• 한국축산식품학회지
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• 제32권5호
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• pp.618-626
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• 2012

Citrus (Citrus unshiu S. Marcoy) industry by-products were used as a source of dietary fiber, and the effects of dietary fiber extracted from citrus peel on the proximate composition, pH, color, protein solubility, cooking loss, emulsion stability, and apparent viscosity of a chicken emulsion in model systems were examined. Chicken emulsions were prepared by adding citrus peel fiber at four different concentrations (1, 2, 3, and 4%). The apparent viscosity, redness, and yellowness of the chicken emulsion with citrus peel fiber were higher than those of the control (p<0.05). The lightness values of the chicken emulsions were lower in treatments containing citrus peel fiber (p<0.05). Furthermore, moisture content, cooking loss, and emulsion stability of the chicken emulsion with 1-2% citrus peel fiber were higher than those of other treatments (p<0.05). Fat content was lower in the treatments with added citrus peel fiber than that in the control (p<0.05). Chicken emulsions with added citrus peel fiber had improved quality characteristics, and the best results were obtained for the chicken emulsion with 2% added citrus peel fiber.

• 복식문화연구
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• 제22권3호
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• pp.431-439
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• 2014

This research verified the usefulness and practicality of citrus peel extract as a natural dye. This study dyed cotton, silk, and cotton/mulberry fiber blended fabrics using citrus peel extract, and measured the dyeability and functional property to verify their usefulness and practicality. The dyeing affinity of the citrus peel extract was measured by dyeing under alkaline conditions to determine the temperature and time for optimal dyeing conditions of the solution. The results show that a temperature and time of $60^{\circ}C$ and 30 minutes were optimal for dyeing cotton fabrics with citrus peel extract, $50^{\circ}C$ and 60 minutes for silk fabrics, and $60^{\circ}C$ and 60 minutes for cotton/mulberry fiber blended fabrics, respectively. In addition the results of measuring the color fastness of the cotton, silk, and cotton/mulberry fiber blended fabrics dyed with the citrus peel extract show that the color fastness was superior for washing, friction, sweat, and water. However, the color fastness for sunlight appeared to be slightly weak. In addition, it was found that fabric dyed with the citrus peel extract showed partial antimicrobial properties. The antimicrobial property appeared the greatest in the silk fabric. The cotton/mulberry fiber blended fabrics had 90% or more Staphylococcus aureus present, but the antimicrobial properties were not high in the cotton fabric. Additionally, the heavy metal content, which is harmful to the human body, appeared to be lower than standard figures, so the dye was found to be innocuous to humans. Therefore, when the results of this study are put together, citrus peel extract is sufficiently useful and practical as an ingredient for a natural dye. Moreover, there is ample possibility to develop citrus peel dyed fabrics as environmentally friendly fashion materials.

• Journal of Microbiology and Biotechnology
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• 제34권6호
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• pp.1206-1213
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• 2024

Citrus fruits offer a range of health benefits due to their rich nutritional profile, including vitamin C, flavonoids, carotenoids, and fiber. It is known that unripe citrus has higher levels of vitamin C, dietary fiber, polyphenols, and flavonoids compared to mature fruits. In this study, we assessed the nutritional components of unripe citrus peel and pressed juices, as well as their anti-obesity potential through the modulation of adipocyte differentiation and the expression of adipogenesis-related genes, specifically PPARγ and C/EBPα, in 3T3-L1 preadipocytes. Our analysis revealed that unripe citrus peel exhibited elevated levels of fiber and protein compared to pressed juice, with markedly low levels of free sugar, particularly sucrose. The content of hesperidin, a representative flavonoid in citrus fruits, was 3,157.6 mg/kg in unripe citrus peel and 455.5 mg/kg in pressed juice, indicating that it was approximately seven times higher in unripe citrus peel compared to pressed juice. Moreover, we observed that the peel had a dose-dependently inhibitory effect on adipocyte differentiation, which was linked to a significant downregulation of adipogenesis-related gene expression. Thus, our findings suggest that unripe citrus possesses anti-obesity effects by impeding adipogenesis and adipocyte differentiation, with the peel demonstrating a more pronounced effect compared to pressed juice.

• 한국조리학회지
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• 제23권3호
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• pp.158-165
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• 2017

This study examined the components and physicochemical properties of citrus peel as a natural health food source by measuring the general and antioxidative contents of citrus peel. Total contents of carbohydrates, crude protein, crude lipid, and ash were 72.1%, 6.6%, 1.3%, and 3.7% respectively. Caloric content of citrus peel was 334.5 kcal, while total dietary fiber was 32.1%. Regarding mineral contents, Ca was the most abundant mineral, followed by K, Mg, and P. Total phenol contents of the 70% ethanolic extracts of citrus peel was $66.4{\pm}8.74mg\;GAE/g$. Total flavonoid contents of the 70% ethanolic extracts were $14.4{\pm}3.28mg\;RE/g$. The antioxidative activities of citrus peel were significantly increasing in a dose dependent manner on DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging, ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt) radical scavenging, FRAP(ferric reducing antioxidant power) activity and reducing power. Therefore, the general nutrients and other antioxidant bioactive materials in citrus peel proved that citrus peel possesses a high potential materials as a nutritious food.

