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Volatile organic compounds (VOCs) comprise a wide range of compounds with low molecular weight that are released from seaweeds as secondary metabolites. Therefore, the aim of this work was to evaluate the profile of VOCs from six sub-Antarctic macroalgae by means of gas chromatography–mass spectrometry. Results indicated that the studied seaweeds contained approximately 40 different compounds found as aldehydes, ketones, hydrocarbons and alcohols, for instance. For brown macroalgae, hexanal was found in greater amounts (12.87–29.46%) followed by 2-pentylfuran (5.52–11.61%) and pentadecane (4.29–10.28%), while red seaweeds were mainly composed of heptadecane (27.79–85.12%), hexanal (1.78–11.62%) and benzaldehyde (1.36–2.87%). Further evaluation using principal component analysis showed that distinct compositions of VOCs could differentiate brown and red seaweeds. Therefore, sub-Antarctic macroalgae had their VOCs elucidated for the first time assisting in the efforts for understanding their biochemical constitution as well as supporting in further potential pharmacological and biotechnological applications.

The SPME-GC-MS analysis of the aroma components of Serapias cordigera, Serapias cordigera subsp. lucana, Serapias vomeracea, Serapias lingua, and Serapias parviflora were reported. The relevant components of the scent of Serapias cordigera were α-amorphene, ethyl oleate, heneicosane, heptadecane, 2-heptadecanone, ethyl elaidate, pentadecane, octadecane, farnesylacetaldehyde, nonadecane, and ethyl stearate. Serapias cordigera subsp. lucana gave α-amorphene, pentadecane, propyl undecanoate, heptadecane, ethyl elaidate and oleate, ethyl stearate, and 8-heptadecene. Serapias vomeracea showed pentadecane, 5-nonadecene, 1-nonadecene, 3-heptadecene, benzyl benzoate, 2-undecanone, and octadecane. Serapias lingua showed the presence of heptadecane, 3-heptadecene, isopropyl myristate, pentadecane, nonadecane, isopropyl palmitate, octadecane, and benzyl benzoate. Serapias parviflora gave pentadecane, pentadecene, hexadecane, heptadecane, nonadecane, and ethyl elaidate.

Aliphatic hydrocarbons in the surface ocean are derived from phytoplankton and oil, but the coexistence and cycling of these two sources is not well-defined. Moreover, phytoplankton and oil can cre...

Interactions between water and hydrocarbons play a significant role in chemical, physical, and biological processes. Here, we present a set of force-field (FF) parameters that define the interactions between coarse-grained (CG) hydrocarbon models ( An , Y. J. Phys. Chem. B , 2018 , 122 , 7143 - 7153 ) and one-site water model ( Bejagam , K. K. J. Phys. Chem. B , 2018 , 122 , 1958 - 1971 ) developed in our recent work. The nonbonded FF interactions between various hydrocarbon beads and the water beads are represented by the 12-6 Lennard-Jones potential. The FF parameters were optimized to reproduce the experimentally measured Gibbs hydration free energies of selected hydrocarbon models (decane and hexadecane with 2:1 mapping scheme and nonane and pentadecane with 3:1 mapping scheme) and the interfacial tensions of decane and nonane models at 300 K. The predicted values of Gibbs hydration free energies of CG decane, hexadecane, nonane, and pentadecane models by the optimized FF parameters were within 8, 12, 11, and 4% of their corresponding experimental values, respectively. These new optimized FF parameters were transferable when used to calculate the Gibbs hydration free energies of different hydrocarbons ranging from pentane to heptadecane at 300 K (minimum error ∼0.5%, and maximum error ∼40.8%). Furthermore, the interfacial tensions of the CG hydrocarbon models calculated by using these new FF parameters showed good agreement with their corresponding experimental values at 300 K. Homogeneous mixtures of CG water and hydrocarbon models were able to exhibit the phase segregation during 1 μs. These new nonbonded interaction parameters were expected to be utilized in modeling the interactions between water and polymer backbones represented with hydrocarbon beads.

The liquid-liquid coexistence curves in a temperature range of about 10 K from the upper consolute critical temperature for binary solutions of {dimethyl carbonate + pentadecane} and {dimethyl carbonate + heptadecane} have been precisely measured. The upper consolute mole fraction xc of n-alkane and the upper consolute temperature Tc were determined to be xc = 0.210, Tc = 312.234 K for {dimethyl carbonate + pentadecane} and xc = 0.183, Tc = 320.496 K for {dimethyl carbonate + heptadecane}, respectively. From the data collected in the near critical point, the critical exponent β was deduced and shown to be consistent well with its theoretical value for the 3-D Ising universality class. The dependences of critical properties on the chain length of n-alkane for a series of {dimethyl carbonate + n-alkane} binary solutions were investigated. Furthermore, it was found that the asymmetric behaviors of the coexistence curve could be well described by the complete scaling theory. The contribution of the heat capacity related term to the asymmetric behaviors of the coexistence curves was discussed.

The reactions to produce liquid biofuels from a palm fatty acid distillate (PFAD) under hydrogen absence were carried out using 10 wt% NiO/zeolite (Ni/Zeo), 10 wt% Co3O4/zeolite (Co/Zeo), and 10 wt% (NiO + Co3O4)/zeolite (NiCo/Zeo) as catalysts. The zeolite was synthesized by a thermal and chemical treatment from natural clay, obtaining a zeolite A and sodalite mixture. Catalytic activity was evaluated as a function of reaction temperature (250, 300, and 350 °C) during 0.5 h and using 5 wt% of catalyst. The reaction products were classified as organic liquid products (OLPs), gaseous products, and solid waste. The OLPs fractions were separated by fractional distillation, and the products were identified and quantified using gas chromatography coupled to a mass spectrometer detector (GC-MS). The results showed yields to OLPs above 50% for all catalysts and temperatures. However, the highest yield to OLPs of 67.9% was reached with a NiCoZeo catalyst at 300 °C. In this reaction, a higher yield to hydrocarbons was obtained (84.8%), indicating a cooperative effect between Ni and Co in the catalyst. Hydrocarbons such as heptadecane (C17H36), pentadecane (C15H26), and other alkanes-alkenes with lower carbon chains were the main products. Therefore, deoxygenation of PFAD using a low-cost Ni-Co catalyst was shown to be an economic and viable way to produce diesel-type biofuels.

