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Prins reaction of isoprenol with butanal provides important intermediate 4-methyl-2-propyltetrahydro-2H-pyran-4-ol, which can be esterified to 4-methyl-2-propyltetrahydro-2H-pyran-4-yl acetate. This desired fragrance with fruity and rose scent is known, e.g., as Clarycet®. Molybdenum-modified MCM-41 materials were obtained by a wet impregnation method using a water solution of ammonium molybdate. We prepared several materials with different MoO3 loadings. These materials were thoroughly characterized (nitrogen physisorption, acidity—temperature-programmed desorption, elemental composition, etc.). The activity of prepared materials was tested in Prins reaction of isoprenol with butanal in batch arrangement. The influence of various reaction conditions (catalyst type, solvent, and water addition) was tested. We showed that modification of MCM-41 with MoO3 led to a significant increase of catalytic activity (butanal conversion at 4 h of reaction: 7% for nonmodified MCM-41 compared to 93% for material 5 wt% of MoO3-MCM-41). Water addition to the reaction mixture positively influenced the selectivity of the desired substituted tetrahydropyranol (selectivity > 70%). Mo-modified materials were also active in the esterification of 4-methyl-2-propyltetrahydro-2H-pyran-4-ol with acetanhydride to 4-methyl-2-propyltetrahydro-2H-pyran-4-yl acetate providing desired product after 5 h with 100% selectivity and total conversion. Reaction in the "one-pot" arrangement was also performed. [ABSTRACT FROM AUTHOR]

Air frying as a new roasting technology has potential for roasted fish production. In this study, the changes in volatile compounds (VCs) during air frying of tilapia were studied by quantitative gas chromatography–ion mobility spectrometry, followed by the identification of key VCs based on their odor activity value (OAV). There were 34 verified VCs, of which 16 VCs were identified as the key VCs with OAV ≥ 1. Most of the VCs were improved by air frying and peaked at 20 min. During the air frying, the total sulfhydryl content markedly decreased, while the protein carbonyl and MDA content significantly increased, suggesting the enhancement in the oxidation of lipids and proteins. The correlation network among the chemical properties and key VCs was constructed. The change in total sulfhydryl, protein carbonyl, and MDA showed significant correlation with most of the key VCs, especially 2-methyl butanal, ethyl acetate, and propanal. The results indicated that the oxidation of lipids and proteins contributed the most to the flavor improvement in air-fried tilapia. This study provides a crucial reference for the volatile flavor improvement and pre-cooked product development of roasted tilapia. [ABSTRACT FROM AUTHOR]

Simple Summary: The main aim of this study was to identify antennally active pheromone components from the citrus long-horned beetle, Anoplophora chinensis, and to test them for behavioral activity. We identified three antennally active male-produced chemical components (nonanal, 4-(n-heptyloxy)butan-1-ol, and 4-(n-heptyloxy)butanal). When tested together in Y-tube behavioral assays, these three compounds were shown to be attractive to adult female A. chinensis. Pheromone production and behavior of A. chinensis are discussed in relation to other closely related Anoplophora cerambycid species. 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. [ABSTRACT FROM AUTHOR]

In this study, three different brands of commercially available marinated tofu were analyzed and compared with homemade products to explore the effect of key flavor substances on their sensory quality, sensory properties, texture characteristics, and volatile components. The texture characteristics and flavor substances of the three brands of commercially available marinated tofu were significantly different from those of homemade products. A total of 64 volatile components were identified by headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS), mainly including 11 hydrocarbons, 11 alcohols, 10 ketones, 15 aldehydes, 4 esters, 1 acid, and 12 other volatile substances. Among these, nine key flavor compounds (ROAV > 1, VIP > 1) were identified using the relative odor activity value (ROAV) combined with a partial least squares discriminant analysis (PLS-DA) and variable importance in projection, including α-Pinene, β-Myrcene, α-Phellandrene, 1-Penten-3-one, Butanal, 3-Methyl butanal, acetic acid ethyl ester, 1,8-Cineol, and 2-Pentyl furan. The correlation heatmap showed that sensory evaluation was positively correlated with hardness, gumminess, chewiness, and springiness while negatively correlated with 2-Pentyl furan, α-Pinene, resilience, α-Phellandrene, 1-Penten-3-one, acetic acid ethyl ester, and 1,8-Cineol. Overall, this study provides a theoretical reference for developing new instant marinated tofu snacks. [ABSTRACT FROM AUTHOR]

The demand for 2-ethylhexanol is rising in several sectors, yet this chemical is actually almost exclusively produced from petroleum resources, calling for sustainable alternatives. Here we review the production of 2-ethylhexanol from lignocellulosic biomass-derived chemicals with emphasis on 2-ethylhexanol synthesis and applications. 2-Ethylhexanol can be synthesized from ethanol, butanol, butyraldehyde, and syngas. Applications comprise biofuels, lubricants, plasticizers, and surfactants. [ABSTRACT FROM AUTHOR]

SO2 plays an important role in wine fermentation, and its effects on wine aroma are complex and diverse. In order to investigate the effects of different SO2 additions on the fermentation process, quality, and flavor of 'Beibinghong' ice wine, we fermented 'Beibinghong' picked in 2019. We examined the fermentation rate, basic physicochemical properties, and volatile aroma compound concentrations of 'Beibinghong' ice wine under different SO2 additions and constructed a fingerprint of volatile compounds in ice wine. The results showed that 44 typical volatile compounds in 'Beibinghong' ice wine were identified and quantified. The OAV and VIP values were calculated using the threshold values of each volatile compound, and t the effect of SO2 on the volatile compounds of 'Beibinghong' ice wine might be related to five aroma compounds: ethyl butyrate, ethyl propionate, ethyl 3-methyl butyrate-M, ethyl 3-methyl butyrate-D, and 3-methyl butyraldehyde. Tasting of 'Beibinghong' ice wine at different SO2 additions revealed that the overall flavor of 'Beibinghong' ice wine was the highest at an SO2 addition level of 30 mg/L. An SO2 addition level of 30 mg/L was the optimal addition level. The results of this study are of great significance for understanding the effect of SO2 on the fermentation of 'Beibinghong' ice wine. [ABSTRACT FROM AUTHOR]

This work presents a novel application of gas-diffusion microextraction (GDME) for the extraction and identification of volatile carbonyl compounds from a dry-process fibreboard (MDF) by combining high-performance liquid chromatography with diode array detection (HPLC–DAD) and mass spectrometry (MS). GDME is a simple, inexpensive, and environmentally friendly technique that allows the simultaneous extraction and derivatization with 2,4-dinitrophenylhydrazine (DNPH) of selected volatiles. The extraction conditions were optimized using design of experiments through a 24 full fractional design followed by a Box–Behnken design, resulting in 35 min of extraction at 45 °C using 500 µL of DNPH 0.15%. The analysis of commercial MDF samples with different characteristics, such as thickness or colour, showed a distinct emission profile of volatile carbonyls. The principal emitting compounds found were formaldehyde, acetaldehyde, acetone, butanal, pentanal, hexanal, heptanal, octanal, and nonanal. A total of 25 compounds were identified using MS, including saturated and unsaturated aldehydes, ketones, dicarbonyls, and benzaldehyde-derivatives. This method can be a valuable tool for the qualitative evaluation of VOCs released from wood-based panels and for the assessment of indoor-air quality. [ABSTRACT FROM AUTHOR]

The exothermic behaviors of butanol, butyraldehyde, butanone, and butyric acid with nitric acid were studied by adiabatic accelerating rate calorimeter(ARC), and the test results were compared and analyzed, and the system risk was evaluated by THI index method. The results show that under the condition of the zero oxygen balance, butyraldehyde-HNO3 system has the most obvious self-exothermic. When the butyraldehyde content is only 0.14 g, the adiabatic temperature of the system rises to 118.4 ℃ and the heat release amount is 776.6 J/g; butanol-HNO3 system begins to emit heat at about 40.2 ℃, and the highest temperature in the exothermic stage of self-reaction reaches 145.7 ℃ and the maximum pressure reaches about 34 bar(1 bar=105 Pa). Butanone-HNO3 system releases heat from 50 ℃ to 136 ℃, and the amount of heat released is 564.0 J/g. No exothermic point is observed in butyric acid-HNO3 system in the temperature range of less than 140.0 ℃. With the increase of nitric acid concentration(2.0→6.0 mol/L), the risk of butanol-HNO3 system increases from medium to high level. The risks of reaction systems of butanol, butyraldehyde, butanone and butyric acid with 4.0 mol/L HNO3 are at higher, higher, middle and middle levels.

