic opening/closing chamber (Model Smart Chamber, LI-COR, Inc., USA) was introduced based on the strengths and weaknesses of the existing measurement methods. A cylindrical collar was manufactured according to the maximum growth height of rice and used as an auxiliary measurement tool. All types of measured data can be monitored in real time, and CH₄ flux is also calculated simultaneously during the measurement. After the measurement is completed, all the related data can be checked using the software called 'SoilFluxPro'. The biggest advantage of the new observation technique is that time-series changes in greenhouse gas concentrations can be immediately confirmed in the field. It can also be applied to small areas with various treatment conditions, and it is simpler to use and requires less effort for installation and maintenance than the eddy covariance system. However, there are also disadvantages in that the observation system is still expensive, requires specialized knowledge to operate, and requires a lot of manpower to install multiple collars in various observation areas and travel around them to take measurements. It is expected that the new observation technique can make a significant contribution to understanding the CH₄ emission pathways from rice paddies and quantifying the emissions from those pathways.

• Journal of Bio-Environment Control
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• v.30 no.1
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• pp.77-84
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• 2021

This study attempted to find a way to maintain the quality of mixing baby wild leaf vegetables with existing baby leaf vegetables in various ratios. The crops for mixing baby leaf vegetables were Peucedanum japoincum Thunberg and Ligularia stenocephala, as wild vegetables, and red romaine, which is widely used in young leafy vegetables. The mixing ratio of red romaine and wild vegetables was red romaine 0: mantilla oil 5: L. stenocephala ratio 5 (R0: P5: L5), red romaine 3.3: P. japoincum 3.3: L. stenocephala ratio 3.3 (R3.3: P3.3: L3.3), red romaine 5: P. japoincum 2.5: L. stenocephala 2.5 (R5: P2.5: L2.5), red romaine 8: P. japoincum 1: L. stenocephala 1 (R8: P1: L1), red romaine 10: P. japoincum 0: L. stenocephala 0 (R10: P0: L0). All treatments were packaged in OTR (oxygen transmittance) 10,000 cc m-2·day-1·atm-1 film and stored for 27 days at 2℃/85% RH conditions. Fresh weight, carbon dioxide, oxygen, and ethylene concentrations of the baby leaf packages were examined approximately every 3 days, and visual quality, chlorophyll content, and chromaticity were examined on the 27th day of storage. The oxygen and carbon dioxide concentration in the packages were affected by the respiration rate of the crop. As the mixing ratio of lettuce, which had a low respiration rate, increased, the oxygen concentration in the packages was higher and the carbon dioxide concentration was lower. Oxygen concentration decreased significantly after 15 days, but was remained above 16%, and on the contrary, carbon dioxide concentration was kept at 1-4% until the 15th, and then gradually increased to 2-5% on the 27th day. The concentration of ethylene was maintained at 3-6 µL·L-1 until the end of storage (27th day). Visual quality score measured at the end of storage was slightly less than 3.0, which is the limit of marketability of all treatments. Although there was no significant difference, the chlorophyll content (SPAD) of red romaine and P. japoincum were most similar with an initial value in R8:P1:1 treatment, and L. stenocephala was higher value in R8:P1:L1 and R5:P2.5:L2.5 treatments at the end of storage. The leaf color (L∗, a∗, b∗, chroma) of the three crops at end of storage compared with the heat map showed the least change in the R5:P2.5:L2.5 and R8:P1:L1 treatments at the end of storage. Among them, R8:P1:L1 treatment maintained the highest chlorophyll content, the second lowest ethylene concentration, and adequate carbon dioxide concentration of 2-3%. Therefore, it is judged that the mixed ratio of red romaine 8: P. japoincum 1: L. stenocephala 1 (R8: P1: L1) is most suitable for the mixed package of baby leaf vegetables of these three crops.

• Korean Journal of Environmental Biology
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• v.38 no.2
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• pp.271-277
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• 2020

Toxicities to many organs caused by humidifier disinfectants have been reported. Recently, humidifier disinfectants have been reported to cause cardiovascular, embryonic, and hepatic toxicities. This study was designed to investigate the toxic mechanism of humidifier disinfectants and compare toxicity in a cellular model and a zebrafish animal model. Because brain toxicity and skin toxicity have been less studied than other organs, we evaluated toxicity in a human dermal cell line and zebrafish under various concentrations of humidifier disinfectants that included polyhexamethyleneguanidine phosphate (PHMG), oligo-[2-(2-ethoxy)-ethoxyethyl-guanidinium-chloride] (PGH) and methylchloroisothiazolinone/methylisothiazolinone (CMIT/MIT). A human dermal fibroblast cell line was treated with disinfectants (0, 2, 4, 6, 8, and 16 mg L^-1) to compare their cytotoxicity. The fewest PHMG-treated cells survived (up to 33%), while 49% and 40% of the PGH- and CMIT/MIT-treated cells, respectively, survived. The quantification of oxidized species in the media revealed that the PHMG-treated cells had the highest MDA content of around 28 nM, while the PGH- and CMIT/MIT-treated cells had 13 and 21 nM MDA, respectively. As for brain toxicity, treatment of the zebrafish tank water with CMIT/MIT (final 40 mg L^-1) for 30 min resulted in a 17-fold higher production of reactive oxygen species (ROS) than in the control. Treatment with PGH or PHMG (final 40 mg L^-1) resulted in 15- and 11-fold higher production, respectively. The humidifier disinfectants (PHMG, PGH, and CMIT/MIT) showed severe dermal cell toxicity and brain toxicity. These toxicities may be relevant factors in understanding why some children have language disorders, motor delays, and developmental delays from exposure to humidifier disinfectants.