• Journal of Microbiology and Biotechnology
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• v.14 no.6
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• pp.1275-1279
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• 2004

Citron peel oil was extracted from citron (Citrus funas) fruit by steam distillation, and was used as starting material for microbial conversion to synthesize attractive flavor compounds by using Enterobacter agglomerans 6L. E. agglomerans was isolated from citron peel and was able to metabolize the citron peel oil and grew well ($A_{600}:\;3.0$) on the citron peel oil as the sole carbon source. Multiple terpene metabolites were produced by E. agglomerans 6L on M9 salt media with citron oil vapor. The identified bioconversion products from the citron peel oil included trans-2-decenal, octanol, $\delta$­valerolactone, $\gamma$-valerolactone, cryptone, hydroxycitronellol, cuminol, and $\gamma$-dodecalactone.

• Korean Journal of Food Science and Technology
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• v.26 no.5
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• pp.552-556
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• 1994

It was aimed to study the chemical characteristics and volatile compounds of juices extracted by press (PE) and centrifugal extractors (CE). Citrons cut up cross direction were used as samples in PE. Proportion ratio of peel, flesh, and seed of citron were 43.9, 39.4 and 16.7%, respectively. Yield of juice increased with weight to 120g of citron fruit. pH, brix, pulp, oily materials, amino nitrogen and yield of juice extracted by CE were higher than those of juice by PE. Acidity and transmittance of juice extracted by PE were higher than those of juice by CE. Free sugars of citron juice were consisted of fructose, glucose and sucrose. Free sugar contents of juice by CE were twice as much as those of PE. Major volatile compounds of total steam distillation matters of citron juice extracted by PE were dl-limonene, ${\gamma}-terpinene\;{\beta}-farnesene$, sabinene, linalool, ${\beta}-myrcene$ and terpinolene, while those by CE were dl-limonene, ${\gamma}-terpinene$, sabinene, ${\beta}-myrcene,\;{\alpha}-pinene$, linalool and terpinolene. dl-Limonene and ${\gamma}-terpinene$ consisted of $73{\sim}83%$ of total volatile compounds. dl-Limonene of juice by CE increased about 6% that of juice by PE. ${\beta}-Farnesene$ were observed trace in juice by CE but presented in 7% in juice by PE. The results would suggested that chemical characteristics and volatile compounds of citron juice seemed to depend on extraction methods.

• Journal of the Korean Applied Science and Technology
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• v.31 no.2
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• pp.285-295
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• 2014

Citrus essential oil were extracted from citron peel of cultivated in Gohong (CCP) using environmentally friendly supercritical carbon dioxide method. Antioxidant activity and aroma composition of the essential oils extracted by the SC-$CO_2$ method were evaluated by comparing with those extracted by organic solvent method. Fatty acid composition, DPPH scavenging, and antioxidant activity of the oils obtained by different extraction condition of SC-$CO_2$ method were investigated and their antioxidant activities were compared with commercially available lavender, eucalyptus and tea tree oils. As the results, linoleic acid was most abundantly found from CCP oil extracted by the SC-$CO_2$ method and cis-11,144-eicosadienoic acids was second abundantly found. Radical scavenging ability of DPPH was 98% when the concentration of CCP oil was 50 mg/mL. This scavenging ability increased with the increase of oil concentration. On the other hand, flavonoids content (84 mg/100g) of the CCP oil extracted by the SC-$CO_2$ method was slightly higher than that (75 mg/100g) by hexane extraction. The results, obtained from CCP oil by GC-MS, indicated that, among 66 components, the content of terpenes was 55.8% and limonene was 27.3%.

• Korean Journal of Food Science and Technology
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• v.33 no.1
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• pp.12-18
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• 2001

The water-soluble extracts of plants used as tea materials were investigated for their antioxidant activities and active components(total phenolics, ascorbate and selenium). Antioxidant activities of the plant extracts were determined by measuring the changes in both peroxide values(POV method) during storage(36 day, $55^{\circ}C$) and conductivity of soybean oil at $110^{\circ}C$(Rancimat method). Soybean oil without any additive was used as a control. Soybean oil treated with 0.02% BHT was used as a positive control. The test samples were prepared by mixing the plant extracts with soybean oil in 0.02% concentration by weight. The water-soluble extracts of lycii fructus(23 d), oolong tea(23 d), orange peel(23 d), citron(22 d), and apricot(22 d) showed longer induction periods, compared to control(21 d) and BHT(21 d) by POV method. Also water-soluble extracts of oolong tea(12 h), instant coffee(11 h), citron(10 h), cinnamomi cortex(10 h), schizandrae fructus(10 h), lycii fructus(10 h) and apricot(10 h) demonstrated longer induction periods, compared to control(8 h) and BHT(8 h) by Rancimat method. The contents of total phenolic compounds were observed to be high in water-soluble extracts of oolong tea, green tea, black tea, coffee, cinnamomi cortex, and cassiae semen. Ascorbate contents were found to be high in coffee, eucommiae cortex, black tea, ganoderma, cinnamomi cortex, persimmon leaf, chicory, green tea and oolong tea extracts. The selenium contents were not detected in all the extracts. The antioxidative effects of some plant extacts were seemed to be the combined effects of various antioxidant components such as phenolics and ascorbate.