• Journal of Plant Biotechnology
• /
• v.45 no.3
• /
• pp.279-286
• /
• 2018

Citrus grandis Osbeck pericarp is used as tea, herbal medicine, etc., but is not commercialized in various ways. So, in this study, we identified potential for use of Citrus grandis Osbeck as health functional foods, cosmetics and food preservatives. Methanol extract of Citrus grandis Osbeck pericarp was fractionated with hexane, dichloromethane, ethyl acetate and butanol, to quantitatively analyze total phenol and flavonoid, and investigate antioxidative and enzyme inhibitory activities. Total phenol and flavonoid contents were highest in ethyl acetate fraction, FRAP and ORAC results also revealed highest activity in proportion to total phenol content. DPPH radical scavenging activity revealed that ethyl acetate, butanol and dichloromethane fraction manifested highest activity without significant difference. However, dichloromethane fraction revealed higher TEAC value and tyrosinase inhibitory activity than ethyl acetate fraction, and hexane fraction manifested best results with superoxide radical scavenging activity and ${\alpha}-glucosidase$ inhibitory activity. Antimicrobial activity also revealed best effect in dichloromethane and hexane fractions. So, based on the following results, use of dichloromethane fraction as material of natural functional cosmetics, ethyl acetate fraction for health functional foods, and hexane fractions for pharmaceuticals and food preservatives, would be most practical for product development.

• Journal of Life Science
• /
• v.9 no.4
• /
• pp.382-388
• /
• 1999

The effects of citrus flavonoids, hesperidin and naringin, on the lipid metabolism were investigated in cultured human hepatocyte HePG2 cells. HepG2 cells were cultured for 6 h and 24 h to the control medium or the media containing hespridin and narigin, which concentrations were 0.5 and 5.0 mg/$m\ell$. There were no significant effects on cell proliferation and cellular protein content, except for increased in these parameters by adding both citrus flavonoids (0.5 mg/$m\ell$). The cellular content of triacylglycerol after 6 h incubation with 0.5 mg/$m\ell$ hesperidin and naringin was markedly increased, and after 24 h incubation that was decreased in both citrus flavonoids supplementation. The supplementation of 5.0 mg/$m\ell$ hesperidin caused a marked decrease in the cellular cholesterol content following 6 h incubation, and that was also reduced markdly, in a dose-dependent manner, during incubation for 24 h. However, there was no significant difference in the cellular cholesterol content in medium supplemented with naringin. The effect of hesperidin and naringin on acyl-CoA: cholesterol acyltransferase (ACAT) activity was studied in vivo and in vitro. The data confirmed that hesperidin inhibit ACAT activity in vivo and in vitro, whereas naringin had no such effect on ACAT activity in vivo but not in vitro. The present study suggests that hesperidin reduces the cellular triacyglycerol and cholesterol contents in human hepatocyte HepG2 cells.

• Korean Journal of Microbiology
• /
• v.43 no.2
• /
• pp.124-129
• /
• 2007

We evaluated the use of citrus fruit fermented by lactic acid bacteria, as a feed supplement for flounder (Paralichthys olivaceus) cultivation. For the fermentation, a lactic acid bacterial strain W-44 showing antibacterial activity was isolated from kimchi. From the phylogenetic analysis based on, 16S rDNA sequence, the strain W-44 was identified as Lactococcus lactis. After the fermentation of citrus fruit with L. lactis W-44, the contents of naringenin and hesperetin, bioactive flavonoid aglycones, were increased about ten-fold and six-fold, respectively. The effects of fermented citrus fruit-based feed additives (CFBFA) were tested on the growth of flounder, Paralichthys olivaceus. There were significant differences in average total length and body weight between the experimental and control group. The growth rate of the experimental group fed with the 0.2% CFBFA-supplemented diet was increased 4.5% and 20.9% more than the control group in total length and body weight, respectively. These results suggest that the fermented citrus fruit could be used as a functional feed additive for flounder cultivation.

