Verification and Evaluation of Male-Produced Pheromone Components from the Citrus Long-Horned Beetle, Anoplophora chinensis (Forster) (Insecta: Coleoptera: Cerambycidae).

The citrus long-horned beetle, Anoplophora chinensis (Coleoptera: Cerambycidae), is a highly polyphagous species native to eastern and southeastern Asia. Detection of these beetles is dependent on visual surveys, which are inefficient and labor-intensive. The identification and development of pheromone-based lures would help improve survey efforts for A. chinensis should it become established within the US. We identified three antennally active male-produced chemical components (nonanal, 4-(n-heptyloxy)butan-1-ol, and 4-(n-heptyloxy)butanal), which were then tested for behavioral activity at our USDA Quarantine laboratory. When tested together in Y-tube behavioral assays, a three-component blend of the identified compounds was shown to be attractive to adult female A. chinensis. Pheromone production and behavior of A. chinensis and other closely related Anoplophora cerambycid species are discussed in relation to mate finding and potential monitoring.

Effect of cellulase on antioxidant activity and flavor of Rosa roxburghii Tratt.

Cellulase can increase the soluble dietary fiber (SDF) content in Rosa roxburghii Tratt (RRT), but the effects on polyphenol content, bioactivity, and flavor are unknown. This study analyzed the changes in SDF content, total phenolic content, antioxidant activity and flavor before and after cellulase treatment. Cellulase treatment increased the SDF and total phenolic content of RRT by 13 % (P < 0.05) and 25.68 % (P < 0.05), respectively, and increased the antioxidant activity. HS-GC-IMS identified a total of 42 volatile compounds present, and ROAV analysis revealed that the characteristic aroma compounds of RRT were mainly aldehydes, alcohols, and ethers. The electronic nose and tongue results were consistent with the HS-GC-IMS analysis, indicating the positive effect of cellulase on the quality of RRT. Cellulase treatment significantly improved the oxidative activity and flavor performance of RRT. These results of RRT, providing practical guidance for improving the flavor and product quality.

The chemical composition of the aerial parts' essential oil of Cynoglossum clandestinum Desf. growing in Sicily, Italy.

Cynoglossum L. is a taxonomically difficult genus belonging to the Boraginaceae family, distributed in Asia, Europe, mainly in Turkey, and in the Mediterranean region. Plants of this genus are used against various diseases in the ethnomedicine of several countries. In the present study, the chemical composition of the essential oil was obtained from the hydrodistillation of aerial parts of the Sicilian accession of Cynoglossum clandestinum Desf. was analysed by GC and GC-MS. The main constituents of the essential oil were aldehydes and ketones (69.9%) with nonanal (18.9%), 4-sec-butoxy-2-butanone (18.1%), and 3-methyl-butanal (13.1%) as main metabolites. No one paper has been previously published on the essential oil of this species, and there is a lack of studies also in the near related genera. The aim of this work is in fact, to study a species that has never been investigated, and through this, try to help place it within the Boraginaceae family.

Plant Growth Promotion by Two Volatile Organic Compounds Emitted From the Fungus Cladosporium halotolerans NGPF1.

Microbial volatiles have beneficial roles in the agricultural ecological system, enhancing plant growth and inducing systemic resistance against plant pathogens without being hazardous to the environment. The interactions of plant and fungal volatiles have been extensively studied, but there is limited research specifically elucidating the effects of distinct volatile organic compounds (VOCs) on plant growth promotion. The current study was conducted to investigate the impact of VOCs from Cladosporium halotolerans NGPF1 on plant growth, and to elucidate the mechanisms for the plant growth-promoting (PGP) activity of these VOCs. The VOCs from C. halotolerans NGPF1 significantly promoted plant growth compared with the control, and this PGP activity of the VOCs was culture medium-dependent. Headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS) identified two VOC structures with profiles that differed depending on the culture medium. The two compounds that were only produced in potato dextrose (PD) medium were identified as 2-methyl-butanal and 3-methyl-butanal, and both modulated plant growth promotion and root system development. The PGP effects of the identified synthetic compounds were analyzed individually and in blends using N. benthamiana plants. A blend of the two VOCs enhanced growth promotion and root system development compared with the individual compounds. Furthermore, real-time PCR revealed markedly increased expression of genes involved in auxin, expansin, and gibberellin biosynthesis and metabolism in plant leaves exposed to the two volatile blends, while cytokinin and ethylene expression levels were decreased or similar in comparison with the control. These findings demonstrate that naturally occurring fungal VOCs can induce plant growth promotion and provide new insights into the mechanism of PGP activity. The application of stimulatory volatiles for growth enhancement could be used in the agricultural industry to increase crop yield.

