Subjek : Minyak Atsiri Tahun 2004-2008 (478 judul) Alvaro Cortes Cabrera, Jose M. Prieto, Application of artificial neural networks to the prediction of the antioxidant activity of essential oils in two experimental in vitro models, Food Chemistry, Volume 118, Issue 1, 1 January 2010, Pages 141-146, ISSN 0308-8146, DOI: 10.1016/j.foodchem.2009.04.070. (http://www.sciencedirect.com/science/article/B6T6R-4W6XYK9- 1/2/708e866c3d7f370d81917ed145af525a) Abstract: Introduction The antioxidant properties of essential oils (EOs) have been on the centre of intensive research for their potential use as preservatives or nutraceuticals by the food industry. The enormous amount of information already generated on this subject provides a rich field for data-miners as it is conceivable, with suitable computational techniques, to predict the antioxidant capacity of any essential oil just by knowing its particular chemical composition. To accomplish this task we here report on the design, training and validation of an Artificial Neural Network (ANN) able to predict the antioxidant activity of EOs of known chemical composition.Methods A multilayer ANN with 30 input neurons, 42 in hidden layers (20 --> 15 --> 7) and one neuron in the output layer was developed and run using Fast Artificial Neural Network software. The chemical composition of 32 EOs and their antioxidant activity in the DPPH and linoleic acid models were extracted from the scientific literature and used as input values. From the initial set of around 80 compounds present in these EOs, only 30 compounds with relevant antioxidant capacity were selected to avoid excessive complexity of the neural network and minimise the associated structural problems.Results and discussion The ANN could predict the antioxidant capacities of essential oils of known chemical composition in both the DPPH and linoleic acid assays with an average error of only 3.16% and 1.46%, respectively. We also discuss on the contribution of different compounds to these chemical activities.Conclusions These results confirm that artificial neural networks are reliable, fast and cheap tools for predicting antioxidant activity of essential oils from some of its components and can be used to model biochemical properties of complex natural products including the prediction of parameters associated with nutraceutical properties of food ingredients. Keywords: Artificial neural networks; Essential oils; Antioxidant activity; DPPH; Linoleic acid; Chemometrics Alejandro Lucia, Susana Licastro, Eduardo Zerba, Paola Gonzalez Audino, Hector Masuh, Sensitivity of Aedes aegypti adults (Diptera: Culicidae) to the vapors of Eucalyptus essential oils, Bioresource Technology, Volume 100, Issue 23, December 2009, Pages 6083-6087, ISSN 0960- 8524, DOI: 10.1016/j.biortech.2009.02.075. (http://www.sciencedirect.com/science/article/B6V24-4WR0CV1- 2/2/1af6ccf32f5ca466d375bf8ca59e6a7d) Abstract: Vapors of essential oils extracted from various species of Eucalyptus (E. gunnii, E. tereticornis, E. grandis, E. camaldulensis, E. dunnii, E. cinerea, E. saligna, E. sideroxylon, E. globulus ssp. globulus, E. globulus ssp. maidenii, E. viminalis and the hybrids E. grandis x E. tereticornis and E. grandis x E. camaldulensis) and their major components were found to be toxic to Aedes aegypti adults, the yellow fever mosquito. An aliquot of each oil was placed in a cylindrical test chamber and the number of knocked-down mosquitoes was recorded as function of time. Knockdown time 50% was then calculated. Results showed that E. viminalis had the fastest knockdown time at of 4.2 min, on the same order as dichlorvos, a standard knockdown agent. A correlation was observed between the content of 1,8- cineole in the Eucalyptus essential oils and the corresponding toxic effect. The correlation between KT50 values and calculated vapor pressures of the essential oil components showed that the fumigant activity of simple organic compounds in insects is correlated with their volatility. Keywords: Mosquito; Fumigant activity; Knockdown; 1,8-Cineole; Vapor pressure Melanie Turgis, Jaejoon Han, Stephane Caillet, Monique Lacroix, Antimicrobial activity of mustard essential oil against Escherichia coli O157:H7 and Salmonella typhi, Food Control, Volume 20, Issue 12, December 2009, Pages 1073-1079, ISSN 0956-7135, DOI: 10.1016/j.foodcont.2009.02.001. (http://www.sciencedirect.com/science/article/B6T6S-4VJM2SM- 1/2/0d19241094af02de14ae9cb1f41362af) Abstract: The aim of this study was to investigate how mustard essential oil (EO) affected the cell membrane of Escherichia coli O157:H7 and Salmonella typhi. Intracellular pH and ATP concentration and the release of cell constituents were measured when mustard EO was in contact with E. coli and S. typhi at