Small molecule organocatalysts are abundant in all living organisms. However, their use as organocatalysts in cells has been underexplored. Herein, we report that organocatalytic aldol chemistry can be interfaced with living Escherichia coli to enable the α‐methylenation of cellular aldehydes using biogenic amines such as L‐Pro or phosphate. The biocompatible reaction is mild and can be interfaced with butyraldehyde generated from D‐glucose via engineered metabolism to enable the production of 2‐methylenebutanal (2‐MB) and 2‐methylbutanal (2‐MBA) by anaerobic fermentation, and 2‐methylbutanol (2‐MBO) by whole‐cell catalysis. Overall, this study demonstrates the combination of non‐enzymatic organocatalytic and metabolic reactions in vivo for the sustainable synthesis of valuable non‐natural chemicals that cannot be accessed using enzymatic chemistry alone. [ABSTRACT FROM AUTHOR]

An efficient method for the synthesis of 2-ethylhexanoic acid has been reported. The method involves the 2-ethylhexanal oxidation using oxygen or air in the presence of N-hydroxyphthalimide in isobutanol as a solvent under mild conditions. A high selectivity of >99% for 2-ethylhexanoic acid was achieved. The influence of catalyst amount, solvent type and quantity, temperature, and reaction time on the product composition was studied. The developed method is in line with the global trends aimed at developing green oxidation processes as well as having potential for implementation in industry due to its high selectivity, cost-effective oxidizing agent, and mild reaction conditions. The use of isobutanol as a solvent is of crucial importance providing an opportunity for potential producers of 2-EHAL from butanal to employ the less valuable alcohol. [ABSTRACT FROM AUTHOR]

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The present study reports on the photocatalytic oxidation of butanols to butanal/butanone using thin film form of facet‐dependent nano‐Pd supported on commercial TiO2 under one‐sun condition and demonstrates the generic nature. Pd‐nanocube (PdNC(100)), Pd‐truncated octahedron (PdTO (100) and (111)), polycrystalline (PdPC), and their counterparts with half‐a‐monolayer Pt‐coated on Pd (0.5θPt‐Pd)) have been used as co‐catalyst. A potentially scalable thin film form of Pd/TiO2 photocatalyst, prepared by drop‐casting method, has been employed to study oxidation of n‐butanol, 2‐butanol, and iso‐butanol to corresponding aldehyde/ketone. 100% selectivity is demonstrated to respective aldehyde/ketone with any catalyst used in the present study with varying degree of butanols conversion by NMR. 0.5θPt‐PdTO/TiO2 shows the highest conversion of 2‐butanol to butanone (13.6% in 4 h). Continuous 10 h of reaction with the most active 0.5θPt‐PdTO/P25 catalyst demonstrates 31% conversion of 2‐butanol to butanone, and catalyst recyclability has been demonstrated. The present protocol can be scalable to large scales to maximize the conversion in direct sunlight. Due to its generic nature, the current method can also be applied to many other alcohols and substrate molecules. [ABSTRACT FROM AUTHOR]

The copolymer synthesis process can be affected by failures in the production process or by contaminating compounds such as ketones, thiols, and gases, among others. These impurities act as an inhibiting agent of the Ziegler–Natta (ZN) catalyst affecting its productivity and disturbing the polymerization reaction. In this work, the effect of formaldehyde, propionaldehyde, and butyraldehyde on the ZN catalyst and the way in which it affects the final properties of the ethylene-propylene copolymer is presented by analyzing 30 samples with different concentrations of the mentioned aldehydes along with three control samples. It was determined that the presence of formaldehyde 26 ppm, propionaldehyde 65.2 ppm, and butyraldehyde 181.2 ppm considerably affect the productivity levels of the ZN catalyst; this effect increases as the concentration of aldehydes is higher in the process; likewise, these impurities affect the properties of the final product, such as the fluidity index (MFI), thermogravimetric analysis (TGA), bending, tension, and impact, which leads to a polymer with low-quality standards and less resistance to breakage. The computational analysis showed that the complexes formed by formaldehyde, propionaldehyde, and butyraldehyde with the active center of the catalyst are more stable than those obtained by the ethylene-Ti and propylene-Ti complexes, presenting values of −40.5, −47.22, −47.5, −5.2 and −1.3 kcal mol−1 respectively. [ABSTRACT FROM AUTHOR]

Clarycet (4-methyl-2-propyltetrahydro-2H-pyran-4-yl acetate) is an important fragrance used in many industrial applications ranging from cosmetics to agrochemical products. There are several procedures for its preparation, while two-step synthesis consisting of Prins cyclization followed by esterification appears to be simpler and higher yielding comparing to other procedures. Therefore, we sought for the optimal reaction conditions of both steps. We found that the highest yields of the desired substituted tetrahydropyranol (THPol) in Prins cyclization of butanal with isoprenol can be achieved under the following conditions: 70 °C, catalyst 1 mol% 10% sulphuric acid, 250 mol% of water, no solvent (butanal conversion 93%, selectivity to THPol 82% after 5 h of reaction). The second reaction step, esterification of THPol with acetic anhydride, was optimized yielding 98% of Clarycet under the following reaction conditions: molar ratio THPol:acetic anhydride 1:5, catalyst 1 mol% FeCl3, room temperature, no solvent, 5 min of reaction. The availability of the catalysts used, the possibility of performing the reactions without the addition of the solvent, and the high yields of the product showed good potential of this arrangement for Clarycet preparation. [ABSTRACT FROM AUTHOR]

[Objectives] This article simulated different temperature fluctuation conditions[-1 ℃, (-1±3)℃, (-1±5)℃], and explored the effect of precise temperature control technology on the preservation of fresh pork during ice-temperature storage. [Methods] The longest pig dorsal muscle was selected as the study object. Total viable counts, volatile base nitrogen, sensory evaluation and volatile organic compounds were determined to study the changes in the quality of fresh pork stored at ice temperature under precise temperature control. [Results] The results indicated that the quality and shelf life of fresh pork during ice-temperature storage were significantly affected by temperature fluctuations. After storage for 12 days, total viable counts in two fluctuating groups increased significantly, TVB-N content were significantly higher than that of -1 ℃ group. The sensory scores of two fluctuation groups were significantly reduced, and the odour was significantly different compared with -1 ℃ group. GC-IMS results showed that the contents of butanal, 2-heptanone, 2-pentanone, ethyl acetate, isoamyl acetate, isopropyl acetate, alpha pinene, styrene and methylpyrazine significantly increased in two fluctuating groups. There was no significant difference of the total viable counts, TVB-N and sensory indicators between two fluctuating groups in the middle and late storage period. [Conclusions] The shelf life of fresh pork in two fluctuation groups [(-1±3)℃ and(-1±5)℃] were shorter than that of -1 ℃ group by 2-3 days, and the stable ice-temperature storage (-1 ℃) was more conducive to maintaining the quality of fresh pork. [ABSTRACT FROM AUTHOR]

