• The Korean Journal of Community Living Science
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• v.16 no.1
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• pp.15-20
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• 2005

To identify and compare the nutritional composition of different kinds of citrus, three examples (Citrus fruit, Kumquat, and Hallabong) were taken from Jeju island in Korea at the same time and their nutritional compositions were measured using the Association of Official Analytical Chemists (AOAC) method. The proximate components (moisture, protein, fat, fiber, ash, and carbohydrates), mineral and vitamin contents were measured. The Nutrient composition revealed some significant differences among the Citrus. The Citrus fruit has more moisture and Fe content than those of the Kumquat. The Kumquat contained more ash, Ca, Na, Mg, Zn, Vitamin A, and B1 than the other Citrus specimens, while the Hallabong had the most protein and Fe. However, fiber, K, Vitamin B₂, C and niacin contents were not significantly different among the specimens. The results demonstrate that the three kinds of citrus used in this study have different nutritional compositions, but they can all be used as a good food for supplementation of K, vitamin A and C. We hope the nutritional analysis of Citrus specimens will be helpful in meeting the consumer's interest in these Citrus, and increase the export of our Citrus produce.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.42 no.5
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• pp.47-53
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• 2010

It is important to utilize the citrus sludge in terms of the reuse of waste materials in the manufacture of corrugated medium. Especially, the mandarin industry occupies the first place in Jeju province. In this paper, the application of citrus sludge mixed with KOCC recycled fibers into the manufacture of corrugated medium was studied. The citrus sludge was acidic in pH value. Also, the constituents of citrus sludge contain some short fibers, fines, and mucus which contain flavonoids, pectins and so on. In papermaking application, these components cause some troubles like foams, bad smell, fouling on the paper machine, and bad drainage and web breaks of wet web. The strength properties of handsheets prepared from KOCC and citrus sludge was decreased, compare to handsheets made of only KOCC. To compensate the problems on strength properties, some kinds of additives were tried to apply into papermaking wet-end system in laboratory scale. As a result, mixing conditions of alum, starch and anionic additives showed the best options in the recovery of strength properties and formations of corrugated medium.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.4
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• pp.529-535
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• 2007

The nutritive values of leaves of Citrus grandis, Citrus aurantium, Citrus oranges, Citrus limon, and Citrus deliciosa were evaluated by chemical composition and in vitro gas production techniques. There were significant (p<0.001) differences among citrus species in terms of chemical composition. Crude protein (CP) contents ranged from 123.0 to 148.3 g/kg DM. Neutral detergent fibre (NDF) and acid detergent fibre (ADF) contents were varied with species in the range 219.4-355.4 and 215.0-278.8 g/kg DM respectively. Condensed tannin (CT) contents were ranged from 5.9 to 10.2 g/kg DM. The PEG addition significantly (p<0.001) increased the gas production and some estimated parameters of citrus tree leaves. However, species showed variable responses to polyethylene glycol (PEG) treatment. There were also significant (p<0.001) differences among species in terms of gas production and estimated parameters. The OMD and ME contents of citrus leaves without PEG supplementation were ranged from 66.5 to 73.3% and 9.8 to 10.9 MJ/kg DM respectively. The improvement in gas production, organic matter digestibility (OMD) and metabolizable energy (ME) with PEG emphasized the negative effect of tannins on digestibility. The increase (%) in the estimated OMD and ME contents ranged from 5.5 to 9.8% and 5.7 to 10.2% respectively. All citrus tree leaves studied in this experiment have potential nutritive values indicated by high crude protein content, OMD, ME and low fiber values.

• Journal of Nutrition and Health
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• v.29 no.7
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• pp.738-746
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• 1996

In order to anticipate the physiological function of dietary fibers, glucose and bile acid retarding effects were experimented by using in vitro methods based on dialysis for commercial fibers and dietary fiber residue of food samples. The glucose retarding effect in commercial fibers increased in the order of alginic acid, guar gum, CM-cellulose, citrus pectin > apple pectin > $\alpha$-cellulose and the effect in food fiber residues increased in the order of sea mustard > Korean cabbage, apple > rice bran, barley, soybean, and tangerine. The bile acid retarding effect in commercial fibers increased in the order of citrus pectin, guar gum > CM-cellulose, alginic acid > apple pectin > $\alpha$-cellulose and the effect in food fiber residues increased in the order of barley, rice bran > sea mustard > tangerine > Korean cabbage, soybean > apple. The higher the retarding effect of glucose movement through the dialysis membrane, the more effective the control of the human blood glucose level. As the retarding effect of bile acid movement across the dialysis membrane increased, the human serum cholesterol level correspondingly reduced. Consequently these in vitro methods can be used as a preceding test before undertaking animal and human experiments to predict the physioloical effects of fiber residues from diverse food samples as well as commercially refined fibers.