Enzymatic hydrolysis and auto-isomerization during ß-glucosidase treatment improve the aroma of instant white tea infusion.

The aroma changes in instant white tea resulting from ß-glucosidase treatment was investigated by quantitative descriptive analysis (QDA), gas chromatography-mass spectrometry (GC-MS), odour activity value analysis (OAV), aroma reconstruction and omission tests. The grassy, floral and sweet notes increased significantly (P < 0.05), and the roasted note decreased significantly (P < 0.05) upon ß-glucosidase treatment. Quantitative analysis showed that the concentrations of benzaldehyde, benzeneacetaldehyde, (Z)-3-hexen-1-ol, linalool, phenylethyl alcohol, cis-linalool oxide, trans-linalool oxide, hexanol, hotrienol and (E)-2-hexen-1-ol increased significantly (P < 0.05) after treatment; however, (Z)-3-hexen-1-ol isomerized to (E)-2-hexen-1-ol. OAV analysis, aroma reconstruction and the omission test showed that the grassy, floral and sweet notes increased as the (Z)-3-hexen-1-ol, cis/trans-linalool oxide and benzeneacetaldehyde increased, whereas the roasted note declined under the same conditions. The enzymatic hydrolysis of glycosidic precursors and the auto-isomerization of volatile compounds provide new information for understanding how ß-glucosidase treatment improves the aroma of tea products.

Thermal properties and volatile compounds profile of commercial dark-chocolates from different genotypes of cocoa beans (Theobroma cacao L.) from Latin America.

There is a growing interest in the identification of chemometric markers that allow the distinction and authentication of dark-chocolates according to their cocoa geographical origin and/or genotype. However, samples derived from Latin American cocoa, including specimens from North and South America, have not been studied in this context. An exploration of the melting behavior, fat composition, bioactive content, and volatile profile of commercial darkchocolates was conducted to identify possible patterns related to the genotype and/or origin of cocoa from Latin America. The melting properties were evaluated by DSC and related to fat content and fatty acids profile. Total polyphenol, anthocyanin, methylxanthine, and catechin content were analyzed. Finally, the volatile compounds were extracted and identified by HS-SPME/GC-MS and were analyzed through Principal Component Analysis (PCA) and the Hierarchical Cluster Analysis Heatmap (HCA Heatmap). The fatty acids profile showed a relationship with the melting properties of dark chocolate. The samples exhibited two glass-transition temperatures (Tg) at ≈19 °C and ≈25.5 °C, possibly related to traces of unstable polymorphic forms of monounsaturated triacylglycerides. The analysis of bioactive compounds demonstrated great variability among samples independent of the cocoa origin, genotype, and content. The PCA and HCA Heatmaps allowed discriminating against the chocolates in relation to the cocoa origin and genotype. Compounds like tetramethylpyrazine, trimethylpyrazine, benzaldehyde, and furfural could be considered as dark-chocolate aroma markers derived from Latin American cocoas (North American region). The 2-phenylethyl alcohol, 2-methylpropanoic acid, 2,3-butanediol, 2-nonanone, and limonene for derived from South America. And the 2-phenylethyl acetate, 3-methyl-butanal, and cinnamaldehyde could allow to distinguishing between regional genotypes.

GC/MS coupled with MOS e-nose and flash GC e-nose for volatile characterization of Chinese jujubes as affected by different drying methods.

