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Yoo K.-S.,Chungbuk National University | Kim J.E.,Chungbuk National University | Moon J.S.,Chungbuk National University | Jung J.Y.,Chungbuk National University | And 6 more authors.
Food Science and Biotechnology | Year: 2010

The aim of this study was to elucidate the Korean consumers' aroma preference on wines. For this, a sensory test on 6 commercial red wines (5 imported and 1 domestic) was conducted by 250 panels and the volatile compounds of those wines were analyzed by gas chromatography-mass spectrometry. Sample 1 obtained the highest mean aroma acceptability score and analysis of volatile compounds revealed that it retained many kinds of esters and alcohols compared to other wines (including 2 acetate esters, 6 ethyl esters, 3 other esters, and 5 alcohols, mostly giving fruity aroma). Sample 1 was made by blending 2 varieties of grapes and this brewing technology might give a preferred aroma balance. The domestic wine, sample 2, made of 'Campbell Early' grape earned relatively higher acceptability score (2nd ranked), being considered its strong grape aroma. In the lower score group, higher concentrations of isoamyl alcohol, 1-isothiocyanto-propane, and volatile phenol were detected and their strong grassy or fatty odor might affect the lower sensory result. Strategies for production of consumer-preferred wines were suggested. © KoSFoST and Springer 2010.


Lim J.Y.,Chungcheongbuk do Agricultural Research and Extension Services | Yoon H.-S.,Chungcheongbuk do Agricultural Research and Extension Services | Kim K.-Y.,Chungbuk National University | Kim K.-S.,Chungcheongbuk do Agricultural Research and Extension Services | And 2 more authors.
Food Science and Biotechnology | Year: 2010

This study investigated the optimum conditions, including pH, temperature, incubation time, and enzyme concentration, for the enzymatic manufacture of citron waste juice by pectinase and cellulase using response surface methodology (RSM). A central composite design was used as an experimental design for the allocation of treatment combination. The highest yield was 71.1% at pH 5.00, 51.15°C, 53.74 min, and 0.44%, whereas the lowest turbidity was 0.20 at pH 4.87, 50.21°C, 49.99 min, and 0.44%. The highest hunter's L (lightness), a (redness), and b- (yellowness) values were 47.39 (pH 4.86, 50.72°C, 51.60 min, and 0.44%), -1.34 (pH 5.48, 49.36°C, 46.29 min, and 0.21%), and 13.18 (pH 5.49, 50.05°C, 43.31 min, and 0.23%), respectively. The highest electron donating activity was 68.36% at pH 4.51, 50.62°C, 47.00 min, and 0.23%. The highest limonin and nomilin contents were 3.49 mg/100 g (pH 4.51, 50.30°C, 48.34 min, and 0.21%) and 1.56 mg/100 g (pH 4.59, 50.08°C, 66.07 min, and 0.30%). © KoSFoST and Springer 2010.


Park K.-R.,Chungbuk National University | Lee W.-J.,Chungbuk National University | Cho M.-G.,Chungbuk National University | Park E.-S.,Metomefood Co. | And 4 more authors.
Journal of the Korean Society of Food Science and Nutrition | Year: 2010

The functional food components from various Basidiomycota were investigated to improve human intestinal microflora, especially associated with obesity. EtOH extract from Gyrophora esculenta fruit body and Coriolus versicolor judae mycelia showed antimicrobial activities on Eubacterium limosum, Clostridium perfrigens, Clostridium paraputrificum, Clostridium difficile and Clostridium ramosum, and on Bacteroides fragilis, respectively. Although the 80% EtOH extract from G. esculenta fruit body and hot-water extract from C. versicolor judae mycelia did not reduce weight of the rats in the high fat diet, these extracts showed stability at high temperatures and at wide pH ranges. In the rat group of feeding 80% EtOH extract from G. esculanta fruit body, Bifidobacterium spp. were increased and Clostridium spp. and Eubacterium spp. were decreased compared to the high fat feeding group. Also sensory evaluation was carried out for the development of prototype drink product. These results demonstrated the possibilities of C. versicolor judae and G. esculenta as a functional food components to control intestinal microbial flora.