Purpose. To analyse the qualitative and quantitative composition of volatile organic substances (VOS) in the petals of six species of dog-rose in the collection of M. M. Gryshko National Botanic Garden of the NAS of Ukraine for further bree­ding. Methods. Volatile organic substances were obtained by steam distillation. VOS was determined using gas chromato­graphy (Chromatograph Agilent Technologies 6890). Results. The qualitative and quantitative composition of volatile organic substances in the petals in such species as Rosa L. (R. roullettii HCh (Correvon), R. multiflora Thunb., R. pimpinellifolia L., R. canina L., R. centifolia L., R. rugosa Thunb.) was investigated. According to the results of the research, 105 VOS were discovered in the dog-rose petals, among which 11 were not identified. The dog-rose petals of identified VOC contained 16 components which share exceeds 5%, 31 – was ranging from 1% to 5%, 47 – was less than 1%. They belonged to different groups including monoterpenoids, sesquiterpenoids, sesquiterpene alcohols, saturated unbranched hydrocarbons etc. The largest number of components were identified in the petals of R. roulettii (49) and R. centifolia (45), while the number of identified components in species R. multiflora (33), R. rugosa (31) and R. canina (30) was relatively smaller. All studied dog-rose species were characterized by the presence of such saturated unbranched hydrocarbons as decan, tetradecane, pentadecane, hexadecane, heptadecane, octadecane, nanodecane, heneicosane, tricosane, tetracosane, pentacosane, heptocosane, hentriacontane. Triterpene hydrocarbon squalene is the important component of the VOS complex in dog-rose pen tals. b-phenylethyl alcohol to be one of the main components of the rose essential oils was found during investigation in the following four dog-rose species as R. centifolia (0.61%), R. pimpinellifolia (3.56%), R. rugosa (4.24%), and R. multiflora (5.43%). Significant content of dihydro-b-ionol (18.46%), dihydro-b-ionone (0.69%), thias­piran A (1.35%), and thiaspiran B (2.17%) were revealed in the petals of R. roulettii, which also have an influence on the aromatic bouquet of the rose oil. Conclusions. For the first time, 105 volatile organic substances were found in the petals of six species of dog-rose, 11 of which were not identified. It was found out that the largest number of components were identified in the petals of R. roulettii (49) and R. centifolia (45). The number of VOS identified in species R. multiflora (33), R. rugosa (31), and R. canina (30) was relatively smaller. Component composition of VOS in the petals of studied dog-rose species is an important constituent in breeding investigations of prospective producers for the various purposes of use.

The effect of various reaction temperature on the hydrocracking of Cerbera manghas oil to produce a paraffin-rich mixture of hydrocarbons with Co-Ni/HZSM-5 as doubled promoted catalyst were studied. The Co-Ni/HZSM-5 catalyst with various metal loading and metal ratio was prepared by incipient wetness impregnation. The catalysts were characterized by XRD, AAS, and N 2 adsorption-desorption. Surface area, pore diameter, and pore volume of catalysts decreased with the increasing of metals loading. The hydrocracking process was conducted under hydrogen initial pressure in batch reactor equipped with a mechanical stirrer. The reaction was carried out at a temperature of 300-375 o C for 2 h. Depending on the experimental condition, the reaction pressure changed between 10 bar and 15 bar. Several parameters were used to evaluate biofuel produced, including oxygen removal, hydrocarbon composition and gasoline/kerosene/diesel yields. Biofuel was analyzed by Fourier Transform Infrared Spectroscopic (FTIR) and gas chromatography-mass spectrometry (GC-MS). The composition of hydrocarbon compounds in liquid products was similar to the compounds in the gasoil sold in unit of Pertamina Gas Stations, namely pentadecane, hexadecane, heptadecane, octadecane, and nonadecane with different amounts for each biofuel produced at different reaction temperatures. However, isoparaffin compounds were not formed at all operating conditions. Pentadecane (n-C15) and heptadecane (n-C17) were the most abundant composition in gasoil when Co-Ni/HZSM-5 catalyst was used. Cerbera Manghas oil can be recommended as the source of non-edible vegetable oil to produce gasoil as an environmentally friendly transportation fuel. Copyright © 2017 BCREC Group. All rights reserved Received: 20 th May 2016; Revised: 30 th January 2017; Accepted: 10 th February 2017 How to Cite: Marlinda, L., Al-Muttaqii, M., Gunardi, I., Roesyadi, A., Prajitno, D.H. (2017). Hydrocracking of Cerbera manghas Oil with Co-Ni/HZSM-5 as Double Promoted Catalyst. Bulletin of Chemical Reaction Engineering & Catalysis , 12 (2): 167-184 (doi:10.9767/bcrec.12.2.496.167-184) Permalink/DOI : http://dx.doi.org/10.9767/bcrec.12.2.496.167-184

Long-chain alkanes are a type of important intermediate-volatile organic compounds (IVOCs) in the atmosphere, which contribute to a large proportion of secondary organic aerosol (SOA). However, the optical properties of SOA derived from long-chain alkanes remain poorly understood. Here, we investigate the refractive index (RI) of SOA derived from photo-oxidation of dodecane (C12), pentadecane (C15) and heptadecane (C17) under low-NOx and high-NOx conditions with the absence or presence of inorganic aerosol seeds. The RIs of these SOAs are found to be in the range of 1.33 to 1.57 at the wavelength of 532 nm. The results from mass spectroscopy indicate that both reaction mechanisms influenced by NOx level and gas-particle partitioning influenced by seeds have important impact on the chemical compositions of SOAs, which further influence the optical properties like RI. Finally, by comparing the RI values to other literature and model results, we suggest that various RIs of SOAs derived from long-chain alkanes should be applied in atmospheric and climate models.

The SPME-GC-MS analysis of the aroma components of Cephalanthera damasonium, Cephalanthera rubra, and Cephalanthera longifolia were reported. The main components found in C. damasonium were pentadecane, hexadecane, heptadecane and α-farnesene. The same compounds were found in the scent of C. rubra. Although C. damasonium and C. rubra have different pollination mechanisms, their spectrum of volatile compounds surprisingly does not differ significantly. In C. longifolia pentadecane and heptadecane were found together with cis-β-farnesene. As C. longifolia is allogamous, the differences in scent composition may play a role in pollinator attraction.

This research aims to investigate the effect of various reaction temperatures on the hydrocracking of Cerbera manghas oil to produce biofuel as a paraffin-rich mixture of hydrocarbons with Co-Ni/HZSM-5 catalyst. Co-Ni/HZSM-5 catalyst was prepared by incipient wetness impregnation. The catalyst was characterized by X-ray diffraction (XRD), N 2 physisorption according to the Brunauer-Emmet-Teller (BET) method, and atomic absorption spectrometry (AAS). The hydrocracking reaction was carried out in a pressure batch reactor, reaction temperatures of 300-375 o C for 2 hours, reactor pressure of 15 bar after flowing H 2 for at least 1 hour, and a catalyst/oil ratio of 1 g/200 ml. The hydrocarbon composition was determined by gas chromatography-mass spectrometry (GC-MS). With the Co(0.88%)-Ni(3.92%)/HZSM-5 catalyst, the highest yield for gasoil was 46.45% at temperature of 350 o C. At this reaction temperature condition, the main abundant hydrocarbon compounds in gasoil-like hydrocarbon were n-paraffin, i.e. pentadecane of 20.06 area% and heptadecane of 14.13 area%. Biofuels produced showed that abundant hydrocarbon compounds were different at different reaction temperatures. Iso-paraffin with low freezing point and good flow property were not found in gasoil-like hydrocarbon. Isomerization depends on reaction condition and type of catalyst.