Volatile compounds in Chinese jujubes dried by different methods - hot-air (HAD), heat-pump (HPD), infrared radiation (IRD), vacuum (VD), vacuum freeze (VFD) and instant controlled pressure drop (DIC) drying - were analyzed using GC-MS, MOS e-nose, and flash GC e-nose. Acids comprised more than 90% of the aroma compounds in the dried jujubes, of which acetic, butanoic, propanoic, hexanoic, octanoic and decanoic acids were the most common. Jujubes dried using VFD had the highest content of total aroma compounds (1061.6 µg/kg), while DIC-dried jujubes had the most diverse profile (26 species). HPD-, IRD-, HAD- and VD-dried jujubes had similar aroma profiles based on GC-MS and flash GC e-nose results. Although the results of GC-MS, MOS e-nose, and flash GC e-nose were significant different (p < 0.05), their combination could characterize aroma profiles more comprehensively.

Characterization of the key aroma compounds in Longjing tea using stir bar sorptive extraction (SBSE) combined with gas chromatography-mass spectrometry (GC-MS), gas chromatography-olfactometry (GC-O), odor activity value (OAV), and aroma recombination.

Longjing tea is the most famous premium green tea, and is regarded as the national tea in China, with its attractive aroma contributing as a prime factor for its general acceptability; however, its key aroma compounds are essentially unknown. In the present study, volatile compounds from Longjing tea were extracted and examined using stir bar sorptive extraction (SBSE) combined with gas chromatography-mass spectrometry (GC-MS). Data obtained from the present study revealed that 151 volatile compounds from 16 different chemical classes were identified by GC-MS analysis. Enols (8096 µg/kg), alkanes (6744 µg/kg), aldehydes (6442 µg/kg), and esters (6161 µg/kg) were the four major chemical classes and accounted for 54% of the total content of volatile compounds. Geraniol (6736 µg/kg) was the most abundant volatile compound in Longjing tea, followed by hexanal (1876 µg/kg) and ß-ionone (1837 µg/kg). Moreover, 14 volatile compounds were distinguished as the key aroma compounds of Longjing tea based on gas chromatography-olfactometry (GC-O) analysis, odor activity value (OAV) calculations, and a preliminary aroma recombination experiment, including 2-methyl butyraldehyde, dimethyl sulfoxide, heptanal, benzaldehyde, 1-octen-3-ol, (E, E)-2,4-heptadienal, benzeneacetaldehyde, linalool oxide I, (E, E)-3,5-octadien-2-one, linalool, nonanal, methyl salicylate, geraniol, and ß-ionone. This is the first comprehensive report describing the aroma characterizations and the key aroma compounds in Longjing tea using SBSE/GC-MS. The findings from this study contribute to the scientific elucidation of the chemical basis for the aromatic qualities of Longjing tea.

Short communication: Sensory characteristics and volatile organic compound profile of high-moisture mozzarella made by traditional and direct acidification technology.

In the present study, the sensory characteristics and the volatile organic compound (VOC) profiles of high-moisture mozzarella made by different acidification techniques were compared. The cheeses were manufactured at the same dairy by fermentation by autochthonous natural whey starter (traditional backslopping method) and direct acidification with citric acid (the most used industrial technology). Three cheesemaking trials were performed from February to June using raw milk from a single farm. The mozzarella samples were subjected to assessment of the chemical, microbiological, and sensory characteristics and to VOC analysis by headspace solid-phase microextraction coupled to gas chromatography-mass spectrometry. The relevant microbiological differences found between the 2 types of products were reflected in different sensory and VOC profiles. The cheeses were clearly discriminated by the panel, and traditional mozzarella had higher intensity attributes. The most discriminating descriptors were elasticity, overall odor and taste intensity, sour milk and fruity/vegetable odors, sour taste, and aftertaste. Even though some variability was observed among the trials, the VOC profile of traditional product was always much more complex than that obtained by direct acidification. In both products the carbonyl compounds were the most abundant chemical class, accounting for about 50% of the total. In detail, 51 compounds were identified in the entire set of samples, and their contribution to cheese aroma was roughly estimated by calculating the odor activity values on the basis of the odor thresholds available in the literature. The results allowed hypothesizing that only 12 of them could play a primary role. The most important among the odor-active compounds was 3-methyl-butanal that can both derive from metabolism of lactic acid bacteria and yeasts. The results of the study may be very useful in view of European Union PDO labeling of the traditional product, in terms of protecting it from imitations.

