• Journal of the Korean Society of Food Culture
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• v.28 no.6
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• pp.640-650
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• 2013

Soy sauce, a basic ingredient in Asian cuisine, is made of fermented soybeans, salt, water, and barley or wheat flour. The sensory characteristics of soy sauce are not only determined through its main ingredients but also by various flavor compounds produced during the fermentation process. This study was conducted to identify the sensory attributes of five different commercial soy sauce samples that differ in Meju types (traditional Meju or modified Meju) and usage types. Thirty three sensory attributes, including appearance (1), odor (16), flavor (14), and mouthfeel (2) attributes, were generated and evaluated by eight trained panelists. The collected data were analyzed by analysis of variance and principal component analysis. There were significant differences in the intensities of all sensory attributes among the soy sauce samples. Soy sauce made with traditional Meju had high intensity of fermented fish, beany, musty odors and salt, Cheonggukjang, fermented fish flavors. Whereas two soy sauces made with modified Meju were strong in alcohol, sweet, Doenjang, roasted soybean flavors. Two soy sauces for soup made with modified Meju had medium levels of briny, sulfury, fermented odors and bitter, chemical flavors and biting mouthfeel characteristic.

• Membrane and Water Treatment
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• v.9 no.2
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• pp.105-113
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• 2018

Maillard reaction products like melanoidins present in industrial fermentation wastewaters are complex compounds with various functional properties. In this work, novel ultrafiltration (UF) mixed matrix membrane (MMM) composed of polysulfone (PSF) and nanocomposites was prepared through a phase inversion process for the recovery of melanoidins. Nanocomposites were prepared with acid functionalized multiwalled carbon nanotubes (MWCNTs) as the reinforcing filler for chitosan-thermoplastic starch blend. Higher nanocomposites content in the PSF matrix reduced the membrane permeability and melanoidins retention indicating tighter membrane with surface defects. The membrane surface defects could be sealed with dilute polyvinyl alcohol (PVA) solution. The best performing membrane (1% nanocomposites in 18% PSF membrane sealed with 0.25% PVA coating) resulted in uniform melanoidins retention of 98% and permeability of 3.6 L/m2 h bar over a period of 8h. This demonstrates a low fouling PSF membrane for high melanoidins recovery.

• The Korean Journal of Food And Nutrition
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• v.33 no.6
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• pp.737-746
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• 2020

In this study, we developed vinegar depending on the quantity consumed and type of peeled and unpeeled roots of Platycodon grandiflorum (PG) using Acetobacter pasteurianus A11-2, analyzed vinegar samples using colorimeter and HPLC for 15 days to assess the characteristics on quality, and evaluated their antioxidant activity using 1,1-diphenyl-2-picry1 hydrazy1 (DPPH) and 2.2'-azinobis-(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical scavenging activities. The major result in PG vinegar was the high acidity of 6.39~6.74% and alcohol was totally converted on the 15th day of fermentation. When we fermented vinegar from peeled roots of 8% PG with a starter culture, we observed high contents of acetic acid, platycodin D, and total polyphenol and high antioxidant activity. Moreover, the vinegar fermented using 8% peeled roots of PG had the high intensity on umami and sour taste and low salty, bitter, and astringent tastes. Consequently, we could develop the PG vinegar with quality and functional characteristics from 8% peeled roots and A. pasteurianus A11-2.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.1
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• pp.78-89
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• 1994

To evaluate of quality of Yakju brewed with different types of fermenters(Nuruk) and brewed by a method described in Sallymkyungjae, blucoamylase and protease and protease activities of Nuruk were measured, and proximate composition , coloring degree, acetaldehyde , alcohol , , fusel oils , amino acid content , mineral content and sugar composition of Yakju samples were also determined. It was foung that the lower the pH, the lower the glucoamylase acitvity in Nuruk samples A to E . In A, B, D and H, protease activity washigher at ph 5.5 than at pH 5.0 . Yakju sampels 1 to 5 during fermentation , total acidity and amino acid content were high at the first step and were getting lower gradually at the second step. In Yakju samples 6 to 11 , ethanol content was high in 6b, 7b, 8a, 8b and 11b. At the second step, residual sugar content was getting higher gradually in 7 a, 11 a and 11b. The coloring degree of Yakju wasinfluenced by not only color of Nuruk but also Fe content in Yakju . Of the Yakju examined , only 9a and 9b contained acetaldehyde in trace amounts. Thanol content was the highest in 8a and 8b. Fusel oil content was high in 8a and 8b. In samples 6 to 9 , aspartic acid content was higher in treatment a than treatment a than treatment b, but tyrosine , histidine and proline contents were higher in treatment a than treatment b. The levels of frucose, melibiose, sorbitol, and arabinose in Yakju brewed from unsteamed rice were higher than in Yakju brewed from steamed rice. K content was the lowest in 9a and 9b. Na content was higher in treatment a than in treatment a than in treatment b. In only 6a, Ca/P ratio was more than one.

