• Journal of the East Asian Society of Dietary Life
• /
• v.10 no.2
• /
• pp.136-141
• /
• 2000

This study was conducted to analyze the properties of the roasted dandelion tea prepared after various pre-treatments such as pre-drying, steaming and air blast drying. The dandelion tea was prepared by roasting the pre-treated dandelion leaves and its total yield, pH, soluble solid content, turbidity, browning and sensory value were evaluated. Total yield and soluble solid content were the highest in case of air blast drying. Turbidity and browning degree were similar in all the teas regardless of their pre-treatment including pre-drying, steaming or air blast drying. The best palatability in the sensory evaluation was obtained at the steaming condition for 60 sec without pre-drying. Longer air blast drying time resulted in the increase in the a and b values. turbidity, browning degree, total yield and soluble solid content in the air blast dried tea.

• Korean Journal of Medicinal Crop Science
• /
• v.20 no.3
• /
• pp.165-170
• /
• 2012

This study was conducted to evaluate the effect of light spectrum using red (660 nm), blue (460 nm), red and blue mixed (Red : Blue = 6 : 4) LED (light-emitting diode), and fluorescent lamp on antioxidant activities and functional components of dandelion (Taraxacum officinale). Total polyphenol contents in dandelion irradiated with the red and blue mixed or the red LED were 121.77 mg/100 g or 115.36 mg/100 g, respectively, which were greater than those in dandelion treated with blue LED and fluorescent lamp. Asparagine showed the highest content among amino acids in leaves and roots regardless of treatments. Total amino acid was the highest when illuminated with the red LED. DPPH (1,1-diphenyl-2-picrylhydrazyl) radical-scavenging activity and SOD (super oxide dismutase) activity of ethanol extracts were increased under all of the LED treatments compared with fluorescent lamp, and the antioxidant activities were increased by the red and the mixed LED illumination. The results indicate that application of the red and the mixed LED illumination promote antioxidant activity and increase functional components during cultivation of dandelion.

• Korean Journal of Food Science and Technology
• /
• v.40 no.3
• /
• pp.283-289
• /
• 2008

This study used response surface methodology (RSM) in an effort to optimize the hot water extraction conditions of dandelion leaves in order to increase antioxidant activity in the extract. A central composite design was applied to investigate the effects of independent variables, which included the ratio of solvent to sample ($X_1$), extraction temperature ($X_2$), and extraction time ($X_3$), on dependent variables of the extracts, including soluble solid ($Y_1$), total polyphenols ($Y_2$), total flavonoid ($Y_3$), 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging ability ($Y_4$), 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical scavenging ability ($Y_5$), and superoxide radical scavenging ability ($Y_6$). The estimated optimal conditions were as follows: $83.77{\pm}1.07^{\circ}C$ of the extraction temperature, $20.85{\pm}0.24 mL/g$ of solvent per sample, and $1.59{\pm}0.12$ hr of extraction time. At the optimal conditions, the predicted characteristic values were: a yield of 38.98%, a total polyphenol level of $74.28{\mu}g/mg$, a total flavonoid level of $74.00{\mu}g/mg$, a DPPH radical scavenging ability ($IC_{50}$) of 0.14 mg/mL, a ABTS radical scavenging ability ($IC_{50}$) of 3.24 mg/mL, and a superoxide radical scavenging ability ($IC_{50}$) of 2.49 mg/mL.

• Applied Chemistry for Engineering
• /
• v.30 no.4
• /
• pp.408-414
• /
• 2019

In this study, an antioxidant was extracted from dandelion leaves using traditional hot water and ultrasonic extraction methods. In order to optimize the extraction yield and total flavonoid, an antioxidant, Box-Behnken design (BBD) model among response surface analysis methods was used. In the case of hot water extraction, the extraction temperature and time as well as the ratio of alcohol/ultrapure water were set as variables, and for the ultrasonic extraction, the ultrasonic survey century and irradiation time and the ratio of alcohol/ultrapure water were variables. Optimum extraction conditions in the hot water extraction method were the extraction temperature and time of $45.76^{\circ}C$ and 1.75 h and the ratio of alcohol/ultrapure water of 41.92 vol.%. While for the ultrasonic extraction method the survey century of 512.63 W, the ratio of alcohol/ultrapure water of 56.97 vol.% and the extraction time of 20.79 min were optimum conditions. Expected reaction yield and flavonoid content values under the optimized condition were calculated as 22.09 wt.% and 28.98 mg QE/mL dw, respectively. In addition, the error value of less than 3% was obtained validating our optimization process.

