• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.7
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• pp.822-832
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• 2017

This study analyzed contents of organic acids, free sugars, and volatile flavor compounds by type of Jerusalem artichoke (Helianthus tuberosus L.). Organic acids in dried Jerusalem artichoke were mainly composed of malic acid, citric acid, and succinic acid. Sucrose, fructose, and glucose were the major sugar components of dried Jerusalem artichoke. Free sugars were more abundant in the white colored sample than in the purple colored sample. In contrast, purple colored sample contained more organic acids than the white colored one. Volatile compounds in Jerusalem artichoke were investigated using the solid-phase micro-extraction method of gas chromatography/mass spectrometry. A total of 117 volatile compounds were identified in Jerusalem artichoke, and chemical classification was as follows: 5 acids, 13 alcohols, 19 aldehydes, 12 hydrocarbons, 15 ketones, 8 miscellaneous, 27 pyrazines, and 18 terpenes in all samples. Terpene was the most abundant in Jerusalem artichoke, and ${\beta}$-bisabolene was the main component in terpenes. The second most common compound was aldehyde, and hexanal was the highest. Pyrazines were the most abundant in the roasted samples, and 2,5-dimethyl-3-ethylpyrazine was present at the highest level, followed by 2,5-dimethylpyrazine. Compared with purple samples, main compounds contained in white samples were aldehydes and hydrocarbons, whereas the major compounds in purple samples were terpenes and alcohols.

• Journal of Ginseng Research
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• v.40 no.4
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• pp.315-324
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• 2016

Background: Biocontrol agents are regarded as promising and environmental friendly approaches as agrochemicals for phytodiseases that cause serious environmental and health problems. Trichoderma species have been widely used in suppression of soil-borne pathogens. In this study, an endophytic fungus, Trichoderma gamsii YIM PH30019, from healthy Panax notoginseng root was investigated for its biocontrol potential. Methods: In vitro detached healthy roots, and pot and field experiments were used to investigate the pathogenicity and biocontrol efficacy of T. gamsii YIM PH30019 to the host plant. The antagonistic mechanisms against test phytopathogens were analyzed using dual culture, scanning electron microscopy, and volatile organic compounds (VOCs). Tolerance to chemical fertilizers was also tested in a series of concentrations. Results: The results indicated that T. gamsii YIM PH30019 was nonpathogenic to the host, presented appreciable biocontrol efficacy, and could tolerate chemical fertilizer concentrations of up to 20%. T. gamsii YIM PH30019 displayed antagonistic activities against the pathogenic fungi of P. notoginseng via production of VOCs. On the basis of gas chromatography-mass spectrometry, VOCs were identified as dimethyl disulfide, dibenzofuran, methanethiol, ketones, etc., which are effective ingredients for antagonistic activity. T. gamsii YIM PH30019 was able to improve the seedlings' emergence and protect P. notoginseng plants from soil-borne disease in the continuous cropping field tests. Conclusion: The results suggest that the endophytic fungus T. gamsii YIM PH30019 may have a good potential as a biological control agent against notoginseng phytodiseases and can provide a clue to further illuminate the interactions between Trichoderma and phytopathogens.

• Food Science and Preservation
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• v.23 no.1
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• pp.117-126
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• 2016

This study was performed to provide information for improving the quality characteristics of tangerine peel Soksungjang. Tangerine peel Soksungjangs were prepared with 10% tangerine peel powder by addition of different koji such as Rhizopus oligosporus (RS, RTS) and Aspergillus oryzae (AS, ATS). As a result, the moisture content was not changed and crude protein content decreased during fermentation in all samples. The pH of RS (Soksungjang manufactured with Rhizopus oligosporus koji) and RTS (Soksungjang manufactured with Rhizopus oligosporus koji and 10% tangerine peel powder) was not changed, whereas pH of AS (Soksungjang manufactured with Aspergillus oryzae) and ATS (Soksungjang manufactured with Aspergillus oryzae koji and 10% tangerine peel powder) decreased rapidly after 10 days of fermentation. The acidity values of all the samples increased during fermentation. The major free sugars were glucose, fructose, and maltose; while, the major organic acids were citric acid, succinic acid, acetic acid, and lactic acid in all the samples. The amino nitrogen content and protease activity were highest in the AS and ATS. Conversely, the reducing sugar content and ${\alpha}$-amylase activity were highest in the RS and RTS. The major free amino acids in all samples were glutamic acid, lysine, leucine, and arginine. Sixty kinds of volatile flavor compounds were identified from all samples; the majority of which were 21 alcohols, 14 hydrocarbons, 5 esters, and others identifies as acids, ketones, and aldehydes.