The high entropy oxides are widely studied as the potential catalytic materials owing to their unique structure and excellent properties. In this work, a new high entropy oxide catalyst MnFeCoNiCuO x was successfully prepared and used for the oxidative condensation reaction of furfural (FUR) and aliphatic alcohol, where the carbon-chain length can be selectively increased under the mild conditions. For the selective oxidative transformation of FUR with n-butanol, a more than 99.0 % conversion of FUR and 91.5 % selectivity of 2-(furanyl-2-methylene) butanal was obtained at 80 ºC for 2 h. In addition, the oxidative condensation of FUR with ethanol, n-propanol, n-pentanol, n-hexanol and n-heptanol was also carried out with the MnFeCoNiCuO x - LiOH as catalyst system in the presence of molecular oxygen, where a moderate to high product yields were acquired. Furthermore, the characterizations of catalyst showed that the existence of abundant oxygen vacancy and high specific area was greatly important to the catalytic reactions. [Display omitted] • The efficient oxidative condensation of furfural with n-butanol is achieved. • High entropy oxides-LiOH system exhibits a prominent catalytic activity. • The fuel precursors of C7-C12 can be synthesized with this approach. • Catalytic mechanism of oxidative condensation reaction is studied. [ABSTRACT FROM AUTHOR]

An air quality monitoring campaign for gaseous pollutants using passive sampling techniques was carried out, for the first time, at 25 locations in the metropolitan area of Luanda, Angola, in June 2023. Concentrations of benzene, toluene, ethylbenzene, xylenes, trimethylbenzenes, SO 2 and NO 2 were generally higher in locations more impacted by traffic. Benzene, SO 2 and NO 2 levels did not exceed the World Health Organisation guidelines. Ozone concentrations surpassed those documented for other African regions. Higher O 3 formation potential values were recorded at heavy-trafficked roads. The top 5 species with potential for ozone formation were m,p-xylene, toluene, formaldehyde, propionaldehyde and butyraldehyde. The Mulenvos landfill presented a distinctive behaviour with a very low toluene/benzene ratio (0.47), while values close to 5 were obtained at traffic sites. The maximum levels of α-pinene, D-limonene, formaldehyde, acetaldehyde, acetone, acrolein, propionaldehyde, butyraldehyde, benzaldehyde, valeraldehyde, hexaldehyde and crotonaldehyde were recorded at the landfill. The formaldehyde/acetaldehyde ratio ranged from 0.40 at the Mulenvos landfill to 3.0, averaging 1.8, which is a typical value for urban atmospheres. Acetaldehyde/propionaldehyde ratios around 0.4–0.6 were found in locations heavily impacted by traffic, whereas values between 0.7 and 1.2 were observed in green residential areas and in places with more rural characteristics. All hazard quotient (HQ) values were in the range from 1 to 10, indicating moderate risk of developing non-cancer diseases. The exception was the Mulenvos landfill for which a HQ of 11 was obtained (high risk). The cancer risks exceeded the tolerable level of 1 × 10−4, with special concern for the landfill and sites most impacted by traffic. A mean lifetime cancer risk of 9 × 10−4 was obtained. The cancer risk was mainly due to naphthalene, which accounted, on average, for 94.6% of the total. [Display omitted] • First air quality campaign in Luanda using passive sampling in 25 locations. • In general, benzene, SO 2 and NO 2 within WHO guidelines, while O 3 exceeded. • Top O 3 forming species: m,p-xylene, toluene, formaldehyde, propionaldehyde, butyraldehyde. • Mulenvos landfill with distinct profile: much higher aldehyde and hydrocarbon levels. • Hazard quotient moderate to high; 900 new cancer cases per million people. [ABSTRACT FROM AUTHOR]

[Display omitted] • In situ FT-IR is performed to understand the DAAC reaction on Ru@MIL-101(Cr). • α and β peaks are used as probes of metal-MOF interface sites and metallic sites. • n-Butanol favors the interface sites while butanal prefers the Ru metallic sites. • In situ FT-IR studies complete dynamic spectra for more analysis of kinetics. • Provide an insight of extraordinary DAAC reaction performance on the catalyst. Comparing to homogeneous systems, direct alcohol to acetals conversion (DAAC) reaction through heterogeneous catalysts has obvious advantages of simple separation, less corrosion and waste. However, progress on this research is quite limited. Recently a breakthrough of Ru@MIL-101(Cr) catalyst was found with high selectivity and conversion for DAAC of aliphatic alcohol and diols towards desired products. In this study, time resolved in situ FT-IR was performed for capturing molecular-level information on the active sites of the catalysis system. Transients analysis of interaction between n-butanol/butanal and two active surface sites induced by Ru loading on MIL-101(Cr) provides key insight into the reaction, revealing that Ru@ MIL-101(Cr) confines the reaction to the ideal acidic sites between Ru nanoparticles and MIL-101(Cr) support for efficient process. [ABSTRACT FROM AUTHOR]

To understand the mechanistic details of the catalytic conversion of ethanol to 1,3-butadiene on metal oxides, both the main reaction and the side reactions should be clarified. Seven side reactions on an MgO catalyst were examined using density functional theory calculations. They were: the condensation of ethanol involving dehydration, which generates diethyl ether; condensation between ethanol and acetaldehyde, which generates ethyl acetal; reduction of acetaldol, which generates 1,3-butanediol (1,3-BDO); dehydration of 1,3-BDO, which generates methyl ethyl ketone; hydrogenation of crotonaldehyde, which generates n-butanol; isomerization of crotyl alcohol, which generates butanal; and dehydrogenation and decarboxylation of acetaldol, which generate acetone. Because the ethanol-to-butadiene conversion proceeds via several reaction steps, which are catalyzed on Lewis acidic and/or basic sites, increasing the efficiency of a reaction step in the main reaction path would also increase side reaction paths of other reaction steps. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Chinese Institute of Food Science & Technology / Zhongguo Shipin Xuebao is the property of Journal of Chinese Institute of Food Science & Technology Periodical Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Carbonyl concentrations in indoor-outdoor air were measured at three urban sites in the Metropolitan Zone of Mexico Valley (MZMV) during the first period of confinements due to COVID-19; the exposure for people living in indoor environments was also assessed. Indoor and outdoor samples were simultaneously collected sequentially with Sep-Pack DNPH-Silica cartridges. Formaldehyde, acetaldehyde, acetone, propionaldehyde, butyraldehyde and acrolein were quantified according to the US-EPA TO-11A method. Acrolein and acetone were the most abundant carbonyls in indoor air, with average concentrations of 55.5 µg m−3 and 46.4 µg m−3, respectively, followed by formaldehyde (29.1 µg m−3), acetaldehyde (21.4 µg m−3) and butyraldehyde (7.31 µg m−3). Propionaldehyde was not detected. Acetone was the dominant carbonyl in outdoor samples with an average concentration of 8.4 µg m−3, followed by formaldehyde (2.8 µg m−3) and acetaldehyde (0.7 µg m−3). Butyraldehyde and acrolein were not detected in outdoor air. Indoor/outdoor (I/O) ratios showed that indoor sources prevail for most aldehydes. Statistical analysis of simple correlations showed that the measured carbonyls were influenced by the presence of indoor sources. The average cancer risk coefficients (LTCR) for formaldehyde and acetaldehyde and the non-cancer risk coefficients (HQ) for acrolein and formaldehyde were higher than the recommended limits, which should be a cause for public concern. [ABSTRACT FROM AUTHOR]

