• Journal of the East Asian Society of Dietary Life
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• v.16 no.2
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• pp.174-179
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• 2006

This study was carried out to investigate the possible for utilization of garbage in pig feed by investigating the functional characteristics of pork from pigs fed tangerine-peels. The samples consisted of the pork loin from pigs not fed with tangerine-peel (control), the pork loin fed with 3% and 5% tangerine-peel during growing and finishing period (TP-1), and fed with 6% and 10% tangerine-peel during growing and finishing period (TP-2) there is no respective comparison here. The pH, VBN content TBARS value, bacterial counts, surface color, water holding capacity, loss degree and rheological properties of the samples were determined by physicochemical properties, and the sensory scores were evaluated. The pH, TBARS value, surface color, water holding capacity and loss degree were not different among the samples, but the VBN content and bacterial counts of TP-1 and TP-2 were significantly lower than those of the control (p<0.05). The hardness, springiness, cohesiveness, gumminess and chewiness, taste, aroma, tenderness and juiciness were not different among the samples, but the shear force value and palatability of TP-1 were the highest among the samples (p<0.05).

• Korean Journal of Food Science and Technology
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• v.28 no.2
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• pp.371-377
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• 1996

Potential health promoting effects such as antiallergic, anti-inflammatory, antiviral, anticancer and anticarcinogenic properties have been ascribed to citrus flavonoids. Dietary fibers have also been used as functional food components due to the various beneficial physiological activities. Two kinds of flavonoids, naringin and hesperidin, were identified both in the pulp and in the peel of Korean tangerine. The contents of naringin and hesperidin in the pulp were 2.95 mg/100 g and 0.53 mg/100 g, respectively. However, the contents of naringin and hesperidin in the peel were much higher (10.77 mg/100 g and 38.90 mg/100 g) thanthose of two identified flavonoids in the pulp. The content of soluble dietary fiber (SDF) in the pulp of tangerine was 1.90%, insoluble dietary fiber (IDF) 0.37%, and total dietary fiber (TDF) 2.27% based on wet matter, respectively. The content of SDF was 1.09%, IDF 4.77% and TDF 1.86% in the peel of tangerine. The total pectin content was 1.53% in the pulp and 0.94% in the peel of tangerine. The peel of Korean tangerine, a by product in tangerine processing, would be a good source for the production of naringin, hesperidin and pectin.

• Journal of the East Asian Society of Dietary Life
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• v.26 no.3
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• pp.250-259
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• 2016

This study was carried out to investigate the effects of tangerine (Citrus unshiu) peel on the physicochemical properties and sensory score of pork patties. Four types of pork patties were evaluated: T0 without tangerine peel, T1 with 0.3% tangerine peel, T2 with 0.7% tangerine peel, and T3 with 1.0% tangerine peel. The pH level changed based on the storage period. The pH levels of T2 and T3 were lower than those of T0 and T1 during storage. The L-value (lightness) of samples did not significantly change, and showed no significant difference during storage. The a-value (redness) decreased during storage, and that of T0 was lowest among the samples. The b-values of samples did not significantly change, whereas that of pork patties with tangerine peel was higher than that of pork patty without tangerine peel. The TBARS increased with a longer storage period, and the values for T0, T1, T2 and T3 were 0.82, 0.32, 0.26 and 0.26 mg/kg, respectively, after 10 days of storage. DPPH radical scavenging activity decreased with a longer storage period, and those of T2 and T3 were significantly higher than those of T0 and T1. The VBN contents of T0 and T1 increased with a longer storage period, and that of T0 was highest among the samples. Water holding capacity decreased, and cooking loss increased, whereas those of samples did not significantly change during storage. Hardness and chewiness increased while springiness and cohesiveness decreased during storage. The results of this study show that tangerine peel is a natural antioxidant, due to its antioxidative activity and does not affect physical characteristics. Therefore, addition of 0.7% tangerine peel may be suitable for manufacture of patties.

