• Journal of the Korean Society of Food Science and Nutrition
• /
• v.40 no.3
• /
• pp.350-356
• /
• 2011

Styela plicata of large (9.82~11.66 g) and small (0.93~2.21 g) sizes harvested at different times was extracted with 4 different solvents (methanol, ethanol, acetone, and water). DPPH radical scavenging and reducing power was the highest in acetone extracts of small ones (38.98% and 1.724, respectively) harvested in November. The lowest radical scavenging activity was found in water extracts of large ones (12.03% and 0.114) in December. On the other hand, large ones harvested in September showed significantly higher inhibition rate of DNA damage (water, 56.54%; methanol, 55.83%; ethanol, 48.63%) than others. Overall, the water extraction of S. plicata tended to show a higher antigenotoxic effect. In addition, water extracts of large S. plicata from November showed the highest angiotensin converting enzyme (ACE) inhibitory activity (64.38%), while that of small ones from December exhibited the lowest (51.33%). Overall the results indicate that antioxidant and antihypertensive activities S. plicata are variable depending on harvesting time, size, and extraction solvent.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.37 no.3
• /
• pp.282-287
• /
• 2008

Gardeniae Fructus (GF) is a fruit of Gardenia jasminoides Ellis (Rubiaceae) which has been used in traditional medicine. It contains not only geniposide but also resveratrol, a kind of stilbene as a natural antioxidant. In this study, we investigated physiological activities of GF extracts by measuring electron donating ability (EDA), nitrite scavenging ability (NSA), super oxide dismutase (SOD)-like activity and inhibitory effect of tyrosinase activity (ITA). As a solvent, it was extracted with water, 50 and 100% ethanol using microwave. At the concentration of 6 mg/mL, EDA was the highest at 50% ethanol extract but the lowest at 100% ethanol extract, $96.43{\pm}0.25%\;and\;77.06{\pm}0.22%$ respectively. NSA showed the strongest activity at 50% ethanol extract like EDA (6 mg/mL: $75.26{\pm}0.28%$). ITAs were below 20% in all samples and their activities reduced according to increasing concentration. Likewise, SOD-like activities decreased with increasing concentration of extracts in all samples. In conclusion, GF extracts showed low SOD-like activities and ITAs but EDAs and NSAs were fairly high; especially EDA of 50% ethanol extract (6 mg/mL) was high as those of 0.1 and 1% L-ascorbic acid. Therefore the results suggest that GF extracts may be useful as potential sources of natural antioxidants.

• Korean Journal of Food Science and Technology
• /
• v.38 no.2
• /
• pp.241-248
• /
• 2006

Conditions for extraction of antimicrobial materials from licorice root, Glycyrrhiza glabra, were optimized. Among solvents tested, 95% ethanol gave highest antimicrobial activity, and was chosen as optimal extracting solvent. Extraction temperature and time were optimal at room temperature and for 12 hr, respectively. Minimal inhibitory concentration (MIC) of 95% ethanol extracts was determined against 14 microorganisms. Reference microorganisms included 6 Gram(-) bacteria, 4 Gram(+) bacteria, and 4 yeast strains. Ethanol extract exerted very strong growth inhibition on Gram(+) bacteria, while was moderately effective for Gram(-) bacteria and yeasts. Treatment at $180^{\circ}C$ for 30 min or extreme pHs merely destroyed antimicrobial activity of ethanol extract. These findings suggest ethanol extract of G glabra may be useful as natural preservative.

