• Culinary science and hospitality research
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• v.23 no.8
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• pp.83-89
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• 2017

Dangyuja (Citrus gradis), a native citrus fruit of Jeju Island, has sour and bitter tastes. Dangyuja is rich in dietary fiber and enhance antioxidant activity. In this study, sponge cake was prepared by adding Dangyuja peel powder, and its quality characteristics were investigated. The freeze-dried Dangyuja peel powder was added to sponge cakes at a content of 0% (control), 2% (DP2), 4% (DP4), 6% (DP6) and 8% (DP8) of wheat flour weight. The specific gravity and baking loss of dough tended to increase with the amount of Dangyuja peel powder added, but the pH value as well as volume index of the cake were decreased. The symmetry index of cake tended to increase. Color values of sponge cake crust showed no significant difference, but L value and a value of crumb were decreased. The hardness and chewiness were increased with adding Dangyuja peel powder. Springiness was the highest at DP2 (91.79%). Cohesiveness did not showed significant difference among all samples. In a consumer preference test, cake groups with Dangyuja peel powder was higher than DP0 in color, texture, and overall acceptability. From these results, it was concluded that Dangyuja affects characteristics of sponge cakes. When making Dangyuja peel sponge cakes, it is suitable for adding 4% Dangyuja peel powder.

• Biomedical Science Letters
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• v.26 no.2
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• pp.109-113
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• 2020

Dangyuja (Citrus maxima (Burm.) Merr.) is a native fruit of great economic importance in Jeju island in Korea. To provide experimental evidence for the antioxidant and anti-inflammation properties on extraction ethanol concentration of Dangyuja, 2 cultivars, including 30-year-old and 120-year-old were evaluated. 30-year-old Dangyuja 50%, 70% ethanol extracts had the highest polyphenol and flavonoid content, and the strongest 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activity. To investigate the anti-inflammatory activity of Dangyuja ethanol extracts, we used BV-2 microglia cells and induced inflammation using lipopolysaccharide (LPS). Then, we measured levels of inflammatory mediators as nitric oxide (NO). Among the 6 extracts, 30-year-old Dangyuja 50% ethanol extracts show the highest anti-inflammatory activity. The results suggest that 30-year-old Dangyuja 50% ethanol extracts provides significant health benefits and may be used for developing new functional materials.

• Food Science and Preservation
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• v.14 no.2
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• pp.160-164
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• 2007

This study was performed to investigate the effects of mixing methods, storage period, and dilution ratio of Dangyuja-sugar mixture on the customer preferences for Dangyuja-tea. Most sensory characteristics such as bitterness, flavor, and taste are influenced more by mixing methods of Dangyuja-sugar mixtiue than by storage period. The Dangyuja-sugar mixture prepared by slice cutting is preferred to those prepared by operating electric mixer, The preference test showed that the appearance is not influenced by storage period but by mixing methods, whereas the tne and texture is more affected by storage period in which the 24 month storage is preferred to 12 month storage. therefore, the overall preference fer Dangyuja-tea is the on that prepared with 20% contents of Dangyuja-sugar mixture which is slice-cut and 24 month stored.

• Food Science and Biotechnology
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• v.18 no.5
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• pp.1063-1070
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• 2009

Dangyuja (Citrus grandis Osbeck) is a native plant growing only on Jeju Island in Korea. In this study, antiinflammatory effect of dangyuja leaves on a murine macrophage cell line was investigated. RAW 264.7 murine macrophage cells were stimulated with lipopolysaccharide (LPS, $1{\mu}g/mL$) to induce expression of pro-inflammatory markers [interleukin (IL)-6 and inducible nitric oxide synthase (iNOS)]. The crude extract (80% MeOH Ex.) and solvent fractions (hexane, $CHCl_3$, EtOAc, BuOH, and $H_2O$ Ex.) were obtained from dangyuja leaves. The $CHCl_3$ fraction inhibited the nitric oxide (NO) and IL-6 production in a dose-dependent manner. Also, the $CHCl_3$ fraction inhibited mRNA expression and protein levels of iNOS in a dose-dependent manner. Furthermore, the $CHCl_3$ fraction inhibited LPS-induced nuclear factor (NF)-${\kappa}B$ activation and phosphorylation of mitogen-activated protein kinases (MAPKs: ERK, JNK, and p38). These results suggest that dangyuja leaves may inhibit LPS-induced production of inflammatory markers by blocking NF-${\kappa}B$ and MAPKs signaling in RAW 264.7 cells.

