• Journal of the Korean Society of Food Science and Nutrition
• /
• v.39 no.1
• /
• pp.92-98
• /
• 2010

Physicochemical properties, free sugar and volatile flavor compounds of citrons harvested in different cultivation areas, such as Geoje, Goseong, Goheung, and Namhae, were analyzed and compared. Total weight of citron, ranging from 107.97 g to 154.86 g, was significantly different according to producing area. Weight ratio of flesh to whole citron was higher than one of peel in citron produced from Geoje, Goheung-improved, or Namhae-native. Citron size was the highest in Namhae-native citron, but the color of peel was significantly the higher in Goheung-native and its improved citron. In the peel of citron, hardness of citron produced from Geoje was the strongest (2337.13 $cm/kg^2$) whereas citron produced from Goseong (1592.38 $cm/kg^2$) showed the softest hardness. Moisture content was 85.35~87.81 g/100 g and ash was contained below 0.8 g/100 g in flesh of all samples. Although crude fiber content in Geoje ctiron was significantly the lowest in the peel, peel was 1.88~2.60 times higher than flesh. The order of sugar content seemed to be fructose> glucose> sucrose in all citrons, and content of fructose or glucose was higher in peel than flesh. Content of total sugar was 8.44~12.19 g/100 g in citron, and contents of improved citrons from Goheung and Namhae were significantly higher than those of native citrons. In addition, major volatile compounds were dl-limonene (59.52~74.30%) and $\gamma$-terpinene (5.60~7.88%) among 15 kinds of volatile compounds identified from citron peel. These results suggested that physicochemical properties and volatile flavor compounds of citrons showed some differences with regard to producing areas.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.34 no.4
• /
• pp.496-502
• /
• 2005

The chemical properties and nitrite scavenging ability were analyzed which on a citron (Citrus junos) of 4 kinds purchased in different regions [Namhae (I, II), Tongyoung and Koheung] in Korea. Four kinds of organic acids were determined. Citric acid contents in flesh and peel of citron were $10.2\pm0.14\~17.7\pm0.17\;g/100g$. The organic acid content was the highest in citron purchased from Koheung. Total mineral content in citron was in a range of $2,844.3\~4,022.4$ mg/100 g, the potassium content was the highest in the range of $1,332.4\pm2.31\~2,308.5{\pm}3.25\;mg/l00g$. The major free amino acid from citron were proline, asparagine and glutamic acid. And the highest in peel of citron purchased from Tongyoung by 326.9 mg/100 g. However, the kinds and contents of chemical components in citron were somewhat different among various regions. The electron donating ability using DPPH method of citron juice was more than $80.0\%$ at the concentration of $0.1\~0.2\%$ and it was stronger by increased the juice concentration in the reaction mixture. SOD-like activity showed $10.2\pm0.50\~20.1\pm0.77\%$ at the concentration of $0.01\~0.2\%$. The nitrite scavenging ability was pH and sample concentration dependent. It was the highest at the pH 1.2 and more than $73\%$ in $0.1\~0.2\%$ citron juice. On the contrary in all concentration of added citron juice lower than $27\%$ at pH 4.2.

• Food Science and Preservation
• /
• v.10 no.1
• /
• pp.60-64
• /
• 2003

This paper was performed to identify and determine dietary fibers considered as nutracerticals and for pharmaceuticals in Korean fruits, citron, jujube and persimmon. In the pulp and peel of citron, jujube and persimmon, the contents of dietary fiber were determined by the method of AOAC and Van Soest et al. The contents of dietary fiber(DF) in the pulp of citron were 2.61％ of insoluble dietary fiber (IDF) and 1.25% of soluble dietary fiber(SDF) based on wet weight. The contents of DF in the peel of citron were 7.32% of IDF and 0.71％ of SDF. The total pectin contents in the pulp and in the peel of citron were 1.77% and 3.19% respectively. The contents of IDF in the pulp of jujube were 2.98%, SDF 0.91 ％ calculated on wet weight basis. The contents of IDF were 16.88%, SDF 1.53% in the peel of jujube. The contents of DF in the pulp of persimmon were 1.95% of IDF and 0.31 ％ of SDF based on wet weight. The contents of IDF were 15.71 ％, SDF 2.46% in the peel of persimmon. In dietary fibers of Korean fruits, citron, jujube and persimmon, IDE were much higher than SDF and mainly in the pulp. Therefore, they would be good source of dietary fibers.

• Journal of Life Science
• /
• v.16 no.3 s.76
• /
• pp.427-432
• /
• 2006

The possibility of citron seed oil for use as food resources of fats was tested by analyzing the composition of fatty acid and oxidative stability. Oil yield from citron seed was 55.4% in without roasting and 56.8% with roasting. Total mineral content in citron seed without and with roasting were 2,820.33 mg/kg, 1,702.55 mg/kg, respectively. For all citron seed oils tested, the potassium content was found to be the highest among four kinds of minerals detected in this study. Further, major fatty acids detected in the citron seed oils were linoleic acid, oleic acid and palmitic acid. Their relative contents with respect to total fatty acid contents were 77.12% in without roasting and 67.67% in with roasting. This result indicated that roasting the citron seed decreased the acid contents. However, POV (peroxide value) and acid value of citron seed oils were in,.eased significantly with increasing the storage days and heating time. In details, POV was $84.17{\pm}1.68meq/kg$ in without roasting and $76.46{\pm}1.19meq/kg$ with roasting, after 28 days. Acid value was $9.52{\pm}0.27mg\;KOH/g,\;8.35{\pm}0.09mg\;KOH/g$, respectively, After the 48 hours heating at $180^{\circ}C$, POV of citron seed oils was increased by 3.8 times, irrespective of roasting. Yet, acid value increased dramatically 8.3 in without and 6.4 times with roasting, exhibiting its dependence on roasting. During storage time, oxidative stability of citron seed oils was higher than heating.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
• /
• 2002.08a
• /
• pp.167-167
• /
• 2002

