• Korean Journal of Food Science and Technology
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• v.52 no.5
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• pp.487-494
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• 2020

This study was performed to evaluate the quality characteristics and antioxidant activities of rice crispy cereal supplemented with dried laver powder. Reducing sugar content decreased in the dried laver-supplemented group. According to the Hunter color system, the L, a, and b values of rice crispy cereal decreased with an increase in the amount of dried laver. The LP5 (rice crispy cereal added with 5% dried laver) group showed the highest phycocyanin and chlorophyll contents, which tended to increase with increased amounts of added dried laver. Total phenolic and flavonoid contents increased with the amount of dried laver, as did 2,2-diphenyl-1-picrylhydrazyl (DPPH) and hydroxyl radical-scavenging activities. Intensity test results showed that the color, flavor, and taste of rice crispy cereal improved with the addition of dried laver. The LP5 group scored the highest on overall satisfaction. These results suggest that the addition of dried laver to rice crispy cereal improves sensory properties by increasing antioxidant activities.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.7
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• pp.999-1008
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• 2014

We evaluated the quality characteristics and antioxidative activities of cookies containing different types of egg yolk (LEY, Liquid Egg Yolk; FEY, Fresh Egg Yolk) and percentages of blueberry powder (5, 10, and 15%). As the amount of blueberry powder increased, the levels of antioxidants based on ABTS and DPPH radical scavenging activities increased in general. Within the 15% group, contents of polyphenols and flavonoids were higher in the FEY group, whereas content of anthocyanins was higher in the LEY group. Measurement of ABTS radical scavenging activity showed that the FEY group had a higher value within the 10% group, whereas the LEY group scored higher within the 15% group. Comparison of sensory properties showed no significant difference between the two egg yolk types. If commercialized, manufacturing cookies with FEY or LEY will not make a significant difference. Regardless, 15% blueberry powder would be the most appropriate, as it scored the highest in terms of antioxidant activity and sensory characteristics.

• Journal of Marine Bioscience and Biotechnology
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• v.2 no.3
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• pp.187-191
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• 2007

The radical scavenging activity of methanol extracts of seaweeds and their active compounds, alginic acid, fucoidan and phloroglucinol, were investigated under in vitro. Among methanol extracts of seaweeds (sea mustard, sea tangle, seaweed papulosa, fusiforme, sea lettuce, purple laver and chlorella), seaweed papulosa and sea tangle showed strong scavenging activities of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and hydroxyl radical (${\cdot}OH$). In addition, under in vitro, the scavenging activities on DPPH radical of alginic acid and fucoidan, which are active compounds of brown algae, and phloroglucinol, the active compound from Ecklonia species, were evaluated and compared. Fucoidan and phloroglucinol showed strong DPPH scavenging effect, in particular, phloroglucinol had strongest activity among the active compounds. On the other hand, alginic acid did not exert DPPH scavenging activity. From the present study, we could confirm the antioxidative activity of seaweeds and its active compounds.

• Korean Journal of Medicinal Crop Science
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• v.10 no.3
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• pp.171-176
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• 2002

Antioxidative effect of 42 medicinal plant extracts was screened to search natural antioxidants. The extracts of Terminalia chebula, Caesalpinia sappan, Sanguisorba officinalis, Rubus coreanus, and Alpinia katsumadai showed strong inhibition effect on DPPH radical, and LDL oxidation. Those of Eugenia caryophyllata, Alpinia officinarum, Zingiber officinale, Xanthium strumarium, Sophora japonica, Aristolochia contorta, and Alpinia katsumadai exhibited potent antioxidative activity on linoleic acid peroxidation. Among 42 medicinal plant materials, the extract of Terminalia chebula showed the highest scavenging activity $(3.08\;{\mu}g/ml)$ on DPPH radical which was higher than that $(13.52\;{\mu}g/ml)$ of ${\alpha}-tocopherol$. The extract of Terminalia chebula showed also stronger inhibition activity on LDL oxidation than that of ${\alpha}-tocopherol$ did.

• Food Science and Preservation
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• v.23 no.3
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• pp.387-392
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• 2016

The antioxidant activities of brownish natural dyeing agents, extracted from seven kinds of plants, were tested. Total polyphenol content, DPPH and ABTS radical scavenging activities, and singlet oxygen quenching effect were determined for hot water extracts and floral waters of plants. DPPH and ABTS radical scavenging activites increased with increasing amounts of the extracts from Uncaria gambir R. and Terminalia chebula R. displayed remarkable scavenging effects at concentrations below 0.1 mg/mL, in comparison with the positive control, ascorbic acid. However, antioxidant effects of the floral water, obtained from steam distillation of tested plants, were inefficient at concentration below 0.2 mg/mL. In particular, the natural dyeing agent effectively suppressed singlet oxygen induced by photosensitizer in in vitro assay systems. The concentrations ($IC_{50}$) required to exert 50% of singlet oxygen were 120 and $190{\mu}g/mL$ for hot water extracts from Uncaria gambir R. and Phellinus linteus, respectively. Among all the tested samples, the Uncaria gambir R. and Phellinus linteus extracts contained higher amount of total phenolic contents. The results suggest that naturally occurring dyeing agents are beneficial as natural antioxidants, encouraging further extensive studies.