• Food Science and Preservation
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• v.20 no.6
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• pp.886-893
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• 2013

Several indigenous sulfite-resistant yeasts were isolated at the microbial succession stage of yeast flora during spontaneous fermentation of Campbell Early grapes using a YPD plate that contained 200 mg/L or 500 mg/L potassium metabisulfite. When they were applied to the wine fermentation using the Campbell Early grape and apple juices, strains S13 and D8 showed strong alcohol fermentation and good flavor production. They were identified as Saccharomyces cerevisiae in the phylogenetic analysis based on their ITS 1-5.8S-ITS II DNA sequences. The two yeast strains grew to a high cell density in the YPD media supplemented with 40%(w/v) glucose. They also grew rapidly in the YPD media at $40^{\circ}C$. While strain S13 showed some differences in cell density at the two temperatures, no marked difference was observed during the culture of strain D8. The strains grew relatively well at pH 5.0 and 9.0 compared with pH 7.0, which was the optimum pH for their growth. Especially, strain S13 cultivated in the YPD media at pH 9.0 grew to 93% of the growth of strain D8, which was obtained at pH 7.0.

• Korean Journal of Food Science and Technology
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• v.50 no.5
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• pp.464-473
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• 2018

The objective of the current study was to evaluate the effects of roasting methods on volatile flavor compounds of boricha using solvent-assisted flavor evaporation-gas chromatography (GC)-mass spectrometry and GC-olfactometry. The barley roasting methods tested were air roasting (AR), drum roasting (DR), and air/drum roasting (ADR). Twenty, twenty-one, and eighteen aroma-active compounds were detected in the products of AR, DR, and ADR, respectively. Guaiacol (smoky), 2-acetylpyrazine (almond-like), and furfuryl alcohol (burnt sugar-like) were detected as high intensity aroma-active compounds. Intensities of most aroma-active compounds produced by the DR method were higher. On the other hand, aroma intensities of phenols produced by the AR method, such as guaiacol and 2-methoxy-4-vinylphenol (curry-like), tended to be stronger. Aroma characteristics of phenols are not considered to be desirable for boricha. Although roasting time for DR was longer than that for AR, DR may be an effective barley roasting method for enhancing desirable aroma characteristics of boricha.

• Korean Journal of Food Science and Technology
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• v.50 no.2
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• pp.123-131
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• 2018

The objective of this study was to evaluate the effect of roasting degree of barley on aroma characteristics of boricha (barley tea) using solvent-assisted flavor evaporation-gas chromatography-mass spectrometry and gas chromatography-olfactometry. Fifteen volatile compounds including pyrazine, ethylpyrazine, butyrolactone, and guaiacol were considered important volatile compounds, which are generated by roasting barley, because concentrations of those volatiles were significantly increased (p<0.05) as roasting degree of barley was darker. Guaiacol (smoky), furfuryl alcohol (burnt sugar), and furfural (caramel) were detected as aroma-active compounds of boricha with high intensity. Aroma intensity of aroma-active compounds in boricha increased with increase in roasting degree of barley. However, one unknown compound with burnt smell was detected as off-flavor in dark roasted barley. Therefore, it is implied that medium roasting of barley is desirable during boricha manufacturing. Furthermore, boricha manufactured with steamed barley contained more abundant volatile flavor compounds, which may lead to better aroma quality of boricha.

