• Journal of the Korean Applied Science and Technology
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• v.33 no.1
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• pp.204-212
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• 2016

This study was carried out to investigate the antioxidant activities, total phenol, and flavonoid contents of 70% methanol, 70% ethanol, and chloroform-methanol (CM, 2:1, v/v) extracts from garlic (Allium sativum L.) peels. Antioxidant activity was evaluated by DPPH (2,2-diphenyl-1-picrylhydrazyl) radical and ABTS [2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt] radical scavenging activity, ${\beta}$-carotene bleaching assay, and ferric reducing antioxidant power. Total phenol and flavonoid were in a range of 32.59-63.05 mg CAE/g, 5.26-9.22 mg QE/g, respectively. Total phenol and flavonoid were predominant with the values of $63.05{\pm}0.20mgCAE/g$ and $9.22{\pm}0.17mgQE/g$ in 70% ethanol extract. Additionally, 70% ethanol extract also displayed the strongest antioxidant activity followed by 70% methanol extract and CM extract in all assays. These results showed that garlic peel can be used as natural antioxidant in nutraceutical preparations to prevent human diseases.

• Journal of the Korean Applied Science and Technology
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• v.33 no.1
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• pp.186-194
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• 2016

Consumption of fruits and vegetables has been conducted to be effective in the prevention of chronic diseases. In this study, 70% methanol, 70% ethanol and chloroform-methanol mixture (CM, 2:1, v/v) were used as solvents in the extraction of apple peels. The total phenol content, total flavonoid content and antioxidant activity of various extracts were investigated using in vitro assays. The extract obtained by 70% methanol showed the highest total phenol content ($20.87{\pm}0.17mgCAE/g$), ABTS [2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt] radical scavenging activity and ferric reducing antioxidant power. However, 70% ethanol extract possessed the strongest antioxidant activity assayed by DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity and ${\beta}$-carotene bleaching method. And CM extract was found to show the highest total flavonoid content with the value of $9.26{\pm}0.06mgQE/g$. These results indicated that apple peels can be used in dietary applications with a potential to reduce oxidative stress.

• Journal of Electrochemical Science and Technology
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• v.8 no.1
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• pp.77-86
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• 2017

The valorization of domestic wastes becomes a very important research axis that can reduce the energy consumption and protect our environment. The objective of this study is to remove zinc ions from wastewater by using banana peels after their activation as sensor in the working electrode for an environmental application. Banana peels were dried, crushed and treated with sulfuric acid then mixed with polyaniline to improve their electrical conductivity. Cyclic voltammetry and chronoamperometry were used for electrochemistry tests. The obtained voltammogramms at well optimized conditions of applied potential of -1.3 V/SCE and initial zinc concentration of 0.2M during 2 hours of electrolysis, showed the reduction peak of the zinc at a potential of -1.14 V/SCE, which confirmed the activity of this electrode. The modeling of experimental data revealed that the adsorption was fitted by the Langmuir isotherm with a maximal adsorption capacity of 3.4188 mg/g. Changes in the structure of the powder after the electrosorption was noticed by SEM and EDX. Finally, the dosage of the electrolytic solution showed a diminution of the zinc concentration with yield of 99.99%.

• Journal of Applied Biological Chemistry
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• v.64 no.3
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• pp.237-244
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• 2021

