Volatile Alcohols Research Articles

Elucidation of Volatile and Morphological Properties of Saffron (Crocus sativus) Flower as Affected by Controlled Drought Stress Induced by Polyethylene Glycol

ABSTRACTCrocus sativus L., known as saffron, is one of the major crops among ornamental and medicinal aromatic plants. Polyethylene glycol (PEG) 6000 is one of the well‐known and efficient simulators used for this purpose. In this study, saffron corms were cultivated in pots containing perlite, and the PEG 6000 solution was applied at 5%, 10% and 15% concentrations. A HS‐SPME‐GC–MS system was used to elucidate volatiles of saffron flowers, and a total of 28 volatiles was detected. Safranal was measured as the most dominant volatile compound in saffron flowers, and the release of marker volatiles was dramatically increased with the increasing PEG 6000 dosage. Eucarvone was found to be an important ketone compound, Phenethyl alcohol was found to be the most abundant volatile alcohol compound. Additionally, ketones pyrrole, lactone, esters and other sulphurous components increased with PEG 6000 application. According to the morphological observations, decreases were observed in plant dry weight (PDW), plant fresh weight (PFW), corm diameter (CD), daughter corm (DCN), and flower number (FN), between the control plants and those treated with PEG 6000. However, an increase was detected in root number (RN) and root length (RL). Leaf length (LL), on the other hand, increased with a 5% PEG application but decreased with higher concentrations.

Identification of Linalool Disaccharide Glycoside (Linalyl β-Vicianoside) in Soybean Leaves and Its Implication for Herbivore Resistance.

Linalool is anticipated to have significant ecological roles. In this study, linalyl 6-O-α-arabinopyranosyl-β-D-glucopyranoside (linalyl β-vicianoside: LinVic) was synthesized, and a linalool diglycoside purified from soybean leaves was identified as LinVic by using liquid chromatography-mass spectrometry. High levels of LinVic were detected in leaves and sepals during soybean plant growth. The LinVic content did not significantly increase following methyl jasmonate treatment of the leaves, indicating that its synthesis is independent of the jasmonic acid signaling pathway. In addition to LinVic, soybean also contains 1-octen-3-yl primeveroside. We treated soybean leaves with vaporized linalool and 1-octen-3-ol to determine whether the glycosylation system discriminates between these two volatile alcohols. Linalool treatment resulted in the accumulation of LinVic, while 1-octen-3-ol treatment caused little change in the amount of 1-octen-3-yl primeveroside, suggesting discrimination between these compounds. Linalool-treated soybean leaves exhibited increased resistance against common cutworms, indicating that LinVic may contribute to herbivore resistance.

Sample suitability and stability in different blood collection tubes for methanol, ethanol, isopropanol, acetone and glycols analysis

AimTo systematically examine the sample suitability and stability for volatile alcohols (methanol, ethanol and isopropanol with its metabolite acetone) and glycols (ethylene/propylene glycols, EG/PG) in different collection tubes.MethodTwo pools of...

Wearable Alcohol Monitoring Device for the Data-Driven Transcutaneous Alcohol Diffusion Model.

