• KSBB Journal
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• v.4 no.1
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• pp.40-47
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• 1989

Changes of principal components of crude green tea were determined after 30 min. of heat treatment at 10$0^{\circ}C$, l15$^{\circ}C$, 14$0^{\circ}C$, 16$0^{\circ}C$. Four kinds of free sugars(sucrose, fructose, glucose, raffinose) and an unidentified sugar compound were separated in green tea by using High Performance LiQuid Chromatography (H.P.L.C.). 26-34 peaks were isolated as aroma compounds of green tea by means of Gas Liquid Chromatography(G.L.C). The typical aroma component of green tea such as linalool, furfural, benzyl alcohol and 13 other substances were identified. Contents of most compounds were decreased by heat treatment. Especially contents of free amino acids, free sugars, vitamin C and tannins were decreased remarkably, while those of total nitrogen and soluble nitrogen were hardly changed. The effect of heat treatment on organoleptic quality of tea extracts were examined by sensory evaluation of which result indicated the most favorable tea was produced at 115$^{\circ}C$. The Percentages of loss in contents of total sugars, reducing sugars, vitamin C, free amino acids and tannins at 115$^{\circ}C$ were 17%, 16%, 36%, 12% and 15% respectively, while those were 38%, 53%, 55%, 74% and 23% at 16$0^{\circ}C$.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.4
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• pp.577-583
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• 2014

In this study, we evaluated fermentation characteristics of microorganism with antimicrobial activity in makgeolli made from various kinds of koji and nuruk during fermentation. The pH of nuruk groups decreased compared to the koji groups after 3 days of fermentation. Acidity and alcohol contents of nuruk groups significantly increased compared to the koji groups. The total sugar contents of the koji groups were significantly higher than those of the nuruk groups after 15 days of fermentation. Sensory scores of koji groups (DKB) were higher than those of other samples. Antimicrobial activities of nuruk group (GND and ANF) against Salmonella enterica, Bacillus subtilis, Escherichia coli, and Bacillus cereus were significantly higher compared to the koji group. ST-1, isolated from (Geumjeonggu nuruk D), showed the highest antimicrobial activity and was identified as Paenibacillus polymyxa strain RCP6 based on 16S rRNA sequencing. Our result suggest that Paenibacillus polymyxa from nuruk group produces a bacteriocin-like substrate with antimicrobial activity.

• Korean Journal of Food Science and Technology
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• v.36 no.4
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• pp.609-615
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• 2004

Old rice showed higher initial pasting and peak viscosity temperatures than new rice. Reducing sugar contents of rice harvested in 1998 were lowest 24hr after digestion with saccharification enzyme, but similar after 36hr, among rice samples tested. Fermentation characteristics and preference of Takju made by fermenting raw rice harvested from 1998 to 2001 far 7 days were investigated. Alcohol contents during Takju brewing rapidly increased for 5 days to 17.3-18.1%, and were 17.5-18.2% on day 7, with those of Takju brewed with rice harvested in 1998 being highest in both cases. Sensory evaluation results showed Takju fermented with rice harvested in 2000 had highest sweetness, preference, and sourness, and that fermented with rice harvested in 1999 had highest sourness, but no voluntariness was shown between each other (meaning not clear). Moisture contents and gelatinization characteristics of old and new rice were slightly different, although factors adversely affecting Takju such as flavor of old rice did not appear in sensory evaluation probably because old rice was stored in rice bran farm for long times and used after milling. Results reveal surplus old rice could be utilized for Takju brewing.

• Korean Journal of Food Science and Technology
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• v.39 no.5
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• pp.546-551
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• 2007

The physicochemical characteristics and sensory properties of Jinyangju were investigated at different degrees of milling (DOM; 0, 5, 7, and 10%) of waxy glutinous rice after 2 weeks of fermentation. The final pH values were 3.50, 3.84, 4.16, and 4.21 at the DOMs of 0, 5, 7, and 10%, respectively. The final total acidities were 1.21, 1.16, 0.94, and 0.91%; final total sugar contents were 6.38, 6.51, 5.54 and 5.40%; and final alcohol contents were 14.50, 14.50, 15.50, and 15.40%, respectively. Hunter L-value of the DOM 5% rice was lower those of the DOM 7% and 10% rice, but its Hunter b-value was higher than those of the DOM 7% and 10% rice. However, Hunter a-value of the Jinyangju were not significantly different among the samples (p>0.05) Hunter L-value. The Jinyangju made with the DOM 7% rice showed the highest overall sensory preference.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.8
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• pp.1090-1096
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• 2009

