• Clean Technology
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• v.18 no.2
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• pp.191-199
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• 2012

In order to reduce or remove off-flavor and volatile organic compounds (VOCs) from Laminaria japonica effectively, continuous treatment process by supercritical carbon dioxide (SC-$CO_2$) was applied. After freeze-drying, Laminaria japonica powdered with $710{\mu}m$ was used. Experiments were carried out at temperature range from 35 to $55^{\circ}C$, and pressure range from 10 to 25 MPa for evaluation of SC-$CO_2$ treatment effect. Flow rate of carbon dioxide used in this reseach was constantly fixed at 26.81 g/min. Before and after treatment of SC-$CO_2$, off-flavor and VOCs from Laminaria japonica were analyzed by gas chromatography-mass spectrometry detector (GC-MSD). Total 47 VOCs emitted from Laminaria japonica were identified before treatment of SC-$CO_2$, major components of seaweed smell (ordor) in Laminaria japonica were identified as alcohols, aldehydes, ester and acids, ketone, halogenated compounds and hydrocarbon. Off-flavor and VOCs in all experimental conditions was reduced or removed after SC-$CO_2$ treatment. Among the experimental conditions, the highest removal yield was at 25 MPa and $55^{\circ}C$.

• 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 Veterinary Research
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• v.35 no.4
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• pp.823-831
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• 1995

The composition of rumen volatile fatty acids(VFA) and the blood chemistry were investigated in 5 clinically health dairy cows(Group I) reared on dairy farms and in 5 cows with post-parturition(POP) primary ketosis(Group II). The determinations were performed on days 5 to 7 pre-parturition(PRP), immediately POP, and on days 5, 10, 15, 20 and 25 POP. In both groups, the total VFA levels gradually increased starting from day 5 POP, but the levels were lower in Group II than in Group I. With regard to POP. changes in the composition of VFA, Group II occasionally showed lower levels of acetic acid and caproic acid than did Group I. Blood glucose levels decreased POP in both groups. In contrast, blood levels of ketone bodies and 3-hydroxybutyric acid were increased POP, but there was no statistically by significant difference between the groups. The aspartate aminotransferase level was transiently increased immediately POP in both groups, and the increase was more marked in Group II than in Group I. Both groups showed a tendency for total cholesterol, free cholesterol, ester cholesterol, phospholipid, and total bile acid to be increased POP, but there was no statistically significant difference between the groups. Clinically healthy dairy cows also showed POP changes in the composition of VFA and blood similar to those in dairy cows with ketosis, suggesting that even apparently healthy cows are at risk of subclinical ketosis POP.