• Journal of Sensor Science and Technology
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• v.27 no.2
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• pp.118-125
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• 2018

An evaluation system for an electronic-nose concept using three types of metal oxide gas sensors that react similarly to the human olfactory cells was constructed for the quantitative and qualitative evaluation of aroma fragrances. Four types of aroma fragrances (lavender, orange, jasmine, and Roman chamomile), which are commonly used in aromatherapy, were evaluated. All the gas sensors reacted remarkably to the aroma fragrances and the good correlation of r=0.58-0.88 with the aromatic odor intensities by olfaction was confirmed. From the results of the analysis of an electronic-nose concept for classifying the characteristics of aroma oil fragrances, aroma oils could be classified using the fragrance characteristics and oil extraction methods with the cumulative variability contribution rate of 95.65% (F1: 69.65%, F2: 26.03%) by principal component analysis. In the pattern recognition based on the artificial neural network, the four aroma fragrances were 100% recognized through the training data of 56 cases (70%) out of 80 cases, and the pattern recognition rate was 57.1%-71.4% through the validation and testing data of 24 cases (30%). The pattern recognition success rate through all confusion matrices was 82.1%, indicating that the classification of aroma oil fragrances using the three types of gas sensors was successful.

• Journal of the Korean Applied Science and Technology
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• v.37 no.1
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• pp.38-48
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• 2020

The aroma pattern was analyzed using electronic nose to examine the possibility of origin discrimination according to the mixing ratio of Chinese and Korean red ginseng concentrates. The origin of Chinese red ginseng concentrate and Korea red ginseng concentrate could be distinguished and the pattern of aroma component detected decreased as the mixing ratio of Chinese red ginseng concentrate increased. Cultivar and habitat of Korean red ginseng concentrated was remarkably distinguished by the chromatogram of frequency pattern, derivative pattern and visual pattern using olfactory images known as vapor print^TM.

• Journal of Korea Society of Digital Industry and Information Management
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• v.4 no.3
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• pp.85-90
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• 2008

Recently, with the sensor technology, research about the electronic nose system which imitated the olfactory organ are being pushed actively. But, in case of general electronic nose system, an aroma is measured at the laboratory space where blocked external environment and is analyzed a part of measured data. In this paper, we propose the system which can measure and recognize an aroma in natural environment. We propose the Entropy algorithm which can detect the sensor reaction section among the continuous detection processing about an aroma. And we implement the aroma recognition system using the PCA(Principal Components Analysis) and K-NN(K-Nearest Neighbor) about the detected aroma. In order to evaluate the performance, we measured the aroma pattern, about 9 aroma oil, 50 times respectively. And we experimented the aroma detection and recognition using this. There was an error of 0.2s in the aroma detection and we get 84.3% recognition rate of the aroma recognition.

• Korean Journal of Food Science and Technology
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• v.33 no.1
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• pp.24-27
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• 2001

This study was performed to analyse aroma patterns of Nagaimo, Ichoimo and Tsukuneimo by the electronic nose with 32 conducting polymer sensors. Response by the electronic nose was analysed by the principal component analysis(PCA). Sensory evaluation also for organoleptic taste and odor of Nagaimo, Ichoimo and Tsukuneimo was performed. Nagaimo was very crunchy and sweet. Tsukuneimo was roasted nutty, hard, viscid taste and sticky. Ichoimo had intensive unique yam flavor and moderate hardness between Nagaimo and Ichoimo. Intensity of Ichoimo for unique yam flavor by the electronic nose was the strongest. The quality factor(QF) of PCA for normalized pattern by thirty two sensors showed less than 2, and so aroma pattern of three yam cultivars had no difference. But when the PCA was performed for normalized pattern by eight selected sensitive sensors, the QF for Nagaimo and Tsukuneimo is 2.057. Thus aroma pattern between Nagaimo and Tsukuneimo could be distinguished.