• Food Science and Preservation
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• v.23 no.1
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• pp.117-126
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• 2016

This study was performed to provide information for improving the quality characteristics of tangerine peel Soksungjang. Tangerine peel Soksungjangs were prepared with 10% tangerine peel powder by addition of different koji such as Rhizopus oligosporus (RS, RTS) and Aspergillus oryzae (AS, ATS). As a result, the moisture content was not changed and crude protein content decreased during fermentation in all samples. The pH of RS (Soksungjang manufactured with Rhizopus oligosporus koji) and RTS (Soksungjang manufactured with Rhizopus oligosporus koji and 10% tangerine peel powder) was not changed, whereas pH of AS (Soksungjang manufactured with Aspergillus oryzae) and ATS (Soksungjang manufactured with Aspergillus oryzae koji and 10% tangerine peel powder) decreased rapidly after 10 days of fermentation. The acidity values of all the samples increased during fermentation. The major free sugars were glucose, fructose, and maltose; while, the major organic acids were citric acid, succinic acid, acetic acid, and lactic acid in all the samples. The amino nitrogen content and protease activity were highest in the AS and ATS. Conversely, the reducing sugar content and ${\alpha}$-amylase activity were highest in the RS and RTS. The major free amino acids in all samples were glutamic acid, lysine, leucine, and arginine. Sixty kinds of volatile flavor compounds were identified from all samples; the majority of which were 21 alcohols, 14 hydrocarbons, 5 esters, and others identifies as acids, ketones, and aldehydes.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.7
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• pp.555-561
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• 2019

This study analyzed the shipbuilding structure of House Tangerine over a ten day period and according to the month in Jeju. By estimating and analyzing the price flexibility function of House Tangerine, the aim was to determine if the shipment control can stabilize and increase the incomes of House Tangerine farmers and derive policy implications. The greatest decline in the coefficients of the ten-day price flexibility occurred in the equations from early June to late July. Therefore, the shipment control of House Tangerine is required more during early June and late July. The coefficient of DUM_Q, indicating the year in which the quality of House Tangerine is somewhat deteriorated, was statistically significant and had a (-) sign. The coefficients of DUM_SUK, indicating the year in which Chuseok (Korean Thanksgiving Day) was in October, was statistically significant and had a (-) sign in the middle and late October. The greatest decline in the coefficient of monthly price flexibility function occurred in July, June, and September. Therefore, shipment control is required more in July, June, and September. The (-) signs of the coefficients of DUM_Q and DUM_SUK suggest that the need for shipment control is more important when the quality is less than better quality and that the necessity of shipment control is required more when Chuseok is in October, respectively.

• Weed & Turfgrass Science
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• v.6 no.4
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• pp.350-354
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• 2017

Conyza canadensis is the weed species which most frequently develops resistance to glyphosate in many agricultural crop fields. The continuous use of glyphosate has resulted in the spontaneous occurrences of resistant biotypes. This research was conducted to investigate the response of suspected C. canadensis biotypes to glyphosate. Seeds of C. canadensis were collected from 18 sites in tangerine orchards in Jeju province of Korea. In the preliminary screening, 6 resistant and 12 susceptible biotypes were found at the recommended glyphosate rate ($3.28kga.i.ha^{-1}$). The susceptible biotypes were completely killed at the field application rate whereas the resistant biotypes were initially injured but recovered 14 days after glyphosate application. This is the first case of glyphosate resistance found in Korea despite the national ban on genetically modified glyphosate tolerant crops cultivation. Extended monitoring should be conducted to understand how widely spread the glyphosate resistant C. canadensis is and to estimate the severity of this weed problem in the tangerine orchards of Korea.

• Korean Chemical Engineering Research
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• v.53 no.6
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• pp.717-722
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• 2015

D-limonene included in citrus fruits is obtainable to extract essential oil as well as separate the oil ingredient. Soxhlet extraction, a type of SDE (Simultaneous steam Distillation and solvent Extraction), was used to extract limonene from tangerine peel. HPLC analysis was performed to quantify extracted d-limonene by using reversed-phase HPLC column. Results of HPLC analysis showed that the optimal extraction time was 2 hours in any solvent, and the extracted amounts of d-limonene in tangerine peel (per g tangerine peel) were 7.77 mg, 0.49 mg, and 0.28 mg in ethyl alcohol, n-hexane, and ether. Because yield was the highest in using ethyl alcohol as a solvent, polarity is stronger factor to effect on yield of extraction than boiling point.