Toxic effects of 1-(N-methyl-N-nitrosamino)-1-(3-pyridinyl)-4-butanal on the reproduction of female mice.

Cigarette smoke can affect female reproductive health by causing follicle destruction and oocyte dysfunction. Third-hand smoke has received increasing attention as a public health issue. However, the effects of third-hand smoke on the female reproductive system, particularly the ovaries, remain unclear. 1-(N-methyl-N-nitrosamino)-1-(3-pyridinyl)-4-butanal (NNA) can be used as a biomarker of third-hand smoke. We studied the in vivo toxic effects of NNA on mice ovaries and offspring development. Three-week-old premature female mice were exposed to NNA at two different concentrations (0.075 µg/kg and 0.15 µg/kg body weight) and tap water (blank control) and diluted dimethylsulfoxide (solvent control) for 30 days. We found that oral administration of NNA (0.075 µg/kg and 0.15 µg/kg) significantly reduced ovary weight (the 0.15 µg/kg group was reduced to 18.69% ±â€¯0.89%) and ovarian follicle number (reduced by about 30%) (p < 0.05). Consumption of 0.15 µg/kg NNA reduced the survival rate of superovulated oocytes from 91.36% to 60.55% (p < 0.05). In addition, treated female mice in each group were mated with normal male mice to observe the effects of NNA on the F1 offspring, and during mating and lactation, all groups were given tap water. Two different concentrations of NNA exposure also significantly reduced body weight and impaired ear opening, tooth eruption and eye opening in F1 offspring, especially those exposed to 0.15 µg/kg NNA (p < 0.05). Our study suggested that NNA exposure had toxic effects on the reproductive health of female mice and their offspring. The results obtained may help evaluate the risks of third-hand smoke to women's reproductive health and to the health of their offspring.

Impact of drying techniques, seasonal variation and organic growing on flavor compounds profiles in two Italian tomato varieties.

The industrial transformation of tomato (Lycopersicon esculentum Mill.) produces processed foods, such as dried tomatoes. In this study two varieties (SaAb and PerBruzzo), grown in three cropping systems (one conventional and two organic ones), were processed by two types of small-scale drying (oven or sun drying), over two years of production. The dried samples were analyzed for their non-volatile and volatile composition, relating the results with sensory analysis. The multivariate analysis performed on collected data allowed a detailed comparison of the effects of processing, year-to year variation and cropping systems. Results indicated that drying methods mainly influenced the composition and flavor profile, also affected by the production year. The cropping system significantly influenced some quality indices, such as the acid and sugar amounts, and the aldehydes, respectively higher and lower in organic samples. The comprehensive PCA analysis allowed discrimination of drying methods and, to a lesser extent, cropping systems.

Toxic effects of 1-(N-methyl-N-nitrosamino)-1-(3-pyridinyl)-4-butanal on the maturation and subsequent development of murine oocyte.

Cigarette smoke can cause follicle destruction and oocyte dysfunction and increase the risks of spontaneous abortion, stillbirth, and tubal ectopic pregnancy, affecting female reproductive health. Third-hand smoke (THS) is residual tobacco smoke existing in the environment long after cigarettes are extinguished, which can react with other compounds in the environment to produce secondary pollutants. However, the effects of THS on the female reproductive system, particularly the maturation of the oocyte, remain unclear. 1-(N-methyl-N-nitrosamino)-1-(3-pyridinyl)-4-butanal (NNA), a component of THS, is a logical biomarker of THS exposure. Thus, this study aims to investigate the toxic effects of NNA on the maturation of murine oocytes and subsequent developmental competence. Herein, murine oocytes were exposed to 0 (control group), 0.1, 1.0, 10, and 50 µM NNA for 24 h. Our results showed that NNA exposure reduced the polar body extrusion rate by causing 8-oxo-deoxyguanosine (8-OHdG) to increase and disrupting the meiotic spindle morphology by inhibiting ERK1/2 activation during in vitro maturation. Additionally, NNA exposure resulted in cleavage and blastocyst rate reduction by altering DNA and histone methylations by reducing 5 mC and H3K4me2 levels and by inducing apoptosis caused by mitochondrial dysfunction and reactive oxygen species accumulation, as shown by the increased superoxide dismutase mRNA level and by the decreased Bcl-x mRNA level. Collectively, our results demonstrate that NNA exposure reduces the maturation and developmental capability of murine oocytes by increasing the risk of DNA damage and abnormal spindle morphology, altering epigenetic modifications, and inducing apoptosis, suggesting the toxic effect of NNA on mammalian productive health.

