Chemical Compositions and Aroma Evaluation of Volatile Oil from the Industrial Cultivation Medium of Enterococcus faecalis.

Enterococcus faecalis is one of the major lactic acid bacterium (LAB) species colonizing the intestines of animals and humans. The characteristic odor of the volatile oils obtained from both the liquid medium after incubation (MAI) and liquid medium before incubation (MBI) in the cultivation process of E. faecalis was investigated to determine the utility of the liquid medium. In total, fifty-six and thirty-two compounds were detected in the volatile oils from the MAI (MAI oil) and MBI (MBI oil), respectively. The principle components of MAI oil were 2,5-dimethylpyrazine (19.3%), phenylacetaldehyde (19.3%), and phenylethyl alcohol (9.3%). The aroma extract dilution analysis (AEDA) method was performed using gas chromatography-olfactometry (GC-O). The total number of aroma-active compounds identified in the volatile oil from MBI and MAI was thirteen compounds; in particular, 5-methyl-2-furanmethanol, phenylacetaldehyde, and phenylethyl alcohol were the most primary aroma-active compounds in MAI oil. These results imply that the industrial cultivation medium after incubation of E. faecalis may be utilized as a source of volatile oils.

Agroecosystem development of industrial fermentation waste -- characterization of aroma-active compounds from the cultivation medium of Lactobacillus brevis.

Volatile oils obtained from both the liquid medium after incubation (MAI) and liquid medium before incubation (MBI) during the cultivation process of Lactobacillus brevis were isolated by hydrodistillation (HD) and analyzed to determine the utility of the liquid waste. The composition of the volatile oils was analyzed by capillary gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). In total, 55 and 36 compounds were detected in the volatile oils from MAI (MAI oil) and MBI (MBI oil), respectively. The principle components of MAI oil were N-containing compounds, including 2,3-dimethylpyrazine (16, 37.1 %), methylpyrazine (4, 17.1 %). The important aroma-active compounds in the oils were detected by GC-Olfactometry (GC-O), and their intensity of aroma were measured by aroma extract dilution analysis (AEDA). Expressly, pyrazine compounds were determined as key aroma components; in particular, 2,5-dimethylpyrazine and 2,3-dimethylpyrazine were the most primary aroma-active compound in MAI oil. These results imply that the waste medium after incubation of L. brevis may be utilized as a source of volatile oils.

Aroma chemical emitted from Gerris paludum insularis.

An aroma chemical emitted from Gerris paludum insularis was analyzed by means of GC and GC-MS. The main constituent was identified as iso amyl alcohol (3-methyl-1-butanol). The chemical showed a characteristic aroma of Gerris paludum insularis.

Chemical composition and major odor-active compounds of essential oil from PINELLIA TUBER (dried rhizome of Pinellia ternata) as crude drug.

The chemical composition of the essential oil from PINELLIA TUBER (Japanese name: Hange), the dried rhizome of Pinellia ternata, was investigated by capillary gas chromatography (GC) and GC-mass spectrometry (MS) analyses. The oil obtained from Pinellia tuber was revealed the presence of 114 compounds, representing 90.6% of the total oil identified. This colorless oil had a spicy and woody odor. The main components of the oil were ß-cubebene (8.8%), atractylon (7.8%), methyl eugenol (6.2%), and δ-cadinene (5.3%). Fifteen major odor-active compounds were identified in the essential oil from PINELLIA TUBER by the GC-olfactometry (GC-O) and aroma extract dilution analysis (AEDA). Among these, safrole (spicy) and ß-vatirenene (woody) showed the highest flavor dilution (FD) factor (128), followed by paeonol (FD = 64; woody, spicy), α-humulene (FD = 64; woody), and ß-phenylnaphthalene (FD = 64; spicy).

Comparison of agitake (Pleurotus eryngii var. ferulae) volatile components with characteristic odors extracted by hydrodistillation and solvent-assisted flavor evaporation.

The chemical composition of volatile oil from agitake (Pleurotus eryngii var. ferulae) was established for the first time using gas chromatography (GC) and GC-mass spectrometry. Sixty-seven and 24 components were extracted by hydrodistillation (HD) using diethyl ether (DE) and dichloromethane (DM), respectively; these components accounted for 80.3% and 91.8% of the total oil, respectively. Thirteen and 48 components of were extracted by the solvent-assisted flavor evaporation method (SAFE), using DE and DM, respectively, and identified; these components accounted for 83.5% and 82.0% of the total oil, respectively. Methylsuccinimide and 2,3,7-trimethyl-2-octene were the most characteristic components by SAFE using DM.Odor evaluation of the volatile oil from agitake was also carried out using GC-olfactometry (GC-O), aroma extraction dilution analysis (AEDA), and the odor activity value (OAV). Sixteen, 8, 5 and 9 aroma-active components were identified using HD (DE and DM) and SAFE (DE and DM), respectively. The main aroma-active components extracted using HD and SAFE were 1-octen-3-ol (mushroom-like) and phenylacetaldehyde (floral), respectively. This study proved that HD and SAFE can be used as complementary extraction techniques for the complete characterization of volatile oil from agitake.