Wearable alcohol monitoring devices demand noninvasive, real-time measurement of blood alcohol content (BAC) reliably and continuously. A few commercial devices are available to determine BAC noninvasively by detecting transcutaneous diffused alcohol. However, they suffer from a lack of accuracy and reliability in the determination of BAC in real time due to the complex scenario of the human skin for transcutaneous alcohol diffusion and numerous factors (e.g., skin thickness, kinetics of alcohol, body weight, age, sex, metabolism rate, etc.). In this work, a transcutaneous alcohol diffusion model has been developed from real-time captured data from human wrists to better understand the kinetics of diffused alcohol from blood to different skin epidermis layers. Such a model will be a footprint to determine a base computational model in larger studies. Eight anonymous volunteers participated in this pilot study. A laboratory-built wearable blood alcohol content (BAC) monitoring device collected all the data to develop this diffusion model. The proton exchange membrane fuel cell (PEMFC) sensor was fabricated and integrated with an nRF51822 microcontroller, LMP91000 miniaturized potentiostat, 2.4 GHz transceiver supporting Bluetooth low energy (BLE), and all the necessary electronic components to build this wearable BAC monitoring device. The %BAC data in real time were collected using this device from these volunteers' wrists and stored in the end device (e.g., smartphone). From the captured data, we demonstrate how the volatile alcohol concentration on the skin varies over time by comparing the alcohol concentration in the initial stage (= 10 min) and later time (= 100 min). We also compare the experimental results with the outputs of three different input profiles: piecewise linear, exponential linear, and Hoerl, to optimize the developed diffusion model. Our results demonstrate that the exponential linear function best fits the experimental data compared to the piecewise linear and Hoerl functions. Moreover, we have studied the impact of skin epidermis thickness within ±20% and demonstrate that a 20% decrease in this thickness results in faster dynamics compared to thicker skin. The model clearly shows how the diffusion front changes within a skin epidermis layer with time. We further verified that 60 min was roughly the time to reach the maximum concentration, Cmax, in the stratum corneum from the transient analysis. Lastly, we found that a more significant time difference between BACmax and Cmax was due to greater alcohol consumption for a fixed absorption time.

The role of hydrogen-rich water in delaying the pulp breakdown of litchi fruit during postharvest storage

Previous studies have indicated that hydrogen-rich water (HW) treatment can delay fruit ripening and senescence. However, little is known about the HW-delaying pulp breakdown. In this study, eight physiological characteristics revealed that HW treatment delayed both pericarp browning and pulp breakdown of litchi fruit. To gain a comprehensive understanding of the changes in litchi pulp, a combination of multiple metabolomics and gene expression analyses was conducted, assessing 67 primary metabolites, 103 volatiles, 31 amino acids, and 13 crucial metabolite-related genes. Results showed that HW treatment promoted starch degradation, decelerated cell wall degradation and glycolysis, and maintained the flavor and quality of litchi fruit. Furthermore, HW treatment stimulated the production of volatile alcohols, aldehydes, ketones, olefins, and amino acids, which might play a vital role in HW-delaying pulp breakdown. This study sheds light on the mechanism by which HW delayed pulp breakdown by investigating small molecule metabolites and metabolic pathways.

Chemiresistive Materials for Alcohol Vapor Sensing at Room Temperature

The development of efficient sensors able to detect alcoholic compounds has great relevance in many fields including medicine, pharmaceuticals, food and beverages, safety, and security. In addition, the measurements of alcohols in air are significant for environmental protection because volatile alcohols can have harmful effects on human health not only through ingestion, but also through inhalation or skin absorption. The analysis of alcohols in breath is a further expanding area, being employed for disease diagnoses. The analyses performed by using chromatography, mass-spectrometry, nuclear magnetic resonance, ultraviolet-visible spectroscopy, Fourier-transform infrared spectroscopy, or Raman spectroscopy often require complex sampling and procedures. As a consequence, many research groups have focused their efforts on the development of efficient portable sensors to replace conventional methods and bulky equipment. The ability to operate at room temperature is a key factor in designing portable light devices suitable for in situ real-time monitoring. In the present review, we provide a survey of the recent literature on the most efficient chemiresistive materials for alcohol sensing at room temperature. Remarkable gas-sensing performances have mainly been obtained by using metal oxides semiconductors (MOSs), metal organic frameworks (MOFs), 2D materials, and polymers. Among 2D materials, we mainly consider graphene-based materials, graphitic carbon nitride, transition metal chalcogenides, and MXenes. We discuss scientific advances and innovations published in the span of the last five years, focusing on sensing mechanisms.

