• Applied Chemistry for Engineering
• /
• v.22 no.6
• /
• pp.627-630
• /
• 2011

We focus on a catalytic process based on direct injection method that can produce high-quality oils of gasoline and kerosene with various carbon-number feed oils. The reaction characteristics of a commercial catalyst were analyzed using a spouted bed reactor. Decane and pentadecane were used to compare the characteristics of the fixed bed and the spouted bed reactor. The yield of gasoline plus kerosene was highest at the reaction temperature of $550^{\circ}C$. For the spouted bed reactor, the at-a-pulse injection was more effective for catalytic cracking of feed oils than multiple consecutive injections. The reaction activity became higher as the carbon number of feed oil is larger.

• Journal of Environmental Science International
• /
• v.19 no.4
• /
• pp.389-397
• /
• 2010

The in vitro toxicities of three crude oils of the Hebei Spirit were examined on laboratory grown plankton, with a focus on the effects of a dispersant. The specific growth rate of phytoplankton and the mortalities of two zooplankton were measured in response to exposure to various concentrations of water accommodated oil, dispersant or both. The effects of the oils varied among the plankton, but were generally low within the range of the oil concentrations used, with little difference in toxicity among the three oils. Such low toxicity appeared to be associated with weathering of the crude oils. Exposure to the dispersant, however, dramatically increased the mortality of zooplankton, with complete inhibition of phytoplankton growth. No synergistic toxic effect was observed with the crude oil and dispersant combination. A better decision making process could be crafted for future application of dispersant in the event of an oil spill in Korean waters to better protect the marine plankton community from the excessive use of dispersant.

• Parasites, Hosts and Diseases
• /
• v.59 no.5
• /
• pp.465-471
• /
• 2021

Culicoides biting midges (Diptera: Ceratopogonidae) are hematophagous arthropod vectors that transmit epizootic arthropod-borne viruses (arboviruses). Arboviruses are recognized as causes of pregnancy loss, encephalomyelitis, and congenital malformations in ruminants. Therefore, continuous monitoring and control of Culicoides, which causes significant damage to industrial animals are necessary. We performed attraction and repellent tests in Culicoides using various essential oils, cow dung, and carbon dioxide (CO₂). Culicoides tended to move more to cow dung (60.8%, P<0.0001) and CO₂ (63.8%, P<0.01). To the essential oils as repellents, 26.1% (P<0.0001), 18.7% (P<0.001), and 25.5% (P<0.01) of the Culicoides moved to the lavender, lemongrass, and eucalyptus chamber, respectively. The Culicoides that moved to the 3 essential oils chambers showed markedly low activity. Collectively, it was showed that Culicoides tended to be attractive to cow dung and CO₂, and repellent from the 3 essential oils.

• Food Science and Biotechnology
• /
• v.15 no.3
• /
• pp.462-465
• /
• 2006

In order to extend the shelf life of sliced raw flatfish, the antimicrobial effects of natural essential oil from mustard and a mixture of ginger and mustard essential oils were tested at various temperatures. In addition, volatile components of the mixed essential oils were analyzed using gas chromatography and gas chromatography mass spectrometry. The viable cell counts of Vibrio parahaemolyticus treated with mixed essential oils from ginger and mustard was 0.7-1.3 log CFU/g lower than those of other treatments during storage at $5^{\circ}C$. During storage at $20^{\circ}C$, the viable cell counts of V. parahaemolyticus, V. vulnificus 01, and V. vulnificus 02 treated with the essential oils increased slightly from 6.53-6.64 log CFU/g at initial stages to 6.77-7.72 log CFU/g after 24-hr of storage, however they were 1.38-1.97 log CFU/g lower than those of the control group (8.74-9.10 log CFU/g). These results show that the growth of V. parahaemolyticus and V. vulnificus inoculated on sliced raw flatfish could be inhibited by treatment with natural essential oils from ginger and mustard at $5^{\circ}C$ of storage. However, the antibacterial effects of the essential oils on Vibrio species observed in this study were not sufficient to merit their use in sliced raw flatfish at temperatures exceeding $20^{\circ}C$.