The behavior of aliphatic hydrocarbons during co-composting of sewage sludge activated with palm tree waste was studied for 6 months using Py-GC/MS. The main aliphatic compounds represented as doublet alkenes/alkanes can be classified into three groups. The first group consists of 11 alkenes (undecene, tridecene, pentadecene, hexadecene, heptadecene, octadecene, nonadecene, eicosene, uncosene, docosene, tricosene) and 15 alkanes (heptane, octane, nonane, decane, undecane, dodecane, tetradecane, pentadecane, heptadecane, octadecane, nonadecane, eicosane, uncosane, docosane, and tricosane), which remain stable during the co-composting process. The stability of these compounds is related to their recalcitrance behavior. The second group consists of five alkenes (heptene, octene, nonene, decene, dodecene) and tridecane as a single alkane that decreases during co-composting. The decrease in these compounds is the combined result of their metabolism and their conversion into other compounds. The third group is constituted with tetradecene and hexadecane that increase during composting, which could be explained by accumulation of these compounds, which are released by the partial breakdown of the substrate. As a result, these molecules are incorporated or adsorbed in the structure of humic substances.

A filamentous cyanobacterium, Limnothrix sp. KNUA012, was axenically isolated from a freshwater bloom sample in Lake Hapcheon, Hapcheon-gun, Gyeongsangnam-do, Korea. Its morphological and molecular characteristics led to identification of the isolate as a member of the genus Limnothrix. Maximal growth was attained when the culture was incubated at 25°C. Analysis of its lipid composition revealed that strain KNUA012 could autotrophically synthesize alkanes, such as pentadecane (C 15 H 32 ) and heptadecane (C 17 H 36 ), which can be directly used as fuel without requiring a transesterification step. Two genes involved in alkane biosynthesis－an acyl-acyl carrier protein reductase and an aldehyde decarbonylase－were present in this cyanobacterium. Some common algal biodiesel constituents－myristoleic acid (C 14:1 ), palmitic acid (C 16:0 ), and palmitoleic acid (C 16:1 )－were produced by strain KNUA012 as its major fatty acids. A proximate analysis showed that the volatile matter content was 86.0% and an ultimate analysis indicated that the higher heating value was 19.8 MJ kg -1 . The isolate also autotrophically produced 21.4 mg g -1 phycocyanin－a high-value antioxidant compound. Therefore, Limnothrix sp. KNUA012 appears to show promise for application in cost-effective production of microalga-based biofuels and biomass feedstock over crop plants.

The effect of cobalt supported on the hierarchical Ni/HZSM-5 on conversion, n-paraffin/aromatic selectivity, the degree of hydrocracking and polymerization in hydrocracking of Sunan candlenut oil was investigated. The hierarchical HZSM-5 was obtained through desilication with 0.2 M NaOH solution. The cobalt (Co), nickel (Ni) and Co-Ni supported on hierarchical HZSM-5 catalysts were prepared by incipient wetness impregnation. Desilication and metal impregnation did not change the crystalline structure of HZSM-5 catalyst. Hydrocracking of Sunan candlenut oil into gasoil-range hydrocarbon was tested with the catalysts at a temperature of 400 °C, and a reactor pressure of 15 bar for 2 h under initial hydrogen pressure in a pressured batch reactor. All catalysts reached conversion almost 100 %. Non-catalytic hydrocracking contained large amounts of undesired compounds (50 %), N-containing compounds around 1 area% and a small amount of compound containing oxygen including ketone (2-heptadecanone) and alcohol (

The used of vegetable oils in transesterified form is a common technological product for biofuel especially biodiesel.In order to develop a specification of biofuel, vegetable oils were converted into bio-alkane fuel by hydroprocessing technology. Selective bio-alkane fuel formation and higher heating value (HHV) of the product were investigated. Hydroprocessing of Calophyllum inophyllum oil as one of vegetable oil was carried out at ranges of parameter process (T = 320-350°C, P H2 = 1-4 MPa, t = 60-240 min, commercial NiMo/Al 2 O 3 catalyst loading = 0-2.5 % mass of feed). Liquid product after hydroprocessed was analyzed to determine the formation of bio-alkane fuel composition and its calorific value. During hydroprocessing the fatty acids in Calophyllum inophyllum oil (mainly palmitic acid (C 16 ), stearic acid (C 18 :0), oleic acid (C 18 :1), and linoleic acid (C 18 :2) were mainly converted into pentadecane (C 15 H 32 ) and heptadecane (C 17 H 36 ). Increase in temperature, hydrogen pressure, and amount of catalyst, the total percentage area of the bio-alkane fuel as well as HHV in the liquid product also increased. Finally, hydroprocessed Calophyllum inophyllum oil selectively produced pentadecane (C 15 H 32 ) and heptadecane (C 17 H 36 ) with small amount of nonane (C 9 H 20 ), decane (C 10 H 22 ), undecane (C 11 H 24 ), dodecane (C 12 H 26 ), tridecane (C 13 H 28 ), tetradecane (C 14 H 30 ), hexadecane (C 16 H 34 ), octadecane (C 18 H 38 ), nonadecane (C 19 H 40 ), eicosane (C 20 H 42 ), heneicosane (C 21 H 44 ), docosane (C 22 H 46 ), and tetracosane (C 24 H 50 ).

Three types of zeolites (Meso-Y, SAPO-34, and HY) loaded with nickel were used to convert waste cooking oil to jet biofuel. Mesoporous zeolite Y exhibited a high jet range alkane selectivity of 53% and a proper jet range aromatic hydrocarbon selectivity of 13.4% in liquid fuel products. Reaction temperature was optimized to produce quality jet biofuel. Zeolite Meso-Y exhibited a high jet range alkane yield of 40.5% and a low jet range aromatic hydrocarbon yield of 11.3% from waste cooking oil at 400°C. The reaction pathway for converting waste cooking oil to jet biofuel was proposed. Experimental results showed that waste cooking oil mainly deoxygenated to heptadecane (C17H36) and pentadecane (C15H30) through the decarbonylation pathway for the first 3h. Long chain alkanes cracked into jet range alkanes (C8-C16). Cycloalkanes and aromatic hydrocarbons were produced through cyclization and dehydrogenation pathways.