• Korean Journal of Food Science and Technology
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• v.32 no.1
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• pp.9-16
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• 2000

Aroma of various extracts of Agastache rugosa O. Kuntze was analyzed by electronic nose with 32 conducting polymer sensor arrays. The 57 extracts were prepared by extraction solvents (hot water, ethanol and NaCl solution), extraction temperatures $(100,\;80\;and\;60^{\circ}C)$, solvent mixture ratios of solvent (10 times 35 times) and parts of Agastache rugosa O. Kuntze(flower, leaf and stem). Aroma pattern of Agastache rugosa O. Kuntze extracts showed big difference in normalized pattern and odor intensity with extraction temperatures and parts, but showed no difference with extraction solvents. Especially in the case of ethanol extracts, because odor of ethanol itself was very strong, difference in aroma of extracts with extraction temperatures and parts did not show through the electronic nose. The organoleptic characteristics such as mint odor, grassy odor, mint taste, medicinal herb taste and sweetness for Agastache rugosa O. Kuntze extracts were determined by the profile test and the result of sensory evaluation by quantitative descriptive analysis was explained to QDA diagram. In correlation with the result of aroma analysis by electronic nose and the sensory evaluation, difference in aroma pattern among the extracts concretely brought to light definite characteristics such as mint odor and mint taste.

• Korean Journal of Food Science and Technology
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• v.34 no.1
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• pp.13-17
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• 2002

The study was to analyze aroma patterns of Gastrodiae Rhizoma by the electronic nose with conducing polymer 32 sensors. Response by the electronic nose was analyzed by the principal component analysis (PCA). Sensory evaluation for the organoleptic characteristics of Gastrodiae Rhizoma was also performed. Raw Gastrodiae Rhizoma was very intensive in overall odor and taste. Hot air-dried $60^{\circ}C$ Gastrodiae Rhizoma was relatively weak in overall odor and taste. Intensity of aroma in the electronic nose was the highest in $60^{\circ}C$ hot air-dried Gastrodiae Rhizoma. As quality factor (QF) calcuated from PCA map of normalized pattern data by thirty two sensors showed less than 2, and so aroma pattern among raw, freezed-dried, and hot-air dried Gastrodiae Rhizoma had no difference. When PCA was performed for normalized pattern data by the selected sensitive ten sensors, QF value between raw and $60^{\circ}C$ hot air-dried Gastrodiae Rhizoma was 2.366. Thus aroma pattern of raw and $60^{\circ}C$ hot air-dried Gastrodiae Rhizoma was discriminated in electronic nose.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.9
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• pp.1500-1506
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• 2018

Objective: Although Hanwoo has been selected as the superior commercial beef cattle breed in Korea, Chikso (Korean brindle cattle) is still recognized as a valuable breed for beef production. The aim of this study was to compare the meat quality, fatty acid composition and aroma volatiles of beef from Chikso and Hanwoo steers maintained under identical feed management, as information regarding these characteristics is still limited. Methods: A total of 19 carcasses with a quality grade of 1 were selected, and strip loin (longissimus lumborum) cuts were collected from 11 Hanwoo carcasses and 8 Chikso carcasses. Meat quality and aroma analyses were performed at day four postmortem. Results: Though Hanwoo strip loin tended to have higher fat content (15.37%) than Chikso (12.01%), no significant differences were observed. Meat pH, water-holding capacity, cooking loss, shear force value, instrumental surface color (Commission International De L'eclairage $L^{\star}$, $a^{\star}$, $b^{\star}$, chroma, and hue angle) and fatty acid composition were not significantly different. Roasted Chikso beef released more intense aroma than roasted Hanwoo beef based on the total area units of identified volatiles. Among identified volatiles, the amounts of toluene, heptanal, octanal, and nonanal were higher in roasted Chikso beef than in roasted Hanwoo beef. In addition, the aroma pattern of the roasted beef from these breeds was well-discriminated by electronic nose. Conclusion: No distinct differences were found in terms of meat quality between Hanwoo and Chikso beef in this study. However, the aroma pattern and volatiles of roasted Hanwoo and Chikso beef were different according to instrumental analysis.

