• Journal of Biosystems Engineering
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• v.41 no.3
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• pp.208-220
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• 2016

Purpose: Fusel oil is a potent volatile aroma compound found in many alcoholic beverages. At low concentrations, it makes an essential contribution to the flavor and aroma of fermented alcoholic beverages, while at high concentrations, it induced an off-flavor and is thought to cause undesirable side effects. In this work, we introduce Fourier transform near-infrared (FT-NIR) spectroscopy as a rapid and nondestructive technique for the quantitative determination of fusel oil in the Korean alcoholic beverage "soju". Methods: FT-NIR transmittance spectra in the 1000-2500 nm region were collected for 120 soju samples with fusel oil concentrations ranging from 0 to 1400 ppm. The calibration and validation data sets were designed using data from 75 and 45 samples, respectively. The net analyte signal (NAS) was used as a preprocessing method before the application of the partial least-square regression (PLSR) and principal component regression (PCR) methods for predicting fusel oil concentration. A novel variable selection method was adopted to determine the most informative spectral variables to minimize the effect of nonmodeled interferences. Finally, the efficiency of the developed technique was evaluated with two different validation sets. Results: The results revealed that the NAS-PLSR model with selected variables ($R^2_{\upsilon}=0.95$, RMSEV = 100ppm) did not outperform the NAS-PCR model (($R^2_{\upsilon}=0.97$, RMSEV = 7 8.9ppm). In addition, the NAS-PCR shows a better recovery for validation set 2 and a lower relative error for validation set 3 than the NAS-PLSR model. Conclusion: The experimental results indicate that the proposed technique could be an alternative to conventional methods for the quantitative determination of fusel oil in alcoholic beverages and has the potential for use in in-line process control.

• Journal of dental hygiene science
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• v.12 no.6
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• pp.696-701
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• 2012

The purpose of this study was to determine pH value of some alcoholic drinks sold in Korea and to provide the basic information which can cause dental erosion. Alcoholic drinks commercially sold were purchased from various big markets in Korea. The sorts of drinks tested in this study consisted of 5 brands of beers, 24 brands of makgeollis, 9 brands of wines and 12 brands of sojus. The test groups were selected randomly and the pH of each beverage was determined using a pH meter he each pH was measured. For statistical data, Mann-Whitney test was used to analyze difference for red wine and white wine and Kruskal-Wallis test was used to compare the pH of each test group. The result of this study was as followings: the mean pH of 5 brands of beers was 4.21, that of 24 brands of makgeollis 3.88, of 9 brands of wines 3.34 and of 12 brans of sojus 7.86. Each test group was significantly different (p<0.05). Except for soju groups, the test groups had a low pH value which can cause dental erosion. In terms of comparing between pH value of red wine and white wine, the result of this study represented that the mean pH of red wine was 3.45 and that of white wine was 3.21. This result showed the pH of two kinds of wine had a low pH which can lead to dental erosion and the difference of two wine were significantly different (p<0.05). As a result, some drinks sold in Korea have a high erosive potential on teeth since they have a comparatively low pH expect soju. Hence, when we consume some kinds of alcoholic drinks, we make sure to remember that the alcoholics which had a low pH, can have an effect on dental erosion that mean we should avoid to drink some alcoholic drinks with low pH for long time.

• Journal of the Korean Society of Food Culture
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• v.24 no.1
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• pp.1-9
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• 2009

The purpose of this research was to investigate consumers' perceptions of foods that are most compatible with traditional Korean liquors. The study participants were a total of 402 customers who visited traditional Korean bars. Thirty-eight percent of the participants drank alcohol once or twice a week, and overall, 79% drank with friends or co-workers. Forty-three percent spent 30,000-40,000 won on alcoholic drinks, and half of them frequently drank distilled Soju whereas 27% drank beer. Those who drank traditional Korean liquor chose to do so because they viewed it as good for their health and the beverage was tasty. Participants selected Yakju/Baekseju (47.5%), Bokbunjaju (21.1%), and Takju/Makgeoli (8.2%) as the most compatible Korean traditional liquors with Korean traditional foods. The most compatible foods with Yakju were identified as Haemulpajeon (11.8%), Dubukimchi (9.8%), and Bossam/Suyuk/Pyeonyuk (7.5%). Bokbunjaju was viewed as a good match with Jangeogui (8.1%), Hunjeori (6.5%), and Saengseonhoe (6.4%). The respondents perceived Deodeokgui (6.7%), Saengseonhoe (5.9%), and Dubukimchi (5.6%) as the most compatible foods with Yakju with mushrooms. Chengju was viewed as a good pairing with Eomuktang (9.2%), Altang/Maeuntang (7.2%), and Saengseonhoe (6.8%). The respondents thought Takju went well with Haemulpajeon (17.7%), Dubukimchi (14.2%), and Kimchijeon (11.7%). And finally, Altang/Maeuntang (11.8%), Samgyeopsalgui (8.7%), and Honghaptang/Jogaetang (8.1%) were mentioned as the most compatible foods with distilled Soju.

• Food Science and Preservation
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• v.30 no.4
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• pp.669-682
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• 2023

The production of distilled soju by fermenting nonsteamed rice was evaluated using commercial enzyme products. White koji and modified nuruk had alpha-amylase activities of 31.90 U/g and 3,532.71 U/g, respectively, and gluco-amylase activities of 698.32 U/g and 4,899.58 U/g, respectively. The enzyme products had activities of 5,604.15-225,182.00 U/g and 13,517.41-120,822.41 U/g, respectively. At enzyme concentrations of >800 mg/L, the Chung-moo-purified enzyme had an alcohol productivity of ≥19%. Nurukzyme R400, Sanferm Yied, and Diazyme X4 exhibited alcohol productivities of >19% at concentrations of >600 mg/L. The alcohol content of the vacuum distillates was 41.31%-44.86%. The volatile component with the alcohol content adjusted to 25% was analyzed and principal component analysis was performed. The volatile components in white koji, Diazyme X4, and Sanferm Yield were similar. The modified nuruk treatment group had a relatively high ethyl lactate content compared to the white koji treatment group. The Nurukzyme R400 treatment group had high contents of butyric acid and ethyl butyrate. The Chung-moo-purified enzyme was characterized by a low component content. Thus, when enzyme products were used in nonsteamed rice fermentation, no effect on the alcohol productivity and quality of vacuum distilled soju was observed, suggesting that it can replace white koji and modified nuruk.