its minimal inhibitory concentration (MIC) and maximal tolerated concentration (MTC). The treatment with mustard EO affected the membrane integrity of bacteria and induced a decrease of the intracellular ATP concentration. Also, the extracellular ATP concentration increased and a reduction of the intracellular pH was observed in both bacteria. A significantly (P [less-than-or-equals, slant] 0.05) higher release of cell constituent was observed when both bacteria cells were treated with mustard EO. Electronic microscopy observations showed that the cell membranes of both bacteria were apparently damaged by mustard EO. In conclusion, mustard EO affects the concentration of intracellular component, such as ATP in both bacteria and affects the pH suggesting that cytoplasmic membrane is involved in the antimicrobial action of mustard EO. Mustard EO can be used as an effective antimicrobial agent. We have demonstrated that mustard EO affected the cell membrane integrity, resulting in a loss of cell homeostasis. Keywords: Mustard essential oil; Escherichia coli O157:H7; Salmonella typhi; Intracellular pH; Cell ATP concentration; Release of cell constituents; Electronic microscopy Jianchun Xie, Baoguo Sun, Shuaibin Wang, Yoichiro Ito, Isolation and purification of nootkatone from the essential oil of fruits of Alpinia oxyphylla Miquel by high-speed counter-current chromatography, Food Chemistry, Volume 117, Issue 2, 15 November 2009, Pages 375-380, ISSN 0308-8146, DOI: 10.1016/j.foodchem.2009.04.011. (http://www.sciencedirect.com/science/article/B6T6R-4W26GFM- 1/2/c34dd3656580680d1ebc23fe7194bcad) Abstract: HSCCC technique in a semi-preparative scale was successfully applied in isolation and purification of nootkatone from the essential oil of fruits of Alpinia oxyphylla Miquel. Twelve kinds of two-phase solvent systems, consisting of seven non-aqueous and five organic-aqueous solvent systems, were selected with not only suitable partition coefficients of nootkatone but also suitable separation factors between nootkatone and valencene, the dominant impurity in the essential oil. Further on HSCCC, n-hexane-chloroform-acetonitrile (10:1:10, v/v) amongst the non-aqueous solvent systems and n-hexane-methanol-water (5:4:1, v/v) amongst the organic-aqueous solvent systems were separately screened out. However, n-hexane-methanol-water (5:4:1, v/v) was thought optimal due to quite shorter elution time and better HSCCC peak form. By eluting the lower phase of this solvent system in head-tail mode, 3.1 mg of nootkatone was obtained at a purity of 92.30% by GC-MS from 80 mg of crude essential oil in one step operation in less than 4 h. The chemical structure of nootkatone fraction was confirmed by EI-MS and 1H NMR. Keywords: Counter-current chromatography; Alpinia oxyphylla Miquel; Sesquiterpenoid; Nootkatone; Flavor; Bioactive component Monica R. Loizzo, Federica Menichini, Filomena Conforti, Rosa Tundis, Marco Bonesi, Antoine M. Saab, Giancarlo A. Statti, Bruno de Cindio, Peter J Houghton, Francesco Menichini, Natale Giuseppe Frega, Chemical analysis, antioxidant, antiinflammatory and anticholinesterase activities of Origanum ehrenbergii Boiss and Origanum syriacum L. essential oils, Food Chemistry, Volume 117, Issue 1, 1 November 2009, Pages 174-180, ISSN 0308-8146, DOI: 10.1016/j.foodchem.2009.03.095. (http://www.sciencedirect.com/science/article/B6T6R-4VYP9BS- 1/2/b7b61692cd6982d04caf5acd4d3df0f8) Abstract: The essential oils of Origanum ehrenbergii and O. syriacum collected in Lebanon were analysed by GC and GC-MS and evaluated for their anticholinesterase, NO production inhibitory activities, and antioxidant properties. O. ehrenbergi essential oil was characterised by the presence of 37 components, representing 94.9% of the total oil of which thymol (19%) and p-cymene (16.1%) were the main abundant compounds. Thirty-six compounds characterised the O. syriacum essential oil, representing 90.6% of the total oil. The most abundant components were thymol (24.7%) and carvacrol (17.6%). O. ehrenbergii demonstrated interesting scavenging effects on DPPH with an IC50 value of 0.99 [mu]g/ml. In addition, both O. ehrenbergii and O. syriacum oils inhibited oxidation of linoleic acid after 30 min of incubation, as well as after 60 min of incubation with IC50 values of 42.1 and 33.6 [mu]g/ml, and 46.9 and 58.9 [mu]g/ml, respectively. Interestingly, O. ehrenbergii oil inhibited NO production in the murine monocytic macrophage cell line RAW 264.7 with an IC50 value of 66.4 [mu]g/ml. Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibition was assessed by modifications of the Ellman's method. O. ehrenbergii exhibited a strong activity against both cholinesterases with IC50 values of 0.3 [mu]g/ml. The data suggest that O. ehrenbergii