• Journal of Microbiology and Biotechnology
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• v.17 no.5
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• pp.847-852
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• 2007

This study investigated an efficient method for the extraction of astaxanthin from the red yeast Xanthophyllomyces dendrorhous. The extraction process comprised three steps: 1) cultivating the yeast; 2) treating the yeast culture suspension with microwaves to destroy the cell walls and microbodies; and 3) drying the yeast and extracting the astaxanthin pigment using ethanol, methanol, acetone, or a mixture of the three as the extraction solvent. Ultimately, various treatment tests were performed to determine the conditions for optimal pigment extraction, and the total carotenoid and astaxanthin contents were quantified. A frequency of 2,450 MHz, an output of 500 watts, and irradiation time of 60 s were the most optimum conditions for yeast cell wall destruction. Furthermore, optimal pigment extraction occurred when using a cell density of 10g/l at $30^{\circ}C$ over 24 h, with a 10% volume of ethanol.

• Journal of Life Science
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• v.30 no.10
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• pp.877-885
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• 2020

Lentinuls edodes has been used for traditional food and medicine around Asia, and a variety of biological effects have been reported. In this study, L. edodes water extract (LWE) was investigated for its anti-photodamage effect in HaCaT keratinocytes. To perform the necessary assays, L. edodes was extracted with distilled water for 8 hr at 40℃ in an extract tank. Anti-photodamage activity was assessed using a scratch wound healing assay, cell proliferation, and a reactive oxygen species (ROS) scavenging test and by measuring the mRNA and protein expression levels of matrix metalloproteinases (MMPs) and type I procollagen. MMPs and collagen expression are major markers of UV-induced photodamage in skin. Prior to photodamage analysis, the total polyphenol and β-glucan contents of the LWE were evaluated and found to be 4.64 mg GAE/g DW and 165.96 mg/g, respectively. Treatment with LWE induced cell migration and cell proliferation in UV-irradiated HaCaT cells, and LWE effectively scavenged the ROS induced by H₂O₂ and UVB irradiation in HaCaT cells. UVB irradiation induced ROS generation and led to increased production of MMP-1 and MMP-9 and to decreased collagen production in human keratinocytes. Treatment with LWE upregulated the expression levels of MMP-1, MMP-9, and type I procollagen in UVB-irradiated HaCaT cells. This study suggests that LWE could be used to develop cosmetic materials with anti-photodamage effects.

• Korean Journal of Agricultural Science
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• v.7 no.2
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• pp.169-175
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• 1980

These studies were conducted to induce the available mutant strains in acetic acid bacteria by the irradiation of UV-light and the treatment of N-methyl-N'-nitro-N'-nitrosoguanidine. 109 strains which were capable of producing acid in the ethanol containing medium were isolated from vinegar and Kimchi collected from the region of Daejeon city. From the collection T-50 strain was identified to have a strong fermentation power and selected as a mother strain for the study. Two mutants were obtained by treating T-50 strain with UV and NTG, and these mutants had a rapid acid production in the initial stage. The study was then made to compare the basic condition for acetic acid production of the mother strain and two mutant strains. The summarized results were as follows; 1. The isolated strain (T-50) was identified as Acetobacter aceti by Bergey's manual and Acetic acid bacteria (Tokyo Univ. press). 2. The selected strain was died completely when the strain was irradiated with 15 W UV-light at a distance of 45 cm for 160 seconds. 3. The mutants such as U-48 and N-67 were rapid in the acetic acid production at the initial stage compare to the mother strain. 4. Acetic acid formation by the shaking culture method was maximized in 2 days culture, and the optimal temperature for acetic acid production was $30^{\circ}C$. 5. Acetic acid was effectively produced by the addition of 0.1% ammonium sulfate as a nitrogen source and was also produced rapidly by the addition of 0.1% glucose.

• Korean Journal of Food Science and Technology
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• v.4 no.3
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• pp.206-212
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• 1972

Oxidative changes in the rice lipids under accelerated condition were studied by measuring the changes in weight gain, total carbonyl compound, malonaldehyde, and fatty acid composition. Rice lipids were prepared by extraction with either n-hexane or ethanol from polished rice grain and purified by Folch's method. The lipid preparations were either incubated in dark at $40^{\circ}C$ or irradiated with ultra-violet light for a period of 55 days. Weight gain by oxygen absorbed sharply increased within 3 days in the rice lipids under UV light irradiation. However, with the rice lipids at $40^{\circ}C$ incubation a moderate increase in weight was observed only after 45 days storage. Their induction periods were one day (hexane extracted, under UV light), 2 days (ethanol extracted, under UV light), 30 days (hexane extracted, at $40^{\circ}C$), and 40 days (ethanol extracted, at $40^{\circ}C$) respectively. Oxidative rancid odor appeared at the end of the induction period. Total carbonyl compound and malonaldehyde markedly increased within 7 days, and decreased in the rice lipids under ultra violet light irradiation, while at $40^{\circ}C$ incubation they were continued to increase slowly through out the storage. The hexane extracted lipid were less stable than ethanol extracted lipid on the basis of oxygen absorption, malonaldehyde and other carbonyl compound formation. With the hexane extracted lipid during 55 days incubation at $40^{\circ}C$, the contents of linoleic and linolenic acids decreased, while the oleic, stearic, and palmitic acids increased.