In the past decade industrial-scale production of renewable transportation biofuels has been developed as an alternative to fossil fuels, with ethanol as the most prominent biofuel and yeast as the production organism of choice. However, ethanol is a less efficient substitute fuel for heavy-duty and maritime transportation as well as aviation due to its low energy density. Therefore, new types of biofuels, such as alkanes, are being developed that can be used as drop-in fuels and can substitute gasoline, diesel, and kerosene. Here, we describe for the first time the heterologous biosynthesis of long-chain alkanes by the yeast Saccharomyces cerevisiae. We show that elimination of the hexadecenal dehydrogenase Hfdl and expression of a redox system are essential for alkane biosynthesis in yeast. Deletion of HFDI together with expression of an alkane biosynthesis pathway resulted in the production of the alkanes tridecane, pentadecane, and heptadecane. Our study provides a proof of principle for producing long-chain alkanes in the industrial workhorse S. cerevisiae, which was so far limited to bacteria. We anticipate that these findings will be a key factor for further yeast engineering to enable industrial production of alkane based drop-in biofuels, which can allow the biofuel industry to diversify beyond bioethanol.

In this study we describe the heterologous expression of the recently identified cyanobacterial pathway for long chain alkane biosynthesis, involving the reduction of fatty acyl-ACP to fatty aldehyde and the subsequent conversion of this into alkanes, in the filamentous fungus Aspergillus carbonarius ITEM 5010. Genes originating from Synechococcus elongatus strain PCC7942, encoding acyl-ACP/CoA reductase and aldehyde deformylating oxygenase enzymes, were successfully expressed in A. carbonarius, which lead to the production of pentadecane and heptadecane, alkanes that have not been previously produced by this fungus. Titers of 0.2, 0.5 and 2.7 mg/l pentadecane and 0.8, 1.6 and 10.2 mg/l heptadecane were achieved using glucose, Yeast malt and oatmeal media, respectively. Besides producing alkanes, we found elevated levels of internal free fatty acids and triglycerides in the alkane producing transformant. These findings can indicate that a yet unidentified, native fatty aldehyde dehydrogenase channels back the fatty aldehydes into the fatty acid metabolism, thus competing for substrate with the heterologously expressed fatty aldehyde deformylating oxygenase. These findings will potentially facilitate the future application of robust, fungal cell factories for the production of advanced biofuels from various substrates. Electronic supplementary material The online version of this article (doi:10.1186/s13568-016-0321-x) contains supplementary material, which is available to authorized users.

Biomass yields and biofuel production were examined in a dual (solid and liquid)-phase cultivation system (DuPHA) with the unique filamentous cyanobacteria, Pseudanabaena sp. ABRG 5-3 and Limnothrix sp. SK1-2-1. Continuous circular cultivation was driven under the indoor closed (IC) or indoor opened (IO) conditions and provided biomass yields of approximately 8–27 g dry cell weight (DCW) floor m−2 d−1. Alkanes of heptadecane (C17H36) or pentadecane (C15H32) as liquid biofuels were also recovered from the lower liquid-phase, in which cyanobacteria were dropped from the upper solid-phase and continuously cultivated with a small amount of medium. After the main cultivation in DuPHA, the upper solid-phase of a cotton cloth on which cyanobacteria grew was dried and directly subjected to a combustion test. This resulted in the thermal power (kJ s−1) of the cloth with microalgae increasing approximately 20–50% higher than that of the cloth only, suggesting a possibility of using the solid phase with microalgae as solid biofuel.

Radiation-induced hydrocarbon contents of dried anchovy, jiri anchovy, and large-eyed herring were evaluated following electron-beam irradiation at doses of 1, 3, 5, 7, and 10 kGy. GC/MS identification of the induced hydrocarbons by irradiation was conducted after lipid separation by soxtec, followed by florosil column chromatography. 1-Tetradecene (C 14:1 ) and pentadecane (C 15:0 ) derived from palmitic acid, 1-hexadecene (C 16:1 ) and heptadecane (C 17:0 ) from stearic acid, and 8-heptadecene (C 17:1 ) and 1,7-hexadecadiene (C 16:2 ) from oleic acid were the major induced hydrocarbons in irradiated dried anchovy, jiri anchovy, and large-eyed herring samples. At the same irradiation dose, concentration of induced hydrocarbons differed from fatty acid composition and increased in accordance with radiation dose level. Radiation-induced hydrocarbons, such as 1-tetradecene (C 14:1 ), 1-hexadecene (C 16:2 ), 8-heptadecene (C 17:1 ), and 1,7-hexadecadiene (C 16:2 ), were confirmed as irradiation marker compounds. Therefore, these marker compounds could be used to distinguish electron-beam irradiated dried anchovy, jiri anchovy, and large-eyed herring from non-irradi-ated ones.

This study determined hydrocarbons induced by gamma and electron beam irradiation of ground beef. The samples were irradiated with 0, 2.5, 5, 7.5, 10, 15, and 20 kGy dosages of gamma-rays and an electron beam. The lipid contents were extracted by hexane and the induced hydrocarbons were separated and identified by gas chromatography–mass spectrometry. The analytical method was validated by characterization of detection limits, linearity, precision, and recovery; satisfactory results were obtained in all cases. The major hydrocarbons detected in irradiated ground beef samples were pentadecane and 1-tetradecene from palmitic acid, heptadecane, and 1-hexadecene from stearic acid, and 8-heptadecene and 1,7-hexadecadiene from oleic acid. The induced hydrocarbons were detected at irradiation levels above 2.5 kGy but not in the absence of irradiation. The induced hydrocarbons showed an increase with radiation dosage, but the concentration was slightly higher for gamma rays than for the electron beam. The 1-tetra...

In this study, hydrocracking of coconut oil over Ni-Fe/HZSM-5 catalyst was carried out in a batch reactor under different reaction temperature. Coconut oil is proposed as one of the potential feedstock for biofuel production. The Ni-Fe/HZSM-5 catalyst was prepared by incipient wetness impregnation method. The characterization of Ni-Fe/HZSM-5 catalyst by X-Ray Diffraction (XRD), Scanning Electron Microscopy-Energy Dispersive X-ray (SEM-EDAX), and Brunauer-Emmett-Teller (BET). The chemical composition of biofuel was analyzed by Gas-Chromatography-Mass Spectrometry (GC-MS). The results from the GC-MS analysis showed that the hydrocracking reaction over 10 % (Ni-Fe)/HZSM-5 catalyst at temperature of 375 oC obtained the highest hydrocarbon content (contained 49.4% n-paraffin, 26.93 % isoparaffin, 3.58 % olefin) and the highest yield of bio-gasoil 38.6 % in the biofuel liquid hydrocarbon. Pentadecane (n-C15) and heptadecane (n-C17) were the most abundant hydrocarbon compounds in biofuel liquid hydrocarbon. Decarboxylation and/or decarbonylation was the dominant reaction pathways in this process. Based on the result, the reaction temperature had a significant effect on the distribution of biofuel composition and yield of biofuel from coconut oil. Copyright © 2019 BCREC Group. All rights reserved

Food irradiation processing needs proper control to facilitate consumer assurance, choice, and protection, including accurate detection of irradiated food. This study was aimed at analyzing hydrocarbons induced by gamma and electron beam irradiation in Camembert and processed cheeses. The samples were irradiated at 0, 1, 3, 5, 7, and 10 kGy doses of γ-rays and an electron beam. The induced hydrocarbons were separated on a florisil column and identified by gas chromatography-mass spectrometry (GC-MS). The detected hydrocarbons were pentadecane and 1-tetradecene from palmitic acid, heptadecane and 1-hexadecene from stearic acid, and 8-heptadecene and 1,7-hexadecadiene from oleic acid. The concentrations of the radiation-induced hydrocarbons increased with irradiation dose. Among the induced hydrocarbons, 1-tetradecene and 1,7-hexadecadiene were found to be the major hydrocarbons in the cheese samples. For most irradiation doses, the concentration of hydrocarbons induced by the electron beam was slightly hig...

