2-ethyl-1-hexanol Research Articles

Sustainable synthesis of 2-ethyl hexyl oleate via lipase-catalyzed esterification: A holistic simulation and cost analysis study

Lipase catalyzed synthesis of fatty acid esters has recently attracted much attention as it represents a cleaner production route compared to the conventional energy intensive chemical method. In this study, the technical and economic viability of 2-ethyl hexyl oleate (2-EHO) synthesis by the catalytic esterification of oleic acid (OA) and 2-ethyl hexyl alcohol (2-EHA) in a stirred tank reactor using Novozym 435 (Candida antarctica lipase B) was investigated. A conversion rate of 91% was obtained by adopting the subsequent optimized parameters: 4% enzyme amount, 2 h reaction time, 4:1 M ratio of alcohol to fatty acid, 150 rpm stirring speed, and 60 °C temperature. The lipase operational stability study showed that enzymes can be used for 30 successive cycles without significant lose in activity. The use of Aspen Plus simulator enabled the development of a detailed process flow diagram, which significantly improved the understanding of this clean production method and assessed the overall costs. A holistic cost analysis revealed a production cost of $2109 per ton of 2-EHO, thereby yielding an approximate 28% profit margin relative to prevailing market rates. Rigorous financial assessments corroborated the project's viability, substantiating a net present value (NPV) of $14.7 MM, a return on investment (ROI) of 583.91% (plant life time = 15 years), projected Payback Period stands at 6 years, and an internal rate of return (IRR) of 23%. These results confirm the technical and economic feasibility of lipase catalyzed production of 2-EHO, highlighting its potential as an environmentally and profitable approach in the synthesis of fatty acid esters.

Hybrid process for separation of morpholine−water mixture: A rigorous design with experimental confirmation based on LLE and VLE data

The separation of morpholine from the aqueous effluent stream is carried out using an efficient hybrid extraction-distillation (HED) system using commercially viable solvents 2-ethyl hexanol and toluene, which makes heteroazeotrope with water. This paper investigated the tie-line, mutual solubility and VLE measurements, and thermodynamic modeling. On comparing the two solvents, 2-ethyl hexanol emerged as an appropriate extractant. The experimental tie-line data regressed by the NRTL model and a deviation of 0.8 indicates a good correlation between experimental and predicted data. Further, the process is designed, simulated, and optimization is performed by minimizing total annual cost (TAC) as the objective function. At extract/solvent to feed ratio S/F of 0.78 mol fraction, number of stages, NT of 28, 99.8% morpholine recovered in the extract phase with TAC of $23.3×104/y. Subsequently, the extract phase is fed to the heteroazeotropic distillation column to remove moisture followed by the final recovery column. Finally, a laboratory-scale experiment was conducted to verify the separation performance in the downscaled (3.5×50 cm) counter-current extraction column.

Effect of volatile compounds produced by Weissella cibaria BWL4 on Botrytis cinerea infection in fruit and complete genome sequence analysis of BWL4

Botrytis cinerea, one of the most harmful pathogenic fungi, causes significant postharvest decay in fruit. In this study, the effects of Weissella cibaria BWL4 on B. cinerea and the gray mold in grape and kiwifruit were evaluated. Additionally, the genome of an antagonistic bacterium BWL4 was sequenced. Results showed that the application of BWL4 inhibited B. cinerea infection in grape and kiwifruit. BWL4 produced antifungal volatile substances against B. cinerea. A gas chromatography–mass spectrometry of solid phase microextraction samples (SPME-GC-MS) analysis showed that BWL4 produced 54 volatiles. Among these volatiles, furfural, 2,6-dimethyl-pyrazine, dimethyl trisulfide, 2-pentyl furan, 2-ethyl hexanol, hexamethyl-cyclotrisiloxane, dodecamethyl-cyclohexasiloxane, 2,4-di-tert-butylphenol, and butylated hydroxytoluene, exhibited antifungal activity against B. cinerea, with MICs of 0.8 g L−1, 0.2 g L−1, 0.9 g L−1, 5 g L−1, 0.4 g L−1, 8 g L−1, 8 g L−1, 80 mg L−1, and 2 g L−1, respectively. In vivo assay showed that these compounds inhibited the disease development in kiwifruit. These compounds except dimethyl trisulfide can also inhibit gray mold in grape. The genome of W. cibaria BWL4 consists of a circular chromosome of 2.42 Mb and 6 plasmids. The genome size is 2.53 Mb, encoding 2327 putative genes. Several genes involved in the biosynthesis of some antifungal volatiles and 17 genes associated with biocontrol were identified. These results suggested that W. cibaria BWL4 can be considered as an effective biological control agent for the postharvest management of B. cinerea infection.

