• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.1
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• pp.170-175
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• 2004

This study was conducted to determine the minimum concentration of citrus juice for basal medium and also to search for an additional carbon source for the best production of the gel. A concentrate of citrus fruit juice of 65$^{\circ}$Brix, it was diluted to be used as a basal medium. Static cultivation of Gluconacetobacter hansenii TL-2C for 14 days at 3$0^{\circ}C$ produced the best gel with 7.5$\pm$0.4 mm thickness in the 6-fold diluted citrus Juice concentrate without any additional nutrient. However, the same thickness could be obtained with 60 to 100-fold diluted juice concentrate when refined white sugar was added at appropriate concentrations. Glucose was the most effective sugar for the both of gel and acid production, and optimal concentration of the sugar was 10$^{\circ}$Brix. Ethyl alcohol at 1.0% had synergistic effects in combination with refined sugar and increased the gel thickness up to 15.1 mm which was 1.85 times thicker than that of refined sugar alone. However, acetic acid was not effective. Gel productivity with supplement of ethanol was 172.6$\pm$8.4 g wet/L, and it was approximately equal to 4.7 g of dry gel/L.

• Journal of Food Hygiene and Safety
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• v.37 no.5
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• pp.332-338
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• 2022

Cereal grains are the dietary staple in many countries, including the Republic of Korea. These grains are usually consumed cooked. Korean grown raw and cooked brown non-glutinous rice (BNR), white non-glutinous rice (WNR), oats, and barley were analyzed to assess the effects of cooking on dietary fiber and free sugar content. The largest decrease in total dietary fiber (TDF) after cooking was observed in barley (11.62±1.26 to 2.96± 0.90 g/100 g), and the smallest decrease was observed in oats (8.1±0.34 to 8.1±0.32 g/100 g). Soluble dietary fiber decreased in oats (3.35±0.94 to 1.25±0.03 g/100 g) while insoluble dietary fiber increased (4.76±0.78 to 6.90±0.30 g/100 g) after cooking. TDF content was not changed. Of the six free sugars routinely assessed, only sucrose was detected in BNR and WNR. Sucrose decreased by about 0.6 g/100 g in BNR, and was not detected in WNR, after cooking. Fructose, sucrose, and raffinose were detected in oats (0.08, 0.83, and 0.19 g/100 g) and barley (0.09, 0.58, and 0.22 g/100 g) Maltose was also detected in barley (0.09 g/100 g). Total sugar content decreased in every cereal grain sample after cooking. This research reveals that dietary fiber and free sugar content can be reduced by cooking cereal grains.

• Food Science and Preservation
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• v.15 no.1
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• pp.150-154
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• 2008

This study investigated 1he fermentation characteristics and sensory properties of white wine made from the Chilean grape varieties Thomson Seedless (T), Red Globe (R), and a mixture thereof (M). The pH fell during fermentation and final pH values of 3.63-3.68 were slightly higher than is usual in white wine. The total acidity increased during the alcoholic fermentation and leveled at 0.56-0.71% Ater 15d, the sugar contents and specific gravities attained final values. The L value of wine made from R grapes increased from 65.05 to 96.77, of wine made from T grapes from 77.41 to 99.6, and of wine made from M grapes from 71.73 to 98.41. The a value of all wines decreased quickly during the first 4 d of fermentation and the b values of T and M wines (not R wine) also fell rapidly during this time. The final alcohol concentrations of the wines were 14 -14.9% (v/v). The white wines made from T, R, and M grapes received similar scores in a directional difference sensory test. The color and flavor of white wine made from T grapes scored highest (5.6 and 5.35 respectively; p<0.05 for both values), but overall acceptabilities of all three wines were similar (4.30-4.85, p<0.05).

