• Journal of Microbiology and Biotechnology
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• v.31 no.7
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• pp.990-998
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• 2021

Melanin is a natural skin pigment produced by specialized cells called melanocytes via a multistage biochemical pathway known as melanogenesis, involving the oxidation and polymerization of tyrosine. Melanogenesis is initiated upon exposure to ultraviolet (UV) radiation, causing the skin to darken, which protects skin cells from UVB radiation damage. However, the abnormal accumulation of melanin may lead to the development of certain skin diseases, including skin cancer. In this study, the antioxidant and antimelanogenic activities of the cell-free supernatant (CFS) of twenty strains were evaluated. Based on the results of 60% 2,2-diphenyl-1-picrylhydrazyl scavenging activity, 21% 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) scavenging capacity, and a 50% ascorbic acid equivalent ferric reducing antioxidant power value, Limosilactobacillus fermentum JNU532 was selected as the strain with the highest antioxidant potential. No cytotoxicity was observed in cells treated with the CFS of L. fermentum JNU532. Tyrosinase activity was reduced by 16.7% in CFS-treated B16F10 cells (but not in the cell-free system), with >23.2% reduction in melanin content upon treatment with the L. fermentum JNU532-derived CFS. The inhibitory effect of the L. fermentum JNU532-derived CFS on B16F10 cell melanogenesis pathways was investigated using quantitative reverse transcription polymerase chain reaction and western blotting. The inhibitory effects of the L. fermentum JNU532-derived CFS were mediated by inhibiting the transcription of TYR, TRP-1, TRP-2, and MITF and the protein expression of TYR, TRP-1, TRP-2, and MITF. Therefore, L. fermentum JNU532 may be considered a potentially useful, natural depigmentation agent.

• Horticultural Science & Technology
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• v.33 no.6
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• pp.812-819
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• 2015

Gladiolus is one of the most popular cut flowers in the world floral market and is highly attractive to consumers. The production of poor-quality gladiolus spikes is one of the most important hurdles to obtaining high prices for this crop. The main objectives of this study were to improve the quantitative characteristics of gladiolus spikes, to increase propagule production and to enhance chemical constituent levels in leaves to help improve plant growth. We performed foliar application of bioregulators, including polyamines (putrescine and spermine) and vitamins (ascorbic acid and thiamine), at different concentrations (0, 0.1, 0.4, 0.7 and 1 mM) to gladiolus plants at the three leaf, five leaf and slipping stages. Application of 1 mM putrescine was the most effective treatment, with prominent effects on economically important spike traits including spike length (55.53 cm), spike diameter (7.53 mm), florets per spike (13.99), first floret diameter (9.66 cm) and first floret weight (4.90 g), followed by spermine treatment. The 1 mM putrescine treatment also had positive effects on corm-associated traits including corm diameter and corm weight, with values of 4.57 cm and 26.16 g compared to 3.47 cm and 17.16 g in control plants, respectively. The contents of chemical constituents in leaves, including total chlorophylls ($8.06mg{\cdot}g^{-1}$), total carotenoids ($1.66mg{\cdot}g^{-1}$), total soluble sugars ($4.75 mg{\cdot}g^{-1}$) and phenolics ($0.89mg{\cdot}g^{-1}$) increased in response to foliar application of 1 mM putrescine compared to the control. Ascorbic acid and thiamine also had positive effects on various plant morphological traits and chemical constituents in leaves compared to control plants, but the growth-promoting effects of polyamines were more pronounced. Hence, applying polyamines to gladiolus leaves will help improve spike production and increasing propagule (cormel) yields.

• Journal of Pharmaceutical Investigation
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• v.41 no.6
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• pp.331-336
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• 2011

The instability of hirsutenone (HST), a potential therapeutic candidate for the treatment of atopic dermatitis (AD) and ovarian carcinoma, is one of the main concerns for the development of drug product. In the present study, aqueous stability of HST was investigated by kinetic analysis, and the effect of several factors covering temperature, nitrogen gas ($N_2$) flushing, and selection of proper antioxidant was compared. Cosolvent system composed of distilled water and methanol (9:1 v/v) was used as a vehicle to dissolve HST at the concentration of $200{\mu}g/mL$. Samples of aqueous solution were prepared under the absence or presence of antioxidants, such as ascorbic acid (AA), sodium edetate (EDTA), and ascorbyl palmitate (AP), and subjected for stability test. The degradation of HST in aqueous solution was followed by the first order kinetics with an extremely short half life of less than a week at room temperature, and was accelerated as the temperature increased. $N_2$ flushing brought a little enhancement in stability compared to control solution, but the effect was insufficient. The addition of AA and EDTA (0.1%) significantly enhanced the stability of HST at $40^{\circ}C$, but the addition of AP (0.01%) was limited due to its water insolubility and revealed no promising result. The stability of HST was increased proportionally by the amount of AA added, showing the difference in degree of stabilization as an order of magnitude. Finally, we conclude that HST was stabilized by the addition of a suitable antioxidant, suggesting AA as the most effective stabilizer.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2003.04a
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• pp.134.2-135
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• 2003

