• Journal of the Korean Society of Food Culture
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• v.33 no.1
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• pp.78-85
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• 2018

This study examined the changes in antioxidant activity and contents of phenolic compounds inblanched, steamed, and autoclaved burdock root (BR). The total polyphenolic and flavonoids contents of raw and cooked BR were determined spectrophotometrically. The antioxidant activity of BR was measured using 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and oxygen radical absorbance capacity (ORAC) assays. The main phenolic compounds in BR were quantified by HPLC (high performance liquid chromatography). Both blanching and steaming treatments significantly increased the antioxidant activities of BR in all groups (5 min, 15 min, and 30 min), whereas in autoclaving treatment, the 30 min treatment only showed an increase in the antioxidant activities of BR. The 30 min blanched BR exhibited the strongest DPPH and ABTS radical scavenging activities and possessed the highest total polyphenol and flavonoid phenolic contents. The 15 min-steamed BR showed the highest ORAC value. The main phenolic compound of the 15 min-steamed BR was CGA (chlorogenic acid). These results suggest that heat cooking methods, such as blanching and steaming, improve the antioxidant activity of BR by increasing the concentration of phenolic compounds.

• Food Science and Preservation
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• v.21 no.4
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• pp.560-564
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• 2014

To investigate the natural antioxidant and antimicrobial phytochemicals from black bamboo (Phyllostachys nigra MUNRO) leaves, the solvent fractions from crude methanol extract were made with n-hexane, ethyl acetate, and butanol, and their antioxidant and antimicrobial activities were determined. The antioxidant activities were examined by 1,1-diphenyl-1-picrylhydrazyl (DPPH) method and ferric ion reducing antioxidant power (FRAP) method, and the antimicrobial activities against Staphylococcus aureus were tested by paper disc agar diffusion method. Total phenolic contents and total flavonoid contents of the solvent fractions were also determined. The ethyl acetate fraction with the highest total phenolic contents among all fractions showed the strong antioxidant activities by DPPH method and FRAP method, and antimicrobial activities against S. aureus at all test concentrations. Caffeic acid, ferulic acid, quercetin, and kaempferol were analyzed by HPLC in the ethyl acetate fraction from black bamboo leaves by the comparison with the standard chemicals. It is supposed that the ethyl acetate fraction from black bamboo leaves could be used as natural preservatives in the food industry.

• Journal of Environmental Science International
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• v.25 no.4
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• pp.567-577
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• 2016

The purpose of this study was to measure the antioxidant activity and bioactivity of black chokeberry (Aronia melanocarpa). The black chokeberry was known to contain many physiologically active substance, such as ascorbic acid, anthocyanin, quercetin. We extracted black chokeberry powder from four solvents such as chloroform:methanol(CM, 2:1, v/v), distilled water (DW), 70% ethanol, 70% methanol. After that, we determined anthocyanin, total phenol, flavonoid content, DPPH radical scavenging activity, ABTS radical scavenging activity, ferric reducing antioxidant power, reducing power and Nitrite scavenging activity of black chokeberry extracts and as results of comparing each extract. respectively. From the above results shows that antioxidant activity and bioactivity of black chokeberry extracts was the highest in 70% methanol (p<0.05). The results suggest that black chokeberry can be used as nutraceutical foods and natural antioxidant.

• Food Science and Preservation
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• v.30 no.3
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• pp.434-445
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• 2023

Hemp (Cannabis sativa L.) seeds have recently been attracting attention as a new high-value-added food material owing to their excellent nutritional properties, and research on the development of functional food materials using hemp seeds is actively progressing. This study aimed to evaluate the antioxidant properties of hemp seed protein hydrolysates. Protein hydrolysates were prepared from defatted hemp seed powder (HS) by enzymatic hydrolysis using five different proteases (alcalase, bromelain, flavourzyme, neutrase, and papain). 2,4,6-trinitrobenzene sulfonic acid (TNBS) assay and SDS-PAGE analysis revealed that HS showed a high degree of hydrolysis after treatment with each enzyme except papain. The total polyphenol content of the protein hydrolysates (<3 kDa) and the RC50 values obtained from two different antioxidant tests showed that alcalase hydrolysate (HSA) had a relatively high level of antioxidant capacity. In addition, treatment with HSA (25-100 ㎍/mL) significantly inhibited linoleic acid peroxidation. These results suggest that hemp seed protein hydrolysates are potential sources of natural antioxidants. Future studies will focus on the identification of active peptides from HSA.

