• Journal of Nutrition and Health
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• v.36 no.6
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• pp.559-569
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• 2003

This study was performed to investigate the effect of whole mandarin, peel, and pulp intake of Citrus unshiu Marc on the antioxidative capacity of 15-month-old rats. Forty-eight male Sprague-Dawley rats weighing 621.9 $\pm$ 10.1 g were separated into four groups according to body weight. The rats were raised with diets containing 5% (w/w) dried mandarin powder for four weeks. Three powders were used, consisting of mandarin peel, pulp, and the entire fruit. Total flavonoids, antioxidant vitamins and dietary fiber was highest in the mandarin peel powder, followed by the whole mandarin powder and the mandarin pulp. The body weight gains of the whole mandarin and mandarin pulp groups were higher, while that of the mandarin peel group was lower than that of the control group. Food intake and ratios of liver, kidney and epididymal fat pad (EFP) weights to body weight were not significantly different among the groups, but ratios of EFP weights per body weight of the experimental groups tended to be lower than that of the control animals. Plasma and liver TBARS concentrations decreased in all the mandarin groups compared to the control group. Plasma and liver xanthine oxidase (XO) activity decreased in all of the mandarin diet groups. Erythrocyte and liver SOD activity in all of experimental groups was not significantly different from the control group. Plasma vitamin A concentration increased significantly in all of the mandarin diet groups. That of the mandarin peel group was 4 times higher than that of the control group. Plasma total carotenoids and vitamin C level also increased in the mandarin peel group. Plasma vitamin I level was not significantly different among the groups.

• Journal of Nutrition and Health
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• v.39 no.7
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• pp.610-616
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• 2006

This study was performed to investigate the effect of whole mandarin, peel or pulp intake of Citrus unshiu Marc. on antioxidative capacity and oxidative DNA damage in fifteen-month aged rats. Forty-eight male Sprague-Dawley rats $(621.9\;{\pm}\;10.1\;g)$ were blocked into four groups according to their body weights as control group, whole mandarin powder group, mandarin peel powder group and mandarin pulp powder group. Rats were raised with diets containing 5% (w/w) freeze dried mandarin formulations for four weeks. Total polyphenol content and total antioxidant status (TAS) of mandarin formulations were highest in peel powder, followed by whole powder and then pulp powder. The 8-hydroxy2'-deoxyguanosine concentrations of kidney in all mandarin groups were significantly lower than that of control group, and that of mandarin peel group was much lower than whole powder and pulp groups. Plasma TAS levels of all the experimental groups were higher than that of control group, and among mandarin groups, peel group showed higher level than remaining two groups. In conclusion, all the mandarin formulations were effective on antioxidative capacity in fifteen-month aged rats, and the peel was most effective one among three formulations.

• Journal of the Korean Wood Science and Technology
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• v.47 no.1
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• pp.66-79
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• 2019

The aim of the study is to use the by-products sawdust, formed during sawing and mandarin peel which are agricultural by products. The boards were manufactured by mixing the sawdust and mandarin peel at different mixing ratio and density. In terms of changes in surface temperature of ceramics, we could found that the velocity was fast in the early time of heat transfer until 10 minutes and after that the velocity increased but not very fast. At the elapsed time of 30 minutes, the surface temperature of ceramics increased with the carbonization temperature and rate of mandarin peel addition did not influence the surface temperature. Far - infrared emissivity had no constant tendency in rate of mandarin peel addition, it decreased with increase of carbonization temperature.

• Preventive Nutrition and Food Science
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• v.7 no.1
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• pp.5-11
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• 2002

The comparison of the volatile flavor components from Korean and Japanese Satsuma mandarin (C. unshiu Marcov. forma Miyagawa-wase) peel oils, isolated by cold-pressing, was performed by gas chromatography, mass-spectrometry and gas chromatography-olfactometry (GC-O). Eighty-five volatile components were identified in each oil by GC and GC-MS. Forty-three components were detected in each oil by GC-O. The total amount of monoterpene hydrocarbons was 95.88% (Korean mandarin) and 95.29% (Japanese mandarin). Limonene, ${\gamma}$-terpinene, myrcene and $\alpha$-pinene were the main components of the cold-pressed oils from the both samples. The volatile composition of the Japanese mandarin was characterized by a higher content of sesquiterpene hydrocarbons, especially bicyclogermacrene, $\alpha$-humullene and valencene. The volatile composition of two samples can easily be distinguished by the percentages of aldehydes, ketones and esters, which were found at higher levels in the Japanese mandarin. The sweet and fruity flavor was stronger in the Korean mandarin oil while herbaceous flavor was stronger in Japanese sample. From GC-O data it is suggested that the sweet and fruity flavor of the Korean mandarin resulted from terpinolene and linalool, and the herbaceous note of the Japanese mandarin from $\alpha$-humullene, nepal, ι-carvone and perill aldehyde.