Effects of fuel composite additives on the vibration, wear and emission performances of diesel engines under hot engine tests

Diesel engines applied for ships are currently facing an escalating demand for energy conservation and emission reduction, which has driven the application of fuel composite additives. Nevertheless, adverse phenomena affecting engine reliability have been observed in practical engine applications with unclear mechanisms. The present study investigated the vibration, wear, and emission performances of three types of composite additives with detergent and synergist function in a diesel engine. Vibration acceleration, cylinder temperature, NOx emission quantity, as well as the wear characteristics of cylinder liner-piston ring (CLPR) friction pairs were selected as characterization parameters. The results revealed that components of additives have a certain impact on vibration, wear, combustion, and emission performance. Specifically, additives of Type Ⅰ containing aviation kerosene and Type Ⅱ containing 2-Ethyl 1-hexanol and 2-Ethylhexyl nitrate compound in diesel were susceptible to cause aggravated engine vibration and thus lead to excessive wear. Furthermore, Type I exacerbates the thermal stress and worsens combustion stability, resulting in increased mechanical vibrations, cylinder temperature, and NOx emission. In contrast, addition of Type Ⅲ containing 2-nitro-propane and toluene results in improved reliability, demonstrating a 7.6% reduction in mechanical vibration energy and a 27.4% decrease in wear mass losses of piston rings, while effectively mitigating abnormal wear on the liner surface. Likewise, it also it also facilitates a mild combustion process and achieves better emission reduction results by reducing the NOx emission by 11.5% while slightly lowering the cylinder temperature by 0.74%.

Influence of different baking temperatures of red kojic rice on the physicochemical properties, antioxidant capacity, and functional components of red starter wine.

To improve the quality of red starter wine, this study explored the effects of baking red kojic rice at varying temperatures on the physicochemical characteristics of red starter wine. Baking was predicated on understanding crucial enzyme activities and starch granule structure of red kojic rice at 75, 95, and 105 °C, leading to the production of three red starter wine variants (BHQW1, BHQW2, and BHQW3). The results revealed an increased alcohol (increase 0.50%), total sugar (increase 0.14 g L-1 ), and total acid (increase 0.54 g L-1 ) content in red starter wine fermented using baked red kojic rice compared with the control group (wine fermented with unbaked rice, HQW). Furthermore, both the 105 °C baked red kojic rice and its resulting BHQW3 demonstrated significantly higher red color values than HQW (increase 2.03 U g-1 and 0.15 U mL-1 respectively). The highest lovastatin content was presented in red kojic rice baked at 105 °C and its corresponding fermented wine (1420.63 ± 507.9 μg g-1 and 3368.87 ± 228.16 μg L-1 respectively). Additionally, BHQW groups displayed higher total flavonoids and phenols content than HQW. Regarding antioxidant capacity, all BHQW groups showed stronger overall antioxidant capacity than HQW. The determination of volatile components revealed the highest content of volatile compounds in BHQW2 (2621.19 ± 548.24 μg L-1 ) and significantly higher volatile esters in BHQW1 (254.46 ± 16.63 μg L-1 ). Moreover, 16 volatile compounds were identified only in BHQW groups, including isoamyl caprylate, 2-ethylhexyl alcohol, and benzaldehyde. Our findings suggested that the baking technique of red kojic rice could enhance the quality of red starter wine through enhancing antioxidant properties, increasing functional components, and enriching volatile flavor compounds, thus providing a foundation for new techniques in red starter wine production. © 2023 Society of Chemical Industry.