• Proceedings of the Korean Fiber Society Conference
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• 2007.11a
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• pp.379-380
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• 2007

• Analytical Science and Technology
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• v.16 no.4
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• pp.277-282
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• 2003

The amount of water for the cultivation of citrus is different based on the growing period. The effect of water stress induces to enhance of sugar accumulation in citrus. The water content in the leaves of citrus can be a index for watering during cultivation. The purpose of this study is to determine the water content of citrus leaves non-destructively by using near infrared spectroscopy (NIRS). Citrus leaves were prepared from 'Okitsu' Satusuma mandarin leaves (Citrus unshiu Marc.) ranging from 20.80 to 69.98% of water content by loss on drying method, and NIR reflectance spectra of citrus leaves were acquired by using a fiber optic probe. It was found that the variation of absorbance band 1450 nm from OH vibration of water depending on the water content change. Partial least squares regression (PLSR) was applied to develop a calibration model over the spectral range 1100-1700 nm. The calibration model predicted the water content for the validation set with a standard errors of prediction (SEP) of 0.97%. In order to validate the developed calibration model, routine analyses were performed using independently prepared citrus leaves. The NIR routine analyses showed good results with those of loss on drying method with a SEP of 0.81%. The rapid and non-destructive determination of the water content in citrus leaves was successfully performed by portable NIR system.

• Food Science and Preservation
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• v.8 no.4
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• pp.442-448
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• 2001

The citrus juice obtained from Jeju mandarines, Citru unshiu, was filtered to remove 20% of its original volume through the hollow fiber ultrafiltration systems equipped with various pore sizes of membranes. As the results of ultrafiltration, the contents of total acids, ascorbic acid, ascorbic acid, free sugars and neohesperidin in retentate showed the tendencies of gradual decreases with the increase of membrane pore sizes from 10K to 100K daltons, but tendencies were inverted when the membrane with 500k was used. The changes of color, soluble solids, total nitrogen, amino-nitrogen, naringin and hesperidin were not consistent with the membrane pore size. Considering all the data obtained using various pen sizes of membranes, the filtration system with NMWC 500K daltons was the most effective to produce citrus juices with hither quality.

• Culinary science and hospitality research
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• v.15 no.4
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• pp.18-27
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• 2009

In oder to investigate the cooking potentiality for Japanese dishes using domestic Citrus sudachi cultivated in Jeju, sauce making, grilling, steaming, pot-boiling, frying, and sushi/sashimi making were prepared and evaluated. The content of moisture, fat, protein, fiber, carbohydrate, and ash in the Citrus sudachi juice were 91.5%, 0.21%, 0.62%, 0.23%, 5.32%, 0.25%, receptively. The acidity, $^{\circ}Brix$ 7.4, pH of sudachi juice were 5.09%, $^{\circ}Brix$ 7.4, pH 3.02, receptively. In Japanese cuisine, it was possible for sudachi juice to replace vinegar in dressing for raw vegetables, and various sauce for fish dishes such as ponzu, wafu dressing, sushi vinegar and tentsuyu. Among thirteen kind of Japanese cuisine with sudachi juice, broiled mackerel, barbecue, tobinmusi showed high acceptability in the sensory evaluation. The most acceptable recipe of vinegar soy sauce was considered by the ratio of 4(soy sauce) : 3(sudachi juice). In addition, it is possible to use processed good made from the Citrus sudachi juice as all kind of Japanese cooking seasoning. Therefore, imported lemons or limes might be replaced with domestic citrus sudachi cultivated in Jeju.

• Journal of Nutrition and Health
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• v.31 no.4
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• pp.809-822
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• 1998

Retarding effects of the dietary fibers from persimmon peels (PTDF ; total dietary fibers, PIDF ; insoluble dietary fibers, PSDF ; soluble dietary fibers) and dried jujubes (JTDF ; total dietary fibers, JIDF ; insoluble dietary fibers, JSDF ; soluble dietary fibers) on glucose, bile acid and cadmium transport were evaluated by in vitro dialysis sack method. These effects were compared with those of commerical citrus pectin, CM-cellulose (CMC) and $\alpha$-cellulose. Yields of PTDF, PIDF and PSDF on wet weight basis were 14.04% , 11.61%, 1.76%, respectively, and those from dried jujubes were 14.80%, 9.98% and 2.80%, respectively. The amount of soluble fibers in JTDF was higher than PTDF. Soluble fibers had the retarding effects on glucose transport but insoluble fibers did not have. CM-cellulose showed the greatest retarding effect, which was followed by citrus pectin and JSDF. Among the soluble fibers, PSDF had the lowest retardig effect. Retarding effect of TDF was dependent upon the amount of SDF in TDF. Regarding bile acid dialysis , insoluble dietary fibers as well as soluble dietary fibers showed the retarding effects, among which JSDF had the greatest retarding effects, among which JSDF had the greatest retarding effect, followed by citrus pectin. Among the extracted fibers, dietary fibers from dried jujubes were more effective than these from persimmon peels, and SDF seemed to show higher retarding effects than IDF and TDF. On cadmium transport retardation , all dietary fibers except $\alpha$-cellulose had the retarding effects and PSDF showed the greatest effect which was followed by PIDF and CMC, The extracted fibers showed higher retarding effect on Cd transport than glucose and bile acid transport, and dietary fibers from persimmon peels showed higher retarding effects than those from dried jujubes.

• 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.