• Korean Journal of Food Science and Technology
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• v.30 no.6
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• pp.1312-1320
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• 1998

Some commercial beef loins in raw state were packaged with PVDC as aerobic and vacuum condition. The other beef samples were cooked until core temperature arrived at $70^{\circ}C$ and then packaged immediately in the same way as the raw state. These samples were irradiated by electron beam (0, 1, 2 kGy), and then stored in refrigerator $(2{\sim}4^{\circ}C)$. Identity and quantity of cholesterol oxides were analysed at the 0, 7th, 14th day of storage. In the samples that were raw and packaged aerobically, $7{\alpha}-hydroxycholesterol,\;{\beta}-epoxide,\;7{\beta}-hydroxycholesterol$ and 7-ketocholesterol were detected over $0.5\;{\mu}g/g$. Cholestanetriol and${\alpha}-epoxide$ were detected at levels below $0.5\;{\mu}g/g$ during storage. In the samples that were raw and vacuum-packaged, $7{\alpha}-hydroxycholesterol$, 7-ketocholesterol and cholestanetriol were detected. In the samples that were cooked and packaged aerobically, cholestanetriol and ${\alpha}-epoxide$ were detected below $0.5\;{\mu}g/g$ during storage. $7{\alpha}-hydroxycholesterol,\;{\beta}-epoxide,\;7{\beta}-hydroxycholesterol$and 7-ketocholesterol were detected as $1.53{\sim}26.81,\;1.07{\sim}5.23,\;40.64{\sim}101.30\;and\;7.16{\sim}33.91\;{\mu}g/g$, respectively. In all results, total amounts of cholesterol oxide increased significantly as irradiation dose and storage time increased (P<0.05).

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.6
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• pp.875-880
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• 2012

This study was conducted to investigate the level of contamination of pathogenic Escherichia (E.) coli in 50 types of red pepper powders collected domestically. Pathogenic E. coli was confirmed using real-time PCR to confirm the 4 types of EAEC, EPEC, EHEC and ETEC. One sample out of 50 was contaminated with pathogenic E. coli. The type of pathogenic E. coli detected in the sample was EAEC. This study was also conducted to determine the effect of alcohol treatment on the reduction of E. coli populations in red pepper powder. The amount of E. coli in the control was $1.2{\times}10^6$ cfu/mL. The amount of E. coli in 10 minutes immersion treatment with 10% alcohol was $1.1{\times}10^6$ cfu/mL. In samples treated with over 20% alcohol, E. coli was not detected. This showed that 10 minutes of immersion in over 20% alcohol might be effective to reduce E. coli. This study was also conducted to determine the effect of UV irradiation on E. coli reduction. The number of E. coli in the control group was $5.0{\times}10^5$ cfu/mL. However, the number of E. coli in 45 min of the UV irradiated sample decreased to $1.0{\times}10^3$ cfu/mL, by $10^2$ cfu/mL. In contrast, E. coli was not detected in an over 60 min UV irradiated sample in $10^{-2}dilution$. This study showed that over 20% alcohol treatment and UV irradiation for 60 min was effective to control E. coli in red pepper powder.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.5
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• pp.613-618
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• 2005

This study was carried out to examine the effects of gamma irradiation on the cytotoxicity and multidrug-resistance reversing activity of methanol extracts from Coix lachryma-jobi L. var. me-yuen Stapf seed. The seed was irradiated with doses of 1, 4, 8, 16, 32 and 64 Gy of the gamma radiation, and then extracted by methanol. The extracts were examined for cytotoxicity on the human cancer cell lines, MCF-7 (human breast adenocarcinoma pleural effusion), Calu-6 (human pulmonary carcinoma) and SNU-601 (human gastric carcinoma) cells, and investigated for multidrug-resistance reversing activity using drug sensitive AML-2/WT and multidrug-resistant AML-2/D100 cells. The growth inhibitory activity of irradiated seed extracts on human cancer cell lines was higher than that of the control. In the case of Calu-6 cell line, the effect of cytotoxicity was observed in the extracts of 4, 8 and 16 Gy. $IC_{50}$ value in the MCF-7 cell line was measured in the only 8 Gy extract. And in the SNU-601 cell line as Calu-6, the effect of cytotoxicity was observed in the extracts of 4, 8 and 16 Gy. But the extracts of gamma-irradiated seed over 32 Gy showed little growth inhibitory effect against human cancer cell lines. In this result, 8 Gy extract had significant growth inhibitory in all human cancer cell lines $(Calu-6:\;633\;{\mu}g/mL,\;MCF-7:\;653\;{\mu}g/mL\;and\;SNU-601:\;683\;{\mu}g/mL)$. The extracts of 4, 8 and 16 Gy strongly potentiated vincristine cytotoxicity in AML-2/D100 cells. The reversal fold (RF) of 4, 8 and 16 Gy extracts was 1.7, 1.8 and 1.6, respectively. But their cytotoxicities to both sensitive AML-2/WT and resistant AML-2/D100 cells were in the same order of magnitude. These results indicate that the above samples would contain some principles which have cytotoxicity and multidrug-resistance reversing activity. Irradiation technology can be applied to promote physiological activities of medicinal plant seeds.