Study of Esterification between Oleic Acid and 2-Ethyl Hexanol by using the Microwave Method

Oleic acid is an unsaturated fatty acid, has a rancid odor and the main component of palm oil. To increase the value of oleic acid which has a C18 chain, it has the potential as a raw material for making long chain fatty acid esters. This fatty acid ester from vegetable oil is an emollient ester which is biodegradable which was synthesized with 2-ethyl hexanol using the Microwave method. In the last ten years, the microwave method has been widely used in organic synthesis. This esterification reaction was carried out using a modified home microwave by making a hole on top as a place for the ball cooler equipped with a stirrer, and using an acid catalyst. Characteristics of long chain fatty acid esters will be tested by FTIR and GC-MS. FTIR test results showed absorption of specific functional groups, while GC-MS was able to show the presence of long chain fatty acid ester compounds.

Synthesis of 12-hydroxystearic estolide and its esters to study the effect of molecular structure on physicochemical properties

The global point of view associated with bio-lubricants has dramatically changed due to depleting petroleum supplies, volatile prices, growing environmental concerns, and strict government regulations. Vegetable oils are considered a potential replacement for petroleum-based lubricants; however, they are constrained by poor cold-flow characteristics, low hydrolytic stability, and low resistance to oxidative deterioration. Increased oxidative and hydrolytic stability and enhanced cold flow properties result from a chemical alteration of vegetable oil by esterification or estolide formation. This work prepares a 12-hydroxystearic acid estolide (HSAE) series, followed by esterification with alcohols (i.e., 2-ethyl hexanol, trimethylolpropane, and pentaerythritol) to obtain estolide esters. The effect of reaction time on the degree of oligomerization of 12-hydroxystearic acid estolide has been studied. Further, the comparative analysis of the physicochemical properties (i.e., kinematic viscosity at 40 °C & 100 °C, viscosity index, and pour point) of estolide esters was also evaluated to study the effect of oligomerization and molecular structure of alcohol on kinematic viscosity, viscosity index, and pour point.

Research on odor characteristics of typical odorants of railway vehicle products.

Odor annoyance was a kind of environmental air pollution. Compared to other indoor environments, vehicle interior materials were not well studied. Especially, there had been little research on odor character of the railway vehicles. This study applied the OAV method to identify the key odorants of railway vehicle materials and discussed the characteristics of these odorants through Weber Fechner law and a dual variable method. The result showed that for single odorant, Weber Fechner law can be used to estimate the perceived intensity of an odor gas sample at different concentration levels. The odorant with smaller slope had significant tolerance to human. For the mixtures of odorants, the overall intensity of the mixture is generally dominated by the strongest odor intensity of the individual substance in the mixture, and positive interaction effect can be observed in mixtures whose intensities had little difference. But there was a kind of odorants, such as methacrylate, in which a very small variation in the concentration of mixtures can affect its odor intensity largely. Meanwhile, the odor intensity modification coefficient was an effective way to identify and evaluate odor interaction effect. The interaction potential of the studied odorants from strong to weak was methacrylate, dibutyl-amine, nonanal, 2-ethyl hexanol. The odor interaction potential and odor nature should be paying much attention in the improvement of odor in railway vehicle product.

Biosynthesis of diisooctyl 2,5-furandicarboxylate by Candida antarctica lipase B (CALB) immobilized on a macroporous epoxy resin.

