• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.6
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• pp.880-886
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• 2010

In this study, volatile compounds in liquor distilled from mash produced using koji or nuruk under reduced or atmospheric pressure were analyzed and eventually, the proper starter material and distillation method was selected. Acetaldehyde was detected two or three times more in the liquor distilled under the atmospheric pressure than under the reduced pressure. Furfural was only detected in the liquor distilled under the atmospheric pressure. Esters were detected more in the liquor distilled under the atmospheric pressure than the reduced pressure. Ethyl pelargonate and 2-phenyl ethanol were particularly detected two times more in the liquor distilled under the atmospheric pressure than the reduced pressure. Methanol was detected two times more in the liquor made with nuruk than that with koji. These results suggest that the liquor distilled from the mash produced using koji under the reduced pressure may have the better quality.

• Journal of the Korean Institute of Gas
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• v.19 no.3
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• pp.54-59
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• 2015

The gas hydrate of 10 trillion tons are buried under continental slope in the world(permafrost : 2%, marine continental slope: 98%), but technology for the the commercial gas recovery has not developed yet. There are normally four representative recovery methods: depressurization method, thermal stimulation method, inhibition injection method, and displacement method. This study focuses on change of dissociation time and gas production according to gas hydrate saturation rate and depressurization rate. It was found that the correlation between depressrization rate and dissociation time was like as $Y=0.0004X^2-0.499X+176.86$. It was also found that the bigger depressurization rate is, the better production is(methane gas is produced over 46.2% at depressurization rate 50% compared with 40%). However, on the contrary to this, it is presumed that gas production is decreased at 60% due to gas hydrate reformation.

• Korean Journal of Food Science and Technology
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• v.46 no.1
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• pp.25-32
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• 2014

This study aimed to analyze the general ingredients and volatile compounds of ipguk (koji) and nuruk soju distilled under reduced pressure (RP) or atmospheric pressure (AP) conditions. After the secondary brewing process, soju made using ipguk had a final fermentation alcohol content of $18.0{\pm}0.6%$, whereas soju made using nuruk reached $14.3{\pm}1.7%$. The level of succinic acid was the highest in ipguk soju ($7,685.33{\pm}34.97$ ppm), but nuruk soju also showed a high level of succinic acid ($5,945.79{\pm}76.30$ ppm) after its final fermentation. In an analysis of fusel alcohol content, the level of n-propanol in ipguk soju (389.10-397.27 ppm) was similar under different RP (50 cm Hg and 60 cm Hg) and AP conditions ($80^{\circ}C$ and $90^{\circ}C$). Under RP and AP conditions, the isoamyl alcohol/isobutanol (A/B) ratio was similar, ranging from 1.32-1.35. In ipguk soju distilled under RP conditions of 50 cm Hg and 60 cm Hg, the amount of the toxic component, acetaldehyde, was 8.59 and 9.27 ppm, respectively. Under AP conditions, the amount of acetaldehyde in ipguk soju distilled at 80 and $90^{\circ}C$ was 9.80 and 10.63 ppm, respectively, indicating that the amount of acetaldehyde did not differ depending on the distilling method used. These results suggest that the liquor distilled from the mash produced using ipguk under RP conditions may be of a higher quality.

• Resources Recycling
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• v.24 no.6
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• pp.54-60
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• 2015

The objective of this study is to develop a belt-type dryer with a capacity of 1 ton/day, thereby improving drying efficiency by more than 70% and reducing the size of dryers by more than 50%, and thus making dryers smaller and lighter to reduce the installation and operation costs by more than 20%. We identified structural improvements by analyzing existing dryers employing indirect heating and verified the superior drying performance of the proposed method through some basic experiments. Furthermore, we verified the improvements in the heat transfer and drying characteristics as we conducted the experiments at reduced pressure.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2001.02a
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• pp.257-263
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• 2001

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.5
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• pp.743-752
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• 2013

The objective of this study was to investigate the quality characteristics of spirits derived from fruit using copper distillation equipment. First, optimal yeast strains were chosen through a fermentation test on raw materials (apples, mandarins and rowanberries). The normal fermentation condition for rowanberries observed at a rowanberry concentration of 8% during mashing included chaptalization with sugar to increase the alcohol content. During the mashing, fruits were fermented and distilled through one of three different types of distillation apparatuses (pot distiller, vacuum distiller, or multistage distiller made of copper). The results revealed that the type of apparatus used affects the content of alcohol and flavor components. The distilled spirits prepared through a copper multistage distiller had a much higher tendency to retain components of fruit aromas such as ethyl acetate and provided higher yields than spirits prepared with a pot distiller or vacuum distiller. Thus, the copper multistage distiller apparatus can be applied to positively influence the taste and flavor of fruit distilled spirits by enhancing fruit aromas, removing impurities such as sulfur components and enhancing yields.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.9
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• pp.6142-6151
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• 2015