• Korean Journal of Food Science and Technology
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• v.44 no.4
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• pp.411-416
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• 2012

This study was carried out to investigate the effects of the extrusion process on the change of components in ginseng. The extraction yields from ginseng by distilled water extraction were highest in the extruded ginsengs, whereas it was lowest in the white ginseng. The contents of crude saponin were highest in the extruded ginseng, and they increased as the extrusion temperature was raised. The total contents of 11 kinds of ginsenosides increased in the order of red, white and extruded ginsengs. In particular, red ginseng showed higher contents of Rg1, Rg3 and Rb2, whereas Re was highest in white ginseng. In addition, the contents of Rg2, Rh1, Rh2 and Rg3 in the extruded white ginseng became higher. Free sugar contents were greatest in red ginseng. However, they were lowest in the extruded ginseng. White ginseng had a greater L value, whereas extruded ginseng demonstrated higher a and b values. In conclusion, the extraction yields, the contents of saponin, and ginsenoside-Rg2, Rh1, Rh2 and Rg3 were increased through the extrusion process.

• Journal of Microbiology and Biotechnology
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• v.30 no.8
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• pp.1227-1234
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• 2020

In this study, yeast cell immobilization was carried out in a packed bed reactor (PBR) to investigate the effects of the volumetric capacity of carriers as well as the different fermentation modes on fuel ethanol production. An optimal volumetric capacity of 10 g/l was found to obtain a high cell concentration. The productivity of immobilized cell fermentation was 16% higher than that of suspended-cell fermentation in batch and it reached a higher value of 4.28 g/l/h in repeated batches. Additionally, using this method, the ethanol yield (95.88%) was found to be higher than that of other tested methods due to low concentrations of residual sugars and free cells. Continuous ethanol production using four bioreactors showed a higher productivity (9.57 g/l/h) and yield (96.96%) with an ethanol concentration of 104.65 g/l obtained from 219.42 g/l of initial total sugar at a dilution rate of 0.092 h^-1. Furthermore, we reversed the substrate-feed flow directions in the in-series bioreactors to keep the cells at their highest activity and to extend the length of continuous fermentation. Our study demonstrates an effective method of ethanol production with a new immobilized approach, and that by switching the flow directions, traditional continuous fermentation can be greatly improved, which could have practical and broad implications in industrial applications.

• Culinary science and hospitality research
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• v.19 no.4
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• pp.147-160
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• 2013

This research investigates the quality characteristics of bread added with honey. The overall effects of honey on white pan bread were examined in terms of mixograph, fermentation rates, pH levels, TPA, colorimeter, water activity, hardness and moisture content of bread through different storage periods(1, 2, 3 days) using sensory evaluation. According to mixograph, all the samples were found to be proper between 3 and 5 minutes of peak time and their peak values were at the level of 60%. Also, HL100 had the highest fermentation rate and fermentation persistence from 60 min to 135 min. HL100 showed the lowest pH level in ingredient, dough, fermentation and crumb, and the highest specific volume. TPA analysis showed that HL100 had the lowest hardness and the highest springiness of all. And HL100 was the lowest in hardness(i.e. highest in softness) and had the highest moisture content after storage of 72 hours. Preference test showed that HL100 got the best texture, flavor, mouth feel, taste and overall acceptance. In these results of experiment, honey affects the quality of dough and bread, and liquid honey could be used as a substitute for sugar in breadmaking.

• Korean Journal of Food Science and Technology
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• v.36 no.6
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• pp.911-918
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• 2004

Three dry red, four sweet red, and two white wines were prepared with domestic grape varieties: Gerbong (G), Campbell Early (C), Muscat Bailey A (M), Seredan (Sd), Seibel (Sb), and Neo-muscat (N). Sample wines were analyzed for titratable acidity, ethanol, pH, sugar content, color intensity and hue, and total phenolic content. Preferences of color, aroma, and overall acceptability were determined by 97 panelists using 9-point hedonic scale. Sweetness, sourness, astringency levels of developed wines were evaluated using 9-point just-about-right (JAR) scale. Mean overall acceptability score of C (6.49) was highest among dry red wines (p<0.05). Among sweet red wines, mean overall acceptability score of Sd (3.27) was significantly lower than those of other wines (p<0.05). In white wines, overall acceptability score of Sb (5.20) was slightly higher than that of N (4.92). Overall sourness levels in dry red wines were higher than optimum level. Based on the results, should be lowered, and sweetness and sourness levels of white wines need to be adjusted sweetness levels of C, G, and Sd for the production of sweer redwines. C and M varieties were considered to be suitable for Korean red wine production.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.2
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• pp.225-234
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• 2009