Diisooctyl 2,5-furandicarboxylate (DEF), an ester derivative of 2,5-furandicarboxylic acid (FDCA, a bio-based platform chemical), resembles the physical and chemical properties of phthalates. Due to its excellent biodegradability, DEF is considered a safer alternative to the hazardous phthalate plasticizers. Although FDCA esters are currently mainly produced by chemical synthesis, the enzymatic synthesis of DEF is a green, promising alternative. The current study investigated the biosynthesis of DEF by Candida antarctica lipase B (CALB) immobilized on macroporous resins. Out of five macroporous resins (NKA-9, LX-1000EP, LX-1000HA, XAD-7HP, and XAD-8) evaluated, the LX-1000EP epoxy resin was identified as the best carrier for CALB, and the XAD-7HP weakly polar resin was identified as the second best. The optimal immobilization conditions were as follows: CALB (500μL) and LX-1000EP (0.1g) were incubated in phosphate butter (20mM, pH 6.0) for 10h at 35°C. The resulting immobilized CALB (EP-CALB) showed an activity of 639U/g in the hydrolysis of p-nitrophenyl acetate, with an immobilization efficiency of 87.8% and an activity recovery rate of 56.4%. Using 0.02g EP-CALB as the catalyst in 10mL toluene, and the molar ratio of 2,5-dimethyl furanediformate (1mmol/mL) and isooctyl alcohol (4mmol/mL) that was 1:4, a DEF conversion rate of 91.3% was achieved after a 24-h incubation at 50°C. EP-CALB had similar thermal stability and organic solvent tolerance compared to Novozym 435, and both were superior to CALB immobilized on the XAD-7HP resin. EP-CALB also exhibited excellent operational stability, with a conversion rate of 52.6% after 10 repeated uses. EP-CALB could be a promising alternative to Novozym 435 in the biomanufacturing of green and safe plasticizers such as DEF.

Efficient biocatalytic synthesis of green plasticizer 2,5-furanediformate isooctyl ester using an immobilized lipase.

2,5-furanediformate Isooctyl is a potential new green biobased plasticizer. At present, most of the preparation methods are chemical methods, which not only have many by-products and are difficult to separate, but also cause environmental pollution. In this paper, the immobilized lipase Novozym435 was used as the catalyst to catalyze the transesterification of 2,5-furanediformate dimethyl ester and isooctyl alcohol to prepare 2,5-furanediformate isoocty in organic medium, and the reaction process was optimized. The optimal process conditions were determined by single factor experiment: in 10 mL toluene system, the additional amount of immobilized lipase Novozym435 was 0.02 g, the molar ratio of 2,5-furanediformate dimethyl ester (1 mmol) and isooctyl alcohol was 1:4, and 1 g 4Å molecular sieve was added to the reaction system, the reaction temperature was 50°C, the reaction time was 24 h, and the conversion rate of 2,5-furanediformate isoocty was 89.63%.

Odor-mediated response of gravid Aedes aegypti to mosquito-associated symbiotic bacteria

Complex oviposition decisions allow gravid Aedes aegypti mosquitoes to select suitable sites for egg-laying to increase the probability that their progeny will thrive. The bacterial communities present in larval niches influence mosquito oviposition behavior, and gravid mosquitoes transmit key microbial associates to breeding sites during oviposition. Our study evaluated whether symbiotic Klebsiella sp., which are strongly associated with mosquitoes, emit volatiles that affect mosquito oviposition decisions. Dual-choice behavioral assays demonstrated that volatile organic compounds emitted by Klebsiella sp. induce a preference in oviposition decisions by Ae. aegypti. Bacterial headspace volatiles were sampled by solid-phase microextraction, and subsequent combined gas chromatography and electroantennogram detection analysis, revealed that the antennae of gravid females detect two compounds present in the Klebsiella sp. headspace. These compounds were identified by gas chromatography and mass spectrometry as 2-ethyl hexanol and 2,4-di‑tert-butylphenol. The binary blend of these compounds elicited a dose-dependent egg-laying preference by gravid mosquitoes. We propose that bacterial symbionts, which are associated with gravid mosquitoes and may be transferred to aquatic habitats during egg-laying, together with their volatiles act as oviposition cues indicating the suitability of active breeding sites to conspecific females.

