• Journal of Food Hygiene and Safety
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• v.20 no.3
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• pp.134-140
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• 2005

Boiling point and distillation range, melting range, and identification methods in general test method of Korea, Japan, Joint FAO/WHO Expert Committee of Food Additives (JECFA), and USA on chemical food additives were compared. Boiling point of propylene glycol was indicated as boiling point in Korea, distillate in Japan, distillation range in JECFA and USA, and its value was up to the standard. Distillation range of propionic acid was indicated as distillate in Korea and Japan, distillation range in JECFA and USA, and its value was up to the standard. There is no standard on distillation range of isopropyl alcohol in Japanese method. Test method of melting range on synthetic food additives was identical in all organizations, and there are 28 items to which this test method applies in Korean Food Additives Code. The standards on molting range of D-mannitol were different in various organizations, and in USA method there are no standards to which L-ascorbic acid, calciferol, and fumaric acid apply. Synthetic food additives performing the identification test were 251 items in Korean Food Additives Code, but there are no items to which manganese, glycerophosphate, bromate, thiosulfate, and bromide apply. Calcium benzoate was dissolved by heating in benzoate test and we could not identify the citrate in ferric citrate by method (2) of Korea and Japan. Identification test methods for ammonium, lactate, magnesium, copper, sulfate, phosphate, and zinc were identical in all organizations, and these could be identifed by current identification methods.

• Korean Journal of Food Science and Technology
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• v.23 no.1
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• pp.76-80
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• 1991

To isolate oryzanol from the by-product of rice bran oil refinning, experiment of solvent fractional crystallization was carried out at various conditions with the dark oil obtained by acidifying the soap stock of micella refinning process and the pitch obtained from vacuum distillation of the dark oil. The impurity interfering the crystallization process such as waxes can be removed as precipitates by cooling the 1:1 mixtrue of acetone and dark oil to $0^{\circ}C$, From the dewaxed dark oil, oryzanol concentrate with 51.3% purity was obtained by fractional crystallization at$0^{\circ}C$ with the mixture of 8 part volume of hexane and 1 part of the dewaxed dark oil. The concentrate was recrystallized at room temperature with 20 part volume of methanol to yield oryzanol crystal of 98.3% purity. The optimum condition of vacuum distillation was temperature of $180^{\circ}C\;at\;0.2{\sim}0.4\;torr$ with 2% steam sparging. At this condition, the free fatty acid in the dark oil was removed as distillate without thermal deomposition to yield 82.3% of oryzanol as the pitch of 27.3% purity. After concentration from the pitch with 20 part volume of hexane to yield yellow powder of 75.4% purity, the yellow powder was recrystallized in methanol at room temperature to obtain the crystal containing 99.0% oryzanol. The overall oryzanol yield from the dark oil and the pitch was 9.5 and 28.5%, respectively. The change of the composition of sterols and triterpenoid alcohols in the compounds isolated during fractionation was analyzed by GC-MS.

• Korean Journal of Food Science and Technology
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• v.47 no.5
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• pp.579-585
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• 2015

Following supplementation with organic acids (acetic, citric, and lactic acids), the pH of the alcohol mash changed from 4.2 control to 3.73-3.97 supplemented, the acidity from 5.06 to 8.13-9.98, and the alcohol content from 17.8 to 17.0-17.8%. Protease activity decreased owing to the pH change, and the total nitrogen content decreased by 13.1-36.9% following organic acid supplementation. Organic acid supplementation did not affect the distillation efficiency; however, thiobarbituric acid values in the crude distillate (40%) decreased 2.2-3.6 fold following supplementation with citric acid and lactic acid. The total isobutanol (B), isoamyl alcohol (A), and 1-propanol (P) contents in each soju (25%) supplemented with organic acid were 1,041.47, 979.50, and 961.48 ppm, respectively, which were higher than those in the control soju (935.27 ppm). The A/P, A/B, and B/P ratios of soju were altered and the acetaldehyde content decreased following supplementation with the organic acid.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.8
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• pp.466-473
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• 2018