Characteristic odor components of volatile oil from the cultivation medium of Lactobacillus acidophilus.

Volatile oils obtained from both the liquid medium after incubation (MAI) and liquid medium before incubation (MBI) in the cultivation process of Lactobacillus acidophilus were isolated by hydrodistillation (HD) and analyzed to investigate the utility of the liquid waste. The composition of the volatile oils was analyzed by capillary gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). In total, 46 and 19 compounds were detected in the volatile oils from MAI (MAI oil) and MBI (MBI oil), respectively. The principle components of MAI oil were fatty acids, including pentanoic acid (12.75%), heptanoic acid (14.05%), and nonanoic acid (14.04%). The important aroma-active compounds in the oils were detected by GC-MS/Olfactometry (GC-O), and their intensity of aroma were measured by aroma extraction dilution analysis (AEDA). Pyrazines were determined as key aroma components; in particular, 2-ethyl-5-methylpyrazine was the most primary aroma-active compound in MAI oil. In addition, as the characteristic aroma-active compounds, 3-(methylthio)-propanal, trimethylpyrazine, and pentanoic acid were also detected in MAI oil. These results imply that the waste medium after incubation of L. acidophilus may be utilized as a source of volatile oils.

Highly selective and asymmetric reductive biotransformation of α-ionone by Epicoccum purpurascens.

The biotransformation of terpenoid C13 norisoprenoid (±)-α-ionone (1) using the plant pathogenic fungus Epicoccum purpurascens as a biocatalyst was investigated for the production of useful novel organic compounds. There are no reported biotransformations using E. purpurascens. The biotransformation of compound 1 via reduction of the C-9 ketone position yielded α-ionol (2) as the major metabolic product. Reduction of the racemic α-ionone [(-)-(6S)- and (+)-(6R)-] resulted in the exclusive formation of the two enantiomers (-)-(6S,9R)- and (+)-(6R,9S)-α-ionol (2). Thus, the enzymatic reduction of α-ionone by E. purpurascens proceeds with high asymmetry.

Comparison of volatile compounds with characteristic odor in flowers and leaves of nojigiku (Chrysanthemum japonense).

The aim of the present study was to investigate the essential oils isolated from flower and leaf in order to get insight into similarities and differences as to their aroma-active composition. The essential oil obtained from the two parts were analyzed by gas chromatography-mass spectrometry and gas chromatography olfactometry (GC-O). Flower and leaf oils, 38 and 36 constituents, representing 96.4 and 91.0% of the total oil composition, respectively, were identified. The main compounds in flower oil were camphor (47.64%), bornyl acetate (11.87%), and nojigiku alcohol (6.29%), whereas those in leaf oil were camphor (39.14%), nojigiku alcohol (10.76%) and γ-muurolene (7.02%). 13 Aroma-active compounds were identified by GC-O analysis in flower oil and 12 in leaf oil. The main aroma-active compounds in flower oil were camphor (camphor, FD (flavor dilution) = 7, OAV (odor active value) = 136913), bornyl acetate (camphor, FD = 6, OAV = 113711), and ß-caryophyllene (spicy, FD = 5, OAV = 116480). In leaf oil, the main aroma-active compounds were camphor (camphor, FD = 7, OAV = 106784), nojigiku alcohol (camphor, FD = 5, OAV = not determined), and ß-caryophyllene (spicy, FD = 6, OAV = 526267).

Novel compound, (2Z,6E)-1-hydroxy-3,7-dimethyl-2,6-octadien-8-oic acid produced from biotransformation of nerol by Spodoptera litura larvae.

Biotransformation of nerol by larvae of the common cutworm (Spodoptera litura) was investigated. The resulting major metabolites were (2Z,6E)-1-hydroxy-3,7-dimethyl-2,6-octadien-8-oic acid and 8-hydroxynerol, and the minor metabolites were 9-hydroxynerol and (2Z,6E)-1-hydroxy-3,7-dimethyl-2,6-octadien-8-al. (2Z,6E)-1-Hydroxy-3,7-dimethyl-2,6-octadien-8-oic acid is a novel compound. The results indicate that biotransformation of nerol by S. litura larvae involved 2 pathways; the main pathway involved oxidation at the methyl group of the geminal dimethyl at C-8 position followed by carboxylation, and the minor pathway involved oxidation at the methyl group of the geminal dimethyl at C-9 position.