Detection of 2-ethyl hexanol and dioctyl phthalate with potentiometric sensor based on ordered ZnO nanorods sensing electrode

In this work, a planar mixed-potential sensor was prepared by in situ growth of ZnO nanorods sensing electrode on yttria-stabilized zirconia (YSZ) electrolyte. The potentiometric sensing properties of the sensor toward two signature gases of early PVC cable fires, 2-ethyl hexanol (2-EH) and dioctyl phthalate (DOP), were studied. High response values of −205.1 mV and −54.1 mV were achieved at 400 °C for ∼171–193 ppm 2-EH and ∼89–109 ppt DOP for ZnO nanorods-based sensor, which were 1.7 and 4.1 times higher than those of ZnO nanoparticles-based sensor, respectively. Furthermore, ZnO nanorods exhibited much better 2-EH and DOP selectivity. The improvement of the gas-sensing performance of ZnO nanorods may be ascribed to the unique three-dimensional electrode morphology.

Scent of knowledge: The molecular fingerprint of volatiles in an emblematic historical library in Italy.

Heritage guidelines recognize odors as a value associated with a place. This study aims to clarify the connection between heritage and volatile organic compounds at the molecular level. At variance with previous studies, usually focused only on book-related compounds from accelerated degradation tests, the whole air of one of the most significant historical libraries in Italy was studied. A sampling of the volatiles off-gassing from the two most iconic rooms, respectively open and forbidden to visitors, was performed via a non-invasive, nondestructive green method, solid-phase-micro-extraction. The gas-chromatographic analyses resulted in the appraisal of olfactory contributions from books, storage environment, and, for the first time, anthropic activities and pollution.Concerning the paper decay process, for the very first time, the presence of 2-ethyl-1-hexanol in the chromatographic signature of the library air is rationalized according to the Guerbet reaction. The presence of all other compounds is explained by the paper decay process, anthropic sources, and pollution. Indoor air comprises analytes related to paper decay, identified by previous studies, and additional compounds never found before.Most volatile compounds are aliphatic and aromatic hydrocarbons, aldehydes, alcohols, terpenes, and terpenoids. Odor contributions from a selected number of analytes were pinpointed. Alkanes dominate the volatiles chromatographic signature, and impart a slight hydrocarbon smell. Aromatics supplement their characteristic aromatic odor. Aldehydes' very low odor threshold makes them strongly contribute to both fruity and fatty descriptors. Benzaldehyde, furfural, vanillin, and camphor add, respectively, an hint of almond, bread, vanilla, and camphor. Alcohols such as 2-ethyl hexanol have a floral scent. Wood-related terpenes and terpenoids contribute to the woody smell of the library.The digital molecular fingerprint of the "scent of knowledge" enables documentation, conservation, and future chemical reproduction of the historical library odor.

Systematic solvent screening and selection for polyhydroxyalkanoates (PHBV) recovery from biomass

The biotechnological production of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) derived from organic waste streams by mixed microbial communities is well established at the pilot-level. However, there is limited research on the recovery of the biopolymer from the microbial biomass, while its impact on product quality and product costs is major. When applying solvent extraction, the choice of solvent has a profound influence on many aspects of the process design. This study provides a framework to perform a systematic solvent screening for PHBV extraction. First, a database was constructed of 35 solvents that were assessed according to six different selection criteria. Then, six solvents were chosen for further experimental analysis, including 1-butanol, 2-butanol, 2-ethyl hexanol (2-EH), dimethyl carbonate (DMC), methyl isobutyl ketone (MIBK), and acetone. The main findings are that the extractions with acetone and DMC obtained the highest yields (91–95%) with reasonably high purities (93–96%), where acetone had a key advantage of the possibility to use water as anti-solvent. Moreover, the results provided new insights in the mechanisms behind PHBV extraction by pointing out that at elevated temperatures the extraction efficiency is less determined by the solvent’s solubility parameters and more determined by the solvent size. Although case-specific factors play a role in the final solvent choice, we believe that this study provides a general strategy for the solvent selection process.