• Journal of Hydrogen and New Energy
• /
• v.24 no.1
• /
• pp.44-49
• /
• 2013

Hydrogen penetration into a metal leads to damages and mechanical degradations and its content measurement is of importance. For a precise measurement, a sample preparation procedure must be optimized through a series of studies on sample washing and drying. In this study, two-step washing with organic solvents and thermal soaking in inert gas were tried with a rod-shaped, API X65 steel sample. The samples were machined from a steel plate and then washed in acetone and etyl-alcohol for 5 minute each and dried with compressed air. After then, the samples were thermally soaked in a home-made nitrogen gas chamber during 10 minute at different heat gun temperatures from 100 to $400^{\circ}C$ and corresponding temperature range in the soaking chamber was from 77 to $266^{\circ}C$ according to the temperature calibration. Hydrogen residue in the samples was measured with a hot extraction system after each soaking step; hydrogen residue of $0.70{\pm}0.12$ wppm after the thermal soaking at $77^{\circ}C$ decayed with increase of the soaking temperature. By adopting the heat transfer model, decay behavior of the hydrogen residue was fitted into an exponential decay function of the soaking temperature. Saturated value or lower bound of the hydrogen residue was 0.36 wppm and chamber temperature required to lower the hydrogen residue about 95% of the lower bound was $360^{\circ}C$. Furthermore, a thermal desorption spectroscopy was done for the fully soaked samples at $360^{\circ}C$. Weak hydrogen peak was observed for whole temperature range and it means that hydrogen-related contaminants of the sample surface are steadily removed by heating. In addition, a broad peak found around $400^{\circ}C$ means that parts of the hydrogen residue are irreversibly trapped in the steel microstructure.

• Korean Journal of Environmental Agriculture
• /
• v.23 no.3
• /
• pp.148-157
• /
• 2004

A rapid analytical method was developed to determine multiple pesticide residues in apples and pears using gas-liquid chromatography (GLC). The samples were extracted with water-miscible solvents and purified by cleanup procedures serially comprising liquid-liquid partition and solid-phase extraction (SPE). Each analyte was separated and determined by a high-resolution GLC equipped with electron-capture detector (ECD) and nitrogen-phosphorous detector (NPD). A total of 196 pesticides, which were previously classified into 5 groups each for ECD and NPD based on their retention behaviors on the capillary column and responses to the detector, were subjected to the recovery experiment. In compliance with the analytical criteria, 70 to 120% of recovery and less than 20% relative standard deviation the proposed method could be successfully applied to analyze 136 and 133 pesticide residues in apples and pears, respectively, which enabled not only rapid screening but quantitation of the residues. Even though less reliability was resulted from unacceptable recovery range, rest of pesticides including 43 and 45 analyzes in apples and pears, could be also detected for their identity. The proposed method fliled to cover 17 and 18 pesticides for apples and pears, which mostly showed high polarity or heat-lability but could be suitable far fast surveilance or monitoring of fruit harvests.

• Applied Biological Chemistry
• /
• v.37 no.5
• /
• pp.409-413
• /
• 1994

Barbaloin in the Aloe vera depending on the various extracting conditions was analyzed by HPLC. The contents of the barbaloin extracted by the solvents increased in the order of methanol>ethanol>water extraction. In setting extraction, the contents of barbaloin extracted with methanol and ethanol were increased from four hours at $60^{\circ}C$ and then decreased. The contents of barbaloin extracted with water were different depending on the temperature and time. Increasing the extracting time and temperature, the contents of barbaloin were decreased in water extract. It was estimated that the barbaloin might be stable in organic solvent, but decomposed with hydrolysis in water.

• Journal of Life Science
• /
• v.17 no.5 s.85
• /
• pp.652-657
• /
• 2007

To make functional fresh-cut yam using natural spices, the water or the methanol extract was prepared from different kinds of natural spices including ginger, wasabi, black pepper, mustard, cinnamon, chinese pepper, garlic, thyme, rosemary, chamomile, and peppermint. The extraction yields were varied as spice sources and extraction solvents used. Among the water extracts, peppermint extract showed strong antithrombosis activity with 26-folds extended thrombin time, and the $IC_{50}s$ of the extracts from cinnamon and rosemary were $61.3{\mu}g/ml\;and\;84.3{\mu}g/ml$ in DPPH scavenging assay, respectively. Whereas, the antimicrobial activity of all water extracts was ignorable. Among the methanol extracts, the extracts from thyme, ginger, and cinnamon showed antimicrobial activity against yam putrefactive bacteria. Strong antioxidative activity was found in the extracts from cinnamon and thyme. Based on these results, the functional fresh-cut yam was prepared using the water extract from peppermint or cinnamon. The antioxidative and antithrombin activities in the fresh-cut yam were maintained at $4^{\circ}C$ for 24 hr. Our results suggest that the natural spices could be applied to production of functional fresh-cut yam.