Synthesis and Characterization of Ru-Loaded Anodized Aluminum Oxide for Hydrogenation Catalysis.

Anodized aluminum oxides (AAOs) are synthesized and used as catalyst support in combination with Ru as metal in hydrogenation catalysis. SEM and TEM analysis of the as-synthesized AAOs reveal uniform, ordered nanotubes with pore diameters of 18 nm, which are further characterized with Kr physisorption, XRD and FTIR spectroscopy. After impregnation of the AAOs with Ru, the presence of Ru nanoparticles inside the tubular pores is evidenced clearly for the first time via HAADF-STEM-EDX. The Ru-AAOs have been tested for catalytic activity, which showed high conversion and selectivity for the hydrogenation of toluene and butanal.

Separation Identification of Chemical Constituents of Lysimachia capillipes / 中国实验方剂学杂志

Objective:To systemically study the chemical constituents of n-butanol fraction from Lysimachia capillipes. Method:The whole plant of L. capillipes was crushed into power,extracted by 70% methanol,concentrated under reduced pressure,and then its n-butanol extract was obtained by fractional extraction. The compounds from n-butanol fraction were isolated and purified by macroporous resin column chromatography,medium pressure ODS,silica gel,Sephadex LH-20 and preparative HPLC. Their structures were identified on the basis of spectral analysis and comparison with literature data. Result:Fifteen compounds including 6 saponins and 9 flavonoid glycosides were isolated from L. capillipes,and were identified as ascapilliposide B(1) and capilliposide C(2),kaempferol-3-O-β-D-xylopyranosyl(1→3)-[4-O-E-p-coumaroyl-α-L-rhamnopyranosyl(1→2)] [β-D-glucopyranosyl(1→6)]-β-D-galactopyranoside-7-O-α-L-rhamnopyranoside(3),kaempferol-3-O-{[β-D-xylopyranosyl(1→3)-α-L-rhamnopyranosyl(1→6)] [α-L-rhamnopyranosyl(1→2)]}-β-D-3-trans-p-coumaroylgalactopyranoside (4),capilliposide K (5),3β-O-{α-L-rhamnopyranosyl-(1→2)-O-β-D-glucopyranosyl-(1→4)-[O-β-D-glucopyranosyl-(1→2)]-α-L-arabinopyranosyl)}-16α-hydroxyolean-28,13β-olide (6),capilliposide I(7),quercetin-3-O-(2″,6″-di-O-α-rhamnopyranosyl)-β-galactopyranoside(8),kaempferol-3-O-{[β-D-xylopyranosyl(1→3)-α-L-rhamnopyranosyl(1→6)] [α-L-rhamnopyranosyl-(1→2)]}-β-D-galactopyranoside(9),kaempferol-3-O-[2-glucopyranosyl(1→3)rhamnopyranosyl-6-rhamnopyranosyl]-β-D-galactopyranoside(10),kaempferol-3-O-α-L-rhamnopyranosy-(1→2)-[α-L-rhamnopyranosy-(1→6)]-β-D-galactopyranoside(11),capilliposide I(12),kaempferol-3-O-{(β-D-glucopyranosyl-(1→3)-[4-O-(E-p-coumaroyl)]-α-L-rhamnopyranosyl-(1→6)-(β-D-galactopyranoside)}-7-O-α-L-rhamnopyranoside (13),kaempferol-3-O-{[β-D-glucopyranosyl(1→3)]-4-O-(E-p-coumaroyl)}-α-L-rhamnopyranosyl(1→6)-β-D-glucopyranoside-7-O(4-O-acetyl)-α-L-rhamnopyranoside (14),and (3β,20S,23S,24R)-3,20,23,24,25,29-hexahydroxydammaran-21-oic acid-21,23-lactone 3-O-β-D-glucopyranosyl-(1→6)-β-D-gluco-pyranoside(15). Conclusion:The compounds 3,4,6,9,10,13-15 were isolated from this plant for the first time.