• Journal of the East Asian Society of Dietary Life
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• v.16 no.6
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• pp.724-730
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• 2006

Two types of powdered chungkookjang, were prepared by a hot air-drying process, and the freeze-drying, and composition and aroma patterns were examined. The fresh chungkookjang was composed of 53.8% moisture, while the hot air-dried and freeze-dried powdered chungkookjang contained 5.2% moisture, $39.3{\sim}39.4%$ crude protein, $18.6{\sim}18.7%$ crude lipid, $4.7{\sim}5.0%$ crude ash, and $31.7{\sim}32.2%$ carbohydrate. The pH of the each powered chungkookjang was similar, ranging from 6.5 to 6.7. The freeze-dried powdered chungkookjang showed the highest lightness (67.30), yellowness (59.37) while the highest redness (43.1) was observed in the hot air-dried chungkookjang. Each chungkookjang was analysed by an electronic nose with metal oxide 12 sensors and SPME-GC/MS. The response by the electronic nose was analysed by principal component analysis (PCA). The proportion of the first principal component was 90.47%, suggesting that each aroma pattern of the prepared chungkookjang was discriminated. SPME-GC/MS was used to identify the pyrazines. The percentage of pyrazines observed in the fresh chungkookjang, freeze-dried powdered chungkookjang, and hot air-dried powdered chungkookjang was 6.6, 3.8 and 15.9%, respectively. A higher overall preference was obtained from the hot air-dried powdered chungkookjang than with the freeze-dried powdered chungkookjang.

• Korean Journal of Food Science and Technology
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• v.31 no.2
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• pp.314-321
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• 1999

This study was performed to test application possibility of electronic nose with 32 conducting polymer sensor arrays for aroma analysis of persimmon vinegar. The 20, 30, 40, 50, 60, and $70^{\circ}Bx$ persimmon vinegar concentrates were prepared by vacuum concentration at $55^{\circ}C$. The recovery yield of water soluble solid to concentrates was 55.5% on $20^{\circ}Bx$ persimmon vinegar concentrate. As the concentration of persimmon vinegar concentrates increased, pH of concentrates increased and acidity as acetic acid decreased. From sensory evaluation for persimmon vinegar concentrates, as the concentration of persimmon vinegar concentrates increased, their cooking odor and umami taste increased, sour taste and acidic odor decreased, salty odor and astringency were not changed. Aroma analysis by electronic nose (AromaScan) showed no difference in normalized pattern and odor intensity among persimmon vinegar concentrates. All quality factors among concentrates also were less than 1.042. And so the electronic nose with conducting polymer sensor was not suitable for aroma analysis of persimmon vinegar concentrate.

• Journal of Ginseng Research
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• v.41 no.1
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• pp.85-95
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• 2017

Background: American ginseng (Panax quinquefolius L.) and Asian ginseng (Panax ginseng Meyer) products, such as slices, have a similar appearance, but they have significantly different prices, leading to widespread adulteration in the commercial market. Their aroma characteristics are attracting increasing attention and are supposed to be effective and nondestructive markers to determine adulteration. Methods: The aroma characteristics of American and Asian ginseng were investigated using gas chromatography-mass spectrometry(GC-MS) and an electronic nose (E-nose). Their volatile organic compounds were separated, classified, compared, and analyzed with different pattern recognition. Results: The E-nose showed a good performance in grouping with a principle component analysis explaining 94.45% of variance. A total of 69 aroma components were identified by GC-MS, with 35.6% common components and 64.6% special ingredients between the two ginsengs. It was observed that the components and the number of terpenes and alcohols were markedly different, indicating possible reasons for their difference. The results of pattern recognition confirmed that the E-nose processing result is similar to that of GC-MS. The interrelation between aroma constituents and sensors indicated that special sensors were highly related to some terpenes and alcohols. Accordingly, the contents of selected constituents were accurately predicted by corresponding sensors with most $R^2$ reaching 90%. Conclusion: Combined with advanced chemometrics, the E-nose is capable of discriminating between American and Asian ginseng in both qualitative and quantitative angles, presenting an accurate, rapid, and nondestructive reference approach.