Camellia sinensis, Green tea, contains phenolic compounds that act to scavenge reactive oxygen species (ROS), such as catechin, epicatechin, etc. In contrast with the tea leaf, the bioactivity of its fruit and the fruit peels remains still unclear. This study focused on the effects of fruit and fruit peels of C. sinensis (FC and PC) against oxidative DNA damage in NIH/3T3 cells. The scavenging effects of FC and PC on ROS were assessed using 1,1-diphenyl-2-picryl hydrazyl or 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid radicals. The measurement of ROS in cellular levels was conducted by DCFDA reagent and the protein expression of γ-H2AX, H2AX, cleaved caspase-3, p53, and, p-p53 was analyzed by immunoblotting. The gene expressions of p53 and H2AX were assessed using polymerase chain reaction techniques. The major metabolites of FC and PC were quantitatively measured analyzed and the amounts of phenolic compounds and flavonoids in PC were greater than those in FC. Further, PC suppressed ROS production, which protects the oxidative stress-induced DNA damage through reducing H2AX, p53, and caspase-3 phosphorylation. These results refer that the protective effects of FC and PC are mediated by inhibition of p53 signaling pathways, probably via the bioactivity of phenolic compounds. Thus, FC and PC can serve as a potential antioxidant in DNA damage-associated diseases.

• Nutrition Research and Practice
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• v.10 no.2
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• pp.131-138
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• 2016

BACKGROUND/OBJECTIVES: Citrus and its peels have been used in Asian folk medicine due to abundant flavonoids and usage of citrus peels, which are byproducts from juice and/or jam processing, may be a good strategy. Therefore, the aim of this study was to examine antioxidant and anti-inflammatory effects of bioconversion of Jeju Hallabong tangor (Citrus kiyomi ${\times}$ ponkan; CKP) peels with cytolase (CKP-C) in RAW 264.7 cells. MATERIALS/METHODS: Glycosides of CKP were converted into aglycosides with cytolase treatment. RAW 264.7 cells were pre-treated with 0, 100, or $200{\mu}g/ml$ of citrus peel extracts for 4 h, followed by stimulation with $1{\mu}g/ml$ lipopolysaccharide (LPS) for 8 h. Cell viability, DPPH radical scavenging activity, nitric oxide (NO), and prostagladin $E_2$ ($PGE_2$) production were examined. Real time-PCR and western immunoblotting assay were performed for detection of mRNA and/or protein expression of pro-inflammatory mediators and cytokines, respectively. RESULTS: HPLC analysis showed that treatment of CKP with cytolase resulted in decreased flavanone rutinoside forms (narirutin and hesperidin) and increased flavanone aglycoside forms (naringenin and hesperetin). DPPH scavenging activities were observed in a dose-dependent manner for all of the citrus peel extracts and CKP-C was more potent than intact CKP. All of the citrus peel extracts decreased NO production by inducible nitric oxide synthase (iNOS) activity and $PGE_2$ production by COX-2. Higher dose of CKP and all CKP-C groups significantly decreased mRNA and protein expression of LPS-stimulated iNOS. Only $200{\mu}g/ml$ of CKP-C markedly decreased mRNA and protein expression of cyclooxygenase-2 in LPS-stimulated RAW 264.7 cells. Both 100 and $200{\mu}g/ml$ of CKP-C notably inhibited mRNA levels of $interleukin-1{\beta}$ ($IL-1{\beta}$) and IL-6, whereas $200{\mu}g/ml$ CKP-C significantly inhibited mRNA levels of $TNF-{\alpha}$. CONCLUSIONS: This result suggests that bioconversion of citrus peels with cytolase may enrich aglycoside flavanones of citrus peels and provide more potent functional food materials for prevention of chronic diseases attributable to oxidation and inflammation by increasing radical scavenging activity and suppressing pro-inflammatory mediators and cytokines.

• Journal of Food Hygiene and Safety
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• v.34 no.4
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• pp.325-333
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• 2019