This study is conducted to develop and optimize fruit spirits by using Schizandra chinensis fruit which are rarely used as spirits in the world. For this purpose, the raw material, main compounds of fermented mash and, quality characteristics of distilled liquor prepared with different distillation methods were analyzed. The studt period lasted six months and the results were follows. Schizandra chinensis was not suitable for alcohol fermentation because the sugar concentration and acidity were low. Therefore, the fermentation condition was appropriate to mix with the weight ratio of fresh Schizandra chinensis fruit, water and sugar as 1:1.5:0.25, and was fermented the mix by adding 0.06 w/w% of $(NH_4)_2HPO_4$ compared to the must total weight. It was also examined to analyze product characteristics of fruit spirits prepared with different methods of distillation(column-pot still, pot still, vacuum still). The result showed that fruit spirits made by vacuum still with fresh Schizandra chinensis fruit indicated the best product quality while the distillation of column-pot still showed the best yield.

• Applied Biological Chemistry
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• v.30 no.1
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• pp.65-70
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• 1987

In Girder to measure the pressure and weight decrease of drying sample during the vacuum drying process of food, sensing devices were designed and constructed with strain gauge. Microcomputer based vacuum drying system was made up of these devices interfaced to apple II microcomputer. The electrical output signal from vacuum sensor which constituted with Bourdon tube whereon strain gauge attached were digitalized and input to microcomputer through the MC 6821 interface I.C. chip. The relationship between read-out digital value (D) from microcomputer and readings of vacuum gauge (P, mmHg) was P=-146.136+3.620D'(r=0.9994) The pressure control of vacuum dryer was successfully conducted in the range of $400{\sim}600\;mmHg$ accuracy. The digitalized load cell output (D) could be correlated with the real weight (W, g) as W=-14,000+0.585D (r=0.9998) Drying curves of green red pepper under $64^{\circ}C$, $400{\sim}600\;mmHg$ was similar to those of red pepper and differently affected by the degree of vacuum pressure but was varied according to their shape (cut or whole). Moisture movement of green red pepper during the vacuum drying process was fitted to Page model. The empirical equations obtained were $M-M_e/M_o-M_e={\exp}\;(-0.0673{\theta}^{1.177})$ and $M-M_e/M_o-M_e={\exp}\;(-0.0655\;{\theta}^{1.477})$ for whole and cut green red pepper, respectively.

• Korean Journal of Food Science and Technology
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• v.19 no.6
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• pp.550-555
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• 1987

Strain gauges attached on the Bourdon tube and load cell were used as the sensors for measuring the vacuum pressure in drying chamber and the weight loss of Shiitake mushrooms respectively. The vacuum drying system was interfaced further with the Bear II microcomputer. The interface devices used were built with such IC chips as MC 6821, ADC 0809, SN 74244 and SN 7424. The relationship between readings of vacuum gauge (P, mmHg) and digital outputs (D) from the microcomputer was represented by P =3.08 D-13.4875(r=0.9999). The weights of drying sample (W) were also related with the digital outputs (D) by W=0.4076 D-6.4762 (r=0.9999). During the vacuum drying of Shiitake mushrooms. the data on pressure and weight were recorded at regular intervals using an acquisition program on the microcomputer system. The Page model was fitted well to the drying data of Shiitake mushrooms. resulting in the following empirical equations : $(M-M_e)/(M_o-M_e)=\exp(-0.1569t^{1.0048})$ at 400 mm Hg up to 14 hours and $(M-M_e)/(M_o-M_e)=\exp(-0.1385_t^{1.2688})$ at 600 mm Hg up to 8 hours.

• Journal of the Korean Institute of Gas
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• v.21 no.3
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• pp.33-38
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• 2017

The domestic vehicles remodeling the "CNG Bi-fuel Kit" are mostly in operation with installing the mechanical regulator applying the Diaphragm. However, due to the material characteristics of Diaphragm and characteristics of mechanical pressure control method, various problems are happening. This study tries to deduce the improvement plan through the checking of performance characteristics according to the pressure control method of CNG regulator and progress of comparative analysis. According to the test result, the decompression method applying the Diaphragm has advantage compared to the method applying the Piston. Furthermore, it was confirmed that through the electronic pressure control, it is possible to improve the general performance of the regulator.