• The Korean Journal of Food And Nutrition
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• v.34 no.3
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• pp.295-301
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• 2021

Steaming is a method that has traditionally been used for medicinal plant extraction. This study investigated nitrite oxide production, ferrous ion chelating activity, α-glucosidase, xanthine oxidase, and acetylcholinesterase inhibitory activities of ethanol, acetone and hot-water extracts of Codonopsis lanceolata prepared by steaming seven times. MTT assay showed that each extract was non-toxic up to a concentration of 700 ㎍/mL confirming that there was no cytotoxicity in all extracts. The α-glucosidase, xanthine oxidase, and acetylcholinesterase inhibitory activities exhibited by the hot-water extract obtained from steaming seven times were higher (83.1%) than the other extracts. Higher production of nitrite oxide and better ferrous chelating activity was recorded with hot-water extract compared to ethanol and acetone extracts. These results indicated that more steaming of Codonopsis lanceolata extracts would be required to validate the possibility of developing antioxidants. Also, further study is needed to determine if the components present in the tested extracts might be useful in the prevention of Alzheimer's disease. These results showed that hot-water extracts may be useful for their antioxidant and the production inhibitory activity of nitrite oxide. It will be helpful in the investigation of the constituent analysis of the steam-processed product of Codonopsis lanceolata.

• Microbiology and Biotechnology Letters
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• v.45 no.2
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• pp.118-123
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• 2017

This study was conducted to determine the antioxidant activities of ethanol and water extracts of Sargassum hemiphyllum. Antioxidant activities were evaluated by assessing total phenolic contents, 2,2-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, chelating effect, reducing power, and using the rancimat method. Total phenolic contents in the ethanol and water extracts were 17.91 and 13.44 mg gallic acid equivalents/g, respectively. Ethanol extract showed higher DPPH radical scavenging activity than water extract and similar activity to that of BHT. The reducing power of ethanol and water extracts increased in a concentration-dependent manner. Particularly, ethanol extract was more effective than water extract. Water extract showed a higher chelating effect compared to ethanol extract. The antioxidant index measured by rancimat was lower than those in BHT, but the ethanol extract showed a higher value than the water extract. The ethanol extract showed higher antioxidant activity than the water extract, except for the chelating effect. These results suggest that the ethanol extract of Sargassum hemiphyllum has more potent antioxidant activity and may be used as a source of natural antioxidants.

• Food Science and Preservation
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• v.21 no.3
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• pp.427-433
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• 2014

Ethanol and hot water extracts were prepared from Lindera obtusiloba Blume (LO) and Zanthoxylum piperitum DC (ZP) and used to evaluate their antimicrobial activities and thermal stability against six foodborne pathogens (3 gram-positive and 3 gram-negative bacteria). The antimicrobial activities were assessed using the agar diffusion method, and the thermal stabilities of extracts were examined after heat treatment at 60, 70, 80, and $100^{\circ}C$ for 10 min. The zones of inhibition by the LO extract or the ZP extract of the tested microorganisms were in the range of 21-30 mm and 19-25 mm, respectively, at 100 mg/mL concentrations. The 60% ethanol extract and the hot water extracts from LO showed the strongest antimicrobial effects against MRSA and Staphylococcus aurues, respectively. For the extract from ZP, the strongest antimicrobial effect was shown against S. aurues by 60% ethanol, and the weakest antimicrobial effect was shown against E. coli by the hot water extracts. The ZP extracts showed that the gram-positive bacteria were more sensitive than gram-negative bacteria. For the thermal stability of the extracts, the antimicrobial effects stabilized after heat treatment. Overall, the data suggest that the extracts have a potential for application in various food products for which a natural antimicrobial additive is desired.

• Food Science of Animal Resources
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• v.22 no.1
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• pp.13-19
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• 2002