Lee A.R.,Chungbuk National University | Li L.,Chungbuk National University | Shin S.-Y.,Chungbuk National University | Moon J.S.,Chungbuk National University | And 2 more authors.
Korean Journal of Microbiology and Biotechnology | Year: 2015

Fucosyltransferases (FucTs) catalyze fucosyl transfer from guanosine-diphosphate fucose (GDP-β-L-fucose) to acceptor molecules to form fucosyloligosaccharides with α-glycosidic linkages. However, when FucT genes have been expressed in Escherichia coli, most cases have resulted in the production of inclusion bodies. In this study, to overcome this drawback, molecular chaperones were co-expressed with α1,2-fucosyltransferase (FucT2) in E. coli. For this, the pACYC184 vector, having genes for chaperones such as GroEL, GroES, DnaK, DnaJ, and GrpE, were transformed into E. coli BL21 (DE3) star harboring pHFucT2, including the FucT2 gene from Helicobacter pylori 26695. The results from SDS-PAGE showed that 5 chaperones were successfully expressed and the soluble fraction of FucT2 was also increased. HPLC analysis revealed that the coexpression of chaperone proteins resulted in a 5-fold increase in the total activity of fucosyltransferase in E. coli. In conclusion, the FucT2 expression system developed in this study can be used as a useful tool for the synthesis of fucosyloligosaccharides. © 2015, The Korean Society for Microbiology and Biotechnology.


Choi H.-S.,NAAS | Lee S.Y.,NAAS | Baek S.Y.,NAAS | Koo B.S.,NAAS | And 3 more authors.
Korean Journal of Food Science and Technology | Year: 2011

This study was conducted to provide information for improving the quality characteristics of Buckwheat Soksungjang (BWS). We determined aminotype nitrogen content, total microbial flora counts, the population of Bacillus cereus, presence of volatile compounds, fibrinolytic activity, antioxidant activity, ACE inhibition rate, and a sensory evaluation. The aminotype nitrogen increased gradually during fermentation. We found a decreasing population of B. cereus during fermentation, thus, the edible period for BWS was more than 30 days after fermentation. Acetaldehyde, butanol, and pyrazine were detected as volatile compounds after fermentation. The fibrinolytic activities of a 10%BWS water extract were high at 120.8 units compared to the control (71.6 units). In a sensory evaluation, Soksungjang with 60% added BW showed a significantly higher score (p < 0.001) for color, taste, smell, texture, and overall. The results suggest that a new type of shortened fermented soybean paste had good safety, bioactivities, and sensory characteristics within 4 weeks. © The Korean Society of Food Science and Technology.


Jung J.Y.,Chungbuk National University | Seo E.,Chungbuk National University | Jang K.-I.,Chungbuk National University | Kim T.-J.,Chungbuk National University | And 2 more authors.
Food Science and Biotechnology | Year: 2011

To investigate possible recycling of a brine solution for the production of salted cabbage (jeolimbaechu), bacterial cell counts in the brine solution and salted cabbages were measured after repeated salting processes. After a salting process with a 13% brine solution for 15 hr at 10°C, the salt concentration in brine and salted cabbage decreased to 9.0-9.9 and 1.5-3.2% (depending on parts), respectively. After 5 repetitions, the total microbial count in the brine solution and salted cabbage gradually increased to 8.9 and 8.7 log CFU/g, respectively. Polymerase chain reaction-denaturing gradient gel electrophoresis (PCRDGGE) showed that the marine bacteria, Pseudoalteromonas sp. and Halomonas sp. appeared from the 3 rd batch; their intensities increased steadily and dominated the recycled brine solution. Meanwhile, Lactobacillus sakei found in the cabbage during the first salting process decreased with successive repetitions. These results show a high risk of marine microbial contamination in salted cabbage when the brine solution is re-used. Therefore, to re-use brine solution, application of proper inhibitory methods to prevent microbial cell growth in the brine solution is required. © KoSFoST and Springer 2011.