The aim of this study was to analyze moisture, crude protein, crude lipid, vitamin C and sugar changes in selected Korean chestnut cultivars such as Danteack, Deabo, Seokchu, Okkwang and Byunggo during storage at $4^{\circ}C$ and $-10^{\circ}C$ for 10 months. The moisture contents of selected Korean chestnut cultivars ranged from 49.9 to 57.4%. The moisture content of Seokchu was the highest. The contents of moisture in white kernel were higher than that in yellow kernel. The content of moisture showed decreasing tendency after 10 months of storage. The crude protein and crude lipid contents in whole kernel of selected Korean chestnut cultivars were $3.3{\sim}4.2%$ and $0.3{\sim}1.6%$, respectively. The crude protein content of Deabo was the highest. The crude protein in Danteack, Seokchu, Okkwang and Byunggo was increased during storage at $4^{\circ}C$ for 10 months, while that in whole kernel of Deabo was decreased and no changes in crude protein in yellow kernels of Deabo were observed. The crude protein in Okkwang was increased during storage at $-10^{\circ}C$ for 10 months. The cold storage was found to have higher composition change of crude protein than the freezing storage. The content of crude lipid in Daebo and Byunggo was decreased during storage at $4^{\circ}C$ and $-10^{\circ}C$. Yellow kernels of Deabo, Okkwang and Byunggo were found to have higher crude lipid content than white kernels. The vitamin C content also decreased during storage at $4^{\circ}C$ and $-10^{\circ}C$ and the decrease in vitamin C content was higher at $4^{\circ}C$ than $-10^{\circ}C$. Vitamin C was not detected after 3 months storage at $-10^{\circ}C$. The sugar content increased at the latter period storage at $4^{\circ}C$ and $-10^{\circ}C$. The sugar content of selected Korean chestnut cultivars ranged from $36.2{\sim}44.3%$ and Dantaek had the highest sugar content.

• Korean Journal of Food Science and Technology
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• v.31 no.3
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• pp.672-677
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• 1999

The saccharification and sensory characteristics of Sikhe, Korean traditional beverage of saccharified rice, made of three cultivars of pigmented rice (Suwon 415, Iksan 427, Suwon 432) were examined. During saccharification, sweetness and reducing sugar of Sikhe made of pigmented rice were observed to be lower by $0.5{\sim}2%$ and by 20%, respectively, than those of Sikhe made of white rice. The changes in pH during saccharification were not much different between Sikhe made of white rice and those made of pigmented rice. For color changes, the redness (a value) of Sikhe was measured as -0.26, 10.45, 0.88 and 0.13 for those in Sikhe made of white rice, Suwon 415, Iksan 427 and Suwon 432, respectively, when rice was saccharified for 6 hours. Sensory evaluation showed that sweetness and flavor of Sikhe made of 50% or 25% pigmented rice were similar with those of Sikhe of white rice. The overall acceptability of Sikhe made of pigmented rice was slightly lower than that of Sikhe made of white rice.

• Korean Journal of Microbiology
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• v.33 no.1
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• pp.38-42
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• 1997

For the purpose of obtaining microorganisms producing high amount of erythritol, the screening test was carried out. Productivity of erythritol was analyzed by paper chromatography and HPLC' methods. Among more than two hundred isolates, one strain(KJX1) was selected as an erythritol prtducer from thc soil of corn shock. The isolated strain was identified as Pmicilliurn sp. KJ81 from the morphological and physiological characteristics. Penicillium sp. KJ81 showed white to green colony color, two- to three-stage branching conidiophcvc and flask-shaped phialides.