• Journal of Life Science
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• v.21 no.6
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• pp.811-818
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• 2011

Physiological activities of hot water (MHW) and 80% ethanol (MEH) extracts from Maesaengi (Capsosiphon fulvescens) were investigated in this study. For the evaluation of antioxidant activities for MHW and MEH, 2,2-diphenyl-1-pic-rylhydrazyl (DPPH) radical scavenging activity and superoxide dismutase (SOD)-like activity were measured. DPPH radical scavenging activity and SOD-like activity of MHW, and MEH were increased weekly in a dose-dependent manner, and were about 10.8, 13.8, 62.4, and 27.1% at 10 mg/ml, respectively. The angiotensin converting enzyme (ACE) inhibitory activities of MHW and MEH were about 5.9% and 49.7% at 1 mg/ml, respectively. The ${\alpha}$-glucosidase inhibitory effect of MHW and MEH were about 1.4% and 67.3% at 1 mg/ml, respectively. To determine the influence of MHW and MEH on alcohol metabolizing activity, the generating activities of reduced-nicotinamide adenine dinucleotide (NADH) by alcohol dehydrogenase (ADH) and acetaldehyde dehydrogenase (ALDH) were measured. Facilitating rates of ADH activity by MHW and MEH were increased weekly in a dose-dependent manner and ALDH activities were not detected. Elastase inhibitory activities of MHW and MEH were 75.9% and 51.2% at 10 mg/ml, respectively.

• Korean Journal of Ecology and Environment
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• v.45 no.1
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• pp.11-20
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• 2012

Methanol extracts of aquatic plants were analyzed for allelopathic activities against Escherichia coli JM109 and $Microcystis$ $aeruginosa$ UTEX2385 which were compared to its 2,2-Diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities. The radical scavenging activities were detected from the extracts of $Persicaria$ $thunbergii$, $Persicaria$ $amphibia$, $Trapa$ $japonica$, $Myriophyllum$ $spicatum$, and $Brasenia$ $schreberi$. Also, the inhibitory activities against cyanobacteria were analyzed according to the order of $B.$ $schreberi$, $T.$ $japonica$, $P.$ $amphibia$, and $M.$ $spicatum$. Most of the extracts from aquatic plants did not show any inhibition against $E.$ $coli$ except $B.$ $schreberi$. We found a positive correlation between the antioxidental activities of methanol extract of aquatic plants and the growth inhibitory activities for cyanobacteria in terms of the DPPH radical scavenging activities ($R^2$=0.381, $P$ <0.0001). The inhibitory activities of methanol extract against $E.$ $coli$ growth was not correlated with the other activities of aquatic plants ($P$ >0.04). We suggest from this study that the allelopathic effects of aquatic plants against cyanobacteria could be screened by using the bioassay based on DPPH.

• Korean journal of food and cookery science
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• v.31 no.2
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• pp.207-213
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• 2015

Free amino acid and mineral analysis of beverages with Gugija (Lycii fructus) extracts performed to determine the antioxidative and anti-diabetes activities of the beverages. The four major free amino acids in the water- or ethanol-extracts of the Gugija beverages were asparagine (115.23, 51.95 mg%), methionine (20.02, 22.07 mg%), aspartic acid (19.65, 13.72 mg%) and taurine (18.64, 22.44 mg%). The mineral contents of the Gugija beverages with water- and ethanol-extracts were in the order K>Mg>Na>Ca>Zn>Fe. Antioxidant activity determined by DPPH and ABTS radical scavenging activity. There was no significant difference in DPPH and ABTS radical scavenging activities between the water-extract beverages and the ethanol-extract beverages, although more phenolics and flavonoids were found in the ethanol-extract beverage. Higher anti-${\alpha}$-glucosidase activity was observed in the ethanol-extract beverage compared to acabose, which was used as the control and is an inhibitor of ${\alpha}$-glucosidase, suggesting that the Gugija beverage with ethanol extract could be a potential hypoglycemic agent.

• Microbiology and Biotechnology Letters
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• v.44 no.3
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• pp.311-316
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• 2016

This study was designed to develop the functional beverage using Salicornia herbacea L (SH). To evaluate the anti-oxidation and anti-thrombosis activities of SH, the ethanol extracts of leaf (LF), stem (ST) and seed (SD) of SH were prepared. Components analysis showed the total polyphenol of LF > ST > SD, and the total flavonoid of LF > SE > ST, respectively. Amounts of total sugar and reducing sugar of LF and ST were similar, but the SD had only 1/10 of sugar contents of LF. Anti-oxidation activities of each extract determined by calculated RC₅₀ showed LF > SD > ST for DPPH anion, nitrite and reducing power, and LF = SD > ST for ABTS cation scavenging activity, respectively. In anti-coagulation assay, SD showed strong inhibition activity against thrombin and blood coagulation factors. All the extracts had no platelet aggregation activities against human platelet and no hemolysis against human RBC. Our results suggest that the SD from SH has a great potential as a new anti-coagulation agent.

• Korean Journal of Food Science and Technology
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• v.32 no.4
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• pp.928-935
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• 2000

This study was carried out to examine the antioxidative, antimicrobial and nitrite scavenging effects of various solvent extracts and different solvent fractions from Schizandra chinensis RUPRECHT(Omija) seed. The results were as follows; The antioxidative activities using lard, soybean oil and linoleic acid were the highest in methanol, ethanol and methanol extract from omija seed, respectively. The free radical scavenging activity using DPPH method was the strongest in acetate fraction of methanol extract from seed. The methanol extract from omija seed had the strongest antimicrobial activities to L. plantarum, B. subtilis, E. coli and P. citrinum, while ethyl acetate extract had the strongest against S. aureus and S. typhimurium. The buthanol fraction from methanol extract had the highest antimicrobial activities, followed by B. subtilis, L. plantarum, E. coli, S. aureus and S. typhimurium. The nitrite scavenging ability was pH dependent, highest at pH 1.2 and lowest at pH 6.0. The buthanol fraction of methanol extract from omija seed had more effective nitrite scavenging ability than other fractions of extracts.