This paper demonstrates the initiated use of relevant refining palm oil for bio-hydrogenated diesel production. The conversions of crude palm oil (CPO) and its physical refining including degummed palm oil (DPO) and palm fatty acid distillate (PFAD) to diesel fuel by hydroprocessing were studied. The effects of operating parameters (i.e. reaction time, operating temperature, and pressure) and catalyst (i.e. Pd/C and NiMo/γ-Al 2 O 3 ) were examined in order to determine suitable operating condition for each feedstock. It was found that the hydroprocessing of CPO with Pd/C catalyst at 400 °C, 40 bar, and reaction time of 3 h provides the highest diesel yield of 51%. When gum which contains phospholipid compounds is removed from CPO, namely DPO, the highest diesel yield of 70% can be obtained at a shorter reaction time (1 h). In the case of PFAD, which consists mainly of free fatty acids, a maximum diesel yield of 81% could be observed at milder conditions (375 °C with the reaction time of 0.5 h). The main liquid products are n -pentadecane and n -heptadecane, having one carbon atom shorter than the corresponding fatty acids according to decarboxylation/decarbonylation pathways. Pd/C catalyst shows good catalytic activity for fatty acid feedstocks but becomes less promising for triglyceride feedstocks when compared to NiMo/γ-Al 2 O 3 .

This Article proposes the catalytic conversion of triglyceride in subcritical water for the purpose of developing a process producing liquid and gaseous fuels without any reagents, such as hydrogen, other than water. The characteristics of the reaction were discussed along with the analysis of the catalytic mechanisms. Pt, Pd, and Ni catalysts supported on carbon were applied to the conversion of a jatropha oil. Pt on activated carbon and homemade Ni on porous carbon catalysts had high enough activities to completely convert the oil into products nearly free from fatty acids at 350 degrees C, but they had distinctly different ways of catalysis, leading to the production of pentadecane/heptadecane and methane, respectively. The hydrogen generated in situ from glycerol by gasification contributed to the increases in the yields of n-alkanes, whereas an unavoidable formation of heavy byproducts, which were undetectable by GC analysis, prevented the jatropha oil from being converted fully into the desired products.

Aims Hydrocarbon components are carcinogens and neurotoxin organic pollutants. Biodegradation of hydrocarbon-contaminated soils has been established as an efficient, economic, versatile and environmentally sound treatment. Our aim was to isolate the 2T engine degrading bacterial culture from automobile workshop contaminated soil. Method A total of nineteen morphological different bacterial cultures were isolated by enrichment and pour plate method. The growth of isolated cultures was studied in liquid M9 medium containing 0.5 % 2T engine oil. On the basis of increasing optical density in M9 medium only one bacterial strains GD18 was selected for further study. On the basis of morphological, physiological and biochemical properties strain GD18 was tentatively identified as pseudomonas sp. The degradation of 2T engine oil hydrocarbon degradation was checked by GC-MS analysis. The strain GD18 degraded completely the following hydrocarbons (Tridecane, Tridecane 6 methyl, Dodecane 2, 6, 10 trimethyl, Naphthalene 1, 6 dimethyl, Pentadecane, Hexadecane, Heptadecane 2, 6, 10, 14 tetramethyl, Heneicosane, 11 decyl) with in 10 days. Conclusion The strain GD18 was able to degrade 96.3 % of total hydrocarbons present in 2T engine oil. This is very efficient hydrocarbon degrading bacterial culture and can be used for successfully removal of 2T engine oil from contaminated soil.

Alkanes of defined carbon chain lengths can serve as alternatives to petroleum-based fuels. Recently, microbial pathways of alkane biosynthesis have been identified and enabled the production of alkanes in non-native producing microorganisms using metabolic engineering strategies. The chemoautotrophic bacterium Cupriavidus necator has great potential for producing chemicals from CO2: it is known to have one of the highest growth rate among natural autotrophic bacteria and under nutrient imbalance it directs most of its carbon flux to the synthesis of the acetyl-CoA derived polymer, polyhydroxybutyrate (PHB), (up to 80% of intracellular content). Alkane synthesis pathway from Synechococcus elongatus (2 genes coding an acyl-ACP reductase and an aldehyde deformylating oxygenase) was heterologously expressed in a C necator mutant strain deficient in the PHB synthesis pathway. Under heterotrophic condition on fructose we showed that under nitrogen limitation, in presence of an organic phase (decane), the strain produced up to 670 mg/L total hydrocarbons containing 435 mg/l of alkanes consisting of 286 mg/l of pentadecane, 131 mg/l of heptadecene, 18 mg/l of heptadecane, and 236 mg/l of hexadecanal. We report here the highest level of alka(e)nes production by an engineered C necator to date. We also demonstrated the first reported alka(e)nes production by a non-native alkane producer from CO2 as the sole carbon source. (C) 2016 International Metabolic Engineering Society.

Lipids in microalgal biomass were recovered by using pyrolysis method. The pyrolysis experiments of two Chlorella sp. KR-1 samples, which have triglyceride contents of 10.8% and 36.5%, respectively were carried out at to investigate the effects of lipid contents in the cells on the reaction characteristics. The conversion and liquid yield of the lipid-rich sample were higher than those of the lipid-lean sample since its carbon to hydrogen ratio was low. There were low molecular weight organic acids, ketones, aldehydes and alcohols in the liquid products from both KR-1 samples, but the pyrolysis oil of the lipid-rich sample was abundant in free fatty acids, particularly palmitic acid, oleic acid and stearic acid while the content of nitrogen containing organic compounds was low. The microalgal pyrolysis oil had two layers composed of the light hydrophobic fraction and the heavy hydrophilic fraction. The light fraction might be originated from triglycerides and the heavy fraction might be from carbohydrates and proteins. In the light fraction of the liquid products, there were considerable linear alkanes such as pentadecane and heptadecane as well as free fatty acids, implying that deoxygenation reaction including decarboxylation was occurred during the pyrolysis. The yield of the liquid products from the pyrolysis of the KR-1 sample having triglyceride content of 36.5% was 56.9% and the light fraction in the liquid products was 68.2%. Also more than 80% of the light fraction was free fatty acids and pure hydrocarbons, thus showing that most triglycerides could be extracted in the form of suitable raw materials for biofuels.