Solvent-induced crack growth in poly(methyl methacrylate)/multiwalled carbon nanotube composites

Understanding the structural integrity of polymer composites in service conditions is of practical importance for the applications of polymer composites. In this work, we investigate the solvent-induced crack growth in poly(methyl methacrylate)/multiwalled carbon nanotube (PMMA/MWCNT) composites in respective organic solvents of 2-ethylhexyl alcohol (2 EA), cyclohexanol, and 1-butanol at different temperatures after being immersed in methanol at 50 °C for 25 min. The areal density of crack lengths and growth rate of a single crack in the PMMA/MWCNT composites increase with the immersion time and temperature for the solvents of 2 EA and cyclohexanol. The areal density of crack lengths in the PMMA/MWCNT composites immersed in 1-butanol is largest at 30 and 40 °C and smallest at 50 °C. The 1-butanol solvent causes the fastest, steady-state crack growth at 30 and 40 °C and the slowest crack growth at 50 °C. Increasing the fraction of MWCNTs reduces the areal density of crack lengths and the growth rate of a single crack in the healed and non-cracked areas. The crack growth is controlled by a thermally activated process. The crack growth rate is faster in the healed area than in the non-cracked area for the same composite and solvent. The activation energy for the motion of polymer chains associated with the single-crack growth in the non-cracked area is smaller than that for solvent-induced cracking because the interaction between cracks hinders crack growth.

Multicolor Nitrogen-Doped Carbon Quantum Dots for Environment-Dependent Emission Tuning.

Carbon quantum dots (CQDs) have potential applications in many fields such as light-emitting devices, photocatalysis, and bioimaging due to their unique photoluminescence (PL) properties and environmental benignness. Here, we report the synthesis of nitrogen-doped carbon quantum dots (NCQDs) from citric acid and m-phenylenediamine using a one-pot hydrothermal approach. The environment-dependent emission changes of NCQDs were extensively investigated in various solvents, in the solid state, and in physically assembled PMMA–PnBA–PMMA copolymer gels in 2-ethyl-hexanol. NCQDs display bright emissions in various solvents as well as in the solid state. These NCQDs exhibit multicolor PL emission across the visible region upon changing the environment (solutions and polymer matrices). NCQDs also exhibit excitation-dependent PL and solvatochromism, which have not been frequently investigated in CQDs. Most CQDs are nonemissive in the aggregated or solid state due to the aggregation-caused quenching (ACQ) effect, limiting their solid-state applications. However, NCQDs synthesized here display a strong solid-state emission centered at 568 nm attributed to the presence of surface functional groups that restrict the π–π interaction between the NCQDs and assist in overcoming the ACQ effect in the solid state. NCQD-containing gels display significant fluorescence enhancement in comparison to the NCQDs in 2-ethyl hexanol, likely because of the interaction between the polar PMMA blocks and NCQDs. The application of NCQDs-Gel as a solid/gel state fluorescent display has been presented. This research facilitates the development of large-scale, low-cost multicolor phosphor for the fabrication of optoelectronic devices, sensing, and bioimaging applications.

