• Journal of Nutrition and Health
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• v.52 no.2
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• pp.157-167
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• 2019

Purpose: This study examined the antioxidant and cancer cell growth inhibitory activities of an ethanol extract and different solvent fractions of Mesembryanthemum crystallinum L. (ice plant). Methods: The ice plant was freeze-dried, extracted with 99.9% ethanol, and then fractionated with hexane, ethyl acetate, butanol, and water. The total polyphenol content (TPC), total carotenoid content (TCC), 2,2-diphenyl-1-picrylhydrazyl radical-scavenging activity (RSA), and ferric reducing antioxidant power (FRAP) were measured. Assays using 2',7'-dichlorofluorescin-diacetate and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide were performed to measure the intracellular reactive oxygen species (ROS) and cell growth, respectively. Annexin V/propidium iodide staining and cell cycle analysis were performed for the detection of apoptosis and cell cycle arrest. Results: TPC, TCC, RSA, and FRAP of the ethanol extract (EE) were 3.7 mg gallic acid equivalent/g, $13.2{\mu}g/g$, 21.0% (at a concentration of 5 mg/mL), and 21.0% (at a concentration of 5 mg/mL), respectively. Among the different solvent fractions, the butanol fraction (BF) showed the highest TPC (5.4 mg gallic acid equivalent/g), TCC ($86.6{\mu}g/g$), RSA (34.9% at 5 mg/mL), and FRAP (80.8% at 5 mg/mL). Treatment of HCT116 human colon cancer cells with EE and BF at concentrations of 250 and $500{\mu}g/mL$ reduced the levels of intracellular ROS. Concomitantly, EE and BF resulted in the dose-dependent inhibition of cell growth (at the concentrations of 125, 250, and $500{\mu}g/mL$ for 24 ~ 48 h) and the induction of apoptosis (at the concentrations of 250 and $500{\mu}g/mL$ for 48 h) in HCT116 cells. An increased G2/M cell population was also found in the BF-treated cells. Conclusion: These results suggest that ice plant possesses antioxidant and growth inhibitory activities in colon cancer cells.

• Korean Journal of Plant Resources
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• v.34 no.5
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• pp.443-450
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• 2021

Peach flesh color is commercially important criteria for classification and has implications for nutritional quality. To breed new yellow-fleshed peach cultivar many cross seedlings and generations should be maintained. Therefore it is necessary to develop early selection molecular markers for screening cross seedlings and germplasm with economically important traits to increase breeding efficiency. For the comparison of transcription profiles in peach varieties with a different flesh color expression, two cDNA libraries were constructed. Differences in gene expression between yellow-fleshed peach cultivar, 'Changhowon Hwangdo' and white-fleshed peach cultivar, 'Mibaekdo' were analyzed by next-generation sequencing (NGS). Expressed sequence tag (EST) of clones from the two varieties was selected for nucleotide sequence determination and homology searches. Putative single nucleotide polymorphisms (SNPs) were screened from peach EST contigs by high resolution melting (HRM) analysis, SNP ID ppa002847m:cds and ppa002540m:cds displayed specific difference between 17 yellow-fleshed and 21 white-fleshed peach varieties. The SNP markers for distinguishing yellow and white fleshed peach varieties by HRM analysis offers the opportunity to use early selection. This SNP markers could be useful for marker assisted breeding and provide a good reference for relevant research on molecular mechanisms of color variation in peach varieties.

• Journal of Nutrition and Health
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• v.55 no.2
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• pp.201-210
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• 2022

Vitamin A (Vit A) is a lipid-soluble vitamin required for diverse normal body functions, including good vision, reproduction, growth, development, and cellular differentiation. The therapeutic effects of Vit A have been demonstrated for the treatments of inflammation, low immunity, and cancer. The present review discusses the scientific evidence for establishing the 2020 Dietary Reference Intakes for Koreans (KDRI) for Vit A, issues caused by unit change of Vit A, and suggestions for the 2025 KDRI revision. Due to the changes in the standard bodyweight observed in several age groups, the 2020 KDRI had minor revisions as compared to the 2015 KDRI. In the 2015 KDRI, the Vit A unit has changed from retinol equivalent (RE) to retinol activity equivalent (RAE) and the activity of carotenoids became half with RAE compared to RE due to this unit change. Since the Vit A intake of Koreans relies heavily on plant-based carotenoids, the dietary intake of Vit A in Koreans as determined by considering the RAE was much lower than values obtained with RE. The analysis for Vit A intake by the Korean National Health and Nutrition Survey only reflects intakes of retinol and beta-carotene. Thus, it would be necessary to include the consumption of other provitamin A, such as alpha-carotene and beta-cryptoxanthin. Moreover, assessing the amounts of Vit A in foods should be customized to Korean diets since there are seasonal variations in the carotenoid concentration of plants. Moreover, other factors such as age- and sex-specific intake data and considerations of baseline micronutrient status, body mass index, and dietary patterns should be considered for developing more precise KDRI. In particular, the Vit A requirement needs to be met by consuming diverse foods, including animal foods.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.2
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• pp.340-354
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• 2021