Nutritional- and flavor-enhancing effects of biomass production by Rhodotorula spp. on cantaloupe juice

To investigate the feasibility of applying Rhodotorula spp. production of biomass in juice to enhance juices’ nutrient and flavor properties of juices. In this study, six strains of Rhodotorula spp. were selected to be inoculated into eight fruit juices, and according to their physicochemical properties and carotenoid production, cantaloupe juice was selected as the juice for the subsequent study. The carotenoid composition and content, fatty acid composition and content, volatile substances, and sensory qualities of cantaloupe juice inoculated with the six Rhodotorula spp strains were determined. The results showed that the carotenoid content of cantaloupe juice inoculated with Rhodotorula alborubescrns H7 increased the most from 13.07 mg/L to 29.78 mg/L, which enhanced the nutrition of cantaloupe juice. The crude fat content of cantaloupe juice inoculated with strain Rhodotorula paludigena H12 was the highest at 5.80 g/L. The types and total amounts of many volatile alcohols, acids and lipids also increased, while most aldehydes decreased. Among the tested strains, the best sensory evaluation was obtained with Rhodotorula alborubescrns H7 and H8, which may be the most suitable for commercial production.

Modeling the mechanical response of microelectromechanical system (MEMS)-based sensors to volatile alcohol vapors: A finite element analysis

The development of microelectromechanical system-based sensors, such as microcantilever sensors, has garnered considerable interest across various fields. Notably, there is a significant focus on the detection of volatile alcohol vapors, which holds promise in mitigating breath-related illnesses. This study employed finite element analysis to simulate the deflection of a silica-based microcantilever coated with polymethyl methacrylate in response to different volatile alcohol vapors (VAVs), such as methanol, ethanol, and isopropanol. A Multiphysics framework was used to analyze the time-dependent response of a microcantilever to different concentrations of VAVs incorporating fluid–structure interaction. This complex model integrated the aspects of laminar flow, solid mechanics, and transport of dilute species. Significant agreement has been achieved between finite element analysis-simulated results and the experimental findings that we had previously documented. This alignment revealed consistent trends, with methanol exhibiting higher levels than ethanol, followed by isopropanol, further validating the robustness and reliability of the sensor system in VAV detection.

Material extrusion printing of WC-8%Co cemented carbide based on partly water-soluble binder and post-processing

In this paper, WC-8%Co cemented carbide parts were fabricated by material extrusion additive manufacturing. Water debinding, thermal debinding and sintering were carried out to obtain densified parts. An optimized binder system consists of 50 vol% polyethylene glycol, 15 vol% polyvinyl butyral, 25 vol% high density polyethylene, 5 vol% stearic acid and 5 vol% polyethylene-wax was developed to prepare printable feedstock. The results show that polyvinyl butyral in binder is contributed to tight bonding of powders, but excessive high polyvinyl butyral content caused separation of binder and powder, inefficiency of debinding and formation of macroscopic defects. Extraction of polyethylene glycol is found to be controlled by both dissolution and diffusion. The insoluble binder can be further removed by heating, the products from pyrolysis of insoluble binder included volatile alcohols and aldehydes, carbon dioxide, hydrocarbon and water. Residual carbon and decarburization during thermal debinding can be minimized by using N2/H2 atmosphere in furnace. The complete debinding body was almost absolutely densified by sintering beyond 1340 °C. The sintered body shows a relative density of 99.0%, HV30 hardness of 1360 ± 16 and transverse rupture strength of 1678 ± 125 MPa with optimal post-processing, which are slightly inferior to those obtained by the conventional pressing method. Extrusion printing method is an alternative method for additive manufacturing of WC-Co cemented carbide with good printability and shape retention in process.

Co-inoculation of Meyerozyma guilliermondii and Saccharomyces cerevisiae reduced alcohol content and improved flavor profiles of red pitaya (Hylocereus polyrhizus) wine