In this study, a hydroxyl radical oxidation system was established to simulate the oxidation process in fermented meat products. This system was employed to examine the structural changes in myofibrillar proteins (MPs) resulting from tryptic hydrolysis after a hydroxyl radical oxidative regime. The effect of these changes on the ability of MPs to bind selected aldehydes (3-methyl butanal, pentanal, hexanal, and heptanal) was also investigated. Moderate oxidation (H 2 O 2 ≤ 1.0 mM) unfolded the structure of MPs, facilitating trypsin-mediated hydrolysis and increasing their binding capacity for the four selected aldehydes. However, excessive oxidation (H 2 O 2 ≥ 2.5 mM) led to cross-linking and aggregation of MPs, inhibiting trypsin-mediated hydrolysis. The oxidised MPs had the best binding capacity for heptanal. The interaction of the oxidised trypsin-hydrolysed MPs with heptanal was driven by hydrophobic interactions. The binding of heptanal affected the structure of the oxidised trypsin-hydrolysed MPs and reduced their α-helix content. • Moderate oxidation unfolds MPs structures, promoting trypsin hydrolysis. • Excessive oxidation cross-links and aggregates MPs, inhibiting trypsin hydrolysis. • Oxidised MPs had the best binding capacity for heptanal. • Trypsin hydrolysis increased the binding of oxidised MPs to aldehydes. • Binding of heptanal alters the structure of oxidised trypsin-hydrolysed MPs. [ABSTRACT FROM AUTHOR]

Hydroformylation reactions promoted by Rh single-atom catalysts typically exhibit a negative reaction order for CO and a positive reaction order for H 2 and alkenes. To enhance the catalytic activity, efforts have been concentrated on reducing the CO adsorption strength and/or enhancing the hydrogenation capacity at Rh sites. This report introduces an optimized Rh single-atom catalyst, utilizing positively charged Mn species to weaken the CO adsorption strength. Our strategy involves placing MnOx clusters in the proximity to the Rh single atom. This arrangement allows the reduction of Rh3+ to produce electronically deficient Rhδ+ species (1 < δ < 2), rather than the usual formation of the lower valence state Rh+ species. The weakened CO adsorption strength on the more positively charged Rhδ+ results in reduced CO coverage on the Rh active site, and enhanced adsorption of propylene. Our mechanistic study reveals that H 2 and CO adsorption on Rh catalyzes the reduction of adjacent Mn(IV) species, inducing the formation of a Rh-MnOx paired active site. The neighboring MnOx clusters hinder the extensive reduction of Rh3+ to Rh+. This study presents MnOx as an inorganic ligand in Rh-MnOx pair site modifies the electronic properties of Rh sites to modulate the hydroformylation activity of Rh single-atom catalysts. [Display omitted] • H 2 and CO on Rh catalyzes the reduction of adjacent Mn(IV) to form Rh-MnOx pair site. • The neighboring MnOx hinder the reduction of Rh3+ to Rh+, forming Rhδ+ (1 < δ < 2). • Rhδ+ shows weakened CO adsorption strength than Rh+ species • Weakened CO adsorption strength on Rhδ+ benefits high hydroformylation activity. [ABSTRACT FROM AUTHOR]

Simple Summary: The stick tea thrip Dendrothrips minowai is a key pest in tea plantations in China. In recent years, plant-derived semiochemicals have attracted considerable attention as promising attractants for the management of thrips, due to their safety and low cost. In this study, compounds that have been reported to attract other thrips or emitted from tea plants were evaluated for their electroantennogram (EAG), behavioral tests and field trapping efficacy for D. minowai. The EAG relative response value of D. minowai evoked by p-anisaldehyde, 3-methyl butanal, (E)-β-ocimene, farnesene, nonanal, eugenol, (+)-α-pinene, limonene, (−)-α-pinene, and γ-terpinene was significantly higher than the other compounds. Meanwhile, p-anisaldehyde, eugenol, farnesene, methyl benzoate, 3-methyl butanal, (E)-β-ocimene, (−)-α-pinene, (+)-α-pinene, and γ-terpinene led to attraction or repellency responses of female D. minowai. In addition, trap capture numbers of female D. minowai on sticky traps baited with p-anisaldehyde, eugenol, farnesene, and 3-methyl butanal were significantly higher than the control in tea plantations. Overall, our results highlight the potential application of plant volatiles in the development of effective, eco-friendly lure formulations for use in the monitoring and management of thrips. The stick tea thrip (Dendrothrips minowai Priesner) is the main pest thrip in tea (Camellia sinensis) plantations in China, and seriously affects the quality and yield of tea. Plant-derived semiochemicals provide an alternative to pheromones as lures and these compounds possess powerful attractiveness. In this study, we selected 20 non-pheromone semiochemicals, including compounds that have been reported to attract other thrips and some volatiles emitted from tea plants as the potential attractant components for D. minowai. In electroantennogram (EAG) assays, 10 synthetic compounds (p-anisaldehyde, 3-methyl butanal, (E)-β-ocimene, farnesene, nonanal, eugenol, (+)-α-pinene, limonene, (−)-α-pinene, and γ-terpinene) elicited significant antennal responses in female D. minowai. In addition, a two-choice H-tube olfactometer bioassay showed that D. minowai displayed significant positive responses to eight compound dilutions (p-anisaldehyde, eugenol, farnesene, methyl benzoate, 3-methyl butanal, (E)-β-ocimene, (−)-α-pinene, and (+)-α-pinene) when compared with the solvent control at both 1 and 2 h. Moreover, γ-terpinene exhibited a significantly deterrent effect on D. minowai. Finally, trap catches of four compounds (p-anisaldehyde, eugenol, farnesene, and 3-methyl butanal, respectively) significantly increase in tea plantations. Among these, the maximum number of D. minowai collected by blue sticky traps baited with p-anisaldehyde was 7.7 times higher than the control. In conclusion, p-anisaldehyde, eugenol, farnesene, and 3-methyl butanal could significantly attract D. minowai in the laboratory and under field conditions, suggesting considerable potential as commercial attractants to control D. minowai populations. [ABSTRACT FROM AUTHOR]

A process technology is developed to recover the effective components in off-gas from the reactive system of hydroformylation of propylene. Methods This technology uses the process route of "dealdehyde-cryogenic separation-stabilization-distillation", i. e., firstly removing the heavy components such as butyraldehyde by distillation column and condensing the components above C3 into liquid by ammonia circulating cryogenic process, and then removing butyraldehyde, trace moisture and non-condensable gas by the stable system, and finally obtaining propylene and propane products by distillation process. Results After the commercial application of this technology, the design capacity of the off-gas effective components recovery unit is 17.72 X 10³ t/ a. The total recovery of propylene, propane and butyraldehyde is 14.28 X 10³ t/a on the basis of operation time of 8 400 hours per year, and their purities are all greater than or equal to 97.00wt%, their yields all exceed 95.0 % . Conclusions The actual values are better than the design ones after calibration. Compared with other units, this unit has the advantages of low energy consumption, no auxiliary material consumption, high yield and purity of products. [ABSTRACT FROM AUTHOR]

