• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.1
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• pp.85-88
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• 2015

This study attempted to establish an HPLC analysis method for determination of marker compounds as a part of material standardization for the development of health functional food materials from Perilla frutescens Britton var. acuta Kudo. The quantitative determination method of rosmarinic acid as a marker compound of P. frutescens Britton var. acuta Kudo extract (PFE) was optimized by HPLC analysis using a C18 column ($4.6{\times}150mm$, $5{\mu}m$) with 0.1% acetic acid as the elution gradient and methanol as the mobile phase at a flow rate of 1 mL/min and detection wavelength of 280 nm. The HPLC/UV method was applied successfully to quantification of the marker compound in PFE after validation of the method with linearity, accuracy, and precision. The method showed high linearity in the calibration curve at a coefficient of correlation ($R^2$) of 0.9995, and the limit of detection and limit of quantitation were $0.36{\mu}g/mL$ and $1.2{\mu}g/mL$, respectively. Relative standard deviation (RSD) values of data from intra- and inter-day precision were less than 3.21% and 1.43%, respectively. Recovery rate test at rosmarinic acid concentrations of 12.5, 25 and $50{\mu}g/mL$ scored between 97.04~98.98% with RSD values from 0.25~1.97%. These results indicate that the established HPLC method is very useful for the determination of marker compound in PFE to develop a health functional material.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.3
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• pp.409-419
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• 2016

The objective of this study was to investigate dietary sodium sources at the dish level in 228 university students (71 men, 157 women) in Gyeonggi-do. Daily sodium intake was estimated from a validated 125-dish frequency questionnaire. In men, body mass index, systolic blood pressure, and sodium intake were significantly higher than in women. Men showed higher sodium intake from soups, fish or shellfish dishes, meat dishes, and soybean dishes than women. The dishes that most largely contributed to daily sodium intake were Napa cabbage kimchi and ramen in both men and women. In addition, relatively higher amounts of sodium from ramen were consumed in men, whereas cookies were the 5th highest sodium source in women. In both men and women, the high sodium intake groups consumed more sodium from kimchi, dishes cooked with kimchi, dishes with broth, and salted mackerel than the low sodium intake group. There were significant differences in major dishes contributing to between-person sodium intake variations between men and women. Short rib soup for men and Korean sausage for women were the largest contributors to sodium variations, which are common dishes served with salt. Men consumed more drinks and also more sodium from drinks than women. In conclusion, there were significant differences in major dishes contributing to absolute and between-person sodium intake variations in university students between men and women. Further studies on effects of gender on blood pressure, sodium and drink intake, and obesity are necessary.

• Journal of agriculture & life science
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• v.45 no.2
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• pp.43-50
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• 2011

Hibiscus cannabinus L. is a plant in the Malvaceae family, that was seeded at June 1st in 2010 and harvested at November 18th. The present study was designated to investigate the safety for host cells, antibacterial effects of Hibiscus cannabinus L. of flower (HCME-F) or leaf (HMEF-L) methanol extract for typical Gram's positive bacteria (St. aureus and Str. epidermidis) or Gram's negative bacteria (S. typhimurium and E. coli). In treatment of different concentrations of HCME-F or HMEF-L (1, 50 and $100{\mu}g/ml$), cytotoxic effects were not shown to RAW 264.7 cells until 24 h incubation. In determination of antibacterial activity of HCME-F or HMEF-L, the antibacterial activities for St. aureus and Str. epidermidis were markedly increased compared to that of untreated control group, but antibacterial activity of HCME-F or HMEF-L for S. typhimurium and E. coli were not changed. Taken together, we demonstrated that methanol extract of HCME-F or HMEF-L showed the safety for RAW 264.7 cells and antibacterial activities for Gram's positive pathogenic bacteria St. aureus and Str. epidermidis. These findings suggest that a methanol extract of Kenaf flower or leaf may be useful alternatives of conventional chemotherapies for dermatitis and mastitis causing Gram's positive pathogens such as Stapylococcus spp. and Streptococcus spp. in domestic animals and humans.