The present study was carried out to identify the distribution characteristics of heavy metals in ginseng and wood-cultivated ginseng reduction of dietary exposure. Samples of ginseng and wood-cultivated ginseng were collected from 14 and 5 regions across Korea, respectively. Lead (Pb), cadmium (Cd) and arsenic (Ar) were detected by ICP-MS after microwave digestion, whereas aluminum (Al) was determined using ICP. Cultivated ginseng peels were 16.2% of whole root, while the peels and fine roots amounted to 21.8% and 16.8% of whole wood-cultivated ginseng, respectively. Taking into account the weight and concentration of the heavy metals by root part, their distribution ratios were calculated and compared. The cultivated ginseng peels contained 40.3% Pb, 25.9% Cd, 47.6% As, and 89.9% Al. Meanwhile, heavy metals consisting of 27.2% Pb, 28.2% Cd, 48.3% As, and 56.8% Al were distributed in the peels of the wood-cultivated ginseng. There was no significant difference between the peels and fine roots of the wood-cultivated ginseng with respect to the distribution proportion of heavy metals, except for Al. These results indicate that the level of dietary exposure to heavy metals could be reduced by peeling ginseng and wood-cultivated ginseng prior to consumption.

• Journal of Applied Biological Chemistry
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• v.44 no.3
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• pp.143-146
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• 2001

Eight flavonoids, including rutin, naringin, hesperidin, quercetin, hesperetin, nobiletin, 3,5,6,7,8,3',4'-methoxylated flavone, and tangeretin, in the peels of satsuma mandarin (Citrus unshiu) species of Halla, Gungcheon, Hungjin, Namgam-20, Illnam-1, and Chungdo harvested between August and December were analyzed through HPLC. Hesperidin content of Halla harvested during early maturation was 28.70 mg/g, and was the highest among the tested citrus fruits. Rutin content of Hungjin harvested during early maturation was 2.66 mg/g. Naringin in all citrus species and hesperetin in Halla, Gungchun, Namgam-20, and Chungdo were only detected in the peel of fruits harvested during early maturation. Hesperidin and rutin were detected mainly in all citrus species, and other flavonoids in trace. Flavonoid content in the peel of fruits was high during early maturation. Flavonoid contents in the peels of all fruit samples were generally high in the early stage of maturation, which then decreased rapidly.

• Korean Journal of Pharmacognosy
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• v.10 no.1
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• pp.13-16
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• 1979

The essential oil composition by means of gas liquid chromatography, and the occurrence and distribution of flavonoid glycosides in leaves, peels and barks of citrus plants native to Je Ju island were investigated. Results indicate that the occurrence of p-cymene, d,l-limonene, linalool, geraniol and linalyl acetate in the essential oils, and of hesperidin in leaves, peels and barks are fairly common to these species.

• Environmental Engineering Research
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• v.19 no.1
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• pp.41-45
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• 2014

The peels of Carya cathayensis Sarg. (PCCS) were treated under subcritical water conditions ($130^{\circ}C$ to $280^{\circ}C$ for 0 to 120 min). The extract from PCCS included reducing sugar, proteins, and compounds with radical scavenging activity. Addressing the reducing sugar that is a resource of bioethanol, we could maximize the reducing sugar under the subcritical water ($190^{\circ}C$ for 60 min) and obtain 0.24 g/g-sample together with 9.7 units/mg-sample of radical scavenging activity. The obtained extract was estimated to correspond to 1 L of bioethanol/100 g-sample. It was therefore considered that the treatment by subcritical water could yield reducing sugar and natural compounds with radical scavenging activity.

• Preventive Nutrition and Food Science
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• v.16 no.4
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• pp.370-375
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• 2011

The antioxidative activity and the polyphenolic composition were examined in four different cultivars of apple (Malus domestica), 'Fuji', 'Tsugaru', 'Hongro' and 'Kogetsu', and their parts (peel, core, pulp and juice). The total phenolics, flavonoids and anthocyanins differed among the tested cultivars and parts. Peel parts had the highest total phenolics and anthocyanin content. Contributions of those phenolics to total antioxidative activity were determined using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging assays, and the linoleic acid oxidation assay. Concentration of phenolics contributes significantly to the total antioxidative activity of apples. Clearly, apple peels, especially from Hongros and Kogetsus, possess high levels of phenolic compounds and antioxidants. Therefore, apple peels may potentially function as a value-added ingredient.