The natural sources extracted from green tea and pine needle were utilized to investigate the effects of extracts on free radical reaction, lipid oxidation and nitrite scavenging ability. The degree of lipid oxidation is very sensitive to kinds of oil emulsion reacted with iron sources and oxygen species. The antioxidants of extracts from green tea and pine needle were different depending on concentration of extracts, which were a lower TBARS value in 0.3% extracts concentration, compared to 0.1% extracts concentration. And also, the binding ability on iron sources was superior in hot water extracts, but oxygen scavenging ability was the lowest TBARS values in ethanol extracts. The hydroxyl radical scavenging ability of green tea and pine needle extracts had a little low TBARS value in 0.1% and 0.3% extracts concentration in deoxyribose. The ethanol extracts of pine needle were higher than those of hot water extracts on the basis of Fe$\_$2+/ ion content. The ascorbic acid content of green tea showed 14.3 mg/100g in hot water extracts and 16.7 mg/100 g in ethanol extracts. Electron donating ability of extracts showed difference depending on extracts concentration, which were higher in ethanol extracts than those of hot water extracts. The nitrite scavenging effects were tended to be different depending on pH value, however they were decreased overall as pH value was increased. Especially, the nitrite scavenging ability of 0.3% extracts from green tea and pine needle were the mosts effective in pH 1.2 and pH 3.0, which were showed 95% nitrite scavenging ability.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.2
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• pp.148-157
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• 2005

This study was investigated to determine antimicrobial activity of the water and ethanol extracts of Korean wild green tea, semi-fermented tea, and fermented tea. Antimicrobial activity was examined against 8 kinds of several microorganisms. The minimum inhibitory concentration (MIC) of the water and ethanol extracts of green tea showed the most active antimicrobial activity against B. subtilis 0.2 mg/mL in Gram positive bacteria and P. fluorescens 0.3∼0.5 mg/mL in Gram negative bacteria. But the extracts did not show antimicrobial activity against lactic acid bacteria and yeast at the level of less than 1 mg/mL. Antimicrobial activity got lower as tea got more fermented. Antimicrobial activity of ethanol extracts from green tea, semifermented tea, and fermented tea was stronger than that of water extracts. Antimicrobial activity of the water and ethanol extracts of green tea, semi-fermented tea, and fermented tea was not destroyed at 50∼121$^{\circ}C$, and pH 3∼11, which proved to be very stable when given over heat, acid & alkali treatment. The ethanol extract of green tea, semi-fermented tea, and fermented tea was fractionated in the order of hexane, diethyl ether, ethyl acetate and water fraction. The highest antimicrobial activity was found in the water fraction, but not found in hexane fraction, while antimicrobial activity of fermented tea was not found in ether fraction.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.53 no.6
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• pp.886-893
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• 2020

The seaweed Hizikia fusiformis is rich in protein, carbohydrates, vitamins, and minerals. This study investigated the antioxidant and physiological activities of H. fusiformis extracts prepared with 70% ethanol, 80% methanol, or distilled water. The extraction yields of these various solvent extracts were as follows: ethanol extract, 15.26%; methanol extract, 17.95%; and water extract, 45.62%. The methanol extract showed the highest total polyphenol content (24.06 mg GAE/g), but total flavonoid content was similar in all extracts. ABTS (2,2'-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)) radical scavenging activity was highest in the ethanol extract (IC50: 0.90 mg/mL), while the methanol extract exhibited the strongest DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity (IC50: 8.09 mg/mL), reducing power (EC50: 0.40 mg/mL), and ferric reducing antioxidant power (0.28 mM). By contrast, tyrosinase and α-glucosidase inhibitory activities were higher in the ethanol extract than in the other extracts. The high BACE1 (β-secretase) inhibitory activity was observed in the ethanol extract (IC50: 1.03 mg/mL). These results indicate that H. fusiformis ethanol extracts may be useful for their antioxidant and functional properties in food and pharmaceutical materials.

• Food Science of Animal Resources
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• v.41 no.6
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• pp.1060-1077
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• 2021

Food additives are required to maintain the freshness and quality of foods, particularly meats. However, chemical additives may not be preferred by consumers, and natural materials with antimicrobial and antioxidant effects may be used as replacements for common chemical additives. Accordingly, in this study, we compared the antimicrobial and antioxidant activities of natural compounds extracted with ethanol and hot water, and emulsion sausage prepared with natural ethanol extracts was analyzed for pH, color, thiobarbituric acid reactive substances (TBARS), and Clostridium perfringens growth during storage. The antimicrobial activities of 49 natural extract candidates against Listeria monocytogenes, C. perfringens, Salmonella spp., and Escherichia coli were analyzed, and six natural materials with excellent antibacterial activities, i.e., Elaeagnus umbellata Thunb. f. nakaiana (Araki) H. Ohba, Punica granatum L., Ecklonia cava, Nelumbo nucifera Gaertner, and Schisandra chinensis (Turcz.) Baill., and Rubus coreanus Miq. were evaluated to determine their total polyphenol contents and DPPH radical scavenging activities. The total polyphenol contents of ethanol extracts were higher than those of hot water extracts, whereas DPPH radical scavenging activity was found to be higher in hot water extracts. The TBARS values of emulsion sausages were significantly increased as storage time increased, and the TBARS values of emulsion sausages prepared with natural extracts were lower than those of control sausages. Natural extract-treated emulsion sausages showed a 99% reduction in bacterial contents compared with untreated sausages on day 2, with greater than 99.9% reduction after day 3. Thus, these results demonstrated that natural extracts could have applications as natural preservatives in meat products.