• Food Science and Industry
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• v.52 no.2
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• pp.188-201
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• 2019

In the past, food additives were classified and managed as chemical synthetic and natural additives according to the manufacturing process, but it was difficult to confirm the purpose or function of food additives.CODEX, an internationalstandard, classifies food additives according to their practical use, based on scientific evidence on the technical effects of food additives, instead of classifying them as synthetic or natural. Therefore, very recently, the food additive standards in Korea have been completely revised in accordance with these global trends. Currently, the classification system of food additives is divided into 31 uses to specify their functions and purposes instead of manufacturing methods. Newer revision of the legislative framework for defining and expanding the scope of the Act as an enlarged area is required. Competition for preempting new food products based on bio-based technology is very fierce in order to enhance the safety of domestic people and maximize the economic profit of their own countries. In this age of infinite competition, it is very urgent to revise or supplement the current regulations in order to revitalize the domestic food industry and enhance national competitiveness through the development of food additives using new biotechnology. In this report, current laws on domestic food ingredients, food additives and manufacturing methods, and a comparison of domestic and foreign advanced countries' regulations and countermeasures strategies were reviewed to improve national competitiveness of domestic advanced biotechnology-based food additives industry.

• Journal of Life Science
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• v.31 no.2
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• pp.209-218
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• 2021

This study aimed to evaluate the anti-obesity effects of Cudrania tricuspidata leaf extract in the order of leaf development on the shoot (L0, L1, L2, L3, L4, and L5). The leaves at the apex of a Cudrania tricuspidata shoot were classified as L0; the next leaves of the apex were classified as L1, L2, L3, and L4 from highest to lowest; and the lowest leaf was classified as L5. A series of 70% ethyl alcohol leaf extracts were screened for the inhibitory effects of adipogenesis in 3T3-L1 preadipocytes. We found that the apical leaf extract of Cudrania tricuspidata (CTL0) was the most effective. Next, a study was conducted on the inhibitory action mechanism of CTL0. Treatment with CTL0 significantly suppressed the differentiation of 3T3-L1 preadipocytes in a dose-dependent manner, as confirmed by the decrease in lipid droplet content observed with Oil Red O staining. Treatment with 12.5 ㎍/ml, 25 ㎍/ml, and 50 ㎍/ml of CTL0 significantly reduced the lipid droplet content. Glucose and cellular triglyceride concentrations were reduced in the 3T3-L1 cells on the CTL0-treated medium compared to the differentiation medium (DM control, DMEM + insulin + dexamethasone + rosiglitazone). Compared with DM, CTL0 significantly inhibited the expression of key pro-adipogenic transcription factors, including peroxisome proliferator-activated receptor γ (PPARγ), LPL, A-FABP, and Glut4. These findings show that CTL0 extract has potent anti-obesity effects.

• Journal of Food Hygiene and Safety
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• v.36 no.3
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• pp.220-227
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• 2021

Fluoroimide is a fungicide and is also used as a pesticide for persimmons and potatoes. The established fluoroimide pesticide analysis method takes a long time to perform and uses benzene, a carcinogen. In addition, a lower limit of quantification is required due to enforcement of the Positive List System. Therefore, this study aimed to improve the analysis method for residual fluoroimide to resolve the problems associated with the current method. The analytical method was improved with reference to the increased stability of fluoroimide under acidic conditions. Fluoroimide was extracted under acidic conditions by hydrogen chloride (4 N) and acetic acid. MgSO₄ and NaCl were used with acetonitrile. C₁₈ (octadecylsilane) 500 mg and graphitized carbon black 40 mg were used in the purification process. The experiment was conducted with agricultural products (hulled rice, potato, soybean, mandarin, green pepper), and liquid chromatograph-tandem mass spectrometry was used for the instrumental analysis. Recovery of fluoroimide was 85.7-106.9% with relative standard deviations (RSDs) of less than 15.6%. This study reports an improved method for the analysis of fluoroimide that might contribute to safety by substituting the use of benzene, a harmful solvent. Furthermore, the use of QuEChERS increased the efficiency of the improved method. Finally, this research confirmed the precise limit of quantification and these results could be used to improve the analysis of other residual pesticides in agricultural products.

• Korean Journal of Food Science and Technology
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• v.54 no.4
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• pp.437-444
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• 2022

This study investigated the optimal quality characteristics of sauerkraut made by adding 0.5, 1.0, 1.5, 2.0, and 2.5% (w/w) sea salt to cabbage according to the storage period. The results showed that the pH and salinity of 0.5-2.5% sauerkraut decreased, while its total acidity increased during storage. After 20 d of storage, 1.5% or less sauerkraut showed low yellowness, but high brightness and hardness. Moreover, the lactic acid bacteria in 0.5-2.5% sauerkraut maintained at least 7.06 log CFU/mL until 28 d of storage, suggesting that the lower the salt concentration, the higher were the amount of lactic acid bacteria. The coliform group was not detected after 4 d of storage. In conclusion, the quality characteristics of sauerkraut with a salt concentration of 1.5% or less were excellent until 20 d of storage at 4℃. This study provides valuable data for the safe and high-quality assessment of low-salt sauerkraut in the future.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.4
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• pp.350-359
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• 1993