• The Korean Journal of Community Living Science
• /
• v.15 no.2
• /
• pp.101-107
• /
• 2004

Many studies have presented results about the antioxidative and antimicrobial activities of Dandelions(Taraxacum officinale). There has yet to be a study which makes comparisons based on the variety or parts of the Dandelion. To compare the physiological activity, antioxidative and antimicrobial activities were measured by using methanol extracts of Korean and Western Dandelions. The Dandelions were taken from Uiryeong in Kyungnam province, and antioxidative and antimicrobial activities of the flower, leaf and root were measured. Antioxidative activities of the methanol extracts were examined with a DPPH test. Antimicrobial activities were examined against 5 microorganisms. Bacillus subtilis and Bacillus cereus served as G(+) microorganisms, while Salmonella typhimurium, Staphylococcus aureus, and Eschrichia coli served as G(-) microorganisms. There was no significant difference in the antioxidative activity of the methanol extracts from leaves and roots between varieties. The antioxidative activity of the flower extracts was higher in the Korean than in the Western samples but the highest level of antioxidant was lower than 70%. No significant difference in antimicrobial activities between the varieties was observed. More research using physiological factors other than antioxidative and antimicrobial activities is needed to identify physiological functions and enhance the utilization of Dandelions.

• The Korean Journal of Mycology
• /
• v.41 no.4
• /
• pp.212-217
• /
• 2013

Unusual mushrooms were observed in the greenhouses of vegetables Chinese chive, cucumber, melon and Korean dandelion in four locations of Korea in 2012. The mushrooms usually grew with the vegetables cultivated on beds in the greenhouses. Occurrence aspects of the mushrooms in the greenhouses and effect of the mushrooms on growth and quality of the vegetables were investigated. Mushroom samples were collected from the beds in the greenhouses and identified based on their morphological characteristics. The mushroom samples collected from the greenhouse of Chinese chive were identified as Coprinus aokii, those from the greenhouse of cucumber as Cristinia eichleri and Coprinus sp., those from the greenhouse of melon as Leucocoprinus cretaceous, Panaeolus fimicola and Conocybe sp., and those from the greenhouse of Korean dandelion as Conocybe rickenii f. tetrasporique. Out of the seven mushrooms identified, L. cretaceus, C. rickenii and C. eichleri were first found in Korea. The investigation results revealed that the mushrooms were originated from compost or soil used in the beds, and showed that C. aokii caused sooty mold on leaves of Chinese chive, and C. rickenii f. tetrasporique hindered growth of Korean dandelion and caused sooty mold on leaves of the plant. The other mushrooms had no effect on growth and quality of the vegetables.

• The Korean Journal of Food And Nutrition
• /
• v.34 no.2
• /
• pp.233-241
• /
• 2021

The purpose of this study was to investigate the contents of apigenin and luteolin in vegetables mainly distributed and consumed in Korea. In this study, the contents of apigenin, apigenin-7-O-glucoside, luteolin, and luteolin-7-O-glucoside in vegetables were surveyed by using liquid chromatography coupled to mass spectrometry (LC-MS/MS). According to the analysis of 27 items (91 samples) in vegetables, the content of total apigenin (the sum of apigenin and apigenin-7-O-glucoside) was quantified in 8 out of the 27 items in vegetables, followed by pepper leaves, parsley, celery, chamnamul, foremost mugwort, and perilla leaves. The content of total luteolin (the sum of luteolin and luteolin-7-O-glucoside) was found in 11 of the 27 items in vegetables, followed by pepper leaves, dandelion, celery, red lettuce, foremost mugwort, and perilla leaves. Celery was divided into stalks and leaves for comparing the contents of apigenin and luteolin. Celery showed higher contents of apigenin and luteolin in leaves than in stalks.

• Natural Product Sciences
• /
• v.17 no.2
• /
• pp.130-134
• /
• 2011

The purpose of this study was to evaluate the therapeutic potential of naturally occurring aldose reductase (AR) inhibitors isolated from Korean native plants. The MeOH extract and stepwise polarity fractions of dandelions were tested on rat lens AR inhibition in vitro. Of these, the EtOAc fractions from the leaves of dandelions (Traxacum coreanum, T. officinale, and T. ohwianum) exhibited an AR inhibitory activity ($IC_{50}$ values, 2.37, 1.73 and 2.68 ${\mu}g/ml$, respectively). A chromatography of the EtOAc fraction from the leaves of T. coreanum led to the further isolation of two flavonoids identified as luteolin and luteolin 7-O-glucopyranoside. These compounds exhibited strong AR inhibitory activity, with $IC_{50}$ values of 0.15 and 1.05 ${\mu}M$, respectively. These results suggested that luteolin is a potent AR inhibitor within dandelions and that it could be a useful lead compound in the development of a novel AR inhibitory agent against diabetic complications.