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.35 no.3
• /
• pp.294-300
• /
• 2006

This study was carried out to evaluate the possibility of citron seed as industrial resource by analyzing chemical properties and the antioxidant activity. Crude lipid content of citron seed was $35.29{\pm}0.18%$. Total mineral content in citron seed was 1171.64 mg/100g and the potassium content ($637.99{\pm}5.38mg/100g$) was the highest. The contents of total phenols and flavonoids in citrus seed were $24.44{\pm}1.10mg/100g$ and $2.27{\pm}0.18mg/100g$, respectively. The electron donating ability using DPPH, hydroxy radical scavenging activity and SOD-like activity were increased significantly by increased the sample concentration in the reaction mixture. The nitrite scavenging ability was dependent on pH of reaction mixture and sample concentration. It was higher activity at pH 1.2 than pH 4.2. During the storage of soybean oil, the peroxide and acid values of the oil were significantly increased regardless of addition of citron extract. But antioxidant activity of soybean oil added with ethanol extract from citron seed was superior to that of control (sample with no addition) at 16 days of storage.

• Food Science and Biotechnology
• /
• v.17 no.2
• /
• pp.373-378
• /
• 2008

Contents of phytochemicals in citron (Citrus junos Sieb. ex Tanaka) seeds and their effects on antioxidant activities were investigated. Methanol extract of defatted citron seeds contained the highest amounts of total polyphenols followed by 70% ethanol and water extracts. Neohesperidin was the most predominant citrus flavanones in these extracts. The highest amounts of limonoids were found in methanol extract, and this extract was the most efficient in scavenging both DPPH and ABTS radicals. All 3 extracts also exhibited good antioxidant activities against attack of linoleate free radicals on $\beta$-carotene. When methanol extract was sequentially fractionated into ether, ethyl acetate, n-butanol, and water fractions, butanol fraction contained the highest amounts of polyphenols otherwise most of limonoids were concentrated in ethyl acetate fraction. A positive relationship between radical scavenging activities and total polyphenol contents in fractions was observed while antioxidant activity on $\beta$-carotene seemed more related with contents of limonoids and other hydrophobic polyphenols.

• Preventive Nutrition and Food Science
• /
• v.18 no.3
• /
• pp.196-202
• /
• 2013

Citron seed extracts (CSEs) were made using distilled water (CSEW), ethanol (CSEE), and n-hexane (CSEH), to measure the total polyphenol contents, DPPH and ABTS radical scavenging activities, and anti-complementary activity. The total polyphenol content was observed the highest in CSEE (188.71 ${\mu}g/mL$), and occurred in the following order: CSEE>CSEW (141.11 ${\mu}g/mL$)>CSEH (26.19 ${\mu}g/mL$) at 10 mg/mL. CSEE (63.56%) and CSEW (56.61%) showed significantly higher DPPH radical scavenging activities when compared with CSEH (28.57%). ABTS radical scavenging activities of CSEE (45.53%) and CSEW (40.02%) were also observed to be higher, whereas CSEH did not show ABTS radical scavenging activity. Anti-complementary activity of CSEE (26.85%) showed a greater activity than that of CSEW (7.84%) at 1,000 ${\mu}g/mL$. Limonin and nomilin contents had the highest values (1.882% and 2.089%) in CSEE, and with 0.327% and 0.139% in CSEW; however, CSEH showed relatively very low values at 0.061% and 0.026%, respectively. Among the CSEs tested, CSEE as a by-product from citron may provide an important source of dietary antioxidant compounds with rich polyphenol and limonoid contents, and immunopotentiating activity, including the complement activation factor.

• Food Science and Preservation
• /
• v.13 no.3
• /
• pp.357-362
• /
• 2006

In other to produce vinegar min citron (Citrusu junos), acetic acid bacteria were selected from several conventional vinegars, and total 25 acetic acid producing bacterial strains were isolated. Among the isolated strains, a strain was selected from the medium which showed the highest productivity of acetic acid. The strain was identified as Acetobacter sp V-16 and it cultural characteristics were also investigated in the medium with citron juice. Optimum temperature for the growth of Acetobacter sp. V-16 was $30^{\circ}\C$. The medium containing 2% acetic acid, 5% ethanol, and 30% citron juice was suitable for acetic acid production with Acetobacter sp. V-16. The acidity of culture medium was reached to 6.8% after 10 days shaking cultivation at $30^{\circ}\C$.

• The Korean Journal of Food And Nutrition
• /
• v.20 no.1
• /
• pp.34-39
• /
• 2007

Microbiological and sensory evaluations were performed on bio-soybean paste treated with citron and immobilized microorganisms from Bifidobacterium animalis DY 64. Aerobic microorganisms in bio-soybean paste stored at room temperature, initially, significantly increased(p<0.05) during 15 days of storage. However, a subsequent, slight decrease(p<0.05) was observed after 30 days. Food pathogens such as Salmonella spp., Staphylococcus aureus and Escherichia coli were not detected in the bio-soybean paste throughout the storage days. Bio-soybean paste treated with 3.0${\sim}$7.0% citron combined with 10% immobilized microorganisms increased consumer acceptance relating odor and flavor. In conclusion, soybean paste treated with citron and immobilized microorganisms from Bifidobacterium animalis could be used as a viable health food with respect to enhancing consumer acceptance.