• Bulletin of the Korean Chemical Society
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• 제25권2호
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• pp.271-279
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• 2004

The aroma component of Hallabong peel has been characterized by GC-MS with two different extraction techniques: solid-phase trapping solvent extraction (SPTE) and headspace solid-phase microextraction (HSSPME). Aroma components emitted from Hallabong peel were compared with those of other citrus varieties: lemon, orange and grapefruit by SPTE and GC-MS. d-Limonene (96.98%) in Hallabong was the main component, and relatively higher peaks of cis- ${\beta}$-ocimene, valencene and -farnesene were observed. Other volatile aromas, such as sabinene, isothujol and ${\delta}$-elemene were observed as small peaks. Also, principal components analysis was employed to distinguish citrus aromas based on their chromatographic data. For HSSPME, the fiber efficiency was evaluated by comparing the partition coefficient ($K_{gs}$Kgs) between the HS gaseous phase and HS-SPME fiber coating, and the relative concentration factors (CF) of the five characteristic compounds of the four citrus varieties. 50/30 ${\mu}$m DVB/CAR/PDMS fiber was verified as the best choice among the four fibers evaluated for all the samples.

• 한국조리학회지
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• 제23권8호
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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.

• 방사선산업학회지
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• 제4권3호
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• pp.215-219
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• 2010

We have subjected to gamma-irradiation to citrus buds and then grafted onto mature citrus tree. Mutant citrus branch lines have been induced. As a result of first selection, we found the several mutant lines showing interesting phenotypes such as higher sugar content. We have selected several branches showing good qualities such as higher sweetness and/or lower acidity. Some branch lines showed over $13^{\circ}Brix$ sugar content and below 0.9% acidity. Other mutant branch lines showed the changes of shape, size, peel thickness, and fiber contents or distribution of fruits. The results suggest that gamma-irradiation is an effective tool for induction of citrus mutant lines.

• 한국식품과학회지
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• 제31권6호
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• pp.1503-1510
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• 1999

영귤을 이용한 다양한 가공제품의 개발을 위한 기초자료로 영귤의 과피와 과즙을 분리하여 수확시기별 (9월 3일부터 11월 8일까지 약 20일 간격) 및 산지별(서귀포, 제주시)에 따른 물리화학적 성분특성을 조사하였다. 영귤의 평균중량은 서귀포산이 제주시산보다 2배 이상이었으며, 평균직경도 10mm 이상 큰 것으로 나타났다. 과피의 수분함량은 $74.0{\sim}78.7%$로 성숙함에 따라 높아지는 경향을 보였으나 과즙에서는 $90.1{\sim}91.9%$ 수준으로 차이를 보이지 않았다. 환원당은 과피와 과즙에서 모두 9월 3일에서 11월 8일 사이에 약 2배 가량 증가하였고, 조섬유는 과피와 과즙에서 모두 감소하는 경향을 나타냈으며 조단백질과 회분의 경우, 과피에서는 감소하는 경향을 나타냈으나 과즙에서는 뚜렷한 차이를 나타내지 않았다. pH와 비타민C는 성숙이 진행됨에 따라 과피 및 과즙에서 다소 감소하는 경향을 나타내었다. 또한 과즙의 경우 중요한 품질인자가 되는 transmittance는 9월 20일에서 10월 13일 사이에 급격히 증가하였다. 그리고 유리당의 함량은 과피의 경우 9월 3일에서 11월 8일까지 2배 가량 증가한 반면에 과즙은 4배까지 증가하였다. 무기질의 경우 과피에는 Ca과 K이 다량 함유되어 있었고 과즙에는 K이 가장 큰 비율로 함유되어 있었으며 각 무기질의 함량은 과실이 성숙함에 따라 감소하는 것으로 나타났다.

• Journal of Nutrition and Health
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• 제36권6호
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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.

• 한국식품과학회지
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• 제28권2호
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• pp.371-377
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• 1996

감귤류에 존재하는 플라보노이드는 항알러지성, 항염성, 항바이러스성, 항암성 등의 활성을 갖고 있는 것으로 알려져 있다. 또한 감귤 유래 식이섬유도 다양한 생리조절 기능때문에 기능성 식품소재로 이용되어 왔다. 한국산 조생종 감귤의 과육과 과피에 나린진과 헤스페리딘이라는 두종류의 플라보이드가 존재하고 있는 것으로 분석되었다. 과육부의 나린진과 헤스폐리던 함량은 각각 100g 당 2.95 mg, 6.53 mg이었으며, 과피에서는 과육부보다 함량이 높아 10.77mg, 38.90mg으로 나타났다. 과육부의 가용성 식이섬유, 불용성 식이섬유, 총식이섬유량은 신선물 기준으로 1.90%, 0.37%, 2.27%이었으며, 과피에는 각각 1.09%, 4.77%, 5.86% 함유되어 있는 것으로 분석되었다. 총펙틴 함량은 과육에 1.53%, 과피에 0.94%존재하는 것으로 나타났다.