Detection of 2-methylpropanal,2-methyl butanal and 3-methyl butanal in workplace air by portable gas chromatography-mass spectrometry / 中国职业医学

OBJECTIVE: To establish a method for detection of 2-methylpropanal,2-methyl butanal and 3-methyl butanal in workplace air by portable gas chromatography-mass spectrometry( GC-MS). METHODS: The workplace air was collected by portable GC-MS sampling probe. After enrichment by Tri-bed tube,the thermal desorption sample was analyzed by retention time and characteristic ion characterization. The characteristic ion peak area was quantified. RESULTS: The linear ranges of 2-methylpropanal,2-methyl butanal and 3-methyl butanal were 0. 079-15. 880,0. 080-16. 080 and 0. 161-32. 120 mg/m~3,respectively. All the correlation coefficients were greater than 0. 999. The detection limits were 0. 012,0. 007 and0. 013 mg/m~3,and the quantitation limits were 0. 041,0. 023 and 0. 044 mg/m~3,respectively. The recovery rates of2-methylpropanal,2-methyl butanal and 3-methyl butanal were 92. 2%-104. 4%. The within-run relative standard deviation( RSD) was 5. 8%-9. 1%. The between-run RSD of different batches samples was 9. 3%-19. 6%. CONCLUSION: This method has high accuracy and is precise,which is suitable for rapid qualitative and quantitative detection of2-methylpropanal,2-methyl butanal and 3-methyl butanal in workplace air.

Olfactory Sensory Neurons of the Asian Longhorned Beetle, Anoplophora glabripennis, Specifically Responsive to its two Aggregation-Sex Pheromone Components.

We performed single-sensillum recordings from male and female antennae of the Asian longhorned beetle, Anoplophora glabripennis, that included as stimuli the two components of this species' aggregation-sex pheromone in addition to various general odorants. We compared the aggregation-sex-pheromone-component responses of olfactory sensory neurons (OSNs) to those of OSNs that responded to a variety of plant-related odorants. In the smooth-tipped, tapered, trichoid sensilla on the most distal antennal flagellomeres nos. 10 or 11 of both males and females, we found OSNs with high-amplitude action potentials that were tuned to the aldehyde and alcohol pheromone components and that did not respond to various plant-related volatiles. Because this OSN type responded to both the alcohol and aldehyde components it cannot be considered to be specifically tuned to either component. These large-spiking OSNs were co-compartmentalized in these sensilla with a second, smaller-spiking OSN responding to plant-related volatiles such as geraniol, citronellal, limonene, 1-octanol, nerol and citral. The large-spiking OSNs thus appear to be a type that will be involved in aggregation-sex pheromone pathways targeting a specific glomerulus in the antennal lobe and in generating pheromone-related behavioral responses in A. glabripennis. In other sensilla located in these distal antennal flagellomeres as well as those located more proximally, i.e., mid-length along the antenna on flagellomere nos. 4-7, we found OSNs in blunt-tipped basiconic sensilla that were responsive to other plant-related volatiles, especially the terpenoids, (E,E)-alpha farnesene, (E)-ß-farnesene, ß-caryophyllene, and eugenol. Some of these terpenoids have been implicated in improving attraction to pheromone-baited traps. Some of these same OSNs responded additionally to either of the two sex pheromone components, but because these OSNs also responded to some of the above plant volatiles as shown by cross-adaptation experiments, these OSNs will not be the types that convey sex-pheromone-specific information to the antennal lobe.

Renewable synthesis of n-butyraldehyde from glucose by engineered Escherichia coli.

