• Korean Journal of Food Science and Technology
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• v.37 no.5
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• pp.856-860
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• 2005

Electronic-nose system was used to discriminate commercial sesame oils (A-F) extracted from imported seeds. Response (delta $R_{gas}/R_{air}$) of sensors gained from electronic nose was analyzed by principal component analysis (PCA). Flavor pattern of sesame oil A was similar to those of sesame oils B, C, and D. Sesame oils blended with corn oil at the ratio of 95:5, 90:10 and 80:20% (sesame oil/corn oil, w/w) could be discriminated from ouch genuine sesame oil.

• Korean Journal of Food Science and Technology
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• v.26 no.5
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• pp.561-566
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• 1994

The kinds of kochujang were discriminated by using their organic acid compositions, GC peak areas of volatile concentrates and flavor intensity determined by sensory evaluation. Tested kochujang were 51 kinds of traditional kochujang and 10 kinds of industry-produced kochujang in the market. The traditional kochujang included 20 kinds of Sunchang kochujang prepared with glutinous rice, 11 kinds of Boeun kochujang prepared with barley and 20 kinds of Sachun kochujang prepared with wheat. Boeun kochujang was distinguished from other kinds of traditional and industry-produced kochujang by using canonical discriminant analysis for the compositions of organic acids. Among organic acids, lactic acid was the most contributing variable for the discrimination of various kochujang. Traditional and industry-produced kochujang could be classified into 4 groups by using discriminant analysis for GC peak areas. The peak number 2, 4, 8 and 11 were found to be highly contributing variables for the discrimination of kochujang by using stepwise discriminant analysis. Industry-produced kochujang was discriminated from traditional kochujang by using canonical discriminant analysis for the intensity of 8 kinds of flavor property. The taste 'umami' was found to be the most contributing variable for the discrimination of kochujang.

• Korean Journal of Food Science and Technology
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• v.37 no.6
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• pp.1048-1064
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• 2005

Detection of specific compounds influencing food flavor quality is not easy. Electronic nose, comprised of electronic chemical sensors with partial specificity and appropriate pattern recognition system, is capable of recognizing simple and complex volatiles. It provides fast analysis with simple and straightforward results and is best suited for quality control and process monitoring of flavor in food industry. This review examines application of electronic nose in food analysis with brief explanation of its principle. Characteristics of different sensors and sensor drift. and solutions to related problems are reviewed. Applications of electronic nose in food industry include monitoring of fermentation process and lipid oxidation, prediction of shelf life, identification of irradiated volatile compounds, discrimination of food material origin, and quality control of food and processing by principal component analysis and neural network analysis. Electronic nose could be useful for quality control in food industry when correlating analytical instrumental data with sensory evaluation results.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.4
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• pp.613-617
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• 2011

This study was conducted to compare the quality of the brown rice (BR) and milled rice (MR) during storage. To assess quality, BR and MR were analysed by their fat acidity and flavor pattern using a SMart Nose$^{(R)}$. BR was stored for 30 days at $30^{\circ}C$, and analysed after 5, 15, 20, and 30 days of storage. MR produced in 2005, 2009, and 2010 were also tested. The fat acidity of both rice groups was increased with extended storage and the fat acidity of BR was more rapidly increased than that of MR in general. The flavor patterns from the SMart Nose$^{(R)}$ results were analyzed by the principal component analysis (PCA). The major groups of atomic mass unit (amu) for good discrimination contribution were from 41 to 85 amus. The PCA1 and PCA2 of BR were 95.64% and 2.78%, respectively when the samples were categorized by storage period. The PCA1 and PCA2 of MR were 81.18% and 13.85%, respectively when the samples were compared by production year. Both rice groups could be practically differentiated into flavor patterns by volatile properties for storage period. With regard to the correlation between fat acidity and flavor pattern, we could find that increasing storage period increased fat acidity value and changed flavor pattern from SMart Nose$^{(R)}$. Accordingly, SMart Nose$^{(R)}$ could be successfully used for easy screening and quality evaluation of stored rice.

• Journal of Life Science
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• v.11 no.3
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• pp.203-210
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• 2001

To produce the instant marsh calm(Corbicula elatior) soup with abundant taste and flavor. optimum conditions of heating temperature and time for extraction were investigated. Excretion rate in a pre-treatment for excretion of estuary was 82% at 15% salt concentration for 6 hr and 95% at pH 7.5 for 10 hr. The contents of glycogen and amino-nitrogen were the most high levels in the treatments extracted at 9$0^{\circ}C$ for 3 hr, at 10$0^{\circ}C$ for 1.5 hr and at 11$0^{\circ}C$for 1 hr. The contents of total free amino acids in the extracts treated at 9$0^{\circ}C$, 10$0^{\circ}C$ and 11$0^{\circ}C$ were 367.05mg/100g, 472.23 mg/100g and 463.54 mg/100g, respectively and optimal temperature was above 10$0^{\circ}C$. The mineral contents was the most high level for the extract treated at 10$0^{\circ}C$ for 1.5hr. The results of sensory evaluation showed that tastes for the marsh calm extracts had no significant discrimination, while external appearances and flavors for the extract done at 10$0^{\circ}C$ for 1.5 hr were excellent. The extracts at 10$0^{\circ}C$ showed a little dark color and those at 9$0^{\circ}C$ smell a little fish flavor.