The purpose of this study is to develop a distilled soju with high quality and stable brewing technology by analyzing the changes of general components and volatile components in the production of distilled soju by the use of fermentation agent such as koji and nuruk. White rice flour was used as a main raw material. White koji, yellow koji, traditional nuruk, and improved nuruk were used as a fermentation agent respectively. Also, yellow koji, traditional nuruk, and improved nuruk were added at a certain ratio to prepare white koji. The distillate was prepared by vacuum distillation and the quality characteristics were compared and analyzed. When the fermentation agent was used alone, the alcohol content was higher in the order of white koji, improved nuruk, yellow koji, and traditional nuruk. The initial acidity was higher than that of other fermentation agents and the highest alcohol content was found to be helpful for stable brewing. The highest content of higher alcohol was found in the yellow koji mash, and ethyl acetate was the highest in the traditional nuruk. When the fermentation agents were mixed, there was no difference in the alcohol content between $1^{st}$ fermentation mash and $2^{nd}$ fermentation mash. On the other hand, the content of higher alcohol was increased with the increase of the input ratio of yellow koji, and it decreased with the increase of the ratio of traditional and improved nuruk. It is expected that it will be possible to manufacture various distilled soju with different flavor and aroma if the yellow koji and the traditional nuruk are appropriately used based on the white koji having excellent fermentation characteristics and it will be very helpful for improving the stability and quality of brewing.

• Applied Chemistry for Engineering
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• v.7 no.1
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• pp.162-170
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• 1996

Light cycle Oil(LCO) contains 2,6-dimethylnaphthalene (2,6-DMNA) which is used as the basic material for high performance engineering plastics and liquid crystal polymer. This study was experimentally investigated to concentrate a mixture of dimethylnaphthalene(DMNA) isomers in the LCO by extraction-distillation combination as a pretreatment for separation and purification of 2,6-DMNA in the LCO. Furthermore, concentration of a mixture of DMNA isomers in the LCO compared between distillation and extraction-distillation combination. The recovery of aromatics in the LCO was performed by batch cocurrent multistage extraction with dimethylsulfoxide and water mixture as solvent. The concentration of naphthalene group(carbon number 10-12) in the extracted mixture is higher than that in the LCO. The yield for naphthalene group increased with decreasing carbon number. The yield for a mixture of DMNA isomers obtained in 5 equilibrium extration runs was about 65%. the separation of individual components with extractedmixture was tested by batch distillation. Futhermore, for recovery of a mixture of DMNA isomers of high concentration, distillate containing DMNA was distilled. As a result, a mixture of DMNA isomers with high concentration such as 60wt% was recovered. The extraction-distillation combination was more effective than the distillation to concentration a mixture of DMNA isomer in the LCO.

• Journal of the Korean Chemical Society
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• v.45 no.5
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• pp.481-490
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• 2001

The purpose of this study was to find out the problems on the fractional distillation experiments in the middle school science textbooks based on the 6th curriculum and to suggest an efficient experiment method for the middle school students. The first step was the classification of the experiments in 8 science textbooks according to heating apparatus and liquid mixtures. The second step was doing each experiment 3 times followed by the experimental process in the textbooks. The third step was developing the alternative experiments for solving the problems found in the second step. The heating method used in the alternative experiments were direct heating, oil bath, and heating mantle. The results of the second step showed that the direct heating experiment of branched round flask was more close to the theoretical prediction than the experiment of water bath heating of branched test tube. Also the direct heating experiment of thermally insulated branched round flask was better than the result of the experiment which was not insulated. The results of the third step showed that the experiment using heating mantle regulated heating power by observing the temperature of distillate gave the closest result to the theoretical prediction. From the above results, it is concluded that the experiment using branched test-tube with water bath heating is not adequate for the fractional distillation and an alternative experiment using insulated branched round flask with heating mantle regulated heating power during experiment is recommended.