BACKGROUND: n-Butyraldehyde is a high-production volume chemical produced exclusively from hydroformylation of propylene. It is a versatile chemical used in the synthesis of diverse C4-C8 alcohols, carboxylic acids, esters, and amines. Its high demand and broad applications make it an ideal chemical to be produced from biomass. RESULTS: An Escherichia coli strain was engineered to produce n-butyraldehyde directly from glucose by expressing a modified Clostridium CoA-dependent n-butanol production pathway with mono-functional Coenzyme A-acylating aldehyde dehydrogenase (Aldh) instead of the natural bifunctional aldehyde/alcohol dehydrogenase. Aldh from Clostridium beijerinckii outperformed the other tested homologues. However, the presence of native alcohol dehydrogenase led to spontaneous conversion of n-butyraldehyde to n-butanol. This problem was addressed by knocking out native E. coli alcohol dehydrogenases, significantly improving the butyraldehyde-to-butanol ratio. This ratio was further increased reducing media complexity from Terrific broth to M9 media containing 2% yeast extract. To increase production titer, in situ liquid-liquid extraction using dodecane and oleyl alcohol was investigated. Results showed oleyl alcohol as a better extractant, increasing the titer of n-butyraldehyde produced to 630 mg/L. CONCLUSION: This study demonstrated n-butyraldehyde production from glucose. Through sequential strain and condition optimizations, butyraldehyde-to-butanol ratio was improved significantly compared to the parent strain. Results from this work may serve as a basis for further development of renewable n-butyraldehyde production.

Non-Oxidative Dehydrogenation Pathways for the Conversion of C2 -C4 Alcohols to Carbonyl Compounds.

Gold nanoparticles (NPs) supported on hydrotalcite (Au/HT) are highly active and selective catalysts for the continuous, gas-phase, non-oxidative dehydrogenation of bioderived C2 -C4 alcohols. A sharp increase in turn over frequency (TOF) is noted when the size of Au NPs is less than 5 nm relating to the strong synergy between metallic Au NPs and the acid-base groups on the support surface. It is shown that catalytic activity depends critically on Au NP size, support composition, and support pretreatments. A reaction pathway elucidated from kinetic isotope effects suggests that the abstraction of ß-H by Au NPs (C-H activation) is the rate-determining step in the dehydrogenation of bioderived C2 -C4 alcohols.

A novel ultrasound-assisted back extraction reverse micelles method coupled with gas chromatography-flame ionization detection for determination of aldehydes in heated edibles oils.

A novel ultrasound-assisted back extraction reverse micelles coupled with gas chromatography-flame ionization detection has been developed for the extraction and determination of some short chain aldehydes in different heated edible oil samples. After the homogenization of the oil samples with Triton X-100, 200 µL of methanol was added to facilitate the phase separation. The aqueous micelle phase has been separated by centrifugation, then it was treated with a mixture of H2O: CHCl3 and ultrasonic vibration, were used to effectively back-extraction of the analytes into the chloroform phase. The sedimented organic phase was obtained after centrifugation, withdrawn into the microsyringe and directly injected into the GC-FID system. The calibration graphs were linear in the range 0.05-20 mg L(-1). The limits of detection were in the range of 0.02-0.15 mg L(-1). This procedure was successfully applied for determination of propanal, butanal, hexanal and heptanal in real heated oil samples.

Development of a method for identification and accurate quantitation of aroma compounds in Chinese Daohuaxiang liquors based on SPME using a sol-gel fibre.

Aroma compositions of Chinese Daohuaxiang liquors, including five kinds of commercial liquors and three kinds of base liquors, were extracted by solid phase microextraction using a sol-gel divinylbenzene/hydroxy-terminated silicone oil fibre. The effectiveness of the fibre was evaluated in comparison with commercial fibres and liquid-liquid extraction. After identification by GC-MS and GC-O, the compounds were accurately quantified by GC-FID using internal standards. Wide linear ranges, low limits of detection, satisfactory precision and recoveries were achieved. A total of 57 volatile compounds were detected and 28 of them were quantified. Most of them were common in these liquors but differed in terms of their relative amounts. Thirteen out of the 28 compounds had odour activity values greater than 1 in all of the liquors, and are suggested to be the key aroma-contributing substances of Daohuaxiang liquors. Besides, the differences among different aroma types and kinds of Daohuaxiang liquors were also discussed.