This study is to develop wine with germinated brown rice and red pepper (Capsicum annuum) and to make effective use of the rice and red pepper. The results of alcohol fermentation were as follows. pH 5.5 was decreased to 4.5$\sim$5.1 during fermentation. The total acidity was changed from 0.56% in initial fermentation to 0.96$\sim$1.42% in after fermentation. Reducing sugar was changed from 0.27% in initial fermentation to 1.33$\sim$1.40% at the end of the fermentation. The ethanol content was 16.6$\sim$17.0% at the end of the fermentation. The addition of 10$\sim$50% red pepper did not have influence on the fermentation. From Hunter's L, a, and b values, a (redness) and b (yellowness) value were increased according to content of red pepper addition. The major volatiles were ethyl acetate, 1-propanol, 2-methyl-1-propanol, 3-methyl-butanol and benzeneethanol. Capsaicin content in the samples of red pepper addition was the highest in 50% and the lowest in 10%. In sensory evaluation, the wine with 20% red pepper had the highest acceptance scores in all of the properties examined than those of other samples.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.31 no.4
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• pp.454-464
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• 1986

To find main factors to affect tobacco culture and quality, NC 2326 (Nicotiana tabacum L.) was cultivated in Korea and in the United States under different plant density, fertilization, mulching and curing. Among the chemical characteristics of the both experimental soils, the organic matters were similar concentration in both locations but effective phosphorous contents were higher in Oxford in the United States. Plant height, length and width of the largest leaf, leaf thickness, and midrib ratios were larger in Oxford than in Suwon in Korea. Also they were larger in non mulching system than in mulching system. But the total numbers of the leaves were decreased in non mulching system. The content of nicotine was higher in the plant grown in Suwon than in Oxford. The concentrations of nicotine and sugar tend to increase in mulching system comparing of non mulching system. During the growing, the concentration of non-volatile organic acids was higher in Suwon, while it was lower in cured leaf produced in Suwon. Also the contents of total fatty acids were lower in the harvested leaf grown in Suwon, but not in cured tobacco. Forty three compounds identified among the volatile oils from these experimental samples were quantified. The concentrations of the major components related to the tobacco flavour such as damascone, damascenone, solanone, nor-solanadione, and megastigmatrienones were higher in the cured tobacco produced in Oxford rather than in Suwon.

• Applied Biological Chemistry
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• v.42 no.3
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• pp.235-239
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• 1999

During storage of $45^{\circ}Bx$ cloudy, $50^{\circ}Bx\;and\;72^{\circ}Bx$ clear apple juice concentrates for 18 months, the changes in microbial counts and physicochemical properties were investigated. Little viable microbial counts were detected in $50^{\circ}Bx\;and\;72^{\circ}Bx$ clear concentrates during all storage time and a few in $45^{\circ}Bx$ cloudy concentrates during the only first storage stage. In all three concentrates, any changes were not found in pH and titrable acidity. But Hunter L values were decreased and a, b values were increased. Alcohol soluble color(ASC) were increased and vitamin C contents rapidly decreased, especially during the first three months. The contents and compositions of free sugars were showed a little change. It seemed that the change in ASC was more closely related with that of vitamin C contents than that of reducing sugar contents.

• Korean Journal of Food Science and Technology
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• v.39 no.3
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• pp.309-314
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• 2007

The physicochemical and sensory characteristics of rice wine, Yakju, made with different additions of red yeast rice (0, 10, 20, 30, and 40%) were investigated. The pH of the rice wine decreased and the total acidity increased with greater additions of red yeast rice. Furthermore, the total sugar content increased and the alcohol content decreased with increasing amounts of red yeast rice. The color L-value diminished and the color a- and b-values increased with increasing amounts of red yeast rice. Among the volatile flavor compounds, esters, aldehydes, alcohols, and acids were the most important aroma-active compounds identified in the rice wine. The sample with the 10% red yeast rice addition had the highest ester content, which is a primary component in fruit fragrance. The highest overall acceptability values in the sensory test for color, flavor, taste, and overall favorite were 5.10, 5.75, 5.15, 4.65, and 4.50, respectively, with the addition of 10% red yeast rice.

• 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.

• Applied Biological Chemistry
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• v.29 no.2
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• pp.227-236
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• 1986

Three types of Kochujang(soybean-red pepper paste) were prepared with glutinous rice flour (group A), glutinous rice grain (group B) or the mixture of flour and grain (group C) to investigate some chemical composition, enzyme activities and the texture during aging period. 'There were no remarkable differences in the contents of moisture, crude protein, crude fat, minerals and alcohols, titrable acidity and pH among the tested groups. Amino nitrogen content, acidic protease and saccharogenic amylase activities were measured to be higher values for group A whereas reducing sugar content higher values for group B. All tested groups contained Ca, Cu, K, Mn, Mg, P and Fe, particularly higher amount of K but a trace of Cu, Mn and Fe. All tested groups showed higher content of aspartic acid, glutamic acid, cystine, proline and lower content of histidine and valine 60 days after the preparation. The total free amino acid content was 16.49 mg/g for group A, 13.68 mg/g for group B and 15.84 mg/g for group C. The measurement of texture showed high values of hardness and adhesiveness with group A immediately after the preparation and with group B at the end of aging. Cohesiveness and springiness were high with group A while low with group B throughout aging period.