• Journal of Bio-Environment Control
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• v.31 no.1
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• pp.28-34
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• 2022

This study was conducted to determine the changes in ginsenosides content according to additional UV-A, and UV-B LED irradiation before harvesting the ginseng sprouts. One-year-old ginseng seedlings (n=100) were transplanted in a tray containing a ginseng medium. The ginseng sprouts were grown for 37 days at a temperature of 20℃ (24h), a humidity of 70%, and an average light intensity of 80 µmol·m^-2·s^-1 (photoperiod; 24h) in a container-type plant factory. Ginseng sprouts were then transferred to a custom chamber equipped with UV-A (370 nm; 12.90 W·m^-2) and UV-B (300 nm; 0.31 W·m^-2) LEDs and treated for 3 days. Growth parameters and ginsenoside contents in shoot and root were conducted by harvesting on days 0 (control), 1, 2, and 3 of UV treatments, respectively. The growth parameters showed non-significant differences between the control and the UV treatments (wavelengths or the number of days). Ginsenoside contents of the shoot was highly improved by 186% in UV-A treatment compared to the control in 3 days of the treatment time. The ginsenoside contents of the roots was more improved in UV-A 1-day treatment and UV-B 3-day treatment, compared to the control by 171% and 160%, respectively. As a result of this experiment, it is thought that UV LED irradiation before harvesting can produce sprout ginseng with high ginsenoside contents in a plant factory.

• Food Science and Preservation
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• v.19 no.3
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• pp.393-399
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• 2012

In this study, the antioxidant and anti-wrinkling effects of extracts from Aruncus diocius var. kamtschaticus (ADV) were investigated. According to the results, the ethanol extract has better antioxidant and anti-wrinkling effects than the water extract. The amounts of total polyphenol and flavonoid compounds in the ethanol extract were 122 and 36 mg/g, respectively, while those in the water extract were 87 and 26 mg/g. The antioxidant activities of the ethanol and water extracts were 395 and 4,682 ${\mu}g/mL$ as the $RC_{50}$ values for the DPPH radical scavenging activity, and 227 and 366 ${\mu}g/mL$ for the $ABTS^+$ radical scavenging activity, respectively. The reducing power of the ethanol extract (1.58 at 2 mg/mL) was higher than that of the water extract (0.88 at 2 mg/mL). The astringent activities of the ethanol and water extracts were 91.27 and 16.35% at 10 mg/mL, respectively. Furthermore, the ADV ethanol extract treatment of the fibroblast cell after UV irradiation resulted in increased cell viability (10% at 100 ${\mu}g/mL$) and collagen biosynthesis (33% at 100 ${\mu}g/mL$), with a lowering in the MMP-1 expression level (16.8 % at 100 ${\mu}g/mL$). These results demonstrate that AVD provides a remarkable and significant tensor and anti-wrinkling effect on the skin, which could be of a great use in anti-aging skin care products.

• Korean Journal of Food Science and Technology
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• v.5 no.2
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• pp.101-107
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• 1973

1) For the purpose of preparation of food and fodder yeasts from nonedible seaweed, two suitable Candida yeasts have been isolated from seaweed compost. 2) They had the ability of fermenting galactose, sucrose and glucose, and could not ferment maltose and mannit, but could assimilate mannit. 3) NaCl concentration from 1 to 2% had no remarkable effect on growth of yeast and the optimum pH was $4{\sim}5$. 4) In the acid hydrolyzate of brown seaweed (Ecklonia cava Kjellman, Sargassum fulvellum AGARDH) an amorphous deposit was produced during storage after neutralization of media and its removal always delayed yeast growth, but addition of $(NH_4)_2SO_4$ and $NaH_2PO_4$ to media could increase the assimilation of reducing sugar and yeast yield. 5) $Co^{60}$ gamma ray irradiation (dose rate : 1 Mrad/hr, BNL shipboard irradiator) of seaweed had not so much effect on the hydrolysis of carbohydrates and nitrogen compounds in seaweed but could increase the yeast production from seaweed hydrolyzate. 6) The yeast yield was $7{\sim}8$ g of dry yeast per 100 g of seaweed by cultivation with jar fermentor.