• Korean Journal of Food Science and Technology
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• v.43 no.1
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• pp.114-118
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• 2011

Resveratrol is a polyphenolic compound frequently found in the diet, and its physiological actions have been extensively investigated. In the present study, modulation of the antioxidant and cytotoxic properties of resveratrol at different pHs by various antioxidants were investigated. To measure its antioxidant effects, resveratrol was incubated at different pHs, including 6.5, 7.4, and 8.0. Resveratrol incubated at pH 6.5 showed significantly higher DPPH radical scavenging activity, whereas resveratrol incubated at pH 8.0 did not show antioxidant effects. Resveratrol produced much higher amounts of $H_2O_2$ at pH 8.0 than 7.4. The cytotoxic effects of resveratrol on HeLa cells were significantly enhanced by several antioxidants, including superoxide dismutase, N-acetyl cysteine, glutathione, and ascorbic acid. The present results suggest that resveratrol shows anti- or pro-oxidant effects in different cellular organelles according to the pH conditions, and blocking of reactive oxygen species from resveratrol enhances its cytotoxic effects.

• Food Science and Preservation
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• v.6 no.1
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• pp.121-135
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• 1999

Effective synthetic antioxidants such as butylated hydroxyanisole(BHA) and butylated hydroxytoluene(BHT) have been widely used in the food industry, but they are suspected to be toxic and carcinogenic effects. Therefore, the development of safely available natural antioxidants such as ascorbic acid, ${\alpha}$-tocopherol, ${\beta}$-carotene, flavonoids and selenium is essential. In particular, flavonoids, 2-phenyl-benzo-${\alpha}$-pyrones, are polyphenolic compounds that occur ubiquitously in food of plant origin. flavonoids occur in foods generally as O-glycosides with sugars bound usually at the C\ulcorner position. And variations in their heterocyclic ring gibes rise to flavones, flavonols, flavanones, flavanols, catechins, anthocyanidins, chalcone and isoflavones. Vegetables, fruits, and beverages are the main dietary sources of the flavonols, primarily as quercetin, kaempferol, and myricetin and the corresponding flavones, apigenin and luteolin. These flavonoids have biological activity such as antioxidant, anti-inflammatory, antithrombotic, antimutagenic, anticarcimogenic antiallergic and antimicrobial activity effects in vitro and in vivo. Flavonoids posses strong antioxidant activities acting as oxygen radicals scavenger, metal chelators and enzyme inhibitor. The antioxidant activity of flavonoids is determined by their molecular structure and more specially, by the position and degree of hydroxylation of the ring structure. All flavonoids with the 3`, 4`-dihydroxy(ortho-dihydroxy) posses marked antioxidant activity. And antioxidant activity increases with the number of hydroxyl groups substituted on the A-and B-rings. There is as yet no certainty about the effect of the presence of a double bond between C\ulcorner and C\ulcorner on the antioxidant activity of flavonoids.

• Korean Journal of Medicinal Crop Science
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• v.18 no.6
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• pp.373-378
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• 2010

In order to obtain basic data for utilization of the aerial parts of Cnidium officinale Makino (APCO), the antioxidant properties of the aerial parts and rhizomes of C. officinale were measured using DPPH and ABTS radicals, and nitrite scavenging assays. The ethyl acetate (EA) fraction prepared from the aerial parts of APCO showed the strongest antioxidant activities, and contained high level of total phenolic compounds (325.81 mgTE/g) and flavonoids (259.16 mgRE/g). The concentrations for 50% reductions ($RC_{50}$) values of the DPPH and ABTS radicals, and nitrite by the EA fraction of APCO were $11.27\;{\mu}g/m{\ell}$, $14.34\;{\mu}g/m{\ell}$, and $10.26\;{\mu}g/m{\ell}$, respectively. APCO exhibited approximately 3-9 times higher antioxidant activity than rhizomes of C. officinale. The antioxidant capacities of APCO were positively correlated with its total phenolic contents. Therefore, it was concluded that the aerial parts of C. officinale can be a useful and cost-effective source of natural antioxidant for food or cosmetics.

