• Korean Journal of Food Science and Technology
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• v.32 no.1
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• pp.17-24
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• 2000

Reverse osmosis (RO) system was applied to improve wine quality. General wine (GEN) and wines containing different sugar levels $24^{\circ}Brix$ (RO-24) and $24^{\circ}Brix$ (RO-28) by removing pure water using RO system without sugar addition on brewing method. And they were compared by wine aroma analysis. The preparing method of analysis was LLCE (liquid-liquid continuous extraction). And volatile aroma compounds of different wines were prepared for raw, and diluted materials in same proportion. The wine aromas were described by trained twelve panelists for QDA (quantitative descriptive analysis) and showed for FD (flavor dilution)-chromatogram. Consequently, overall acceptability of RO-28 showed better than that of other treatments. Aromas of RO-28 also were represented the high contents of positive aroma compounds such as ethanol and ethyl acetate, which were identified by GC-O and GC-MS.

• Korean Journal of Food Science and Technology
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• v.39 no.4
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• pp.366-371
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• 2007

The volatile components in Eoyuk-jang, a traditional Korean fermented food, were isolated using solvent extraction, and analyzed by gas chromatography-mass spectrometry (GC-MS). A total of 36 components, including 11 aliphatic hydrocarbons, 4 acids, 2 ketones, 5 phenols, 7 alcohols, 1 pyrazines, 4 pyrones and furanones, and 2 miscellaneous components, were found in Eoyuk-jang; among them, butanoic acid was quantitatively dominant. In addition, the aroma-active compounds were determined by gas chromatography-olfactometry (GC-O) using aroma extract dilution analysis (AEDA). A total of 20 aroma-active compounds were detected by GC-O. Butanoic acid (rancid) and methional (cooked potato-like) were the most potent aroma-active compounds with the highest FD factors $(Log_3$, FD), followed by 2-methyl-2-butanol (soysauce-like), 3-hydroxy-2-butanone (buttery), and 2-furanmethanol (burnt sugar-like).

• Korean Journal of Food Science and Technology
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• v.33 no.3
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• pp.373-377
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• 2001

Egg white mix (EWM) added with different ratios of cream $(10{\sim}15%,v/v)$ was fermented with Lactobacillus acidophilus (KCTC 2182) and changes of volatile aroma compounds during fermentation for 21 h were investigated. The amount of volatile aroma compounds between pre-fermented EWM, 15 h-fermented EWM, soft ice cream prepared from fermented EWM, and hard ice cream prepared from soft ice cream was compared. The results were as follows: (1) The amount of ethanol increased gradually until 9 h and increased rapidly to maximum value at 12 h and then decreased rapidly. The amount of acetone at 12 h was slightly higher, but it was not changed markedly during fermentation. Diacetyl was detected at 3 h and increased gradually to maximum value until 15 h and then decreased slightly. The amount of butanol was not changed markedly during fermentation. Acetoin was detected at 3 h and increased rapidly until 15 h and then increased gradually. (2) The amount of acetone, ethanol, diacetyl and butanol of pre-fermented sample, 15 h-fermented sample, soft ice cream and hard ice cream increased in proportion to the amount of cream added to EWM. However, the amount of butanol was relatively constant regardless of added cream ratio. The amount of volatile aroma compounds of soft ice cream was higher than that of other samlples, while that of pre-fermented sample was lower than that of other samples. Diacetyl and acetoin were not detected in pre-fermented sample.

• Korean Journal of Food Science and Technology
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• v.46 no.6
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• pp.734-738
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• 2014

This study was conducted to investigate whether four hot-water extraction steps could effectively remove off-flavor from bovine bone extracts and produce compounds with pleasant aroma. Experiments were performed using a mass spectrometry-electronic nose and Fourier transform-near infrared spectrometer (FT-NIR). Off-flavor compounds were removed by washing and extraction with hot water. Steaming treatment produced compounds with a better aroma, such as 4-methylthiazole. In addition, a change in flavor compounds was observed in treated samples.

• Journal of Microbiology and Biotechnology
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• v.28 no.8
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• pp.1260-1269
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• 2018

Production of good Koji primarily depends upon the selection of substrate materials and fermentative microflora, which together influence the characteristic flavor and aroma. Herein, we performed comparative metabolomic analyses of volatile organic compounds (VOCs) and primary metabolites for Koji samples fermented individually with Bacillus amyloliquefaciens and Aspergillus oryzae. The VOCs and primary metabolites were analyzed using headspace solid phase microextraction (HS-SPME) followed by gas chromatography time-of-flight mass spectrometry (GC-TOF-MS). In particular, alcohols, ketones, and furans were mainly detected in Bacillus-fermented Koji (Bacillus Koji, BK), potentially due to the increased levels of lipid oxidation. A cheesy and rancid flavor was characteristic of Bacillus Koji, which is attributable to high content of typical 'off-flavor' compounds. Furthermore, the umami taste engendered by 2-methoxyphenol, (E,E)-2,4-decadienal, and glutamic acid was primarily detected in Bacillus Koji. Alternatively, malty flavor compounds (2-methylpropanal, 2-methylbutanal, 3-methylbutanal) and sweet flavor compounds (monosaccharides and maltol) were relatively abundant in Aspergillus-fermented Koji (Aspergillus Koji, AK). Hence, we argue that the VOC profile of Koji is largely determined by the rational choice of inocula, which modifies the primary metabolomes in Koji substrates, potentially shaping its volatolome as well as the aroma characteristics.