Indoor air concentrations of formaldehyde, furfural, benzaldehyde, and 11 aliphatic aldehydes (C2‐C11) were measured in residences of 639 participants in the German Environmental Survey for Children and Adolescents 2014–2017 (GerES V). Sampling was conducted using passive samplers over periods of approximately seven days for each participant. The most abundant compounds were formaldehyde and hexanal with median concentrations of 24.9 µg m−3 and 10.9 µg m−3, respectively. Formaldehyde concentrations exceeded the Guide Value I recommended by the German Committee on Indoor Guide Values (Ausschuss für Innenraumrichtwerte ‐ AIR) (0.10 mg m−3) for 0.3% of the participating residences. The sum of aliphatic n‐aldehydes between C4 (butanal) and C11 (undecanal) exceeded their Guide Value (0.10 mg m−3) for 2.0% of the residences. The geometric mean concentrations of most aldehydes were lower than in the earlier GerES IV (2003–2006) study. Formaldehyde and hexanal concentrations, however, were comparable in both studies and showed no significant difference. Indoor aldehyde concentrations did not exhibit significant correlations with factors collected in questionnaires, such as the age of the participants, their socio‐economic status, the location of the residence (former East/West Germany), migration background, tobacco exposure, and the type of furniture used. The validity of the passive sampler measurements was verified against active sampling techniques in a test chamber experiment. [ABSTRACT FROM AUTHOR]

The potential harms and benefits of e-cigarettes, or electronic nicotine delivery systems (ENDS), have received significant attention from public health and regulatory communities. Such products may provide a reduced risk means of nicotine delivery for combustible cigarette smokers while being inappropriately appealing to nicotine naive youth. Numerous authors have examined the chemical complexity of aerosols from various open- and closed-system ENDS. This body of literature is reviewed here, with the risks of ENDS aerosol exposure among users evaluated with a margin of exposure (MoE) approach for two non-carcinogens (methylglyoxal, butyraldehyde) and a cancer risk analysis for the carcinogen N-nitrosonornicotine (NNN). We identified 96 relevant papers, including 17, 13, and 5 reporting data for methylglyoxal, butyraldehyde, and NNN, respectively. Using low-end (minimum aerosol concentration, low ENDS use) and high-end (maximum aerosol concentration, high ENDS use) assumptions, estimated doses for methylglyoxal (1.78 × 10 -3 -135 μg/kg-bw/day) and butyraldehyde (1.9 × 10 -4 -66.54 μg/kg-bw/day) corresponded to MoEs of 227-17,200,000 and 271-280,000,000, respectively, using identified points of departure (PoDs). Doses of 9.90 × 10 -6 -1.99 × 10 -4  μg/kg-bw/day NNN corresponded to 1.4-28 surplus cancers per 100,000 ENDS users, relative to a NNN-attributable surplus of 7440 per 100,000 cigarette smokers. It was concluded that methylglyoxal and butyraldehyde in ENDS aerosols, while not innocuous, did not present a significant risk of irritant effects among ENDS users. The carcinogenic risks of NNN in ENDS aerosols were reduced, but not eliminated, relative to concentrations reported in combustible cigarette smoke., (© 2024 John Wiley & Sons Ltd.)

BACKGROUND: The reaction integration of butanal self‐condensation and successive hydrogenation (that is, one‐step synthesis of 2‐ethylhexanol from butanal) is an efficiency way to simply process flow and reduce energy consumption for the commercial manufacture of 2‐ethylhexanol (2EHO). In the present work, a NiO‐MnO2/Nb2O5‐TiO2 catalyst was prepared for the integration reaction to reach a high 2‐ethylhexanol selectivity. Furthermore, the reaction integration was investigated kinetically for the next scale‐up. RESULTS: A 2EHO selectivity of 90.0% was achieved at a complete conversion of butanal with the help of reduction‐in‐reaction technique in this reaction integration. The reaction rate of butanal is determined by the reversible aldol self‐condensation reaction and its direct hydrogenation reaction. The reaction order with respect to butanal in the two reactions is, respectively, 2.004 and 1.004. The activation energy of the hydrogenation reaction is higher than that of the forward reaction of the self‐condensation, suggesting the suppressive effect the reaction integration on the direct hydrogenation. CONCLUSION: The reaction integration promotes butanal self‐condensation and successive hydrogenation and it suppresses butanal direct hydrogenation by using NiO‐MnO2/Nb2O5‐TiO2 catalyst with the help of reduction‐in‐reaction technique, giving rise to a pretty high selectivity of 2‐ethylhexanol. The establishment of the integration reaction kinetics will lay the foundation for reactor design and analysis. © 2021 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

• Butanal-H 2 reaction proceeds through hydrogenation and decarbonylation routes. • Co-feed CO eliminates interference on kinetic measurement from decarbonylation. • Alkoxy and Hydroxy pathways show different kinetic and isotopic behaviors. • Water shows reversible promotional effects on vapor phase hydrogenation turnover. • Water promotes O H formation rates but has no obvious effect on C H formation step. Kinetic assessments, Fourier-transform infrared spectroscopy, and H/D kinetic and isotopic exchange studies establish the sequence of H-addition steps and reveal how water induces a shift in their kinetic relevance during butanal hydrogenation on Ru/SiO 2. Without water, hydrogenation turnovers are slower than the H/D exchange rates at the carbonyl carbon and increase linearly with butanal and H 2 pressures. Thus, hydrogenation occurs via quasi-equilibrated H-addition to the carbonyl carbon, which forms an alkoxy intermediate, before the second, kinetically relevant H-addition to the oxygen. Water vapor does not alter C H formation rates but promotes the O H formation rates by stabilizing the transition state through hydrogen bonds, making the first H-addition that forms the C H bond kinetically relevant, thus decreasing the apparent order to H 2. This study provides the mechanistic context behind the water promotional effects during butanal hydrogenation, as the chemical potential of water increases and hydrogen bonding prevails and mediates catalysis. [ABSTRACT FROM AUTHOR]

The thermal decomposition of gas-phase butyraldehyde, CH3CH2CH2CHO, was studied in the 1300-1600 K range with a hyperthermal nozzle. Products were identified via matrix-isolation Fourier transform infrared spectroscopy and photoionization mass spectrometry in separate experiments. There are at least six major initial reactions contributing to the decomposition of butyraldehyde: a radical decomposition channel leading to propyl radical + CO + H; molecular elimination to form H2 + ethylketene; a keto-enol tautomerism followed by elimination of H2O producing 1-butyne; an intramolecular hydrogen shift and elimination producing vinyl alcohol and ethylene, a β-C-C bond scission yielding ethyl and vinoxy radicals; and a γ-C-C bond scission yielding methyl and CH2CH2CHO radicals. The first three reactions are analogous to those observed in the thermal decomposition of acetaldehyde, but the latter three reactions are made possible by the longer alkyl chain structure of butyraldehyde. The products identified following thermal decomposition of butyraldehyde are CO, HCO, CH3CH2CH2, CH3CH2CH=C=O, H2O, CH3CH2C≡CH, CH2CH2, CH2=CHOH, CH2CHO, CH3, HC≡CH, CH2CCH, CH3C≡CH, CH3CH=CH2, H2C=C=O, CH3CH2CH3, CH2=CHCHO, C4H2, C4H4, and C4H8. The first ten products listed are direct products of the six reactions listed above. The remaining products can be attributed to further decomposition reactions or bimolecular reactions in the nozzle. [ABSTRACT FROM AUTHOR]