• The Korean Journal of Mycology
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• v.14 no.1
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• pp.31-36
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• 1986

The volatile aroma concentrates were isolated from Pleurotus ostreatus by simultaneous distillation-extraction and analyzed by gas chromatography and combined gas chromatography-mass spectrometry. The aroma concentrates obtained had a typical raw or slightly cooked mushroom-like odor, and the yield was 123 ppm. Of 27 components identified, the major components were 3-octanone, 3-octanol, 2-octenal, n-octanol and 2, 4-decadienal, including 1-octen-3-ol contributing 67.06% of the total volatiles, and the $C_8$ compounds comprised about 80% of the total volatiles. On the other hand, the $C_6$ and $C_8$ alcohols in mushroom increased gradually with increase of standing time after homogenation, while aldehydes, ketones, and linoleic acid decreased, and also $C_6$ and $C_8$ compounds were significantly increased when linoleic and linolenic acid were added in homogenates. It appears that most of volatile aroma components in Pleurotus ostreatus were probably produced enzymatically from unsaturated fatty acids containing cis, cis-1, 4-pentadiene moiety.

• Journal of Life Science
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• v.23 no.7
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• pp.933-940
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• 2013

The aim of this work was to determine the chemical composition of essential oil from aerial partsof Mentha arvensis L. f. piperascens (MAO) and to evaluate the effect of its fragrant chemicals on electroencephalographic (EEG) activity of human brain. The MAO was obtained by supercritical $CO_2$ extraction. The maximum yield was 2.38% at conditions of $70^{\circ}C$ and 200 bar. There were 32 volatile chemicals with 6 alcohols (67.11%), 13 hydrocarbons (17.05%), 9 esters (11.50%), 2 ketones (7.16%), 1 oxide (2.77%), and 1 aldehyde (0.56%). The major components were (Z,Z,Z)-9,12,15-octadecatrien-1-ol (50.06%), 2-hydroxy-4-methoxyacetophenone (7.50%), and 3,4-dihydro-8-hydroxy-3-methyl-1H-2-benzopyran-1-one (6.60%). Results of the EEG study showed that inhalation of MAO significantly changed the EEG power spectrum values of relative gamma, relative fast alpha, and spectral edge frequency 90%. During the inhalation of MAO, the value of relative fast alpha was significantly increased (p<0.05). On the other hand, the values of gamma and the spectral edge frequency 90% were significantly decreased (p<0.05). The present study suggests that fragrant chemicals of essential oil of M. arvensis reduce the level of mental stress and that they could be used in the treatment of psychophysiological disorders.

• Korean Journal of Food Science and Technology
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• v.29 no.5
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• pp.827-838
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• 1997

Optimal substrates and reaction conditions were studied to develop boiled or roasted meat flavor by Maillard reaction under a model system. Sugars for the reactions were xylose, ribose, glucose, lactose, maltose, and sucrose. Amino acids were cystine, cysteine, methionine, lysine, and glycine as the reaction substrates. The reacted solutions were measured their absorbances at 278 nm and 420 nm and were evaluated their sensory properties. Except cysteine, the pentose mixtures with all of the four amino acids showed a faster reaction rate than those mixtures with hexose or disaccharides. pH was decreased rapidly until 8 hours and then changed a little thereafter. Sensory evaluation showed that cystine-lactose or cystine-xylose from single substrate and cystine-lactose-maltose, and cystine-lactose-xylose from mixed substrates reacted at $100^{\circ}C$ for 16 or 20 hours were found to be close to boiled or roasted meat flavor. The volatile compounds from the four selected sugar-amino acid solutions by GC/MS were 8 hydrocarbons, 10 aldehydes, 6 ketones, 7 alcohols, 2 aromatics (benzene), 1 ester, 4 furans, 1 base and 5 sulfur compounds.