• Korean Journal of Food Science and Technology
• /
• v.50 no.1
• /
• pp.111-116
• /
• 2018

Roasting process of grains modifies their physicochemical characteristics that affect flavor, color, taste, and textures, as well as composition of bioactive compounds. We roasted oats at different temperatures (150, 200, and $250^{\circ}C$) and for different time periods (15 and 30 min). The polyphenol and flavonoid contents in different solvent extracts (methanol, fermented ethanol, and water) were also investigated. The total polyphenol and flavonoid contents were highest in the methanolic extract (135 mg gallic acid equivalent/g and 29 mg catechin equivalent/g, respectively, at $250^{\circ}C/30min$ roasting) and increased with roasting time and temperature. In addition, the avenanthramides were most abundant as accessed ($266{\mu}g/g$) in the methanolic extract upon roasting at $200^{\circ}C$ for 15 min. The radical scavenging activities, using 2,2-diphenyl-1-picrylhydrazyl and 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid scavenging, increased with roasting temperature and time. The roasting process may modify the physicochemical structure of oats, thereby, improving polyphenol extraction and antioxidant activity. The results of this study could be used for the manufacture of foods using roasted oats.

• Korean Journal of Food Science and Technology
• /
• v.53 no.3
• /
• pp.296-303
• /
• 2021

The antioxidant and anti-neuroinflammatory activities of water, 30, 70, and 100% ethanol extracts of leaves of three different species of bamboo (Phyllostachys nigra, P. bambusoides, and Sasa borealis) were investigated. The levels of total polyphenol and flavonoid were measured, and antioxidant activity was evaluated using various antioxidant assays (DPPH, ABTS, and FRAP). Lipopolysaccharide (LPS)-induced BV2 microglial cell activation was used to evaluate the anti-neuroinflammatory properties of the bamboo leaf extracts. Treatment with both aqueous and ethanolic extracts showed no cytotoxicity in BV-2 microglial cells. Pre-treatment of BV-2 cells with bamboo leaf extracts significantly inhibited LPS-induced excessive production of nitric oxide in a dose-dependent manner. Moreover, phytochemical analysis based on the extraction solvent showed that caffeic acid, p-coumaric acid, and tricin are the principal constituents of all three bamboo leaf extracts. Therefore, our findings suggest that bamboo leaf extract contains potent antioxidants and anti-neuroinflammatory compounds that can be used as potential therapeutic agents for the treat neuroinflammatory diseases.

• Journal of Life Science
• /
• v.33 no.5
• /
• pp.383-390
• /
• 2023

The goal of this study was to identify new bioactive peptides in extracts derived from Tenebrio molitor (T. molitor) larvae for the development of functional foods. After extraction from freeze-dried T. molitor larvae with various solvents on time course, the extracts showed the highest 2,2,1-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity at 5 and 10 hr per total protein and solid contents, respectively. When the water extract was fractionated, a high methanol concentration led to a reduced level of high-molecular-weight proteins in the centrifugal supernatant, whereas increased DPPH activity in the supernatants suggests low-molecular-weight peptides may mediate antioxidant activity in the supernatant. Most of the organic solvent partitions, excluding butanol, showed similar activities in the water phases, and the organic solvent partition fraction exhibited a 28~44% decrease in activity following heat treatment, implying that some components in the fraction become unstable in the presence of heat. The addition of proteinase K to the water extract increased DPPH activity by 10~20%, suggesting that peptides, when released from total proteins, partially increase antioxidant activity. Therefore, we suggest that the antioxidants in T. molitor larval extracts make them a potential source of functional animal food.