• Preventive Nutrition and Food Science
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• v.6 no.2
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• pp.122-125
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• 2001

A potential mechanism through which the jujube extract might produce a cholesterol-lowering effect was compared with that of tangerine peel extract in vivo. Two extracts were prepared using ethanol. Male rats were fed a high cholesterol (1%, w/w) lab chow with jujube extract (1.2%) or tangerine peel extract (6.3%, w/w) for 3 weeks. Activities of hepatic HMG-CoA reductase (289.6$\pm$12.9 and 296.7$\pm$11.6 nmole/min/mg vs. 347.9$\pm$17.5 nmole/min/mg) and ACAT (554.8$\pm$18.2 and 451.7$\pm$19.4 nmole/min/mg vs. 602.6$\pm$21.4 nmole/min/mg) were significantly lowered by both supplements compared to the control group. These two supplements also substantially reduced the concentrations of plasma cholesterol (103.3$\pm$15.9 and 101.6$\pm$19.4 mg/dL vs. 141.6$\pm$18.1 mg/dL) and triglyceride (61.3$\pm$5.5 and 55.5$\pm$3.9 mg/dL vs. 96.0$\pm$4.2 mg/dL). The inhibition of HMG-CoA reductase resulting from the supplementation of jujube or tangerine extracts could count for the reduction in plasma cholesterol. Accordingly, lipid-lowering action of both supplements appears to be similar in high-cholesterol fed rats.

• Journal of the East Asian Society of Dietary Life
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• v.19 no.3
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• pp.363-368
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• 2009

In this experiment, three different diets were produced to investigate the effects of Jeju native chicken meat, from chickens that were fed a tangerine by-product, on physiological activities in rats. The first diet did not contain any chicken (TS), the second diet contained 10% chicken that had not been fed the tangerine by-product (T0), and the third diet contained 10% that had been fed the by-products (T1). These diets were provided to 11-week-old male rats for four weeks. Weight gain, feed intake, feed efficiency, liver, kidney, and epididymis fat weights were not significantly different among the TS, T0, and T1 groups. Total lipid, triglycerides, and cholesterol levels in the liver were significantly lower in T0 and T1 than in TS (p<0.05). And total lipid, phospholipid, triglycerides, total cholesterol, HDL-cholesterol, DL+VLDL-cholesterol, HDL-cholesterol/total cholesterol, and atherogenic index levels in the blood serum were similar between T0 and T1, which did not present any significant differences. The feed containing the tangerine by-product did not cause any statistically significant differences in serum protein, glucose, or hemoglobin. Finally, T0 and T1 showed similar trends in terms of $\gamma$-GTP, ALT, AST, and ALP activities, which again did not present any statistically significant differences.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.6
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• pp.212-217
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• 2020

The purpose of this study was to analyze the volatility and properties of a time series for tangerine prices in Jeju using the GARCH model of Bollerslev(1986). First, it was found that the time series for the rate of change in tangerine prices had a thicker tail rather than a normal distribution. At a significance level of 1%, the Jarque-Bera statistic led to a rejection of the null hypothesis that the distribution of the time series for the rate of change in tangerine prices is normally distributed. Second, the correlation between the time series was high based on the Ljung-Box Q statistic, which was statistically verified through the ARCH-LM test. Third, the results of the GARCH(1,1) model estimation showed statistically significant results at a significance level of 1%, except for the constant of the mean equation. The persistence parameter value of the variance equation was estimated to be close to 1, which means that there is a high possibility that a similar level of volatility will be present in the future. Finally, it is expected that the results of this study can be used as basic data to optimize the government's tangerine supply and demand control policy.