• Korean Journal of Food Science and Technology
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• v.29 no.4
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• pp.745-751
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• 1997

Volatile flavor components of kochujang made from a glutinuous rice by traditional method were analyzed by using purge and trap method during fermentation, and identified with GC-MSD. Fifty-one volatile components including 19 alcohols, 13 esters, 7 acids, 3 aldehydes, 1 alkanes, 2 ketones, 2 amines, 1 benzene, 1 alkene, 1 phenol and others were found in kochujang made by traditional method. The number of volatile components detected immediately after making kochujang were 22 and increased to 41 components after 30 day of fermentation. The most number 51 of volatile components were found after 120 day of fermentation. Twenty-two volatile components were commonly found through the fermentation period such as acetic acid ethyl ester, ethanol, butanoic acid ethyl ester, 1-butanol, 2-methyl-1-propanol, 3-methyl-1-butanol, butanoic acid and ethenone. Peak area(%) of 1-butanol was the highest one among the volatile components at immediately after mashing while ethanol showed the highest peak area after 30 day of fermentation. Although the various types of peak areas of volatile components were shown in kochujang during the fermentation days, acetic acid-ethyl ester, ethanol, butanoic acid-ethyl ester, 1-butanol, 3-methyl-1-butanol and 2-methyl-1-propanol were mainly detected during fermentation. Those might be the major volatile components in kochujang made by traditional method.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.6
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• pp.1050-1056
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• 2000

To identify the irradiation-induced volatile flavor compounds, which were not detected in unirradiated sample and had positive correlation with the increment of irradiation dose, the volatile flavor compounds of irradiated (0, 1, 3, 5, 10 kGy) chicken were analyzed by liquid liquid continuous extraction (LLCE) and gas ehromatographyimass spectrometry (GC/MS) methods. One hundred twenty nine compounds were detected in irradiated chicken, and these compounds were composed mainly of hydrocarbons (62 compounds), aromatic compounds (44), aldehydes (9), ketones (5) and miscellaneous compounds (10). Among these, only 3 volatile compounds including 2-methylpentanal (r=0.24), 4-methylcyclohexene (r=0.08) and cyclotetradecene (r=0.92), were detected as irradiation-induced volatile flavor compounds in irradiated chicken. However, only cyclotetradecene was selected as a marker compound for detecting irradiation dosages with high correlation coefficient in irradiated chicken.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.6
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• pp.1042-1049
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• 2000

Irradiation-induced volatile flavor compounds in irradiated (1, 3, 5, 10 kGy) beef were analyzed by liquid liquid continuous extraction (LLCE) and gas chromatography/mass spectrometry (GC/MS) methods. One hundred fifty volatile compounds were detected in irradiated beef. These compounds were composed mainly of 71 hydrocarbons, 35 aromatic compounds, 15 aldehydes, 7 ketones, 4 acids, 6 esters and 12 miscellaneous compounds. Among these, only 6 volatile compounds including (E) -2-hexenal, nonene, 2-nonenal, cyclodecene, dodecene and cyclododecene were detected as irradiation-induced volatile flavor compounds, comparing with unirradiated beef meat. However, 4 volatile compounds, such as cyclodecene (r=0.88), (E)-2-hexenal (r=0.85), nonene (r=0.74) and 2-nonenal (r=0.70), having a positive correlation coefficient with the increment of irradiation dose, were considered as marker compounds for detecting irradiation dosages in irradiated beef.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.2
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• pp.204-210
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• 2002

The quality characteristics and sensory evaluation of chungkookjang were investigated. The samples were prepared and fermented by the inoculation of Bacillus strains; B. subtilis, B. natto and B. licheniformis as a single starter, and mixed culture of B. natto and B. licheniformis on the industrialized model system. It was shown that microbial growth, protease activity, contents of amino-and ammonia-nitrogen and contents of organic acid were higher in B. subtilis inoculated sample, and were lower in B. licheniformis inoculated one. General quality characteristics of sample inoculated by mixed culture of B. natto and B. licheniformis took a middle position between each B. natto and B. licheniformis inoculated one. Fifty eight species of odor components were identified. Ethanol, 3-methyl-1-butanol, acetic acid, benzaldehyde and alkyl pyrazines were identified in all samples and most of other flavor components were strain specific. The contents of unpleasant smell components, alkyl pyrazines and benzaldehyde, were lower in B. licheniformis inoculated sample. The sensory evaluations showed that chungkookjang manufactured from mixed culture of B. natto and B.licheniformis was most acceptable. Therefore, results indicated that chungkookjang manufactured from mixed culture of B. natto and B. licheniformis induced better sensory quality than that of the control.