Abstract Red pitaya (Hylocereus polyrhizus) is cultivated in tropical and subtropical regions worldwide. Red pitaya is rich in nutritional and medicinal ingredients. Oenological yeasts play vital roles in wine fermentation by metabolizing a variety of aromatic compounds that affect the flavor and sensory properties of wine. In this study, we examined the influence of Meyerozyma guilliermondii on the physicochemical parameters, sensory properties, and aroma chemical composition of red pitaya wine co-inoculated with Saccharomyces cerevisiae. The results showed that mixed inoculation of M. guilliermondii and S. cerevisiae reduced the alcohol content of red pitaya wine. Moreover, using M. guilliermondii and S. cerevisiae as fermentation starters increased the content of volatile alcohols, aldehydes, ketones, and other compounds, as well as the types of alcohols, aldehydes, and ketones. In addition, M. guilliermondii did not affect the sensory characteristics of the red pitaya wine. Therefore, co-inoculation of M. guilliermondii and S. cerevisiae was helpful in enhancing the richness and complexity and improving the aromatic flavor properties of red pitaya wine. The results obtained in this study could serve as a reference for the production of red pitaya wine and other fruit wines.

Resonant sandwich-structured piezoelectric cantilever for volatile alcohol level monitoring

The demand for accurate and real-time liquid level monitoring of storage tanks has increased dramatically in recent decades, particularly in industries such as chemical processing and petroleum refining. However, challenges can arise when liquid levels drop due to volatilization. To address this issue, we propose a resonant Sandwich-structured piezoelectric transducers-cantilever system for volatile alcohol level monitoring. We conducted a COMSOL numerical simulation to determine the frequency shift caused by volatilization at different alcohol levels. Experimental results confirmed the simulation and showed a linear trend within a certain range. This system has potential applications in micro-scale level monitoring systems for various industries.

Antibacterial Activity of Hexanol Vapor In Vitro and on the Surface of Vegetables.

Hexanol is a volatile alcohol and a major component of plant essential oils (EOs). However, the antibacterial activity of hexanol vapor has not been well studied. This study aimed to evaluate the antibacterial activity of hexanol. In this study, seven food-related bacteria were exposed to 1-, 2- or 3-hexanol vapor on agar media to evaluate their growth. Additionally, the total viable counts in three vegetables when exposed to 1-hexanol vapor were measured. The results showed that 1-hexanol exhibited antibacterial effects against Gram-negative bacteria but did not affect Gram-positive bacteria. However, compounds 2- and 3-hexanol did not show antimicrobial activity against any bacteria. For the vegetables, exposure to 1-hexanol vapor decreased the total viable bacterial counts in cabbage and carrot and inhibited bacterial growth in eggplants. In cabbage, 1-hexanol vapor at concentrations over 50 ppm decreased the total viable count within 72 h, and 25 ppm of vapor showed bacteriostatic activity for 168 h. However, 1-hexanol vapor also caused discoloration in cabbage. In summary, 1-hexanol has the potential to act as an antibacterial agent, but further studies are required for practical use. Moreover, the study results may help determine the antimicrobial activity of various EOs in the future.

A chemometric approach to the evaluation of sparkling ciders produced by Champenoise and Charmat methods

The production of sparkling cider could intercept the needs of non-habitual consumers of this alcoholic-beverage. This investigation was aimed to develop procedures for the production of sparkling ciders using the Italian apple variety ‘Limoncella’ by application of both Champenoise and Charmat methods.First of all, the authors apply a chemometric approach to evaluate the effects of duration of the pectolytic treatment carried out on crushed apples and of the sugar added before refermentation on physicochemical, and sensory characteristics of the Champenoise sparkling ciders. The pectolytic treatment was able to influence colour, alcohol, pH, bitterness (higher when the treatment was shorter), titratable and volatile acidity, soluble solids, CO2, total phenolics, sweetness, saltiness, bitterness, and volatile alcohols (higher when the treatment was longer). The addition of sugar increased alcohol, soluble solids, and CO2, and decreased the production of volatile compounds.Then, the effects of the refermentation methods (Champenoise or Charmat) on the same parameters were evaluated. Charmat and Champenoise sparkling ciders differed for parameters showing higher values in the second type, i.e. colour (9.982 and 14.296 SRM), organic acid concentrations, CO2 (6.35 and 7.55 g/L), phenolic (313 and 424 mg/L) and volatile content, foam persistence (2.2 and 3.8), and saltiness (2.1 and 3.2) –– and for some sensory attributes such as taste quality and harmony that received higher scores in Charmat sparkling ciders (4.9 ± 0.7 and 4.9 ± 0.0, respectively) than the Champenoise ciders (3.7 ± 0.5 and 3.7 ± 0.4, respectively). Several esters, alcohols, terpenes, acids, phenols, and norisoprenoids had odour activity values > 1. Principal Component Analysis (PCA) was able to homogeneously group Champenoise ciders based on the duration of the pectolytic treatment and the addition of sugar before fermentation. PCA was also able to distinguish sparkling ciders by refermentation methods.The results indicated that the chemometric approach is a sensitive tool to monitor the quality and authenticity of local sparkling cider productions. The reduction of the pectolytic treatment time was critical to avoid dramatic increases of lactic acid content. The Champenoise method preserved the cider phenolic content but negatively affected their sensory quality.