Auricularia auricula is a kind of nutrient-rich edible fungus, which has the reputation of "king of vegetarians." In this paper, the electronic nose combined with GC-MS technology was used to analyze the volatile components of A. auricula in Heilongjiang, Jilin, Shanghai, and Sichuan provinces to investigate the differences and characteristics of A. auricula in different origins. The results showed that the electronic nose could obviously distinguish the samples from Jilin and Shanghai with a high degree of discrimination, while it was inappropriate to distinguish the samples from Heilongjiang and Sichuan Province. GC-MS was used to further analyze the volatile compounds in A. auricula qualitatively and quantitatively. The results showed that 98 volatile components were detected and 23 of them were common components, including alcohols, aldehydes, acids, esters, hydrocarbons, and other volatile components. The relative content of acetic acid and diethyl azodicarboxylate in A. auricula from the four origins was relatively high. According to the relative odor activity value (ROAV), it was found that the key compounds that caused the aroma difference between different origins were 1-octene-3-ol, cis-3-nonene-1-ol, (E)-2-octenal, (E)-2-nonenal, (E,E)-2,4-nonadienal, and 3-methyl butanal. [ABSTRACT FROM AUTHOR]

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

• K^Rh clusters are confined in situ within silicate-1 zeolites. • K species build a steric hindrance microenvironment on the surfaces of Rh clusters. • K species decrease acidic sites to inhibit the isomerization of long-chain olefins. • The regioselectivity to linear butyraldehyde is enhanced from 46% to 83%. • Zeolite confinement can stabilize the K x ^Rh structure to obtain a long lifetime. Regioselectivity is a key point in hydroformylation reactions and its control is still a challenge in heterogeneous catalysis. Here, we demonstrate that regioselectivity in heterogeneous hydroformylation can be steered by a surface microenvironment around Rh clusters, which are surrounded by K species and confined within silicate-1 zeolites. The K species create a steric hindrance microenvironment on the surfaces of Rh clusters and tune the electronic properties of Rh species, mimicking the Rh–phosphine molecular complex. This microenvironment benefits the linear adsorption of olefins, realizing 83% regioselectivity to linear butyraldehyde with TOF as high as 7328 h−1 in propylene hydroformylation. Other K species which reduce acidic sites can also inhibit the isomerization of long-chain olefins, thus boosting regioselectivity. The confinement structure can stabilize the K x ^Rh clusters to enhance the catalyst lifetime. This work provides an alternative route for developing selective heterogeneous catalysts through steering the catalyst surface microenvironment. [ABSTRACT FROM AUTHOR]

Butanal conversion has been studied over Zr‐BEA zeolites with different amount of partially hydrolyzed open Zr‐sites and fully condensed closed sites. The kinetic study pointed that the main reaction pathway of butanal conversion involves its self‐condensation into 2‐ethyl‐2‐hexenal (2‐EN), the selectivity to 2‐EN being within 80–85 %. Besides, small amounts of 1‐butanol and butanoic acid are formed via Cannizzaro disproportionation of butanal. Secondary reactions include butanoic acid ketonization to 4‐heptanone and esterification to butyl butanoate and tandem hydrogenation/dehydration of 2‐EN into octadienes. A number of techniques, including FTIR spectroscopy of adsorbed CO, pyridine, 2,6‐di‐tert‐butylpyridine (DTBPy), TPD of isopropylamine and selective poisoning with DTBPy were applied for characterization of Zr‐sites and elucidation of their activity. Open Zr‐sites were found to be more active with respect to closed Zr‐sites in butanal condensation: the TOF values estimated at 433 K being 1.4 s−1 for open Zr‐sites and 0.6 s−1 for closed sites. On the contrary, selectivity into 2‐EN was similar for open and closed sites. The results point that Zr‐BEA catalysts with enhanced content of open sites are perspective catalysts for the selective synthesis of 2‐EN. [ABSTRACT FROM AUTHOR]

The trade-off between gas permeance and filtration accuracy in SiC ceramic membranes has constrained their utilization in gas/solid filtration. Herein, a polyvinyl butyraldehyde (PVB) solution was introduced as a prefilling layer to impede membrane particles from penetrating the macroporous SiC support (average pore size: 23 μm). The PVB layer could be removed postsintering, thereby producing a ceramic membrane devoid of any intermediate layer, which showed great potential in enhancing the gas permeance. Initially, the PVB concentration was optimized to ensure membrane integrity and strong adhesion between the support and separation layer. Thereafter, suitable dispersants and drying conditions were investigated in detail. The resultant asymmetric SiC membranes fabricated under these optimized conditions had a thickness ranging between 50 and 60 μm. These membranes demonstrated exceptional gas permeance, varying from 71.1 to 178.1 m3 m−2 h−1 kPa−1 by tuning the membrane pore size from 1.02 to 3.03 μm. Additionally, the membranes achieved 99.94 % dust rejection for particles approximately 0.3 μm in size. When compared to traditional ceramic membranes with several intermediate layers, the prefilling approach employed herein circumvents the ceramic intermediate layer. This method resolves the mismatch between particle sizes of the ceramic support and the membrane layer, offering an effective strategy for developing high-permeance SiC membranes suited for gas/solid filtration applications. [Display omitted] • SiC membranes without the middle layer were produced by using prefilling method. • The prefilling layer prevented the particle penetration completely. • The membranes exhibited great gas permeance compared with the literature. • The membranes showed above 99.94 % rejection towards PM 0.3 nanoparticles. [ABSTRACT FROM AUTHOR]

[Display omitted] • Xantphos coordination enhances steric hindrance at Rh active sites. • Improved regioselectivity for butyraldehyde (n/i ratio equal to 13) achieved. • Propylene adsorption configuration shifts from hybrid modes to the terminal mode. • Electron-rich Rh sites with P/Rh ratio of 3 benefits activity. Single-atom Rh catalysts have been reported to exhibit high activity in olefin hydroformylation, yet with limited regioselectivity. We develop a Xantphos ligand coordinated single-atom Rh/CeO 2 catalyst, which exhibits improved regioselectivity for butyraldehyde (n/i ratio equal to 13) while maintaining good activity (TOF = 476 h−1) in hydroformylation of propylene. The unique coordination environment created by Xantphos enhances steric hindrance at Rh active sites, thereby improving its regioselectivity for n-butyraldehyde. That is, two P atoms from a Xantphos ligand bind directly to Rh, while a P atom from another Xantphos attaches to an oxygen vacancy on CeO 2 near Rh, achieving a P-Rh coordination number of 3. This unique structure shifts the propylene adsorption configuration from hybrid modes to the terminal mode, favoring n-butyraldehyde formation. The creation of electron-rich Rh sites with P/Rh ratio of 3 benefits the formation of Rh-H species for the rate-determining step, thus showing commendable activity. [ABSTRACT FROM AUTHOR]

Cordyceps Sinensis, renowned for its diverse pharmacological properties and the rarity of its natural species, faces significant challenges due to rampant adulteration by counterfeit products. Consequently, there is a crucial need to reliably identify Cordyceps species to ensure their quality and efficacy. While current analytical techniques predominantly rely on LC–MS, there remains a notable deficiency and substantial demand for the development of a unified, reproducible, and fast method suitable for commercial applications. In this study, we employed a cost-effective and straightforward approach utilizing headspace GC–MS to authenticate Cordyceps sinensis. This method enables the comprehensive analysis of the chemical profile, facilitating the identification of quality and authenticity in Cordyceps samples. Through a comparative analysis of the chemical profiles of seven authentic Cordyceps samples with seven other Cordyceps samples, we propose a Quality Assessment System for Authentic Cordyceps, encompassing the following criteria: 1) the presence of 29 compounds commonly found in authentic Cordyceps within the chemical profile, and 2) the area ratio of 3-methylbutanal to 2-methylbutanal falling within the range of 2.09–3.01. This method exhibits considerable promise as a standardized, reproducible, and expeditious technique for the quality assessment and authentication of Cordyceps. ● An authenticate assessment method for cordyceps sinensis was proposed. ● chemical profiling were investigated by headspace GC–MS analyses. ● Total 176 compounds were being identified. ● 29 compounds commonly found in authentic Cordyceps. ● The area ratio of 3-methyl butanal and 2-methyl butanal were identified as marker. [ABSTRACT FROM AUTHOR]

