• Korean journal of food and cookery science
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• v.18 no.4
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• pp.455-460
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• 2002

This experiment was conducted to obtain basic information on the natural spice of Elsholtzia splendens, which is one of the native Korean aromatic plants for aromatic, medicinal and ornamental uses. The overall acceptability and the masking effects on the fetid smell of beef were investigated with Elsholtzia splendens-flavored oils by sensory evaluation. The ability of an electronic nose with six metal oxide sensors to classify Elsholtzia splendens flavored oils based on their odors was studied. The response by electronic nose was analyzed by principal component analysis (PCA). In EOI, EOII, and ESI, (이것들이 무엇을 의미하는지 기술할 필요가 있음). overall acceptability of French dressing showed a same level of preference during storage. Fetid smell of beef was not changed by the addition of 4 types of Elsholtzia splendens-flavored oil during storage. In EO I -flavored oil, the proportion of 1st principal component was 0.829, and the proportion of 1st principal component was 0.818 in ESI-flavored oil. The PCA plot was used to detect stored Elsholtzia splendens flavored oils.(앞 뒤 문맥이 안맞음. 뒤에 이어지는 글이 있는지\ulcorner).

• 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.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.39-42
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• 2004

We have designed a portable electronic nose(e-nose) system using an array of commercial gas sensors for recognition and analyzing the various odours. In this paper, we have implemented a portable e-nose system using an array gas sensors and personal digital assistants(PDA) for recognizing and analyzing volatile organic compounds(VOCs) in the field. Field screening for pollutants has been a target of instrumental development for number of year. A portable e-nose system can be substantial benefit to rapidly localize the spacial extent of a pollution or to find pollutants source. And, by using PDA, E-nose have a better function such as the easy user-interface and data transfer by internet from on- site to remote computer. We adapted the Levenberg-Marquardt algorithm based on the back-propagation and proposed the method that could be predicted concentration levels of VOCs gases after classification by separating neural network into two parts.

• Journal of Biomedical Engineering Research
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• v.25 no.5
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• pp.329-334
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• 2004

The electronic nose (E-nose) recently finds its applications in medical diagnosis, specifically on detection of diabetes, pulmonary or gastrointestinal problem, or infections by examining odors in the breath or tissues with its odor characterizing ability. The odor recognition performance of E-nose can be improved by manipulating the sensor array responses of vapors in time-profile forms. The different chemical interactions between the sensor materials and the volatile organic compounds (VOC's) leave unique marks in the signal profiles giving more information than collection of the conventional piecemal features, i.e., maximum sensitivity, signal slopes, rising time. In this study, to use them in vapor recognition task conveniently, a novel time-profile method was proposed, which is adopted from digital image pattern matching. The degrees of matching between 8 different vapors were evaluated by using the proposed method. The test vapors are measured by the silicon-based gas sensor array with 16 CB-polymer composites installed in membrane structure. The results by the proposed method showed clear discrimination of vapor species than by the conventional method.

• Korean Journal of Food Science and Technology
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• v.48 no.2
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• pp.187-191
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• 2016

The objective of this study was to analyze the volatile compounds in rice under various milling degrees using a mass spectrometry-based electronic nose and discriminant function analysis (DFA). Less volatile components were more frequently found in rice with a lower milling degree. Milling degree resulted in a shift of DF1 to the left side of the DFA plot. This indicated that the DF1 scores were correlated with the milling degree of rice. Brown rice was found to have more volatile components regardless of the milling degree. Thus, rice prepared at different milling degrees could be effectively discriminated with electronic nose analysis. Moreover, more volatile components were detected with an increase in storage time. A slight change in volatile components was found with an increase in the milling degree. The electronic nose could predict the milling degree and storage time of rice.

• Food Science and Preservation
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• v.12 no.6
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• pp.613-616
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• 2005

The aging degree of Kimchi fermented at $4^{\circ}C$ for 29 days was evaluated by the correlation between the flavor and the acidity analysis. The Kimchi fermentation induced a gradual reduction in pH and an increase in acidity from $0.26\%$ (initial) to $1.15\%$ (29th day). Flavor pattern of the fermented Kimchi was obtained by the electronic nose system with 12 metal oxide sensors. Electronic nose analysis could differentiate the flavor profiles of Kimchi according to the fermentation periods, making 5 group in the principal component analysis (PCA) plot Therefore, aging degree of Kimchi could be differentiated by flavor patterns analysed by electronic nose.

• Korean Journal of Food Science and Technology
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• v.40 no.1
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• pp.47-55
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• 2008

The objectives of this study were: 1) to develop the sensory lexicons of milk marketed in Korea, 2) to investigate the effects of pasteurization and milk composition on the sensory qualities of milk, and 3) to evaluate the correlation between descriptive analysis and the electronic nose method. Electronic nose and descriptive analyses were conducted to analyze the sensory characteristics of 14 milk samples. The 14 samples were provided from 4 manufacturers with different pasteurization methods, and varied in fat, calcium, and lactose content. Twenty-six sensory lexicons were developed to describe the sensory characteristics of the samples. The low temperature, long-time processed milk had a distinctive 'bi-rim' flavor regardless of the milk composition. The lactose-free milks were sweet, and the low-fat milks had relatively low intensities for most flavor attributes. The electronic nose method successfully grouped the milk samples primarily based on their composition, but grouped them weakly by pasteurization method.

• 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.

• 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.38 no.1
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• pp.16-21
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• 2006

Effect of heat (160, 190, and $220^{\circ}C$ for 24 hr) on coconut oil was examined by principal component analysis using electronic nose consisting of six metal oxide sensors. Increase in heating temperature decreased ratio of resistance and first principal component score (from +0.952 to -0.325), indicating rancidity of coconut oil increased at high heating temperature. Result of electronic nose based on GC with surface acoustic wave sensor showed significant changes in volatile profiles of coconut oil. High resolution olfactory imaging $(VaporPrint^{TM})$ was particularly useful for evaluating oil quality. Peak numbers and areas increased with increasing heating time and temperature (160, $220^{\circ}C$). Electronic nose analysis can provide simple, fast, and straightforward results and is best suited for quality control and process monitoring in flavor field of food industry.