• Food Science of Animal Resources
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• v.34 no.2
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• pp.166-171
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• 2014

The aim of this study is to examine the influences of spices on the amounts and compositions of volatile compounds released from cooked beef patty. Beef patty with 0.5% of spice (nutmeg, onion, garlic, or ginger powder, w/w) was cooked by electronic pan until they reached an internal temperature of $75^{\circ}C$. A total of 46 volatile compounds (6 alcohols, 6 aldehydes, 5 hydrocarbons, 6 ketones, 9 sulfur compounds, and 14 terpenes) from cooked beef patties were detected by using purge-and-trap GC/MS. The addition of nutmeg, onion, or ginger powder significantly reduced the production of the volatile compounds via lipid oxidation in cooked beef patty when compared to those from the control. Also, the addition of nutmeg and garlic powder to beef patty generated a lot of trepans or sulfur volatile compounds, respectively. From these results, the major proportion by chemical classes such as alcohols, aldehydes, hydrocarbons, ketones, sulfur compounds, and terpenes was different depending on the spice variations. The results indicate that addition of spices to the beef patty meaningfully changes the volatile compounds released from within. Therefore, it can be concluded that spices can interact with meat aroma significantly, and thus, the character of each spice should be considered before adding to the beef patty.

• Journal of Microbiology and Biotechnology
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• v.10 no.4
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• pp.476-481
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• 2000

A linear correlation, by the stepwise multiple regression analysis, was found between the sensory test of Sigumjang aroma and the gas chromatographic data which were transformed with logarithm. GC data is the most objective method to evaluate Sigumjang aroma. A multiple correlation coefficient and a determination coefficient of more than 0.9 were obtained at the 9th and 13th steps, respectively. At step 31, the coefficient of determination level of 0.95 was attained. The accuracy of its estimation became higher as the number of the variables entered into the regression model increased. Over 90% of the Sigumjang aroma was explained by 13 compounds indentified on GC. The contributing proportion of the peak 26 was the highest followed by peaks 57 (9.27%), 29 (7.51%), 54 (6.01%), 8 (5.99%), 49 (4.97%), and 13 (4.11%).

• Culinary science and hospitality research
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• v.24 no.1
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• pp.140-150
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• 2018

In this study, effects of microground coffee on the quality characteristics and acceptability of instant coffee with probiotics were investigated. A central composite design with two factors (roasting degree and dose of microground coffee) was used and ranges of roasting degree and dose were 30~50 (L value) and 5~10% respectively. Aroma preference, sweetness intensity, bitterness intensity, acidity intensity, body intensity and overall acceptability were evaluated as sensory characteristics and quadratic regression models of all the properties were significant. Especially in aroma preference and overall acceptability, the higher roasting degree and dose of microground coffee, the more aroma preference and overall acceptability of the coffee increased. And this results accorded with the object of this study to increase aroma preference and overall acceptability by blending microground coffee with instant coffee. On the other hand, 129 of aroma compounds were detected in instant coffee with microground coffee but 2,5-dimethyl-pyrazine, ethyl-pyrazine and furfural were significant in quadratic regression models. The optimal conditions were predicted by response surface methodology and desirability function approach and the optimal conditions of roasting degree and dose of microground coffee were 30(L value), 8.4%(w/w) respectively to maximize 2 sensory characteristics (overall preference, aroma preference) and 3 aroma components (2,5-dimethyl-pyrazine, ethyl-pyrazine, furfural).

• Korean Journal of Food Science and Technology
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• v.33 no.5
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• pp.529-533
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• 2001

This study was carried out to characterize aroma of semi-fermented teas made traditionally in Korea temple. These teas had favorable floral aroma. The extraction of aroma compounds was accomplished by a simultaneous distillation and extraction method using a Likens and Nickerson's extraction apparatus. The concentrated extract was analyzed and identified by GC and GC-MSD. The main aroma components of these teas were 3-methylbutanal, 2-methylbutanal, (E)-2-hexenal, phenylacetaldehyde, 2-phenyl ethanol, geraniol, ${\beta}-ionone$ and nerolidol. Particularly, the concentration of phenylacetaldehyde was much higher concentration in semi-fermented teas than in green tea prepared from same place. The GC patterns of the aroma components in the semi-fermented teas were slightly different, though they were prepared in same place.

• Proceedings of the KAIS Fall Conference
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• 2005.05a
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• pp.287-289
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• 2005

Repellent effcacies of two natural aroma compounds. citronella and citronellal, against mosquitoes were evaluated both in field and in vitro. In vitro, the experiment was conducted with three controlled bands impregnated with $30\%$ citronella extract, $15\%$ citronella extract and $30\%$ citronellal extract, and with band impregnated $30\%$ citronella in field. Raw data was obtained by the means of counting numbers bitten by mosquitoes per unit time, namely human bait method. Comparative repellent efficacies of above three controlled bands were calculated at $86\%$, $73\%$, and $78\%$, respectively in vitro, and $80\%$ in field, showing high repellent effectiveness against mosquitoes. This estimation was also confirmed by t-test compared between control group and each experimental group.