• The Korea Journal of Herbology
• /
• v.36 no.1
• /
• pp.77-85
• /
• 2021

Objective : This study was designed to investigate effect of immature fruits from Citrus unshiu Markovich to mature them on antioxidative and antiaging-related enzyme activities in vitro. Methods : Fruits from Open field-cultivated C. unshiu Markovich (ripe and unripe fruits of Citri) made a purchase in Jeju island. We measured total polyphenol and flavonoid contents in mature C. unshiu Markovich (MC) and immature C. unshiu Markovich (IMC) 70% ethanol extract. DPPH free radical, ABTS radical, and hydroxyl radical scavenging activities in both extracts were determined. Also, reducing power, SOD-like activities, elastase inhibition, and collagenase inhibition activities of these extract were assayed at 5, 1, 0.5, and 0.1 mg/㎖. Results : The total polyphenol contents in the ethanol extract of IMC were higher than those of MC (26.99 ± 0.89 mg/TAEg). And total flavonoid contents in them were very similar to both extract (MC; 7.25 ± 0.4 mg/RUEg and IMC; 7.44 ± 0.18 mg/RUEg). DPPH free radical scavenging activities, ABTS radical scavenging capacity, reducing power, and SOD-like activities of IMC-treated group showed significant increase compared to those of MC group in all treated concentrations. Particularly, DPPH free radical scavenging and elastase inhibition activities in IMC-treated group at 5 mg/㎖ showed similar with positive control group. Besides, IMC extract at 5 mg/㎖ concentration surpassed positive control (BHA or Vit. C) in SOD-like activities and ABTS radical scavenging capacity. Conclusion : These results suggest that IMC ethanol extract may be used as a natural antioxidant and a antiaging material for development of functional foods and cosmeceuticals.

• Food Science and Preservation
• /
• v.18 no.4
• /
• pp.567-574
• /
• 2011

In this work, the major flavonoid content of citrus peel ethanol extract and the changes in the serum lipid and body fat of high-fat-diet-fed rats were examined. The subjects were divided into four groups: the normal, control, O1 (0.1% citrus peel ethanol extract), and O5 (0.5% citrus peel ethanol extract) groups. The experimental groups (O1 and O5) were fed a high-fat diet mixed with 0.1 and 0.5% citrus peel ethanol extract, respectively, for 10 weeks. The results of the analysis showed that the main ingredients of the flavonoid in the citrus peel ethanol extract (60 brix) were $38.21{\pm}1.37$ mg/g hesperidin and $15.02{\pm}0.48$ mg/g narirutin. With regard to the changes in the serum total-cholesterol level, compared with the control group's $79.1{\pm}4.6$ mg/dL, the serum total-cholesterol levels of the O1 and O5 groups were significantly lowered to $64.6{\pm}5.4$ and $59.5{\pm}4.7$ mg/dL, respectively. As for the changes in the LDL-cholesterol level, compared with the control group's $18.4{\pm}3.7$ mg/dL, the LDL-cholesterol levels of the O1 and O5 groups were significantly lowered to $13.0{\pm}3.6$ and $13.0{\pm}1.9$ mg/dL, respectively. For the changes in the serum triglyceride level, compared with the control group's $74.5{\pm}13.2$ mg/dL, the serum triglyceride level of the O5 group was significantly lowered to $48.6{\pm}11.2$ mg/dL. Finally, with regard to the changes in body fat, compared with the control group, the 05 group showed a significant decrease. In conclusion, it was observed that citrus peel ethanol extract was effective in lowering the total-cholesterol, LDL-cholesterol, and triglyceride levels of high-fat-diet-fed rats.

• Journal of Nutrition and Health
• /
• v.42 no.3
• /
• pp.278-290
• /
• 2009

This study aims to evaluate the changes of flavonoid contents and antioxidants activity of Jeju native citrus fruits juice according to the harvest date. Flavonoids such as quercatagetin, narirutin, hesperidin and neohesperidin were contained most plentifully in the juice of Jigak (Citrus aur-antium) by 573.73 mg/100 mL, Sadoogam (C. pseudogulgul) by 393.99 mg /100 mL, Soyooja by 29.63 mg/100 mL and Jigak (C. aurantium) by 201.23 mg/100 mL in the late August, respectively. The highest contents of nob-iletin, sinensetin and tangeretin among polymethoxyflavones were found in the juice of Hongkyool (C. tachibana) by 7.39 mg/100 mL, 2.24 mg/100 mL, 0.63 mg/100 mL in the late August, respectively. 3,5,6,7,8,3',4'- Heptamet- hoxyflavone recorded the highest amount in Punkyool (C. tangerina) by 0.27 mg/100 mL in the late August, but the other polymethoxyflavones including 3',4',7,8-tetramethoxyflavone, 3',4'-dimethoxyflavone, 4'-methoxyflavone, 5,6,7,3',4',5'-hexamethoxyflavone, scutellarein tetramethylether were observed only trace amount in all the citrus fruits. Flavonoid contents in the citrus fruit juices were the highest during early maturation and decreased rapidly while ripening. Total polyphenol contents were the highest in the late August and decreased with ripening. However from the late December, the contents were increased again. Antioxidant activities of the fruits were evaluated as electron donating ability and were the lowest in the late September and increased with the fruit ripening. These results suggest that quercetagetin among all the flavonoids was most plentiful in Jigak and Dangyooja (C. grandis), so that the fruits could be used for industrial material of flavonoids and antioxidant agents.