• Food Science and Preservation
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• v.18 no.6
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• pp.884-890
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• 2011

In this study, the quality characteristics of eight kinds of non-sterilized commercial makgeolli were investigated. The alcohol contents of five kinds of makgeolli were determined to be as follows: 5.7~5.8%, G $6.7{\pm}0.1%$, D $6.8{\pm}0.2%$, and C $7.5{\pm}0.1%$. As for the titratable acidity, makgeolli C and D showed higher than 0.5%, H showed $0.49{\pm}0.02%$, and the rest showed 0.45% or less. For the pH levels, there were no significant differences among the samples. The reducing-sugar content was approximately 200 mg%, and those of makgeolli A and F were lower by approximately 90 mg%. As for the organic acids, malic acid was detected only in makgeolli A and G while the acetic-acid content was high in makgeolli C and D. Concerning free sugars, fructose and sucrose were not detected, and the glucose content of makgeolli G was shown to be the highest ($335.1{\pm}40.3$ mg%). The maltose contents were similar ($23.5{\pm}1.0{\sim}45.0{\pm}1.1$ mg%), except for makgeolli G, whose maltose content was $73.5{\pm}1.8$ mg%. For the alcoholic ingredients, 0.4~0.5 mg/mL 1-propanol, 2-methyl-1-propanol, and iso-amylalcohol were detected, a suitable table wine standard. Further studies involving the quality analysis of the leavening agents, fermentation conditions, and fermentation types are needed.

• Food Science and Preservation
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• v.15 no.4
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• pp.512-517
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• 2008

Fermentation characteristics of chestnut-added yakju prepared using various proportions of raw materials such as rice koji, rice flour, cornflour koji and cornflour were investigated. The pH of chestnut-added yakju prepared with cornflour koji and saccharified cornflour showed a higher value than that of chestnut-yakju prepared with rice koji and saccharified rice flour. The total acid content of chestnut-added yakju prepared with rice koji and saccharified rice flour was higher than that of chestnut-added yakju prepared using cornflour koji and sacharified cornflour. The reducing of sugar in chestnut-added yakju prepared with saccharified rice flour or saccharified cornflour was rapid at the first brewing stage, decreased dramatically after 2 days, and then decreased slowly after 5 days of fermentation. The value of L and a, the Hunter values, were high in chestnut-added yakju prepared with cornflour koji, and value b was high in chestnut-added yakju with rice koji. The content of iso-amyl alcohol was the highest of seven kinds of fusel oil found in chestnut-added yakju. Ethanol content increased to $17.6{\sim}18.2%$(v/v) after 8 days of fermentation. The content of lactic acid was the highest of all organic acids in the chestnut-added yakju. Sensory test results on chestnut-added yakju prepared with saccharifed corn flour showed that if rice flour is used as a sugar supplement for chestnut, the yakju prepared using koji had better flavor and taste. If cornflour was used in the preparation of chestnut-added yakju, the used of saccharified cornflour offered superior flavor and taste.

• Journal of Life Science
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• v.23 no.6
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• pp.796-803
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• 2013

Property changes and bacterial characterizations by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) were investigated during the fermentation of Makgeollies by 5 isolated yeast strains. Changes of pH were large between day 0 (pH 6) and day 2 (pH 3) and showed less variation after then. ANOVA analyses revealed that pHs were statistically different with fermentation times (p<0.001), while strains (p=0.60) did not. Acidities were changed from 0.19 to 1.04% and showed rather high increase from day 2, and fermentation times (p<0.001) and strains (p=0.006) represented statistical differences. All strains showed less than 0.150% at amino-type nitrogen contents except S strain showed 0.442% at day 8, and there were no statistical differences with fermentation times (p=0.4558) and strains (p=0.3513). Saccharinities of C strain were higher from day 4, and fermentation times (p<0.0001) and strains (p=0.007) showed statistical differences. Large variation of alcohol concentrations (%) were observed between day 0 (0%) and day 2 (10%) and showed less variation after day 2, and there was no statistical difference with strains. Dominant prokaryotes were Lactobacillus fermentum and Pediococcus pentosaceus, which producing acids and functional materials. Dominant eukaryote was Saccharomyces cerevisiae, which might be resulted from addition of yeasts.