The aim of this study was to investigate the spatial and temporal distribution of phytoplankton biomass and community composition in Jinhae Bay on the southern coast of Korea. Phytoplankton pigment analysis was conducted using ultra performance liquid chromatography (UPLC) were conducted from April to December 2019 at seven stations. Temperature, salinity, and dissolved oxygen (DO) and inorganic nutrients (dissolved nitrogen, dissolved phosphorus, and orthosilicic acid) were measured to investigate the environmental factors associated with the structure of phytoplankton community. Phytoplankton biomass (Chl-a) was the highest in July (mean 15.4±4.3 ㎍/L) and the lowest in December (mean 3.5±0.6 ㎍/L). Fucoxanthin was the most abundant carotenoid and showed a similar variation pattern to Chl-a, peridinin, and Chl-b. Phytoplankton community composition analysis showed that diatoms were a predominant group with an average abundance of 70 % whereas chlorophytes, cryptophytes, and dinoflagellates often appeared with lower averages. Further, the dominance of diatoms was closely correlated with water temperature and N:P ratio, which might be influenced by high temperatures in the summer and nutrient loading from the land. Additionally, freshwater and nutrient input by rainfall was estimated to be the most important environmental factor. Hence, the spatial and temporal variations in the composition of phytoplankton pigments and phytoplankton community were correlated with physicochemical and environmental parameters.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.33 no.3
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• pp.242-247
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• 1988

To elucidate the relationship of the quality of aromatic tobaccos to their chemical constituents, certain chemical components and leaf quality by price were compared among cured leaves produced under different soil moisture levels during growing season. As the soil moisture increased, plant height and the length and width of largest leaf increased. days to flower was shortened and total chlorophyll and carotenoid content of green leaf decreased. As the soil moisture increased, leaf quality was deteriorated. The content of nicotine, pet. ether ext. and total nitrogen increased with slight increment of nonvolatile organic acids and higher fatty acids, but ash content and pH of cured leaves decreased under high soil moisture content. Volatile organic acids such as 3-methyl pentanoic acid, the main compounds contributing to the aroma of oriental tobacco, and most volatile neutrals decreased conspicuously under high soil moisture. The content of pet. ether ext., volatile organic acids, volatile neutrals, ash and pH of cured leaves were found to be the appropriate factors for the quality evaluation of aromatic leaves grown under under different soil moisture.

• Analytical Science and Technology
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• v.36 no.3
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• pp.105-112
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• 2023

Lycopene, a carotenoid hydrocarbon is known to have effects on reducing cardiovascular risk factors, blood lipids, and blood pressure. Thus, a lot of supplementary foods with lycopene in several dosage forms like soft capsule filled with liquid and hard capsule filled with powder are available in a market. Recently, however, our research group found that the lycopene assay in Supplementary Food Code of South Korea is only valid for oily lycopene preparation. Thus, here, we developed a simple method to determine lycopene in solid preparations for Supplementary Food Code of South Korea using saponification and liquid chromatography with an absorbance detector. The method was validated following Ministry of Food and Drug Safety guidelines. All validation parameters observed in this study were within acceptable criteria of the guidelines (selectivity, linearity of r² ≥ 0.991, lower limit of quantification of 0.0149 mg/mL, accuracy as recovery (R) between 92.70 and 97.18 %, repeatability as relative standard deviation (RSD) values of R between 0.85 and 1.59 %, and reproducibility as the RSD value of interlaboratory R of 3.70 %). Additionally, the practical sample applicability of the validated method was confirmed by accuracy between 98.81 and 101.59 % observed from its lycopene certified reference material (CRM) analyses. Therefore, the present method could contribute to fortify the supplementary food safety management system in South Korea.

• Journal of Bio-Environment Control
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• v.32 no.3
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• pp.217-225
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• 2023

This experiment was conducted to investigate the effects of microwave irradiation on the growth and secondary metabolite contents of lettuce seedlings. Seedlings at three weeks after sowing were treated by a microwave oven for 0, 4, 8, and 12 seconds with 200 W. After cultivation in a close plant production system for 4 weeks, plant growth measurements and secondary metabolite analysis were performed. The results showed that the fresh and dry weights of the shoot and root, leaf area, leaf length, and the number of leaves were decreased as increasing the microwave treatment times. Chlorophyll a and b, total carotenoids were increased and total phenolics were decreased at the 12-second treatment compared to the 4-second treatment. Total flavonoid contents were decreased at the 8-second treatment compared to the control. These results suggest that the changes in the levels of secondary metabolites were caused by oxidative stress. Although there was no significant difference in secondary metabolite contents excluding total flavonoid contents on the microwave treatments compared to the control, the significant difference suggests that the microwave treatment of 200 W and 2.45 GHz may alter secondary metabolite contents of lettuce after 4 weeks.