• Asian Pacific Journal of Cancer Prevention
• /
• v.16 no.12
• /
• pp.5125-5135
• /
• 2015

Background: Total fat intake may be associated with increased risk of breast cancer, and fish oil has been suggested as a protection factor to breast cancer. But the effect of vegetable oils is inconclusive. We aimed to investigate the association with high vegetable oils consumption and breast cancer risk, and evaluated their dose-response relationship. Design: We systematically searched the MEDLINE, EMBASE, Cochrane databases, and CNKI updated to December 2014, and identified all observational studies providing quantitative estimates between breast cancer risk and different vegetable oils consumption. Fixed or random effect models were used to estimate summary odds ratios for the highest vs. lowest intake, and dose-response relationship was assessed by restricted cubic spline model and generalized least-squares trend (GLST) model. Results: Five prospective cohort studies and 11 retrospective case-control studies, involving 11,161 breast cancer events from more than 150,000 females, met the inclusion criteria. Compared with the lowest vegetable oils consumption, higher intake didn't increased the risk of breast cancer with pooled OR of 0.88 (95% CIs:0.77-1.01), and the result from dose-response analyses didn't show a significant positive or negative trend on the breast cancer risk for each 10g vegetable oil/day increment (OR=0.98, 95% CIs: 0.95-1.01). In the subgroup analyses, the oils might impact on females with different strata of BMI. Higher olive oil intake showed a protective effect against breast cancer with OR of 0.74 (95% CIs: 0.60-0.92), which was not significant among the three cohort studies. Conclusions: This meta-analyses suggested that higher intake of vegetable oils is not associated with the higher risk of breast cancer. Olive oil might be a protective factor for the cancer occurrence among case-control studies and from the whole. Recall bias and imbalance in study location and vegetable oils subtypes shouldn't be ignored. More prospective cohort studies are required to confirm the interaction of the impact of vegetable oils on different population and various cancer characteristic, and further investigate the relationship between different subtype oils and breast cancer.

• Fisheries and Aquatic Sciences
• /
• v.18 no.1
• /
• pp.27-33
• /
• 2015

Seasoned laver Pyropia spp. is one of the most well-known Korean traditional seafoods, and is becoming more popular worldwide. Various mixed oils are used in the preparation of seasoned laver; however, there is no information available regarding the effects of the blending ratio of oils on the quality of seasoned laver. In this study, the effects of the blending ratio of corn, sesame, and perilla oils on the oxidation and sensory quality of seasoned laver were monitored and optimized using a response surface methodology. An increase in the proportion of corn and sesame oils resulted in an excellent oxidation induction time, whereas a high ratio of perilla oil reduced the thermal oxidative stability of the mixed oil. In the sensory test, the seasoned laver with the highest proportion of sesame oil was preferred. The optimal blending ratio (v/v) of corn, sesame, and perilla oils for both oxidation induction time ($Y_1$) and sensory score ($Y_2$) was 92.3, 6.0, and 1.7%. Under optimal conditions, the experimental values of $Y_1$ and $Y_2$ were $4.41{\pm}0.3h$ and $5.58{\pm}0.8$points, and were similar to the predicted values (4.34 h and 5.13 points). Our results for the monitoring and optimization of the blending ratio provide useful information for seasoned laver processing companies.

• The Korean Journal of Food And Nutrition
• /
• v.27 no.2
• /
• pp.194-202
• /
• 2014

This study investigates the chemical compositions of Aster koraiensis Nakai essential oils and the quantitative changes of major terpene compounds according to various harvesting times. The essential oils obtained by hydrodistillation from the aerial parts of Aster koraiensis Nakai are being analyzed by GC and GC-MS. The essential oil compositions of Aster koraiensis Nakai are characterized byhigher contents of sesquiterpene compounds. Ninety-seven volatile flavor compounds are being identified in the essential oils from Aster koraiensis Nakai harvested in 2010, and caryophyllene oxide (8.38%), aristolene (7.08%), epiglobulol (5.57%), and ethyl furanone (4.73%) are the most abundant compounds. Ninety-five compounds are identified in the essential oils from the plants harvested in 2011, and aristolene (11.56%), calarene (9.33%), phytol (8.28%), ethyl furanone (7.63%), and epiglobulol (7.18%) are the most abundant compounds. Ninety-five compounds are being identified in the essential oils from the plants harvested in 2012, and calarene (15.3%), aristolene (14.24%), ethyl furanone (7.21%), phytol (6.98%) are the major compounds. The contents of aristolene, ${\alpha}$-caryophyllene, ${\alpha}$-muurolene, ${\alpha}$-calacorene, aromadendrene oxide, and calarene increase significantly from 2010 to 2012. The contents of ${\alpha}$-cubebene, isocaryophyllene, and diepi-${\alpha}$-cedrene epoxide decrease significantly from 2010 to 2012. The quantitative changes of aristolene and calarene according to harvesting time can be served as a quality index of the Aster koraiensis Nakai essential oils.