채소류는 생리적인 특성상 수확후 저장 및 유통되는 동안에 호흡작용, 증산작용 등의 작용이 활발해질 뿐만 아니라 곰팡이를 비롯한 식물병이 미생물의 오염 및 성장으로 부패현상을 일으키고 채소류 자체의 경도가 저하되며, 수분, 비타민, 유기산, 당분, 색소함량 등이 떨어져서 외관, 맛 신선도 등의 감소하게 된다. 본 연구에서는 채소류(오이, 호박, 방울토마토)의 선도를 연장하기 위한 저장조건을 실시하여 최적 습도 및 온도범위를 결정하였고, 이를 토대로 하여 시설채소산물을 습도조절이 가능한 원적외선 방사체 저장고(5~8$^{\circ}C$의 온도와 90% 습도유지)에 저장하면서 무처리구인 대조구와 비교하여 저장중 시료의 중량손실율, Ascorbic acid함량, 총균수(PCA사용법에 의거), pH의 변화를 측정하였고, 시료의 표면색도는 색도계(Minolta CR-300, Japan)를 사용하여 Hunter의 L, a, b값을 측정하였다. 이 결과, 채소류의 선도유지기간이 연장되는 것을 확인하였고, 중량손실율은 원적외선 방사체 저장고에 저장한 채소류가 중량손실율이 대조구에 비하여 낮게 나타났다. 따라서 습도조절이 가능한 원적외선 방사체 저장고에 채소류를 저장함으로서 채소류의 수분손실을 방지할 수 있음을 확인할 수 있었으며, 일정기간동안 원적외선 방사체 저장고에 저장함으로써 ascorbic acid함량의 감소를 대조구에 비하여 낮은 비율로 억제할 수 있었다. 총균수의 경우 채소류 시험구에서 원적외선 방사체 저장고에서 저장할수록 오염미생물의 총균수가 낮게 나타났다. 표면색도의 경우, a값은 모든 시험구에서 감소하였으며 원적외선 방사체 시험구에 비하여 대조구 저장시료의 표면색도가 청색도를 증가시키는 변화를 관찰할 수 있었고, b값은 시료간에 유의성 있는 차이없이 다소 증가하는 것으로 나타났다. 부패율은 수분 함유율이 높은 채소류일수록 원적외선 방사체 저장시설을 이용하는 경우, 부패율을 낮게 유지할 수 있었다. 따라서, 원적외선 방사체 저장시설내에 오이, 호박 및 방울토마토와 같은 채소류를 저온고습도상에서 저장할 경우, 채소류의 품질변화를 최소화 할 수 있어 갓 수확한 채소류의 선도유지기간을 연장할 수 있는 저장법이 될 수 있음을 확인하였다.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.6
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• pp.837-842
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• 1995

Hot red pepper(Capsicum annum L.) has been extensively used as a spicy food additive and preservative in Korea. In this study, we investigated the effect of dietary hot red pepper powder on humoral immune response in rats. Sprague-Dawley rats were divided into 4 groups and fed experimental diets containing 0, 2, 5, 10% hot red pepper powder for 27 days. All groups were immunized with sheep red blood cells. In order to measure the immune response, plaque-forming cell number, agglutination titer, and serum antibody level were measured. Tissue ascorbic acid contents were also determined by high-performance liquid chromatogrphy. There was an increased plaque-forming cell number, agglutination titer, and serum IgG level in the groups supplemented with hot red pepper powder as compared to control. Tissure ascorbic acid contents in the hot pepper powder supplemented group were higher than those of control. The results suggest that the dietary hot red pepper powder enhances humoral immune response in rats, indicating that the hot pepper contains biological response modifier.

• Applied Biological Chemistry
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• v.48 no.4
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• pp.435-439
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• 2005

Antioxidant activity of the ethanol extract from boiled-water of Hizikia fusiformis (EBH) were compared with those of BHA, L-ascorbic acid, gallic acid, caffeic acid and (-)-catechin. The free radical scavenging ability against DPPH (1,1-diphenyl-2-picrylhydrazyl), authentic peroxynitrite and reducing power were measured as indices of antioxidant activity. EBH showed the potent DPPH radical and peroxynitrite scavenging activities, showing 85.23 and 96.97% at final concentration of $1000{\mu}g/ml$, respectively. The reducing power increased with the increasing amount of EBH (final concentration of 1, 10, 100 and $1000{\mu}g/ml$). Total phenolic content of EBH was 588 mg (-)-catechin/g at the final concentration $1000{\mu}g/ml$. Total phenolic contents correlated with DPPH radical scavenging activity $(R^2=0.766)$ and reducing power $(R^2=0.944)$. These results suggested that EBH could be a natural antioxidative source containing antioxidative components.