Jang M.-U.,Chungbuk National University | Kang H.-J.,Chungcheongbuk do Agricultural Research and Extension Services | Jeong C.-K.,Advanced Protein Technologies Co. | Park J.-M.,Chungcheongbuk do Agricultural Research and Extension Services | And 4 more authors.
Korean Journal of Microbiology and Biotechnology | Year: 2013

A putative cyclomaltodextrinase (LLCD) gene was cloned from the genome of Lactococcus lactis subsp. lactis KCTC 3769 (ATCC 19435), which encodes 584 amino acids with the predicted molecular mass of 68.7 kDa. KCTC 3769 shares approximately 40% of amino acid sequence identity with the CDase-family of enzymes. The dimeric enzyme with C-terminal six-histidines was heterologously expressed and purified from recombinant E. coli. LLCD showed the highest activity against β-cyclodextrin (CD) at pH 7.0 and 37°C. In particular, LLCD exhibited extremely low activity against starch and pullulan, while its CD-hydrolyzing activity was about 80 times higher than starch. Due to its much higher activity on CD over starch, LLCD has been identified as a member of CDases. However, LLCD can be distinguished from the other common CDases on the basis of its extremely low hydrolyzing activity against starch, pullulan, and acarbose. © 2013, The Korean Society for Microbiology and Biotechnology.


Yoo K.-S.,Chungbuk National University | Kim J.E.,Chungbuk National University | Seo E.,Chungbuk National University | Kim Y.J.,Chungbuk National University | And 4 more authors.
Journal of Microbiology and Biotechnology | Year: 2010

This study was performed to investigate the effects of adding a dual starter on the chemical and sensory characteristics of red wine made of Campbell Early grape. The yeast starter, Saccharomyces cerevisiae, and lactic acid bacteria (LAB) starter, Oenococcus oeni, were used for inoculation in the winemaking process for alcoholic fermentation and malolactic fermentation (MLF), respectively. After 200 days of incubation, the chemical compositions of yeast/LAB-added wine (YL-wine) were compared with those of no-starter-added wine (control) and yeast-added wine (Y-wine). The results show that no significant differences were observed in pH, total sugar, and alcohol content among the wine samples, but the malic acid content in YL-wine was significantly reduced, and various esters and higher alcohols were synthesized. The sensory test revealed that the addition of dual starters resulted in improved overall acceptability in wine. This study emphasizes the importance of O. oeni in addition to yeast in making Campbell Early wine. © The Korean Society for Microbiology and Biotechnology.


Lee G.-J.,Chungcheongbuk do Agricultural Research and Extension Services | Lee G.-J.,South Korean National Institute of Animal Science | Kim S.-D.,Chungcheongbuk do Agricultural Research and Extension Services | Yoon J.-B.,South Korean National Institute of Animal Science | And 2 more authors.
Korean Journal of Horticultural Science and Technology | Year: 2014

This study was carried out to investigate the effects of night-time far-infrared irradiance quality of red pepper dried in greenhouses. This study involved 4 treatments: sunlight alone (control), or sunlight plus nightly far-infrared irradiation at 250 W-6.6 m2 (250 W-6.6 m2), far-infrared irradiation at 250 W-3.3 m2 (250 W-3.3 m2), or far-infrared irradiation 500 W-3.3m-2 (500 W-3.3 m-2). The drying periods were 12 days in 500 W-3.3 m2 and 250 W-3.3 m2, and 14 days in 250 W-6.6 m-2, and 15 days in the control. The daytime temperature was same among the treatments. The lowest temperature was at 23.8°C in control, and 29.5-37.2°C in far-infrared irradiation treatments. The marketable yield was 7-14% higher in far-infrared irradiation treatments compared to the control. The rate of marketability was higher in far-infrared irradiation treatments (93.6-96.3%) than in the control (87.0-87.5%). The American Spice Trade Association (ASTA) value was greatest in the 250 W-3.3 m-2 treatment, followed by 250 W-6.6 m-2, then 500 W-3.3 m-2, and finally the control. Capsaicinoid content showed no regular trend among the treatments. Our results provide an optimized method for reducing drying time of red pepper under sunlight, and improving the quality of dried red pepper. © 2014 Korean Society for Horticultural Science.

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