• Korean Journal of Food Science and Technology
• /
• v.45 no.5
• /
• pp.598-604
• /
• 2013

This study was designed to evaluate the usability of the following citrus peel extracts (CPEs): Citrus sinensis (orange), C. unshiu (mandarin orange), C. limon (lemon), and C. paradise (grapefruit) as natural antibrowning agents. Overall, 0.1% of the CPEs were effective in reducing the browning of apple slices. The appearance of apple slices dipped in C. limon peel extracts (LPE) were found to be excellent and their Hunter L and ${\Delta}E$ values were similar to the values obtained when apple slices were dipped in ascorbic acid. The pH values of the different CPEs were not significantly different from each other, but were higher than that of ascorbic acid. LPE was found to possess the highest total phenolic content, flavonoid content, DPPH radical scavenging activity, and copper ($Cu^{2+}$) chelating activity. All these results suggest that citrus peel extracts, especially lemon peel extract, can be used as natural antibrowning agents.

• Korean Journal of Food Science and Technology
• /
• v.36 no.4
• /
• pp.669-676
• /
• 2004

Functional characteristics of citrus products fermented with lactic acid bacterium and yeast were investigated. Flavonoid composition of fermented citrus extracts increased significantly compared to control, leading to increases of naringenin and hesperetin concentrations. All citrus extracts showed anti-apoptotic effects in HepG2 cells regardless of fermentation, with citrus-fermented products showing greater anti-apoptotic effect and intracellular Reactive Oxygen Species content reduction compared to native citrus extracts. Male Sprague-Dawley rats were orally dosed with native or fermented citrus extracts. Singnificantly higher body weight reductions were observed in higher fermented citrus-dosed (100 mg/kg body weight) group compared to the other groups. Plasma total cholesterol level was slightly, but not significantly, reduced. Fatty liver formation induced by high-fat diet was significantly suppressed in rats administered with fermented citrus extracts. Results suggest fermented citrus extracts have potent anti-apoptotic and anti-oxidative activities in vitro, and inhibitory activity against fatty liver formation by high-fat diet in vivo.

• Journal of Food Hygiene and Safety
• /
• v.37 no.5
• /
• pp.356-363
• /
• 2022

To investigate the functional activity of different citrus fruit peels, antioxidant compounds in 70% ethanol extracts of mandarin, lemon, orange, and grapefruit peel powders were identified, and antioxidant and antibacterial activities were quantitated. Mandarin peel contained the highest content of total phenolic compounds and total flavonoid substances (21.46±0.12 mg GAE/g and 11.57±0.05 mg RE/g, respectively). The total phenolic compound content of the three other citrus fruits was 14.16±0.18-18.44±0.07, and their total flavonoid content was 5.51±0.10-7.46±0.09 mg RE/g. DPPH radical scavenging activity was the highest in lemon peel (87.64±0.21%), and mandarin peel displayed the best antioxidant activity with respective ABTS radical scavenging activity and FRAP measurements of 43.20±0.61% and 78.82±1.06 mM TE/g. Grapefruit peel antimicrobial activity increased with treatment time, and was the most potent among the four tested citrus species, inhibiting Staphylococcus aureus by about 4.05 log cycle. These findings demonstrate that mandarin and grapefruit peel can be used to prevent oxidation, improve food storage capabilities, and potentially preserve food quality.

• Korean journal of food and cookery science
• /
• v.26 no.1
• /
• pp.88-94
• /
• 2010

This study was carried out to investigate the total polyphenol and flavonoid contents and antioxidative activities of the methanol extracts of Citrus sunki, C. unshiu and C. natsudaidai peels before and after drying. Total polyphenolic content was high in the citrus peels before drying compared to the dried peels, and highest in the order of C. sunki, C. natsudaidai and C. unchiu. On the other hand, flavonoid content was high in the dried citrus peels than in the citrus peels before drying, and was highest in the order of C. unshiu, C. natsudaidai, C. sunki, but in dried peels it was highest in the order of C. natsudaidai, C. unshiu, C. sunki. DPPH radical scavenging activity was highest in the order of C. natsudaidai, C. unchiu, C. sunki, and that in the citrus peels before drying was higher than in the dried peels. Inparticular, C. natsudaidai peels before drying showed higher activity than vitamin C in 0.5 or 1.0 mg/100 g. Hydrogen peroxide scavenging activity was highest in the order of C. unshiu, C. natsudaidai, and C. sunki in the citrus peels before drying. The dried peels were highest in the order of C. unshiu, C. natsudaidai, C. sunki at 0.5 mg/100 g, but high in order of C. natsudaidai, C. unshiu and C. sunki at more than 1.0 mg/100 g. Inparticular, all C. natsudaidai peels displayed high activity more than 87% at 2.0 mg/100 g. Clear patterns in alkyl radical scavenging activity could not be confirmed in Citrus species whether before or after drying of peels. Hydroxyl radical scavenging activity was highest in the order of C. natsudaidai, C. unshiu and C. sunki but was relatively low compared to the scavenging activity of other activated oxygen species.