The chemical ecology of the parasitoid Acerophagus papayae Noyes and Schauff was studied with Gas Chromatography-Mass Spectrometry (GC-MS) volatiles analysis. The biochemical constituents and secondary metabolites in the host plant leaves revealed variation in influencing the growth and development of papaya mealybug Paracoccus marginatus Williams and Granara de Willink, which indirectly influenced the parasitoid efficiency too. Healthy and infested leaves of papaya and tapioca were analysed for the released volatile compounds (VOCs), and identified with GC-MS. It was observed that the VOCs like octanol, isocaryophyllene, hexadecane, pentadecane, heptadecane, morphinan and octasiloxane might probably attract the mealybug for sustained feeding in papaya. In tapioca, heptane, pyran, a-ocimene, octadien-3-ol, decane, butylated hydroxytoluene and dibutyl phthalate (DBP) were observed as probable reasons for repelling or prohibiting the mealybug from feeding.

BACKGROUND: Perilla and sesame seeds, a rich source of energy, are commonly utilized in different forms in many countries. During the post-harvest period, they are contaminated with insects as well as microbes that may have importance for keeping quality and quarantine, and thus they can be treated with ionizing radiation for insect disinfestation and microbial decontamination. Reliable and routine methods to identify whether or not a food has been irradiated are needed to help consumers' understanding of irradiated food and promote international trade. In the present study, fat-derived hydrocarbons from irradiated perilla seeds and sesame seeds of Korean and Chinese origin were analyzed in order to identify irradiation treatment by comparing their properties during the post-irradiation period. RESULTS: Gas chromatographic–mass spectrometric analysis showed that several saturated hydrocarbons, such as tetradecane, pentadecane, hexadecane and heptadecane, were found in the non-irradiated control samples, while four radiation-induced unsaturated hydrocarbons (R2 = 0.647–0.997), such as 1,7,10-hexadecatriene (C16:3), 1,7-hexadecadiene (C16:2), 6,9-heptadecadiene (C17:2) and 8-heptadecene (C17:1), were detected in all irradiated samples at 0.5 kGy or higher, with variations according to sample and origin. Concentrations of all hydrocarbons were reduced during storage and could not be detected in 0.5 kGy irradiated Chinese sample of either seed after 8 months. CONCLUSION: Radiation-induced hydrocarbons (C16:3, 16:2, 17:2, 17:1) could be used as markers to identify irradiated perilla and sesame seeds of both Korean and Chinese origin at 1 kGy or higher for 8 months' storage at room temperature. Copyright © 2009 Society of Chemical Industry

Hydrocarbons are ubiquitous in the ocean, where alkanes such as pentadecane and heptadecane can be found even in waters minimally polluted with crude oil. Populations of hydrocarbon-degrading bacteria, which are responsible for the turnover of these compounds, are also found throughout marine systems, including in unpolluted waters. These observations suggest the existence of an unknown and widespread source of hydrocarbons in the oceans. Here, we report that strains of the two most abundant marine cyanobacteria, Prochlorococcus and Synechococcus, produce and accumulate hydrocarbons, predominantly C15 and C17 alkanes, between 0.022 and 0.368% of dry cell weight. Based on global population sizes and turnover rates, we estimate that these species have the capacity to produce 2-540 pg alkanes per mL per day, which translates into a global ocean yield of ∼ 308-771 million tons of hydrocarbons annually. We also demonstrate that both obligate and facultative marine hydrocarbon-degrading bacteria can consume cyanobacterial alkanes, which likely prevents these hydrocarbons from accumulating in the environment. Our findings implicate cyanobacteria and hydrocarbon degraders as key players in a notable internal hydrocarbon cycle within the upper ocean, where alkanes are continually produced and subsequently consumed within days. Furthermore we show that cyanobacterial alkane production is likely sufficient to sustain populations of hydrocarbon-degrading bacteria, whose abundances can rapidly expand upon localized release of crude oil from natural seepage and human activities.

The potential utilization of cyanobacteria for the biological production of alkanes represents an exceptional system for the next generation of biofuels. Here, we analyzed a diverse group of freshwater and marine cyanobacterial isolates from Indian culture collections for their ability to produce both alkanes and alkenes. Among the 50 cyanobacterial isolates screened, 32 isolates; 14 fresh water and 18 marine isolates; produced predominantly alkanes. The GC-MS/MS profiles revealed a higher percentage of pentadecane and heptadecane production for marine and fresh water strains, respectively. Oscillatoria species were found to be the highest producers of alkanes. Among the fresh water isolates, Oscillatoria CCC305 produced the maximum alkane level with 0.43 μg /mg dry cell weight, while Oscillatoria formosa BDU30603 was the highest producer among the marine isolates with 0.13 μg /mg dry cell weight. Culturing these strains under different media compositions showed that the alkane chain length was not influenced by the growth medium but was rather an inherent property of the strains. Analysis of the cellular fatty acid content indicated the presence of predominantly C16 chain length fatty acids in marine strains, while the proportion of C18 chain length fatty acids increased in the majority of freshwater strains. These results correlated with alkane chain length specificity of marine and fresh water isolates indicating that alkane chain lengths may be primarily determined by the fatty acid synthesis pathway. Moreover, the phylogenetic analysis showed clustering of pentadecane-producing marine strains that was distinct from heptadecane-producing freshwater strains strongly suggesting a close association between alkane chain length and the cyanobacteria habitat.

WOS: 000356122500030, In this work, we synthesized a series of four nanocapsules containing n-alkanes (CnH2n+2), namely tetradecane, pentadecane, hexadecane, and heptadecane, in poly(styrene-co-ethylacrylate) using an emulsion copolymerization method. The nanocapsules were characterized according to their geometric profiles, phase transition temperatures, phase transition heats, mean particle sizes, and chemical stabilities by means of scanning electron microscopy, differential scanning calorimetry, thermal gravimetric analysis and Fourier transform infrared spectroscopy. Furthermore, we also focused on the effect of the core/shell mass ratio on the phase change properties of the nanocapsules. We found that microcapsules were synthesized successfully and that the best core/shell mass ratio was 3:1 for this study. These results indicate that encapsulated n-alkanes with poly(styrene-co-ethylacrylate) have an excellent potential for energy storage. (C) 2014 Elsevier Ltd. All rights reserved., Scientic & Technical Research Council of Turkey (TUBITAK) [TUBITAK 111M614], We would like to thank The Scientic & Technical Research Council of Turkey (TUBITAK) (The Project Code: TUBITAK 111M614) for their financial support for this study. And also we would like to thank Mr. Suleyman Konuklu for his technical support for this study. Finally, we would like to extend special thanks to the editor and the anonymous reviewers for their constructive comments and suggestions in improving the quality of this paper.