• The Korean Journal of Food And Nutrition
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• v.36 no.1
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• pp.42-49
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• 2023

To enhance the efficacy of Abeliophyllum distichum leaves, extracts were prepared using different solvents for hydrolytic enzyme-treated Abeliophyllum distichum leaves. Physicochemical quality and antioxidant activity were measured. Soluble solids, reducing sugar, ascorbic acid, flavonoids, and polyphenols contents showed the lowest values in the control without enzyme treatment. However, they showed high contents in ethanol extract. In the case of enzyme treatment, their values were higher than those of the control. In particular, verbascoside content increased about 220 times more than that of the control group when treated with enzymes and extracted with 50% ethanol. pH was lowered upon enzymatic treatment. Regarding DPPH radical scavenging activity, for enzyme-free, 25% ethanol extract showed the highest activity among extracts with different solvents. For cellulase and pectinase-treated leaves, water extract showed the highest DPPH radical scavenging activity among extracts with different solvents. For leaves treated with enzyme combination, 50% ethanol extract showed the highest DPPH radical scavenging activity among extracts with different solvents. Regarding ABTS radical scavenging activity, it was generally higher in the 50% ethanol extract than in the water extract and 25% ethanol extract. In particular, verbascoside content was increased when the extract was prepared by co-treatment with enzymes and 50% ethanol.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.4
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• pp.67-74
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• 2017

This study analyzed the antioxidant activities and antibacterial effects of extracts from the fruit of Citrus junos. Theextracts were obtained in both 70% ethanol solution and distilled water at a distillation temperature of $50^{\circ}C$.Three experiments were carried out between November 2016 and March 2017. The averages and the standard deviations of the results were measured. The total polyphenol and tannin contents of the ethanol extracts were $7.8{\pm}0.02mgGAE/g$ and $9.9{\pm}0.01mgTAE/g$, respectively, which were higher than the concentrations in the water extracts. Furthermore, the ethanol extracts scavenged $46.1{\pm}4.76%$ of DPPH radicals and $37.1{\pm}1.23%$ of ABTS radicals. The scavenging capability of the ethanol extracts was also higher than that of the water extracts. However, the scavenging capability of both types of extracts depended on their concentrations.All the extracts showed active antibiosis effects against every bacteria tested except for C. albicans. E. coli at 25 mg/disc showed antibiosis with $18{\pm}1.73mm$ for the water extracts, while S. epidermidis and S. aureus showed antibiosis with $17{\pm}4.36mm$ and $19{\pm}2.86mm$ for the ethanol extracts, respectively. This antibiosis rate is considerably higher. The results suggest that fruit extract from Citrus junos could be useful as a primary material for beauty or skin-related products such as soaps, shampoos, and scalp enhancers.

• Journal of the Korean Wood Science and Technology
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• v.42 no.5
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• pp.624-633
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• 2014

This study separated the crude extract (70% ethanol) of and its three fractions (hexane, chloroform and ethyl acetate extracts) on the basis of polarity indexes, and examined for their insecticidal activities against aphid (Uroleucon lactucicola). For crude extraction, the 70% ethanol extract showed the best extract yield (58.0%) and insecticidal activity (69.0%) among the various concentrations tested (water, 30% ethanol, 50% ethanol, 70% ethanol and 95% ethanol). The major chemical compounds of different fractions (hexane, chloroform and ethyl acetate extracts) were identified as eugenol by head space-GC-MS analysis. The hexane extract showed the highest eugenol content (43.7%) and insecticidal activity (80.0%). The insecticidal activity is accordingly believed to be attributable to the eugenol component. This may provide a useful starting point for the development of bio-pesticides.