A novel class of bio-lubricants are synthesized by epoxidation of 10-undecylenic acid-based esters

Mineral-based lubricants are being supplanted by bio-based lubricants because of environmental concerns and the depletion of fossil resources. The derivatives of edible and non-edible oils are considered potential alternatives to existing natural mineral oil base stocks in certain lubricant applications, where immediate intraction with the environment is predicted. A new class of epoxides were synthesized from the undecylenic esters of 2-ethyl hexanol, neopentyl glycol (NPG), and trimethylolpropane (TMP). These unsaturated esters were epoxidized by using meta chloro perbenzoic acid. The synthesized epoxides were characterized by spectral studies (1HNMR, 13CNMR, IR) physio-chemical (density, specific gravity) and lubricant properties (kinematic viscosity, viscosity index, flash point, fire point, cloud point, pour point, copper strip corrosion). TMP epoxide has a high viscosity index, high flash point, and low pour point compared to 2-ethyl hexyl epoxide and NPG epoxide.

Separation of 4-hydroxy-3-methoxybenzoic acid with 2-ethyl hexanol, isobutyl acetate and 1-butanol

4‑hydroxy-3-methoxybenzoic acid (vanillic acid), a benzoic acid derivative, is an oxidised version of vanillin that is widely utilised as a flavouring and smell ingredient, particularly in the food and pharmaceutical sectors. It is easily created through a clean and environmentally friendly fermentation process, however separating the acid from the fermenter is a difficult procedure. At normal temperature and pressure, 2-ethyl hexanol, isobutyl acetate, and 1-butanol were employed to separate vanillic acid from aqueous stream solvents. The performance of various solvents was evaluated using characteristics as distribution coefficient (KD), as well as extraction efficiency (%).The maximum extraction efficiency of 72.59% was obtained using solvent 2-ethyl hexanol at vanillic acid concentration of 3.87 mmol L−1 at 298.15 K and atmospheric pressure The data acquired will be valuable in the design of an integrated process for the aqueous streams vanillic acid separation from fermentation broths and effluents.

Whole-cell bacterial biosensor for volatile detection from Pectobacterium-infected potatoes enables early identification of potato tuber soft rot disease

Half of the harvested food is lost due to rots caused by microorganisms. Plants emit various volatile organic compounds (VOCs) into their surrounding environment, and the VOC profiles of healthy crops are altered upon infection. In this study, a whole-cell bacterial biosensor was used for the early identification of potato tuber soft rot disease caused by the pectinolytic bacteria Pectobacterium in potato tubers. The detection is based on monitoring the luminescent responses of the bacteria panel to changes in the VOC profile following inoculation. First, gas chromatography-mass spectrometry (GC-MS) was used to specify the differences between the VOC patterns of the inoculated and non-inoculated potato tubers during early infection. Five VOCs were identified, 1-octanol, phenylethyl alcohol, 2-ethyl hexanol, nonanal, and 1-octen-3-ol. Then, the infection was detected by the bioreporter bacterial panel, firstly measured in a 96-well plate in solution, and then also tested in potato plugs and validated in whole tubers. Examination of the bacterial panel responses showed an extensive cytotoxic effect over the testing period, as seen by the elevated induction factor (IF) values in the bacterial strain TV1061 after exposure to both potato plugs and whole tubers. Moreover, quorum sensing influences were also observed by the elevated IF values in the bacterial strain K802NR. The developed whole-cell biosensor system based on bacterial detection will allow more efficient crop management during postharvest, storage, and transport of crops, to reduce food losses.

Solvent-free direct esterification of acrylic acid with 2-ethylhexyl alcohol using simple Zn(II) catalysts

Direct esterification of acrylic acid with 2-ethylhexyl alcohol was investigated using low toxic and cheap Zn(II) salts as catalysts. An initial screening using Zn(ClO4)2, ZnCl2, Zn(OAc)2 and ZnO disclosed that the most effective was the perchlorate, which was used for the subsequent refining of the study. In optimized conditions (0.5 % mol of polymerization inhibitor, 0.1 % mol of catalyst, 170 °C, 4 h) the product was obtained in 99 % yield. A kinetic model was proposed to quantify the contribution of each chemical reaction of the network, allowing a quantitative comparison of the effect of the inhibitors on the acrylic acid esterification side-reactions.