Impact of solvents on doctor blade coatings and bathocuproine cathode interlayer for large-area organic solar cell modules

Efforts to commercialize organic solar cells (OSCs) by developing roll-to-roll compatible modules have encountered challenges in optimizing printing processes to attain laboratory-level performance in fully printable OSC architectures. In this study, we present efficient OSC modules fabricated solely through printing methods. We systematically evaluated the impact of processing solvents on the morphology of crucial layers, such as the hole transport, photoactive, and electron transport layers, applied using the doctor blade coating method, with a particular focus on processability. Notably, deposition of charge transport layer using printing techniques is still a challenging task, mainly due to the hydrophobic characteristic of the organic photoactive layer. To overcome this issue, we investigated the solvent effect of a well-studied cathode interlayer, bathocuproine (BCP). We were able to form a uniform thin BCP film (∼10 nm) on a non-fullerene based organic photoactive layer using the doctor bladed coating method. Our results showed that the use of volatile alcohols in the BCP processing required a delicate balance between wettability and vaporization, which contrasted with the results for spin-coated films. These findings provide important insights into improving the efficiency of printing techniques for depositing charge transport layers. The fully printed OSC modules, featuring uniform and continuous BCP layer formation, achieved an impressive power conversion efficiency of 10.8% with a total area of 10.0 cm2 and a geometrical fill factor of 86.5%.

Quality characteristics of soybean fermented by Mucor, Rhizopus, and Aspergillus from meju

Three candidate starter strains—Aspergillus oryzae SNU-G, Mucor sp. KACC 46077, and Rhizopus oryzae KACC 40256—were inoculated into soybean, as individual strains or in combination, to assess their roles in fermentation. All the strains increased the pH, amino-type nitrogen, and moisture content of the soybean during fermentation, and decreased the lightness, redness, and yellowness. The inoculated strains increased to an average density of 1.37 × 108 spores/g (from the initial 5.0 × 107 spores/g) after 20 days of fermentation. Forty-two volatile compounds, including an acid, alcohols, carbonyls, furans, and a pyrazine, were more abundant in soybean fermented with starters than in controls. A. oryzae SNU-G increased the pH more than the other strains and produced more volatile alcohol compounds. R. oryzae KACC 40256 resulted in the lowest reduction of redness and yellowness during the fermentation and produced large amounts of carbonyl compounds, including two specific volatile compounds, 2-hydroxy-3-methylcyclopent-2-en-1-one and (3E)-3-ethyl-2-methylhexa-1,3-diene. Mucor sp. KACC 46077 contributed the least to pH change and volatile compound production, and did not produce specific volatile compounds. Although no significant synergy in the production of volatile compounds was found when using mixtures of strains compared with application of single strains, the quality of fermented soybeans was confirmed to be different depending on the strain(s) applied.