• Food Science of Animal Resources
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• v.33 no.6
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• pp.689-695
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• 2013

This study was conducted to investigate the effects of in vitro human digestion on the antioxidant activity of blueberry leaf extracts (BLE) in emulsion-type sausages (ETS). Leaves from four cultivars of blueberries (Bluecrop, Bluegold, Duke, and Northland) collected from a wild blueberry farm were extracted with 80% ethanol. ETS were prepared with 0.2% BLE. The samples were then passed through an in vitro human digestion system which simulates the composition of the mouth, stomach, and small intestine juice. Only one phenolic compound (chlorogenic acid) was detected in the BLE. Northland BLE had appreciably higher amounts of chlorogenic acid than that of other BLE, both before and after in vitro human digestion. Antioxidant activity of any BLE was not influenced by in vitro human digestion, whereas the antioxidant activity of chlorogenic acid standard increased in response to in vitro human digestion in both 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) and ferric-reducing ability of plasma (FRAP). In the present study, the antioxidant activities of the BLE were not strongly influenced by in vitro human digestion, and the antioxidant activity depended on the chlorogenic acid content of ETS. Thus, compounds from blueberry leaves may have important applications in the future as natural antioxidants for meat products.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.11
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• pp.1308-1315
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• 2017

This study was conducted to develop Momordica charantia L. juice fermented by four Lactobacillus species such as Lactobacillus paracasei (LPA), Lactobacillus plantarum (LPL), Lactobacillus rhamnosus (LRH), and Lactobacillus reuteri (LRE) as well as to investigate their inhibitory effects against digestive enzymes and antioxidant activities. Fermentation was performed at $37^{\circ}C$ without nutrient supplementation for 72 h. The pH and total lactic acid contents were within the ranges of 3.75~3.96 and 5.21~10.04% in fermented juices, respectively. The type of starter culture and fermentation time induced changes in flavonoid contents more than total phenolic contents. All juices fermented for 48 h strongly inhibited ${\alpha}$-glucosidase activity with the percentage of inhibition ranging of 91.24~95.05%. Antioxidant activities of all juices mostly increased after 48 h of fermentation. Our results suggest that fermented juice possesses inhibitory activity against digestive enzymes and antioxidant activity, and they can be used as health functional beverages.

• Nutrition Research and Practice
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• v.6 no.6
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• pp.491-498
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• 2012

Glycyrrhiza uralensis (or licorice) is a widely used Oriental herbal medicine from which the phenylflavonoids dehydroglyasperin C (DGC), dehydroglyasperin D (DGD), and isoangustone A (IsoA) are derived. The purpose of the present study was to evaluate the antioxidant properties of DGC, DGD, and IsoA. The three compounds showed strong ferric reducing activities and effectively scavenged DPPH, $ABTS^+$, and singlet oxygen radicals. Among the three compounds tested, DGC showed the highest free radical scavenging capacity in human hepatoma HepG2 cells as assessed by oxidant-sensitive fluorescent dyes dichlorofluorescein diacetate and dihydroethidium bromide. In addition, all three compounds effectively suppressed lipid peroxidation in rat tissues as well as $H_2O_2$-induced ROS production in hepatoma cells. This study demonstrates that among the three phenylflavonoids isolated from licorice, DGC possesses the most potent antioxidant activity, suggesting it has protective effects against chronic diseases caused by reactive oxygen species as well as potential as an antioxidant food additive.