• Food Science and Biotechnology
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• v.15 no.2
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• pp.312-316
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• 2006

Crude extract of young dangyuja (Citrus grandis Osbeck) fruit was investigated for its antioxidant activity as measured by 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity. Among the samples, including 4 Citrus species and various solvent-extracted-fractions of young dangyuja fruit, the water-extracted fraction (WF) and butanol-extracted fraction (BF) showed the greatest DPPH free radical scavenging activity. WF and BF were further examined for their antioxidant activities by three different in vitro assays. The cell viability tests using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reduction assay showed that both fractions significantly reduced $H_2O_2$-induced cytotoxicity in HepG2 cells dose-dependently. Generation of the reactive oxygen species (ROS) was also reduced in cells pretreated with both fractions. In addition, BF showed a higher level of lipid peroxidation inhibitory capacity than WF in $H_2O_2$-treated HepG2 cells. Taken together, these results indicate that young dangyuja fruit can be used as an easily accessible source of natural antioxidants.

• Food Science and Biotechnology
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• v.17 no.5
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• pp.1086-1091
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• 2008

The antioxidant activities of the extracts of dangyuja (Citrus grandis Osbeck) leaves were evaluated. The highest phenolic content was obtained from the ethyl acetate fraction (EF) (202.1$\pm$0.8 mg GAE/g dried extract) and it exhibited the highest 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity. The cytoprotective effects of EF on oxidative damage induced by tert-butyl hydroperoxide (t-BHP) in a human hepatoma cell line, HepG2 cells, were investigated to understand the intracellular antioxidant mechanisms. Treatment of HepG2 cells with EF prior to oxidative stress was found to inhibit reactive oxygen species (ROS) generation, lipid peroxidation, and DNA damage in a dose-dependent manner. Gas chromatography-mass spectrometry (GC-MS) studies on EF resulted in tentative identification of 19 compounds representing 94.3% of the total content. Taken together, these results demonstrated that EF has excellent antioxidant activities and thus dangyuja leaves have great potential as a source for natural antioxidant which can be applied in food products.

• Applied Biological Chemistry
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• v.50 no.3
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• pp.238-243
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• 2007

The contents of limonin, nomilin and limonin glucoside in different tissues of dangyuja (Citrus spp.) were measured during fruit growth and maturation by liquid chromatography-mass spectrometry(LC-MS). Both nomilin and limonin contents increased from June, peaked in October and in December, respectively, and then decreased afterwards. In contrast, the content of limonin glucoside increased from October and remained at high levels throughout the maturation. The contents of limonin, nomilin and limonin glucoside in peel decreased gradually throughout the growth and the trends of changes were similar to each other. However, all three limonoid contents in juice sac increased dramatically at the end of fruit maturation. The highest concentration of limonin and nomilin was observed in seed, followed by segment membrane, whereas the highest limonin glucoside concentration was observed in segment membrane, followed by juice sac.

• Journal of Plant Biotechnology
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• v.46 no.1
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• pp.45-55
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• 2019

TheCitrus grandis Osbeck is a special product in the Jeju island. The product has been as a remedy for liver damage and hang over. This study demonstrates how to investigate and compare the antioxidant, phenol content, tyrosinase and ${\alpha}$-glucosidase inhibitory activity, antimicrobial, and alcohol dehydrogenase (ADH) and acetaldehyde dehydrogenase (ALDH) activity with the C. grandis leaves extracted in different ethanol concentrations. From the yield, a 20% ethanol extract demonstrated the highest results among the other extracts. The distilled water extract showed the most abundant in a total phenol content and highest ABTS radical scavenging activity and reducing power assay. In the DPPH radical scavenging activity, ${\alpha}$-glucosidase and tyrosinase inhibitory assay (used ${\text\tiny{L}}$-tyrosine as substrate), the 80% ethanol extract exhibited a higher value than other extracts. The 60% ethanol extract showed prominent activities in the tyrosinase inhibitory (used ${\text\tiny{L}}$-dopa as substrate), ADH and ALDH activity assay. In the minimum inhibitory concentration (MIC) assay, 60% and 80% ethanol extracts inhibited the bacterial growth almost similarly. Moreover, the gram-positive bacteria was more restrained than the gram-negative bacteria. The resultsrevealed that the distilled water and 80% ethanol extract showed a relatively higher antioxidant activity compared to other extracts. The 60 ~ 80% ethanol extracts demonstrated potential tyrosinase, ${\alpha}$-glucosidase inhibitory, antimicrobial, ADH and ALDH activities. Therefore, the C. grandis is suggested to be considered as a functional material for various proposes.