The essential oil of Cercis siliquastrum L. was isolated from the flowers of C. siliquastrum and the oil was obtained with 0.08% yield, which was analysed by GC and GC/MS. Twenty-one compounds were characterized representing 83.9% of the total components detected. Studies of essential oil revealed heptadecane (26.2%), nonadecane (13.7%), pentadcecane (12.6%), linalyl acetate (8.5%), eicosane (6.5%), limonene (5.9%) as the main constituents.

Hydrocarbons induced by gamma-irradiation of green, black, and oolong teas were analyzed to determine whether the hydrocarbons can be used as markers for detecting post-irradiation of these teas. The samples were irradiated at 0, 2.5, 5, 7.5, and 10 kGy. Detection was attempted by extracting fat from the teas, separation of hydrocarbons with florisil column chromatography, and identification of hydrocarbons by gas chromatography-mass spectroscopy (GC-MS). Concentration of hydrocarbons increased with the irradiation dose. The major hydrocarbons in irradiated green, black, and oolong teas were 1-tetradecence (14:1), pentadecane (15:0), 1,7-hexadecadiene (16:2), 1-hexadecene (16:1), 8-heptadecene (17:1), and heptadecane (17:0). Radiation-induced hydrocarbons in teas were 1,7- hexadecadiene and 8-heptadecene. These compounds were not detected in non-irradiated samples, so the hydrocarbons (16:2, 17:1) can be used as markers for detecting post-irradiation of the teas. Furthermore, detection of hydrocarbons after 12 months storage at room temperature remains a suitable method for identifying irradiated teas.

Candida bombicola was grown using a variety of lipophilic carbon substrates. Most of the hydrocarbon and carboxylic acid substrates resulted in a mixture of sophorolipids consisting of free acids and the more desirable lactones. The ratio of diacylated lactone to free acid in these mixtures was a maximum when produced using hexadecane and heptadecane. All of the other lipophilic substrates resulted in significant amounts of free acids being produced. These lactone products were unique in that they precipitated as crystals, which were easily separated from the culture medium. All of the other products were isolated as oils as is usually reported in the literature. Finally, the amounts of these crystals recovered were significantly higher than those observed for any of the oily products. It was possible to determine the degree of direct incorporation of the lipophilic substrates into the sophorolipids for a homologous series of alkanes. The amount of direct incorporation increased with increasing chain length to a maximum for pentadecane, hexadecane and heptadecane. As the length of the alkane substrate increased further, the amount of direct incorporation then decreased until there was no apparent incorporation for eicosane.

Bioassay studies carried out on the egg parasitoids Trichogramma brasiliensis and T. exiguum with 11 straight chain-saturated hydrocarbons, revealed that pentacosane and hexacosane recorded very high parasitoid activity index (PAI) and parasitism for both the parasitoids indicating high kairomonal activity. These were followed by docosane, tricosane, heneicosane, hexatriacontane and tetracosane, which may be grouped as favourable hydrocarbons showing varying levels of kairomonal activity for T. brasiliensis, as compared to eicosane, pentadecane, octacosane and heptadecane, which can be grouped as non-favourable hydrocarbons. In the case of T. exiguum, pentacosane-treated egg cards showed maximum parasitism followed by hexacosane, pentadecane, hexatriacontane, tricosane and docosane thereby indicating their kairomonal activity in comparison with heptadecane, tetracosane, eicosane, heneiocosane and octacosane which recorded low levels of parasitism. In the case of T. brasiliensis, tetracosane recorded the highest response at the lowest concentration, C 1 (62.5 ng/cm 2 ), which decreased as the concentration increased. Eicosane, heneicosane and docosane recorded the highest parasitism at C 2 (125 ng/cm 2 ). In heptadecane, tricosane, pentacosane and hexatriacontane the highest parasitism was recorded at the medium concentration, C 3 (250 ng/cm 2 ). Octacosane recorded the highest response at C 4 (375 ng/cm 2 ). Pentadecane and hexacosane-treated egg cards showed their highest response at C 5 (500 ng/cm 2 ). In the case of T. exiguum, the lowest concentration, C 1 evoked the highest response in hexacosane, whereas heptacosane, heneicosane, docosane and tetracosane recorded the highest parasitism at C 2 . Eicosane, pentacosane and octacosane recorded maximum parasitism, at C 3 , whereas tricosane and hexatriacontane showed maximum parasitism at C 4 and pentadecane at C 5 . These concentrations can be taken as the optimum concentration to increase parasitization by these parasitoids. The favourable hydrocarbons at their optimum concentration can be used for efficient management of these parasitoids in field releases.

Radiolytic compounds of lipids, as hydrocarbons and 2-alkylcyclobutanones, were determined to detect the irradiated dried Mytilus coruscus. The detection methods were composed of fat extraction by Soxtec apparatus from dried Mytilus coruscus, isolation of hydrocarbons and 2-alkylcyclobutanones with a florisil column chromatography and identification of GC/MS. Concentrations of the radiation-induced hydrocarbons and 2-alkylcyclobutanones increased with the irradiation dose. The major hydrocarbons in irradiated Mytilus coruscus were pentadecane and 1-tetradecene originated from palmitic acid, and heptadecane and 1-hexadecene originated from stearic acid. 2-(5`- Tetradecenyl)cyclobutanone of 2-alkylcyclobutanones was high relatively. The radiation - induced hydrocarbons and 2-alkylcyclobutanones from dried Mytilus coruscus were detected at 0.5 kGy over and not detected at the non-irradiated.

The speed of sound in liquid n-pentadecane and n-heptadecane was measured using a pulse technique operating at 3 MHz. The measurements were carried out at pressures up to 150 MPa in the temperature range from 293 to 383 K. The experimental results have been used to evaluate various thermophysical properties such as density and isentropic and isothermal compressibilities up to 150 MPa with the help of additional density and heat capacity data at atmospheric pressure.

Three Brazilian municipal and industrial sludges were subjected to the Low Temperature Conversion (LTC) process. They include activated, digested and lacquer sludges. The activated sludge recorded the highest yield of LTC oil (31.4%), followed by lacquer sludge (14.0%) and the digested sludge 11%. 1 H-NMR studies of the oils indicated that they consisted mainly of aliphatic and olefinic compounds, while the concentration of aromatics was below 2.5%. The major hydrocarbons in the oils were pentadecane and heptadecane. The distribution pattern of hydrocarbons present in the oils was similar to what is known from the conversion of other sludges. In addition the LTC oil from activated sludge contained 26% fatty acids, while the oils from digested and lacquer sludge contained only about 3% fatty acids. Recovery studies on the fate of heavy metals in the sludges indicated that they were accumulated in the char. Partial gasification studies of the LTC chars resulted in active carbons with quite low iodine and methylene blue numbers. However, even if their use is limited the production of active carbon together with the recovery of LTC oil constitutes a complete disposal of the sludges.