The effect of gibberellic acid ($GA_3) and abscisic acid (ABA) on KCl-enhanced proteolysis of senescing leaves of rice(Oryza sativa L. cv. Chilsung) was studied. Emphasis was given to their effects on KCI-enhanced efflux of amino acids and proteinase activity. When treated singly, $GA_3 affected leaf proteolysis little, while ABA increased proteolysis, the rate of amino acid efflux, and ribulose -1,5 -bisphosphate carboxylase / oxygenase (Rubisco)-degrading endoproteinase activity. An additive increase in all three parameters mentioned above was observed when leaves were treated with ABA and KCl. No such an additive effect was found when $GA_3 was treated with KCl. Both $GA_3 and ABA helped to alleviate the KCI-suppressed activity of Rubisco-degrading exoproteinases. The additive increase in proteolysis of rice leaves in the presence of both ABA and KCl could thus be ascribed to a further increase in the efflux of protein hydrolyzates and Rubisco-degrading endoproteinase activity. An increase in proteolysis was accompanied by a decrease in water absorption, and the combined treatment of ABA with KCl resulted in a further reduction of water absorption.

• Clean Technology
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• v.29 no.1
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• pp.10-21
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• 2023

Hydrogels that are made of natural polymer-based double networks have excellent biocompatibility, low cytotoxicity, and high water content, assuring that the material has the properties required for a variety of biomedical applications. However, hydrogels also have limitations due to their relatively weak mechanical properties. In this study, hydrogels based on an alginate di-aldehyde (ADA) and gelatin (Gel) double network that is reinforced with additional hydrogen bonds formed between the hydroxyl (-OH) groups of the hyperbranched polymer (HPG) and the functional groups present inside of the hydrogels were successfully synthesized. The enhanced mechanical properties of these synthesized hydrogels were evaluated by varying the amount of HPG added during the hydrogel synthesis from 0 to 25%. In addition, magnetite nanoparticles (Fe₃O₄ NPs) were synthesized within the hydrogels and the structures and the magnetic properties of the hydrogels were also characterized. The hydrogels that contained 15% HPG and Fe₃O₄ NPs exhibited superparamagnetic behaviors with a saturation magnetization value of 3.8 emu g^-1. These particular hydrogels also had strengthened mechanical properties with a maximum compressive stress of 1.1 MPa at a strain of 67.4%. Magnetic hydrogels made with natural polymer-based double networks provide improved mechanical properties and have a significant potential for drug delivery and biomaterial application.

• Laboratory Medicine Online
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• v.1 no.1
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• pp.57-63
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• 2011

Background: ABO antibody titration is useful for the evaluation of ABO-incompatible bone marrow or solid organ transplantations, yet the results quite vary between different test methods used. We compared the results of microcolumn agglutination and tube methods. Methods: Anti-A and anti-B isoagglutionin titers were determined in 63 healthy individuals (23 O, 20 A, and 20 B blood groups) using 4 different methods: immediate spin tube (tube), microcolumn agglutination without anti-human globulin (AHG) (CAT), tube with AHG (tube-AHG) and microcolumn agglutination with AHG (CAT-AHG). Results: The median (range) titers of anti-A and anti-B in group O individuals by tube, CAT, tube-AHG, and CAT-AHG methods were 64 (8-512), 64 (8-512), 128 (8-2,048), and 128 (16-2,048); 64 (16-128), 128 (16-256), 128 (16-512), and 256 (16-512), respectively. The median (range) titers of anti-A in group B and anti-B in group A individuals by the four methods were 64 (16-128), 128 (8-128), 128 (8-256), and 256 (8-256); 64 (8-128), 64 (8-128), 32 (8-128), and 64 (8-256), respectively. The isoagglutinin titer measured by CAT-AHGmethod was the highest. The titers measured by CAT and CAT-AHG methods were 0-1 titer higher than those by tube and tube-AHG methods, respectively. Whatever method was used, the isoagglutinin titers were higher in women than in men. Conclusions: CAT-AHG was the most sensitive method among the four methods tested. Since AHG titer values are critical for the clinical management and CAT has less manual procedures than tube method, CAT-AHG method could be used for the standardization of ABO antibody titration in different institutions.