Comparative Study on Effectiveness of Organic Apple Juice Vinegar Over Commercially Available Vinegar Using Chemical Titration Technique for Chicken Quality Analysis

Aim: The purpose of this research is to develop a new apple vinegar based on Podophyllum peltatum and analyze the fermentation process using a new methodology. Materials and Methods: The vinegar-making process began with the addition of Saccharomyces cerevisiae (yeast) and l (acetic bacteria) with apple. Chemical titration method is used to find out the apple juice microbial and compared to the microbial in vinegar. The microorganisms Saccharomyces cerevisiae and Acetobacter pasteurianus were found respectively. Fermentation began with fewer Saccharomyces cerevisiae and Acetobacter pasteurianus, but they were present throughout the alcoholic and acetic phases. Both microbial strains produced ethanol and acetic acid using apple as a substrate. The vinegar also produced acetate, volatile alcohols, and aldehydes. Two groups are taken with 9 sample size per group, G power 80%, coincidence intervals will be 95%. Results and Discussion: The innovative apple vinegars had an acetic acid yield of 8.1%. In the sensory evaluation, apple vinegar was well received. The technology proposed here is innovative in that it employs mixed inocula instead of separate ones (p=0.001). It also uses cell biomass instead of centrifugation at the end of the fermentative process. When compared to commercial vinegar (5%), apple vinegar has a high acetic acid concentration (8.1%). Conclusion: Reduce the working time and also be less expensive. Higher acetic acid concentration in vinegar is helpful to improve the taste of the food.

Comparative proteome and volatile metabolome analysis of Aspergillus oryzae 3.042 and Aspergillus sojae 3.495 during koji fermentation

Aspergillus oryzae 3.042 and Aspergillus sojae 3.495 are crucial starters for fermented soybean foods since their abundant secreted enzymes. This study aimed to compare the differences in protein secretion between A. oryzae 3.042 and A. sojae 3.495 during the soy sauce koji fermentation and the effect on volatile metabolites to understand the fermentation characteristics of the strains better. Label-free proteomics detected 210 differentially expressed proteins (DEPs) enriched in amino acid metabolism and protein folding, sorting and degradation pathways. Subsequently, extracellular enzyme analysis showed that three peptidases, including peptide hydrolase, dipeptidyl aminopeptidase, and peptidase S41, were up-regulated in A. sojae 3.495. Seven carbohydrases, including α-galactosidase, endo-arabinase, β-glucosidase, α-galactosidase, α-glucuronidase, arabinan-endo 1,5-α-l-arabinase, and endo-1,4-β-xylanase were up-regulated in A. oryzae 3.042, contributing to the difference in enzyme activity. Significantly different extracellular enzymes influenced the content of volatile alcohols, aldehydes and esters such as (R, R)-2,3-butanediol, 1-hexanol, hexanal, decanal, ethyl l-lactate and methyl myristate in both strains, which affected the type of aroma of koji. Overall, this study revealed the differences in molecular mechanisms between A. oryzae 3.042 and A. sojae 3.495 under solid-state fermentation, providing a reference for targeted enhancement strains.

Effects of Heat-Moisture Treatment Whole Tartary Buckwheat Flour on Processing Characteristics, Organoleptic Quality, and Flavor of Noodles.

The effects of heat-moisture treatment whole tartary buckwheat flour (HTBF) with different contents on the pasting properties and hydration characteristics of tartary buckwheat noodle mix flour (TBMF), dough moisture distribution, cooking properties, texture properties, and flavor of noodles were studied. The results showed that the optimal additional amount of HTBF is determined to be 40%. The peak viscosity, trough viscosity, breakdown value, and final viscosity decreased significantly, and the optimal cooking time of the noodles decreased with increasing HTBF. Compared with the sample without HTBF, HTBF addition increased the water absorption of the sample and decreased its water solubility. When the amount of HTBF >30%, the content of strongly bound water in dough increased significantly; at HTBF >40%, the water absorption and cooking loss of noodles increased rapidly, and the hardness of noodles was decreased; and with HMBF addition at 60%, the chewiness, resilience, and elasticity decreased. Moreover, HMBF addition reduced the relative content of volatile alkanes, while increasing the amount of volatile alcohols. HTBF addition also elevated the content of slow-digesting starch (SDS) and resistant starch (RS) in noodles, providing noodles with better health benefits in preventing chronic diseases. These results proved the possibility of applying heat-moisture treatment grains to noodles, and they provide a theoretical basis for the research and development of staple foods with a hypoglycemic index.