• Korean Journal of Food Science and Technology
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• v.5 no.3
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• pp.183-187
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• 1973

Soong-Neung is a Korean traditional beverage served after meals and is made from Soong-Neung producing rice (Noo-Roon-Bap) which is cooked and toasted rice produced on the bottom of the container during the rice cooking process. In order to study the chemical changes occurring in Soong-Neung producing rice with temperature$(20{\sim}220^{\circ}C)$ during the cooking process, thermal analysis, total sugars, total nitrogen, reducing sugars, water soluble nitrogen, total acid, carbonyl content, phenolic compounds were determined. Thermal analysis showed that decrease of weight and endothermic reaction caused by evaporation of water in the sample appeared at $95{\sim}130^{\circ}C.$ The production of volatile compounds increased gradually beginning at $130^{\circ}C$, however, those compounds increased markedly at $160^{\circ}C$ and above. Maximum absorption of ultraviolet spectra of an aqueous distillate occurred at about $273m{\mu}$. Organoleptic analysis showed that an acceptable flavor was produced in the temperature range of $125{\sim}155^{\circ}C.$

• Transactions of the Korean Society of Mechanical Engineers B
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• v.37 no.1
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• pp.81-86
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• 2013

Exhaust gas from a small portable electric generator is simply exhausted to the surroundings because the capacity and quality of the waste heat of this gas is generally not sufficient to recover and utilize. We have proposed a seawater distiller utilizing the thermal energy of waste gas from an electric generator. The distiller recovers heat from the waste gas by means of a heat pipe and uses it effectively through a multiple-effect diffusion-type structure. We constructed an experimental apparatus with a vertical single-effect still having a 4-stroke 50 cc generator engine and found that the experimental results for distillate productivity show good agreement with the theoretical predictions. The results show that the distiller can recover 52 W of waste heat from the gas at $171^{\circ}C$, and ~85% of the recovered heat can be utilized for distillation to produce 70 g/h of fresh water. This is equivalent to a productivity of 500 g/h in the case of a 10-effect still. Therefore, the proposed distiller should be useful in remote areas where electricity and water grids are inadequate.

• Applied Biological Chemistry
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• v.45 no.2
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• pp.59-65
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• 2002

Different amounts of the Opuntia ficus-indica var. saboten fruit were soaked in different alcohol concentrations of a Korean rice wine distillate for 4 months. Changes in pH, brix degree, contents of reducing sugar and polyphenol compound, alcohol concentration, turbidity, and color were analyzed during the soaking period. Quality of the final product was determined through the analysis of the volatile flavor compounds and sensory evaluation. During the soaking periods, pH, alcohol concentration, and contents of polyphenol compound decreased, whereas the content of reducing sugar increased. These changes were affected more by the content of the fruit than the alcohol concentration of the soaking media. Turbidity of the wine increased with higher fruit contents, while the increase of alcohol concentration resulted in the turbidity decrease. As the soaking period increased, lightness and yellowness increased but redness decreased. Acetaldehyde, acetyl acetone, ethyl alcohol, guaiacol, thymol, and acetic acid phenyl ester were detected in all liquors. Significant differences in all sensory attributes test were shown by six experimental groups (p<0.05), and the best overall acceptability was obtained from the liquor made of 67% fruits and 30% alcohol concentration.

• Journal of Ginseng Research
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• v.23 no.4
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• pp.211-216
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• 1999

The red ginseng marc was roasted at various conditions and its organo-leptic properties and flavor components were investigated. Scorched-rice odor and roasted odor and the roasted red ginseng marc powder were much stronger than those from the unroasted red ginseng marc powder while earth odor, old-rice odor, metalic off-odor and woody odor were much weaker than those from the unroasted red ginseng marc. Savory odor and scorched-rice odor as well as savory taste and astringent taste from the water-extract of red ginseng marc roasted at $200^{\circ}C$ were stronger, but smoky odor, woody odor, biner taste and rough taste were weaker than those roasted at $230^{\circ}C$. Seven kinds of pyrazines, two kinds of carbonyl compounds, seven kinds of acids, two kinds of esters, five kinds of phenolic compowlds, maltol and six other compounds were identified as flavor components in distillate from red ginseng marc roasted at $200^{\circ}C$ for twenty minuties. Of them pyrazines and maltol are thought to be compounds which have characteristic odor such as roasted odor and/or scorchedrice odor in the roasted red ginseng marc.