• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.4
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• pp.481-485
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• 2011

This study was to investigate catalpol content and antioxidant activities in five cultivars (Kokang, Suwon 10, Suwon 11, Jiwhang 1 and Korea) of Rehmannia Radix. Catalpol content was analysed by HPLC using $C_{18}$ column ($150{\times}4.6\;mm$, $5{\mu}m$), 1% acetonitrile and a UV detector. The standard curve was found to be a linear regression of y=0.0483x-0.0841 ($R^2$=0.999). The catalpol content ranged from 85.2 mg/g to 144.9 mg/g, of which the Korea was the highest among cultivars. The total phenol content in Rehmannia Radix was 0.358~0.459 mg/g, of which the Korea was the highest among cultivars. The antioxidant activities determined by DPPH and hydroxyl radical scavenging activities were the highest in Korea with $IC_{50}$ of 205.8 mg/g for DPPH radical scavenging activity and $IC_{50}$ of 38.8 mg/g for hydroxyl radical scavenging activity. Based on these results, the Korea among Rehmannia Radix cultivars was suggested to be a potent medicinal plant material for antioxidant activities.

• The Korean Journal of Mycology
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• v.41 no.2
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• pp.104-111
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• 2013

Phellinus baumii is a medicinal mushroom used in Asian countries for a long period of time. The purpose of this study was to investigate the skin whitening activities of methanol extracts from fruiting bodies of P. baumii. To evaluate the antioxidant activities of the extract, polyphenol and flavonoid contents, and 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity and chelating activity on ferrous ions were studied. For assay of skin whitening activities, tyrosinase and DOPA inhibitory activities, and tyrosinase and melanin synthesis inhibitory activities of B16/F10 melanoma cells treated with the methanol extract were investigated. The total polyphenol content of P. baumii methanol extract was 4.19. DPPH scavenging ability of P. baumii methanol extract was 88.26% in $25{\mu}g/mL$ concentration. We tested tyrosinase inhibitory activity and melanin contents in melanoma cells. The tyrosinase activity was inhibited to 65.17% at the concentration of $125{\mu}g/mL$ and melanin synthesis was inhibited to 57.61% at the concentration of $25{\mu}g/mL$. Overall, the experimental results showed that P. baumii methanol extract had inhibitory activities of tyrosinase and melanin synthesis by dose dependent manner in B16/F10 melanoma cells. Strong ultra-violet absorption spectra in the range of 270~370 nm indicated that ethanol extract of P. baumii could protect the skin from UV. Therefore, P. baumii methanol extract might be used for development of skin whitening, anti-UV and skin care agents.

• Journal of Preventive Medicine and Public Health
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• v.21 no.1 s.23
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• pp.183-194
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• 1988

This study was carried out to investigate for resistance of V. parahaemolyticus that isolated from patients of food poisoning and fish and shellfish, captured in east coast of Kyungpook province of Korea from 1985 to 1986. VP ATCC 17802 and NAG V. ATCC 6538 were used as control. In fish, shellfish and seaweed, the more temperature increased, the shorter survival time was. In case of sea-water, the more temperature rose up, the longer survival time was, particularly in $37^{\circ}C$ and $25^{\circ}C$, the strains had survived after 6 months. And in tapwater, it was sterilized in 150 mins. and survived for 11.5 days on maximum in ground water. In kimchi, at room temperature, germicidal time was shorter more than 6 times compared with that which had been kept in refrigerator. It survived for 57.1 days in milk, 49.2 mins. in yougurt. Strains had been surviving in frozen condition at $-70^{\circ}C$ even after 6 months, present study time. In resistance test in water bath at several degrees of temperature, all the strains were sterilized in 20 mins. with $60^{\circ}C$. In resistance test to driness, number of surviving strains dropped rapidly in 10-11%) water contents. In UV $2538{\AA}$, strains were sterilized in 20 mins. In resistance test to alcohol, strains had survived for 0.1-4 mins. in fermentative wine of below than 25% and distilled wine of over than 25% in alcohol concentration. The bactericidal concentration of disinfectant was 1% in phenol and 3% in cresol. In 0.1M acetic acid and 0.1M lactic acid, number of surviving colonies decreased rapidly but not in citric acid. The more NaCl concentration rose up, the lower decreasing rate of number of surviving colonies was. The strains had showed sensitive response to vancomycin, chloramphenicol, gentamicin, and resisted to carbenicillin, ampicillin and kanamycin. When one day culture strain was cultured till 25th day, resistant strains to tetracycline and cephalothin were changed to sensitive.

• 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.

• Korean Journal of Food Science and Technology
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• v.34 no.2
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• pp.141-150
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• 2002

Owing to a need for simple extraction and purification for analysis of water soluble vitamins in food samples by RP-HPLC with UV-detector, the methods of bromelain and protease hydrolysis and $C_{18}$ Sep-Pak solid phase extraction were employed. The recoveries of standard water soluble vitamins by the bromelain and protease hydrolysis and $C_{18}$ Sep-Pak solid phase extraction were significantly high compared to AOAC methods in most of vitamins. The contents of pyridoxal determined with protest in the pork was similar, but in the bromelain hydrolysis and AOAC method, was high compared to the results of reference. The niacinamide, thiamin and riboflavin determined with bromelain and protease hydrolysis showed similar values to the results of references. In the potato, pyridoxamine was detected in the AOAC method, which was not detected in the bromelain and protease hydrolysis methods. Pyridoxal contents in the protease hydrolysis and AOAC methods were very similar to the results of references. The recoveries of fortified standard vitamins in food samples were significantly high and accurate compared to those of AOAC methods. The extraction and purification with $C_{18}$ Sep-Pak solid extractor might be considered superior method for the determination of water soluble vitamins in food samples.