• Food Science and Biotechnology
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• v.14 no.4
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• pp.554-557
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• 2005

As a device for taste sensation, an 8-channel taste evaluation system was prepared and applied for discriminant analysis of marketed liquor. The biomimetic polymer membranes for the system were prepared through a casting procedure by employing polyvinyl chloride, bis (2-ethylhexyl)sebacate as plasticizer and electroactive materials such as valinomycin in the ratio of 33:66:1, and were separately attached over the sensitive area of ion-selective electrodes to construct the corresponding taste sensor array. The sensor array in conjunction with a double junction reference electrode was connected to a high-input impedance amplifier and the amplified sensor signals were interfaced to a personal computer via an A/D converter. When the signal data from the sensor array for 3 groups of marketed liquor like Maesilju, Soju and beer were analyzed by principal component analysis after normalization, it was observed that the 1st, 2nd and 3rd principal component were responsible for most of the total data variance, and the analyzed liquor samples were discriminated well in 2 dimensional principal component planes composed of the 1st-2nd and the 1st-3rd principal component.

• Journal of the Korean Home Economics Association
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• v.27 no.4
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• pp.51-58
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• 1989

The purpose of this study was to investigate the state of eating out and the food preference of college students in Seoul. This survey was carried out through questionaires, and the subjects were 158 male and 159 female students. The results obttained were summarized as follows; 1) Students who took late evening meal at home after eating out were 35.7% and most of the reasons were to custom. 2) During eating out, 30% of students had drinking. Male students had Soju (45.6%), and female had Beer (56.0%). 3) The most cases in date time, eating out cost were 5,000w. They were fond of Western Restaurant and the favorite food were Dongas. 4) Freqency of eating out with family had more than once a month (35%), because of a memorial day and event day, and the most favorite food was Sogalbigui. 5) Male and female students's choice in food at restaurant type were very different.

• Journal of the Korean Applied Science and Technology
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• v.16 no.3
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• pp.223-230
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• 1999

This study was performed to determine optimum level of ethanol intake with weanling male rats. The weanling rats and the experimental diets were divided into 5 groups, control, A, B, C, D group in according to the levels of ethanol intake for 10 weeks. In the result of their serum analyses, we suggest that an adequate intake of ethanol is 1.47ml/kg/day. If body weight of any man is 60kg, he can drink about 90ml(1.47*60=88.2) ethanol/day. It corresponds to 360ml [90=360*(25/100)] of 25% SOJU.

• Journal of the Korean Society of Food Culture
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• v.14 no.3
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• pp.251-257
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• 1999

To investigate the drinking pattern and behaviors of Yangsan College students, a self-administrated survey was conducted to the subjects, composed of male 336 and female 165. The results of this study were as follows: 1. With regards to kind of alcoholic beverage, 71.6% of subjects responds have a preference for soju, which is favored more by male than by female. 2. The most favorite side dishes are stew and soup(48.2%), then roasted meats and fruits. 3. In the drinking habit, 40.4% of subjects responded that they drink themselves to sleep, 20.6% have more chatter, and 12.5% become silent. 4. 80% of the subjects, some of which recognized overdrinking, responded that the culture to have a drinking after official events is essential, while 6.6% responded that it goes wrong.

• Journal of the Korean Society of Food Culture
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• v.32 no.2
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• pp.144-149
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• 2017

This study was designed to investigate the contents of icariin during ripening of Epimedium koreanum with sugar and Soju (25, 30, and 35% alcohol contents) using a homemade method. Contents of icariin of Epimedium wine were examined using high performance liquid chromatography. Icariin levels in Epimedium wine increased during the first 3 days of storage; after 6 days, icariin contents decreased gradually until 30 days. Contents of icariin in Epimedium wine by storage temperature (5 and $20^{\circ}C$) were not different during storage. After 30 days, icaiin was not detected in all tested Epimedium wines. Epimedium wines were assessed for 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) and (ABTS) radical scavenging activity. DPPH and ABTS radical scavenging activities increased in early storage periods, however, after 6 or 9 days, activities decreased gradually.

• Journal of the Korean Society of Food Culture
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• v.9 no.1
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• pp.61-69
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• 1994

Northern Kyungbuk around Andong is a mountainous and more or less dry region geomorphogically. Since this area located in the valley was less invaded by foreign countries, the folk traditions have been maintained for a long time. Also as the center of Confucian culture, this region respects ceremonies and so, the simple and noble ceremonial-foods such as Ddok, Hankwas, and Buchiki have been firmly preserved in many distinguished families. And besides Andong-Soju, many traditional liquors produced in different methods can be found in this region. As Gogi-Sikhae(a fermented beverage utilizing rice and fish) is still preserved in eastern coastal area, Sosikhae(Sikhae without fish) is maintained in this region and furthermore the unique Andong Sikhae developed by modifying Sosikhae is being consumed currently. Since it is difficult to get fish here geographically, the soybean foods were developed for protein intake, for example, various fermented soybean pastes, Andong-Songuksu(a hand-made noodle using raw soybean flour), and Siragiguk(a vegetable soup).