• 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.

• Journal of Applied Biological Chemistry
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• v.60 no.3
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• pp.283-291
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• 2017

Rice that the half of population in the world eats as a staple food is mostly produced and consumed in Asia. However, its consumption is nowadays decreasing mainly due to diet diversity. Accordingly, some attempts are in demand to enhance the utilization of rice. In this study, profiling of volatile and non-volatile flavor components in rice pastes obtained by ${\alpha}$-amylase was performed and compared according to nine different rice cultivars domestically cultivated in Korea using gas chromatography-mass spectrometry combined by solid phase microextraction and gas chromatography-time of flight-mass spectrometry after a derivatization, respectively. In total, 46 volatile compounds identified included 6 alcohols, 6 aldehydes, 4 esters, 4 furan derivatives, 4 ketones, 1 acid, 1 sulfur-containing compound, 7 hydrocarbons, 5 aromatics and 8 terpenes. The non-volatile flavor components found were composed of 12 amino acids, 6 sugars and 4 sugar alcohols. In principal component analysis, rice paste samples could be discriminated according to cultivars on the score plots of volatile and non-volatile flavor compounds. In particular, some volatile compounds such as pentanal and 4,7-dimethylundecane could contribute to distinguish Senong 17 white and Senong 17 brown, whereas ethanol, 6-methylhep-5-en-2-one, and tridecane could be highly related to the discrimination of Iipum from other cultivars. Among non-volatile compounds, some amino acids such as glycine, serine and ${\gamma}$-aminobutyric acid and some sugars such as sucrose and fructose were mainly responsible for the discrimination of Danmi from the other cultivars. On the other hand, galactose, arabitol and mannose were more closely related to Senong 17 white than Senong 17 brown.

• Korean Journal of Food Science and Technology
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• v.45 no.5
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• pp.652-656
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• 2013

The geographical origin of red ginseng extract (RGE) was studied using a mass spectrometry based electronic nose. Imported RGE and domestic RGE were diluted to 12oBx. The treated RGE was analyzed, and discriminant function analysis (DFA) was used for discriminating of geographical origins. The DFA plots indicated a significant separation of imported RGE and domestic RGE. The F-value of discriminant function first score (DF1) was much higher than that of discriminant function second score (DF2), indicating that discrimination was mainly affected by DF1. Based on DF1, the concentration of domestic RGE to imported RGE shifted to the left side of DFA plot, and the mixing ratio highly correlated to DF1 value. Unknown sample (#2) was closely located to the sample of mixed imported : domestic (6:4) RGE. In the bar graph, the DF1 value correlated to the mixing ratio. Unknown samples (#2) were thought to be mixed with the imported RGE. This technique could be used to efficiently differentiate the geographical origin of RGE.

• Food Science and Preservation
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• v.12 no.4
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• pp.361-366
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• 2005

An electronic nose equipped with metal oxide sensor(MOS) was used for investigating the quality of reconstitute orange juice added different recoverable oil(cold pressed valencia oil) contents during 21 days of storage at $4^{\circ}C$. Quality changes in orange juice was described in terms of the sensitivity(${\Delta}R_{gas}/R_{air}$) of the sensors. Principal component analysis(PCA) was carried out using data obtained from twelve metal oxide sensors. The flavor of orange juice contained with the different recoverable oil contents($0.01\%{\sim}0.05\%$) was separated in PCA plot, in which the first principal component score was correlated with the content of recoverable oil. As storage periods prolonged, no significantly different sensitivity score of orange juice was observed in electronic nose. The content of recoverable oil in orange juice was reduced rapidly within 14 days, and then the decreasing ratio was slow on the next 7 days during storage at $4^{\circ}C$. The sensory score for overall and orange flavor of orange juice added $0.03\%$ recoverable oil was decreased during the 14 days and then rapidly dropped next 7 days of storage at $4^{\circ}C$.

• Korean Journal of Poultry Science
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• v.37 no.3
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• pp.215-219
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• 2010

The applicability of electronic nose was tested to detect lipid peroxidation in chickens and to measure antioxidant effect of astaxanthin in chicken carcasses. Two sources of astaxanthin were fed to 62-wk-old spent laying hens to improve meat quality: natural astaxanthin (NA) from the red yeast, Phaffia rhodozyma, and synthetic astaxanthin (SA) from chemical synthesis. One hundred forty four ISA Brown laying hens were used in a 6-wk feeding trial. Three treatments consisted of the basal diet (control), SA (100 mg astaxanthin/kg basal diet) and NA (50 mg astaxanthin/kg basal diet). The astaxanthin levels of SA and NA were set to give a similar degree of skin pigmentation. After 6-wk feeding of astaxanthin, the skins from NA and SA were discriminated from the control by electronic nose. However, electronic nose failed to distinguish between SA and NA skins after 6-wk feeding. The astaxanthin level differences between skins of SA and NA were not remarkable during the 6-wk trial. The lipid peroxide formation in skin was significantly decreased by SA but not by NA. The antioxidation effect of SA was detected by electronic nose because SA skin was discriminated from others. NA was a better pigmentation agent than SA, but the reverse was true in antioxidation. Electronic nose is applicable for detecting astaxanthin in chicken, and meat off-flavor caused by lipid peroxidation during storage.