The profiles of diffuse layers, which are present in diffraction patterns of urea inclusion compounds, are interpreted quantitatively by a longitudinal positional paracrystalline order of the alkane guest molecules within the channels of the urea-host framework structure, in agreement with the expected behaviour of a one-dimensional system. With decreasing temperature there is a gradual transition into long-range order behaviour. This ordering process remains unaffected by structural changes related to lateral correlations within and between both host and guest substructures, including a structural phase transformation. The differing behaviour of a mixed system (pentadecane/hexadecane) with average period almost commensurate with the urea host lattice is explained by the superposition of main and satellite layers. The distribution of both molecules within each tunnel is random.

The unsaponifiable fraction of subcutaneous fat of dry-cured Iberian hams from pigs fed on different systems during the finishing-fattening period and its feasibility as a method for classifying the hams according to the pigs' feeding background are studied. Unsaponifiable fraction and n-alkane content of subcutaneous fat from ten dry cured hams from Iberian x Duroc pigs raised on two different man agement systems ( Montanera, fed extensively on acorns and pasture, and Pienso, fed on a concentrate diet) are analyzed. The proportion of unsaponifiable material and n-alkanes [pentadecane (n-C15), heptadecane (n-C17), octadecane (n-C18), nonadecane (n-C19), eicosane (n-C20) and pentacosane (n-C25)] were higher ( P < 0.05) in hams from pigs raised under extensive conditions than in those from pigs receiving concentrate feeds. The unsaponifiable fraction assay of the fat from dry-cured Iberian hams is a promising technique for classifying hams based on the pigs' feeding background.

Studies on the effect of saturated hydrocarbons on parasitization by the egg parasitoid Trichogramma chilonis Ishii were carried out in the laboratory and net house. Bioassay of 11 hydrocarbons, viz. pentadecane, heptadecane, ecosane, heneicosane, docosane, tricosane, tetracosane, pentacosane, hexacosane, octacosane and hexatriacontane, were carried out under controlled conditions in the laboratory. These were also tested on potted maize plants in a net house. Among the saturated hydrocarbons, octacosane recorded the highest parasitoid activity index followed by docosane and tricosane. However, tricosane caused the highest percentage of parasitization, which was at par with octacosane and docosane. A positive correlation was found between concentration and kairomonal activity only in case of tricosane. In the net house, tricosane recorded the highest parasitization. Response of the parasitoid to egg cards treated with hydrocarbons decreased with increase in distance between the release point and host eggs. No parasitization was observed in host eggs placed at 8 m and 10 m away from the point of release except in the case of tricosane and pentacosane.

Analyses by GC and GC/MS of an essential-oil sample obtained from dry fruits of Scandix balansae Reut. ex Boiss. allowed the identification of 81 components, comprising 91.4% of the total oil composition. Interestingly, the major identified volatile compounds were medium-chain-length n-alkanes, i.e., tridecane (6.7%), pentadecane (13.4%), and heptadecane (19.3%), and a long-chain homolog nonacosane (7.6%). A number of minor oil constituents, among them tetradecyl 3-methylbutanoate, and octadecyl 2-methylpropanoate, 3-methylbutanoate, and pentanoate, turned out to have a restricted natural occurrence not only in umbellifers but also in the Plant Kingdom, whereas the last ester is a new natural compound in general. The identity of these rare plant constituents that present excellent chemotaxonomic marker candidates for Scandix species was unambiguously confirmed by co-injection of the oil sample with appropriate standards, which were synthesized for this purpose and fully characterized ((1) H- and (13) C-NMR, IR, MS). To explore the possible applicability of the essential oils' compositional data in the taxonomy of Apiaceae, the herein studied and additional 58 oils obtained from Scandiceae taxa were compared using multivariate statistical analyses (MVA). MVA demonstrated that the evolution of the volatiles' metabolism of Scandiceae taxa was neither genera-specific nor follows their morphological evolution.

To determine the effects of irradiation on the chemical attributes of sausages, TBARS values, volatile compounds, gas compounds, and hydrocarbons of vacuum-packaged sausages were analyzed during 60 d of refrigerated storage. A sulfur-containing volatile compound (dimethyl disulfide), a gas compound (methane), and radiation-induced hydrocarbons (1-tetradecene, pentadecane, heptadecane, 8-heptadecene, eicosane, 1, 7-hexadecadiene, hexadecane) were mainly detected in irradiated sausages, and the concentrations of the compounds were irradiation dosedependent. Especially methane and a few hydrocarbons were detected only in irradiated sausages and their amounts were dose-dependent. On the other hand, TBARS values, other off-odor volatiles (carbon disulfide, hexanal), and gas compounds (carbon monoxide, carbon dioxide) were found both in irradiated and nonirradiated sausages. Therefore, it is suggested that irradiation-induced hydrocarbons (1-tetradecene, pentadecane, heptadecane, 8-heptadecene, eicosane, 1, 7-hexadecadiene, hexadecane), dimethyl disulfide, and methane can be used as markers for irradiated sausages.

X-ray diffuse scattering phenomena and satellite reflections in urea inclusion compounds with guest molecules of varying lengths (tridecane, tetradecane, pentadecane, heptadecane and a mixture of pentadecane and hexadecane) were investigated between room temperature and 30 K. It was found that diffuse s-layers, which are due to weak lateral correlations of the guest molecules, are not sharp parallel c* at room temperature as assumed previously, but show a broadening of their widths with increasing order. With decreasing temperature the widths of the s-layers decrease and become sharp within the resolution limit at very low temperature, i.e. there is an ordering of the guest molecules along the urea host tunnels. The modulations of the s-layers point towards a lateral correlation of the guest molecules at room temperature which can be described by a box-shaped distribution function. A model is described which explains the existence of (numerous) satellite reflections and satellite s-layers at low temperatures. Some of the satellites are also observable at room temperature in inclusion compounds with guest molecules longer than tetradecane. They can be assigned to a non-negligible interaction between host and guest. Possible commensurations of these satellite reflections with main (guest-) reflections have been a source of misinterpretations in the literature.

A method to detect the irradiation of raw-milk Camembert cheeses by gas chromatographic analysis of radio-induced volatile hydrocarbons, formed by radiolysis of myristic, palmitic and stearic acids, is proposed. The presence, in the sample, of tridecane, 1-dodecene, 1-tetradecene and 1-hexadecane, in association with an increase in levels of pentadecane and heptadecane, can be considered an indication of irradiation. Moreover, the quantity of radio-induced volatile hydrocarbons, formed from the same fatty acid precursor, is proportional to the fatty acid composition in the sample and the 1-alkene/alkane ratio remains constant (∼1·3) and independent of the fatty acid precursor. In spite of the hydrocarbon stability during ripening and storage and the good linear correlation between the hydrocarbon concentration and the irradiation dose (up to 3·97 kGy), the determination of the latter is approximate because of the experimental error (±20%) and the possible fluctuations of certain parameters of the ionizing treatment (e.g. temperature and dose rate).