• Journal of the Korean Wood Science and Technology
• /
• v.49 no.4
• /
• pp.371-383
• /
• 2021

Plant essential oils are used in products such as fragrances and cosmetics due to their individual aromatic characteristics. Currently, essential oils are not only used in cosmetics but also in pharmaceutical products with anti-bacterial, anti-viral, anti-fungal, anti-parasitic, insecticidal, anti-cancer, neuroprotective, psychophysiological, or anti-aging effects. Despite their pharmaceutical properties, some studies reported cytotoxic effects in high doses. Therefore, for pharmaceutical purposes, the margin of safety of essential oils needs to be examined. Herein, we evaluated the IC₅₀ of 10 essential oil from Korean native plants: Juniperus chinensis L. var. sargentii Henry, Citrus natsudaidai Hayata, Citrus reticulata Blanco, Citrus unshiu (Yu. Tanaka ex Swingle) Marcow, Artemisia capillaris Thunb, Aster glehnii F. Schmidt, Juniperus chinensis L, Zanthoxylum schinifolium Siebold & Zucc, Zanthoxylum piperitum (L.) D, and Cinnamomum loureirii. In addition, gene regulation of the cell-cycle gene and apoptosis marker CASP3 was examined at the IC₅₀ level. The purpose of this study was to describe the toxic concentrations of essential oils extracted from Korean native plants, thereby providing toxic concentration guidelines for inclusion in a toxicity database and in the application of plant essential oils in various fields.

• Korean Journal of Agricultural Science
• /
• v.50 no.4
• /
• pp.675-696
• /
• 2023

Terpenoids, also referred to as terpenes, are a large family of naturally occurring chemical compounds present in the essential oils extracted from medicinal plants. In this study, a nondestructive methodology was created by combining ATR-FT-IR (attenuated total reflectance-Fourier transform infrared), and Raman spectroscopy for the terpenoids assessment in medicinal plants essential oils from ten different geographical locations. Partial least squares regression (PLSR) and support vector regression (SVR) were used as machine learning methodologies. However, a deep learning based model called as one-dimensional convolutional neural network (1D CNN) were also developed for models comparison. With a correlation coefficient (R²) of 0.999 and a lowest RMSEP (root mean squared error of prediction) of 0.006% for the prediction datasets, the SVR model created for FT-IR spectral data outperformed both the PLSR and 1 D CNN models. On the other hand, for the classification of essential oils derived from plants collected from various geographical regions, the created SVM (support vector machine) classification model for Raman spectroscopic data obtained an overall classification accuracy of 0.997% which was superior than the FT-IR (0.986%) data. Based on the results we propose that FT-IR spectroscopy, when coupled with the SVR model, has a significant potential for the non-destructive identification of terpenoids in essential oils compared with destructive chemical analysis methods.

• Natural Product Sciences
• /
• v.14 no.2
• /
• pp.138-142
• /
• 2008

The composition of essential oils from Chrysanthemum zawadskii var. latilobum and C. indicum were analyzed and compared. The results of gas chromatography-mass spectrometry revealed there were distinctly different compositional patterns between C. zawadskii var. latilobum and C. indicum essential oils. The combinatorial effect of the oil of C. zawadskii var. latilobum and C. indicum, with various antibiotics was assessed against antibiotic-susceptible and -resistant strains of Staphylococcus aureus and Streptococcus pneumoniae. The essential oil fraction significantly inhibited most of the tested antibiotic-susceptible and -resistant strains of S. pneumoniae, with minimum inhibiting concentrations (MICs) ranging from 0.5 to 4.0 mg/ml. The fractional inhibiting concentration indices (FICIs) of the oils when combined with antibiotics against S. aureus and S. pneumoniae ranged from 0.26 to 0.75, and showed synergistic or additive effects.