[Display omitted] • Hydrogenation of butanal on H-precovered Pd(111) proceeds via keto-enol tautomerization in the first step at cryogenic temperatures. • Enol form of butanal can be efficiently produces and stabilized via hydrogen bonding to co-adsorbates at cryogenic temperatures. • Strong correlation between the abundance of the enol species and hydrogenated product of butanal. • Strong reduction of the overall activation barrier for hydrogenation of the carbonyl group on H-containing Pd(111) via a two-step process: keto-enol tautomerization followed by hydrogenation of the C=C bond. Hydrogenation of carbonyl-containing compounds to alcohols is a crucial step in various technological processes, including reversible green hydrogen storage. Activation of the highly stable C=O bond, however, is highly challenging and typically proceeds under harsh reaction conditions. Recent theoretical predictions on low-barrier hydrogenation pathway of carbonyl compounds suggest that this step proceeding over a high activation barrier can be overcome in an alternative low barrier process, which comprises two steps: keto-enol tautomerization followed by hydrogenation of the C=C bond in the newly formed enol. The major challenge of this predicted pathway is the low stability of enol species, which would readily convert to ketone if not intentionally stabilized. In this study, we performed atomistic-level investigation on keto-enol tautomerization and low-temperature hydrogenation of butanal over well-defined Pd(111) model catalyst by combination of surface sensitive infrared reflection absorption spectroscopy (IRAS) and molecular beam techniques. Specifically we show that different types of enol species can be formed on the H-containing Pd(111) surface, whose appearance and abundance strongly dependent on the surface temperature. Importantly, the evolution of the partly hydrogenated product of butanal – C-butoxy species attached to Pd via C atom – was detected already at cryogenic temperatures, which points to a possibility of low temperature hydrogenation. A very clear correlation between the abundance of the enol species and the C-butoxy hydrogenated product was detected: the growing concentration of enol species was found to result in the formation of the C-butoxy product. In contrast, strong decrease in the abundance of enol adsorbates lead to full vanishing of the hydrogenation product C-butoxy. With this, we experimentally show a strong link between the population of the enol species and hydrogenation of butanal at cryogenic temperatures. Finally, we discuss the chemical nature of different enol species, which appear to be stabilized on the surface in different ways via hydrogen bonding, and propose the reaction mechanisms of low-barrier butanal hydrogenation that are consistent with all experimental observations. Obtained atomistic-level insights in low-barrier hydrogenation of carbonyl compounds provide important information on the elementary reaction steps of this potentially highly promising class of reactions for green hydrogen storage. Related phenomena can be employed for controlling keto-enol tautomerization and enol stabilization via mutual lateral interactions on functionalized catalytic surfaces for the broad range of aldehydes and ketones to enable their low-barrier hydrogenation. [ABSTRACT FROM AUTHOR]

We conducted a two-year inhalation study of butyraldehyde using F344/DuCrlCrlj rats. The rats were exposed to 0, 300, 1,000 and 3,000 ppm (v/v) for 6 hr/day, 5 days/ week for 104 weeks using whole-body inhalation chambers. The incidence of squamous cell carcinoma of the nasal cavity was increased in the 3,000 ppm groups of both male and female rats, with Fisher's exact test and the Peto test indicating that the incidence was significant. In addition to squamous cell carcinoma in the nasal cavity, in the 3,000 ppm groups one male had an adenosquamous carcinoma, one male had a carcinosarcoma, one male had a sarcoma NOS (Not Otherwise Specified), and one female had a squamous cell papilloma in the nasal cavity. The combined incidence of squamous cell carcinoma, adenosquamous carcinoma and carcinosarcoma was significantly increased in male rats and the combined incidence of squamous cell papilloma and carcinoma was significantly increased in female. Based on these results, we conclude that there is clear evidence of butyraldehyde carcinogenicity in male and female rats.

Copyright of China Brewing is the property of China Brewing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Highlights • The optimal condition of roasted sweet potato was determined by RSM. • 38 kinds of volatile compounds in roasted sweet potato were determined by GC–MS. • 2-Methyl butanal was the main aromatic compound in roasted sweet potato. • Low-field NMR showed that the proportion of free water increased after roast process. • The total phenolic content and antioxidant activity increased after roast process. Abstract The study evaluated the optimal condition for roasting sweet potato using response surface methodology. Proximate composition, antioxidant activity, volatile compounds, and water migration of roasted sweet potato were also determined. The results revealed that the optimal roasting condition included a roasting time of 40 min, a roasting temperature of 235 °C, and a roasting speed of 40 rad/min, the reducing sugar and vitamin C of roasted sweet potato obtained under optimal condition was 47.79 g/100 g (DW) and 60.25 mg/100 g (DW), respectively. After roasting, starch, protein and vitamin C content of sweet potato were significantly decreased, while total phenolic content and antioxidant activity were increased. 2-Methyl butanal was the main aromatic compound. Low-field NMR indicated that the proportion of free water increased and relaxation times (T 2) were decreased after roast process, indicated that the bound water in sweet potato was diffused from inside to outside, thus the texture became softer. [ABSTRACT FROM AUTHOR]