Study on the physicochemical indexes, nutritional quality, and flavor compounds of Trichiurus lepturus from three representative origins for geographical traceability.

Trichiurus lepturus (hairtail) is an important economic component of China's marine fishing industry. However, due to the difficulty in identifying the appearance of hairtail from different geographical distributions, hairtails with geographical indication trademarks were imitated by general varieties. In this study, the texture characteristics, color, basic nutrients, amino acids, mineral, fatty acids, and volatile flavor substances were used as indicators for multivariate statistical analysis to determine whether three origins of hairtails from the habitats of Zhoushan (East China Sea, T.Z), Hainan (South China Sea, T.N), and Qingdao (Yellow Sea, T.Q) in the market could be distinguished. The findings revealed that there were significant differences in amino acids composition, mineral composition, fatty acid composition in lipids, and volatile flavor substances among the hairtails of three origins (P < 0.05), but no differences in color, texture, protein content. T.Z had moisture, crude fat, essential amino acids (EAA), flavor amino acids (FAA), unsaturated fatty acids (UFA), and docosahexaenoic acids and dicosapentaenoic acids (ΣEPA + DHA) contents of 74.33, 5.4%, 58.25 mg⋅g-1, 46.20 mg⋅g-1, 66.84 and 19.38%, respectively, and the contents of volatile alcohols, aldehydes and ketones were 7.44, 5.30, and 5.38%, respectively. T.N contains moisture, crude fat, EAA, FAA, UFA and ΣEPA + DHA as 77.69, 2.38%, 64.76 mg⋅g-1, 52.44 mg⋅g-1, 65.52 and 29.45%, respectively, and the contents of volatile alcohols, aldehydes and ketones as 3.21, 8.92, and 10.98%, respectively. T.Q had the contents of moisture, crude fat, EAA, FAA, UFA, and ΣEPA + DHA 79.69, 1.43%, 60.9 mg⋅g-1, and 49.42 mg⋅g-1, respectively. The contents of unsaturated fatty acid and ΣEPA + DHA were 63.75 and 26.12%, respectively, while the volatile alcohols, aldehydes, and ketones were 5.14, 5.99, and 7.85%, respectively. Partial least squares-discriminant analysis (PLS-DA) multivariate statistical analysis showed that volatile flavor compounds could be used as the most ideal indicators for tracing the source of hairtail. In conclusion, the findings of this study can distinguish the three hairtail origins using some basic indicators, providing ideas for hairtail geographical identification.

Detection of Volatile Alcohol Vapors Using PMMA-Coated Micromechanical Sensors: Experimental and Quantum Chemical DFT Analysis

Micromechanical sensors, in which the sensor response is created as a result of molecular interactions on the sensors’ surfaces, have been employed as a powerful technique for rapid and sensitive detection of low concentrations of chemical and biological materials. In the study reported herein, poly(methyl methacrylate) (PMMA)-coated microcantilever (MCL) sensors were used to detect the vapors of volatile alcohols (methanol, ethanol, and isopropanol) at three different concentrations. A vapor generator was used to generate and flow the alcohol vapor onto the PMMA coated MCL surface in a closed system chamber. The vapor adsorption onto the MCL surface results in a rapid and measurable deflection of the MCL. No significant deflections of the uncoated MCL occurred when the different vapors were passed through into the microcantilever chamber. Linear concentration–deflection responses were observed, with the highest sensitivity shown with methanol, followed by ethanol and then isopropanol. Density functional theory (DFT) quantum chemical calculations were conducted to estimate the electronic interaction energies (ΔIE) between the alcohol molecules and MMA and two different model tetrameric segments of PMMA. The computed ΔIEs were in the same order as the experimentally observed order: methanol &gt; ethanol &gt; isopropanol.