• Journal of Microbiology and Biotechnology
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• v.2 no.4
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• pp.260-267
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• 1992

Pectate lyase from alkalitolerant Bacillus sp. YA-14 is an endo-type pectate lyase which acts randomly at the $\alpha$-1, 4-galacturonan linkage, and requires calcium or strontium ions for its activity. The enzyme is active on low methyl esterified pectin, but the activity toward a high methyl esterified substrate is reduced. The apparent Km's of the enzyme toward sodium polygalacturonic acid, polygalacturonic acid, and various pectins such as apple pectin, citrus pectin, and genu pectin are 0.826 mg/ml, 0.685 mg/ml, and 1.14 mg/ml, respectively. The enzyme activity is inhibited by SDS, urea, and sodium azide, but not by various reducing reagents, such as $\beta$-mercaptoethanol, Na-thiosulfate, Na-sulfate, cystein, and L-ascorbic acid. The enzyme is inactivated by N-bromosuccinimide, $I_2, H_2O_2$. PMSF, and iodoacetate. Judging from the results of their inhibition types, we speculate that tryptophan and serine residues are directly involved in enzyme activity, while tyrosine and methionine residues are indirectly involved in its activity.

• Journal of Electrochemical Science and Technology
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• v.11 no.3
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• pp.310-317
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• 2020

A development of disposable strip-type galactose sensor for point-of-care testing (POCT) was studied, which was constructed using screen-printed carbon electrodes. Galactose levels were determined by the redox reaction of galactose oxidase in the presence of potassium ferricyanide as an electron transfer mediator in a small sample volume (i.e., less than 1 µL). The optimal performance of biosensor was systematically designated by varying applied potential, operating pH, mediator concentration, and amount of enzyme on the electrode. The sensor system was identified as a highly active for the galactose measurement in terms of the sensitivity (slope = 4.76 ± 0.05 nA/µM) with high sensor-to-sensor reproducibility, the linearity (R² = 0.9915 in galactose concentration range from 0 to 400 µM), and response time (t_95% = <17 s). A lower applied potential (i.e., 0.25 V vs. Ag/AgCl) allowed to minimize interference from readily oxidizable metabolites such as ascorbic acid, acetaminophen, uric acid, and acetoacetic acid. The proposed galactose sensor represents a promising system with advantage for use in POCT.

• The Korean Journal of Community Living Science
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• v.27 no.3
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• pp.509-520
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• 2016

This study was carried out to investigate the effects of adding rosemary extract powder (REP) to pork teokgalbi on its quality and storage characteristics. Five types of teokgalbi were tested, viz. with no REP added (normal, N), with 0.05% ascorbic acid added (control, C) and with 0.05% (R1), 0.1% (R2) and 0.2% (R3) of REP added. The proximate composition, calorific value, water holding capacity and cooking loss were not significantly different among the different types of pork teokgalbi. The L and a values of the teokgalbi containing REP were significantly lower than those of the N and C groups. As regards the textural characteristics, the addition of 0.2% REP increased the springiness value. In the sensory evaluation, the teokgalbi with the addition of 0.1% REP had higher scores in flavor and total acceptability. The 2-thiobarbituric acid (TBA) value, total microbial count and volatile basic nitrogen content of the teokgalbi containing 0.2% REP were lower than those of the N group. In conclusion, R3 was significantly more effective in delaying lipid peroxidation than the other treatment groups. Therefore, rosemary extract could be used as a natural antioxidant in meat products.

• Journal of the East Asian Society of Dietary Life
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• v.6 no.3
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• pp.355-363
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• 1996

Physicochemical properties of marketing and intensive persimmon vinegar were investigated, the results are as following; Total acidity in D, H, S, J, sweet persimmon(SP) and persimmon vinegar were 4.20, 3.03, 2.58, 3.30, 5.92 and 5.81%, respectively, and the value of intensive persimmon(IP) vinegars wre higher than that of others. SP sample was lower than any other vinegar as compared to L value in colors, no sample was lower than H and S vinegar inturbidity and browning. Brix of IP samples were lower than that of other vinegars, there was a little fructose in the all samples. Among the organic acids, galacturonic acid content except acetic acid was the highest, and ascorbic and malic acid were detected a little, Calium content was the highest of minerals in persimmon vinegars, phosphorus was detected a little. Alcohols of 5~6 types were analyzed in each samples, free amino acids of 17~24 dypes were analyzed, D and IP vinegars have more acohols and amino acids, and their contents were higher than the others. Volatile components of 6~9 types were analyzed in each samples, these have more ethanols except acetic acids than other volatile components, and the contents of IP samples were higher than that of marketing persimmon vinegars.