• Journal of the Korean Wood Science and Technology
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• v.51 no.2
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• pp.98-108
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• 2023

In this study, the boards were manufactured according to the mandarin peels addition rate using sawdust and mandarin orange peel. After that, the mechanical properties and density profile of ceramics prepared by conditions through resin impregnation process and carbonization process were investigated. The bending and compression strengths of ceramics tended to increase as the resin impregnation rate increased. When the resin impregnation rate was 70%, the highest values were 8.58 MPa and 14.77 MPa, respectively. Also, the mechanical properties of ceramics according to carbonization temperature showed the highest values at 1,200℃ for bending strength of 11.09 MPa and compression strength of 17.20 MPa. The bending strength and compression strength according to the mandarin peels addition rate showed the highest values at 8.62 MPa and 14.16 MPa, respectively, when the mandarin orange peel addition rate was 5%. The mechanical properties tended to decrease when the addition rate of mandarin orange was increased. The density profile of ceramics showed a similar tendency to the mechanical properties. It can be seen that the density distribution from the surface layer to the center layer is more uniform as the resin impregnation rate and carbonization temperature increase and the mandarin peels addition rate decreases.

• Culinary science and hospitality research
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• v.18 no.1
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• pp.27-39
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• 2012

This study was conducted to examine the characteristics of bread quality as per addition rate of citrus mandarin peel powder since interests and concerns about healthy functional food have been increased in contemporary society. The result of mixogram from Mixograph showed that dough added with 3% citrus mandarin peel powder was suitable for baking quality. Stickiness of dough was decreased with addition of citrus mandarin peel powder. Compared with the controlled group, fermentation rate was decreased as the level of citrus mandarin peel powder increased while pH levels of dough and bread were significantly decreased. The TPA analysis showed that the hardness and adhesiveness levels increased as the level of citrus mandarin peel powder increased whereas springiness, cohesiveness and chewiness became decreased. Crumb fineness and elongation became higher as seen from the result of crumbScan. Volume and specific volume was decreased. The result of preference test presented that crumb color, texture, flavor and taste were the highest in the M3, which showed highest point in overall preference. In conclusion, M3 was the best in preference, taste and texture, thus determined as the optimal rate in association with the addition of citrus mandarin peel powder.

• Microbiology and Biotechnology Letters
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• v.21 no.1
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• pp.13-17
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• 1993

When mandarin orange peel was used for a substrate of citric aCid fermentation by Aspergillus niger, principal enzyme activities were investigated. Not only the activity of polygalacturonase and pectin esterase being capable of digesting pectin and crude fiber of mandarin orange peel. but also that of carboxymethyl cellulase, xylanase and amylase was high. In carbohydrate metabolism, the activity of enzymes related in HMP pathway was higher than that in EMP pathway at the orange peel medium designed hereby rather than synthetic medium. Productivity of citric acid was significantly increased when the activity of citrate synthetase was high and 5imultaneously those of aconitase and NADP-dependent dehydrogenase were low.

• Preventive Nutrition and Food Science
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• v.10 no.3
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• pp.219-223
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• 2005

[ $\beta-Cryptoxanthin$ ] content was determined in Shiranuhi mandarin fruits harvested at monthly intervals from October to February in Jeju Island. Crude carotenoids were extracted from both peel and flesh of Shiranuhi mandarin fruits and analyzed using TLC and HPLC; $\beta-cryptoxanthin$ was indicated the Rr value of 3.2 and retention time of 23 min, respectively. $\beta-Cryptoxanthin$ contents in both peel and flesh were increased gradually as the citrus fruits ripened fully until harvesting season (February). According to the harvesting time, $\beta-cryptoxanthin$ contents in the peel were $0.15\;mg\%\;(October),\;0.28\;mg\%\;(November),\;0.38\;mg\%\;(December),\;1.23\;mg\%\;(January),\;and\;1.71\;mg\%\;(February).$In the flesh, $\beta-cryptoxanthin$ contents were lower than those of peels, having $0.06\;mg\%\;(October),\;0.08\;mg\%\;(November),\;0.19\;mg\%\;(December),\;0.26\;mg\%\;(January),\;and\;0.65\;mg\%\;(February).$ These results demonstrate that $\beta-cryptoxanthin$ in Shiranuhi mandarin fruits accumulated during ripening of the citrus fruits. In particular, the peels had much higher concentrations of $\beta-cryptoxanthin$ and have potential for use as a functional ingredient.

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

• Microbiology and Biotechnology Letters
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• v.17 no.6
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• pp.556-562
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• 1989

The bioconversion of mandarin orange peel press liquor to single cell protein (SCP) by two yeast strains, F-60, and C-7, which were isolated from mandarin orange peel was carried out and compared with that of using Candida utilis IFO 0598. Experiments were directed toward the high yield of biomass and high protein in cultures of the strains mentioned above. Candida utilis IFO 0598, F-60 and C-7 strains were cultivated at 3$0^{\circ}C$, pH 5.2 for 3 days in shaking flasks. The effects of some nutrients on cell growth were studied. Cell mass and protein content per cell mass were increased by addition of urea 1%, KH$_2$PO$_4$ 0.1% and MgSO$_4$ㆍ7$H_2O$ 0.05%, When the F-60 strain cultured under the optimal conditions, cell mass, growth yield and protein content were 41.2g/l, 53.9%, 59.7%, respectively. Cell mass was also increased up to 15% by modifying the fermentation condition on the bench type 20l jar fermentor. Crude fat content (10.3%) of dried C-7 cell was higher than those of C. utilis and F-60, 4.9% and 5.6% respectively. Total protein content of the F-60 strain was 59.7% per dry weight. And we compared their amino acid compositions with that of FAO provisional pattern. In the case of the F-60 strains, amino acid contents such as lysine, leucine and isoleucine were much higher than those of methionine, cystine and tryptophan.