• Journal of Microbiology and Biotechnology
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• v.33 no.10
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• pp.1292-1298
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• 2023

PAMB 00755^T, a bacterial strain, was isolated from Korean fir leaves. The strain exhibits yellow colonies and consists of Gram-negative, non-motile, short rods or ovoid-shaped cells. It displays optimal growth conditions at 20℃, 0% NaCl, and pH 6.0. Results of 16S rRNA gene-based phylogenetic analyses showed that strain PAMB 00755^T was most closely related to Sphingomonas chungangi MAH-6^T (97.7%) and Sphingomonas polyaromaticivorans B2-7^T (97.4%), and ≤96.5% sequence similarity to other members of the genus Sphingomonas. The values of average nucleotide identity (79.9-81.3%), average amino acid identity (73.3-75.9%), and digital DNA-DNA hybridization (73.3-75.9%) were significantly lower than the threshold values for species boundaries; these overall genome-related indexes (OGRI) analyses indicated that the strain represents a novel species. Genomic analysis revealed that the strain has a 4.4-Mbp genome encoding 4,083 functional genes, while the DNA G+C content of the whole genome is 66.1%. The genome of strain PAMB 00755^T showed a putative carotenoid biosynthetic cluster responsible for its antioxidant activity. The respiratory quinone was identified as ubiquinone 10 (Q-10), while the major fatty acids in the profile were identified as C_18:1ω7c and/or C_18:1ω6c (summed feature 8). The major polar lipids of strain PAMB 00755^T were diphosphatidylglycerol, phosphatidylethanolamine, sphingoglycolipid, and phosphatidylcholine. Based on a comprehensive analysis of genomic, phenotypic, and chemotaxonomic characteristics, we proposed the name Sphingomonas abietis sp. nov. for this novel species, with PAMB 00755^T as the type strain (= KCTC 92781^T = GDMCC 1.3779^T).

• Korean Journal of Environmental Biology
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• v.41 no.3
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• pp.283-290
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• 2023

The Republic of Korea reclaimed land to increase its food self-sufficiency rate, but the yield was reduced due to abnormal climate. In this study, it was hypothesized that rapid and continuous monitoring technology could help improve yield. Using the vegetation index (VI) analysis, the drought stress index was calculated and the drought stress for corn grown in Hwaong, Saemangeum, and Yeongsan River reclaimed tidal land was predicted according to drying treatment. The vegetation index of corn did not decrease during the last 20 days of irrigation when soil moisture rapidly decreased, but decreased rapidly during the 20 days after irrigation. The reduction rate of the vegetation index according to the drying treatment was in the order of Saemangeum>Yeongsan River>Hwaong reclaimed tidal land, and normalized difference vegetation index(NDVI) decreased by approximately 50% in all reclaimed tidal lands, confirming that drought stress occurred due to the decrease in moisture content of the leaves. In addition, structure pigment chlorophyll index (SIPI) and photochemical reflectance index (PRI), which are calculated based on changes in light use efficiency and carotenoids, were reduced; drought stress caused a decrease in light use efficiency and an increase in carotenoid content. Therefore, vegetation index analysis was confirmed to be effective in evaluating and predicting drought stress in corn growing on reclaimed tidal land corn.

• Food Science and Preservation
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• v.22 no.2
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• pp.232-240
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• 2015

This study investigated the microbiological and nutritional characteristics of bimonthly radish sprouts purchased at a local market. The total bacteria and coliform measurements were highest in summer (June and August) and lowest in winter (February and December). The total phenol content was $16.82{\pm}0.69GAEmg/g$, and it did not significantly differ during the investigation period. The total carotenoid contents were highest in February (about $12.81{\pm}0.49$ ${\beta}$-carotene mg/g) and lowest in April (about $8.09{\pm}1.01$ ${\beta}$-carotene mg/g). However although total glucosinolates content differ between the total crude glucosinolate and the sum of the individual glucosinolates, it was highest in December. The individual glucosinolates were found to have been gucoraphenin, glucoerucin, glucobrassicin and gluconasturtiin in radish sprouts via HPLC analysis. The purchasing time of the glucoraphenin content did not significantly differ. The measured glucoerucin was highest in February and lowest in October. The gucobrassicin and gluconasturtiin were higher in summer than in winter, but did not significantly differ. The antioxidant activity (i.e., the $IC_{50}$ values of the DPPH radical scavenging) was highest in February. In conclusion, the microbial contamination, total carotenoids, and antioxidant activity changed according to the purchasing season, but the total phenolic compounds and total glucosinolates were maintained regardless of the time in the radish sprouts.