Abstract Due to liquid electrolyte limitation in dye sensitized solar cells (DSSCs), GPEs were prepared and optimized. Poly(vinyl butyral-co-vinyl alcohol-co-vinyl acetate), P(VB-co-VA-co-VAc) acted as host polymer and tetrapropylammonium iodide, TPAI as dopant salt. The prepared gel polymer electrolytes (GPEs) with different TPAI salt content were characterized using electrochemical impedance spectroscopy, Fourier transform infrared spectroscopy and X ray diffractogram. An optimum ionic conductivity of 1.93 mS cm−1 was obtained with 40 wt% of TPAI salt added along with the lowest activation energy of 0.064 eV. Temperature dependence ionic conductivity behaviour of GPEs were studied and found that the systems obeyed the Arrhenius behaviour in the temperature range of 303–373 K. The dielectric results studies showed typical behaviour of both ε ′ and ε ′ ′ inversely proportional to frequency and directly proportional to temperature. Structural studies of GPEs were performed using XRD and FTIR and confirmed the existence of complexation of P(VB-co-VA-co-VAc) and TPAI salt. GPEs were used to assemble dye sensitized solar cells (DSSCs). The power conversion efficiency of 4.615% achieved with a maximum short circuit current density (J sc) of 13.585 mA cm−2, open circuit voltage (V oc) of 0.678 V and fill factor of 50.1% at 40 wt% TPAI salt under A.M 1.5 (100 mW cm−2) illumination. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • C 4 H 8 O removal using (UV-TiO 2 /plasma) + catalytic-bed system is studied. • Specific catalysts are tested for C 4 H 8 O/O 3 removal at pilot scale. • Impacts of operating parameters on process performance are defined. • Highly efficient synergetic association was obtained. • Better performance in mineralization rate via ozone valorization. Abstract This study focuses on Butyraldehyde (C 4 H 8 O) degradation using catalytic ozonation oriented to the optimization of non-thermal plasma/photocatalytic coupled processes. After the first oxidation by non-thermal plasma coupled photocatalytic processes, a second oxidative step leading to the decomposition of the residual Butyraldehyde by Ozone is catalyzed by Mordenite, ZSM-5 and γ-alumina. The Butyraldehyde degradation in the presence of Ozone under operational parameters such as plasma energy, Butyraldehyde inlet concentration, relative humidity and the height of the catalytic bed are reported in detail. The optimum operating conditions found were: Q air = 1 m3 h-1, [C 4 H 8 O] = 100 mg m-3, SIE plasma = 18 JL-1, for Butyraldehyde degradation mediated by ZSM-5. The formation of intermediate by-products was monitored during the degradation of Butyraldehyde in the presence of Ozone and ZSM-5 catalyst to suggest a degradation pathway. The coupling of catalytic ozonation by non-thermal plasma/photocatalysis lead to the total decomposition of Ozone when catalyzed by ZSM-5and presents a positive effect on the mineralization capacity. The pollutants degradation intermediates were identified by GC-MS and the oxidative states on the catalytic bed were characterized by XPS. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • SiO 2 with weak acidity exhibited stable catalytic activity in the aldol condensation of butanal. • Both large pore size and large surface area of SiO 2 efficiently promoted the catalytic activity. • 2-Ethyl-2-hexenal selectivity of 90% with 48.3% conversion was obtaiend over SiO 2 at 240 °C. • Silanol groups on SiO 2 surface were suggested to be the active sites for the reaction. Abstract Vapor-phase aldol condensation of butanal to form 2-ethyl-2-hexenal was carried out over several oxide catalysts such as SiO 2 -Al 2 O 3 , Al 2 O 3 , ZrO 2 , and SiO 2. Catalysts with moderate and strong acid sites such as Al 2 O 3 and SiO 2 -Al 2 O 3 were active for the reaction in the initial period, whereas they deactivated rapidly. In contrast, SiO 2 with weak acidity showed a low but a stable catalytic activity for the formation of 2-ethyl-2-hexenal. Thermogravimetric analyses of the samples used after the reactions indicate that SiO 2 has the smallest amount of carbonaceous species that contributed to its stable activity among the tested catalysts. SiO 2 catalysts with different pore sizes and specific surface areas were examined: SiO 2 with a mean pore diameter of 10 nm and a surface area of 295 m2 g−1 showed the best catalytic performance and gave a 2-ethyl-2-hexenal selectivity of 90% at a conversion of 48% at 240 °C. In the catalytic test using deuterated SiO 2 , which was prepared by contacting SiO 2 with deuterated water before the reaction, it was confirmed by a mass spectrometer that the deuterium atom of SiOD was transferred to a 2-ethyl-2-hexenal molecule during the reaction. It is indicated that silanol groups on the SiO 2 surface played a role as an active site. [ABSTRACT FROM AUTHOR]

Objective: This study was performed to compare fat content, reducing sugar contents, sensory traits, and fatty acid (FA) and volatile compound profiles in longissimus thoracis (LT) among Korean cattle (KC), Holstein (HO), and Angus (AN) steers. Methods: Twelve LT samples (about 500 g each) of KC with an average age of 31±0.42 months, an average carcass weight of 431±12.5 kg, and a quality grade (QG) of 1+ were obtained from the joint livestock products market. Twelve LT samples of HO cattle with an average age of 24±0.54 months, an average carcass weight of 402±7.81 kg, and a QG of 2 were also obtained from the same market. Twelve LT samples of AN steers with an average age of about 20 months and a QG of choice were purchased from a beef delivery company. After slaughter, samples were kept at 4°C for 42 days and prepared for immediate analysis or stored at appropriate conditions. The chemical composition, color, pH, shear force, collagen content, reducing sugars, sensory evaluation, FA composition, and volatile compound content for each LT sample were analyzed. Results: The LT of KC had the highest (p<0.05) fat content, the highest reducing sugar content, and the highest scores in the sensory evaluation (flavor, tenderness, juiciness, and overall acceptance). All the sensory traits were positively correlated (p<0.001) with intramuscular fat and reducing sugar content. Several FAs and volatile compound profiles varied among the breeds. KC LT had the highest (p<0.05) concentrations of acetaldehyde, 3-methyl butanal, and 3-hydroxy-2-butanone, and these volatile compounds were positively correlated (p<0.05) with all the sensory traits. Conclusion: Variations in fat content and reducing sugar contents and FA and volatile compound profiles may contribute to differences in the sensory quality of LT among breeds. [ABSTRACT FROM AUTHOR]

Highlights • 2-Methyl-4-phenylbutyraldehyde, safety assessment based on RIFM's criteria. • Safety assessment based on 7 human health endpoints plus environmental. • All endpoints were cleared using target data, read-across, and/or TTC. [ABSTRACT FROM AUTHOR]

Residential indoor exposure to volatile organic compounds (VOCs) is a major public health concern. However, the relevant pollution sources have not been well characterized in China. In this study, the 24-h integrated concentrations of 55 VOC species in 27 urban residences, Beijing were measured in the summer. The sources were characterized with positive matrix factorization (PMF) and general linear model (GLM). The most abundant species in terms of geometric mean concentration were formaldehyde (55.1 μg/m 3 ), acetaldehyde (18.7 μg/m 3 ), acetone (14.8 μg/m 3 ), toluene (14.1 μg/m 3 ), hexanal (13.8 μg/m 3 ), n -hexadecane (8.9 μg/m 3 ) and n -pentadecane (8.5 μg/m 3 ). PMF generated 7 factors associated with VOC sources, including aldehydes from ozone-initiated secondary reactions, butyraldehyde from hydrolysis of building materials and furniture, wood flooring emission, wooden furniture emission, wall coverings emission, mobile emission and halogenated hydrocarbons of miscellaneous outdoor origin. GLM identified leather sofa as another source of indoor terpenes and formaldehyde. GLM also found composite wood flooring had stronger emission of VOCs than solid wood flooring, except 1,4-dichlorobenzene. A comparison with multiple studies across the world suggested that: (1) more intensive ozone-initiated secondary reactions resulted in the significantly higher indoor carbonyl concentrations in Beijing than in Japan and USA in the summer; (2) the indoor concentrations of benzene and C 12 -C 17 alkanes were much higher in Beijing, due to the traffic conditions and prevalent use of wood flooring varnishing. [ABSTRACT FROM AUTHOR]

Dielectric barrier discharge DBD-plasma based technologies have been widely investigated for the abatement of air pollutants. More recently, photocatalysis (TiO 2 /UV-lamp) has also showed promising results for air pollution abatement. In this work, these two methods were used separately and combined (TiO 2 /UV-lamp/DBD-plasma) in order to enhance the performance of the process for air pollutants degradation/mineralization. Ammonia (NH 3 ) and butyraldehyde (C 4 H 8 O) have been firstly treated alone and then an equimolar mixture (NH 3 /C 4 H 8 O) was monitored in a continuous reactor. Effect of operational parameters such as pollutants inlet concentration, flowrate, humidity and specific energy of plasma were thoroughly determined. Results showed that coupling both methods in the same reactor improves removal efficiency for single pollutant or a mixture of two pollutants. This processes combination showed a synergy between DBD-plasma and photocatalytic oxidation. Moreover, pollutant mineralization and potential intermediate byproducts have been characterized and discussed. Coupling both processes contributes to enhanced mineralization in comparison with DBD-plasma alone regarding the CO 2 selectivity. As for selectivity of byproducts: (i) Relative Humidity (RH), (ii) mixture effect and (iii) (TiO 2 /UV-lamp/DBD-plasma) combined processes inhibit ozone production during the pollutants removal/oxidation. [ABSTRACT FROM AUTHOR]