Nonanal

Metabolomics of exhaled breath in critically ill COVID-19 patients: A pilot study.[Pubmed:33279860]

EBioMedicine. 2020 Dec 3;63:103154.

BACKGROUND: Early diagnosis of coronavirus disease 2019 (COVID-19) is of the utmost importance but remains challenging. The objective of the current study was to characterize exhaled breath from mechanically ventilated adults with COVID-19. METHODS: In this prospective observational study, we used real-time, online, proton transfer reaction time-of-flight mass spectrometry to perform a metabolomic analysis of expired air from adults undergoing invasive mechanical ventilation in the intensive care unit due to severe COVID-19 or non-COVID-19 acute respiratory distress syndrome (ARDS). FINDINGS: Between March 25(th) and June 25(th), 2020, we included 40 patients with ARDS, of whom 28 had proven COVID-19. In a multivariate analysis, we identified a characteristic breathprint for COVID-19. We could differentiate between COVID-19 and non-COVID-19 ARDS with accuracy of 93% (sensitivity: 90%, specificity: 94%, area under the receiver operating characteristic curve: 0*94-0*98, after cross-validation). The four most prominent volatile compounds in COVID-19 patients were methylpent-2-enal, 2,4-octadiene 1-chloroheptane, and Nonanal. INTERPRETATION: The real-time, non-invasive detection of methylpent-2-enal, 2,4-octadiene 1-chloroheptane, and Nonanal in exhaled breath may identify ARDS patients with COVID-19. FUNDING: The study was funded by Agence Nationale de la Recherche (SoftwAiR, ANR-18-CE45-0017 and RHU4 RECORDS, Programme d'Investissements d'Avenir, ANR-18-RHUS-0004), Region Ile de France (SESAME 2016), and Fondation Foch.

High-throughput sequencing-based characterization of the predominant microbial community associated with characteristic flavor formation in Jinhua Ham.[Pubmed:33279069]

Food Microbiol. 2021 Apr;94:103643.

Our purpose was to investigate the main bacterial microbiota and volatile profiles in the Chinese traditional dry-cured product-Jinhua ham during different processing stages and to analyze the role of the main microbiota in the formation of characteristic flavor. We determined the microbiota of Jinhua ham by using 16 S high throughput sequencing, and found that Staphylococcus constituted the predominant microbiota throughout the flavor formation process. Based on the volatile profiles of Jinhua dry-cured products from 11 different processing via SPME-GC-MS analysis, Aldehydes were the main groups of volatiles, with the most abundant ones being hexanal (13.89%) and Nonanal (3.96%). To further investigate the relationship between predominant microbiota and the major volatile compounds in Jinhua ham, we screened and isolated genus Staphylococcus with high protease and lipase activities. The main Staphylococcus isolates, S. saprophyticus (53.4%) and S. equorum (31.0%) are related to the yields of aldehydes by producing hexanal, Nonanal, benzaldehyde, and phenylacetaldehyde, indicating their contributions on the formation of characteristic flavor substances in Jinhua ham.

Sensory Quality Evaluation of Korla Pear from Different Orchards and Analysis of Their Primary and Volatile Metabolites.[Pubmed:33260963]

Molecules. 2020 Nov 27;25(23). pii: molecules25235567.

Metabolites play vital roles in shaping the quality of fresh fruit. In this study, Korla pear fruit harvested from twelve orchards in South Xinjiang, China, were ranked in sensory quality by fuzzy logic sensory evaluation for two consecutive seasons. Then, gas chromatography-mass spectrometry (GC-MS) was applied to determine the primary metabolites and volatile compounds. Sensory evaluation results showed that the panelists were more concerned about 'mouth feel' and 'aroma' than about 'fruit size', 'fruit shape' and 'peel color'. In total, 20 primary metabolites and 100 volatiles were detected in the pear fruit. Hexanal, (E)-2-hexenal, Nonanal, d-limonene, (Z)-3-hexen-1-yl acetate and hexyl acetate were identified as the major volatile compounds. Correlation analysis revealed that l-(+)-tartaric acid, hexanoic acid, trans-limonene oxide and 2,2,4-trimethyl-1,3-pentanediol diisobutyrate were negatively correlated with sensory scores. Furthermore, OPLS-DA results indicated that the fruit from three orchards with lower ranks in quality could be distinguished from other samples based on the contents of l-(+)-tartaric acid and other eight metabolites, which were all associated with 'mouth feel' and 'aroma'. This study reveals the metabolites that might be closely associated with the sensory quality attributes of Korla pear, which may provide some clues for promoting the fruit quality in actual production.

Effects of an Extract from Olive Fruits on the Physicochemical Properties, Lipid Oxidation and Volatile Compounds of Beef Patties.[Pubmed:33255479]

Foods. 2020 Nov 24;9(12). pii: foods9121728.

The aim of this work was to evaluate the effect of an olive extract (OE) on the physicochemical and microbiological characteristics, lipid oxidation and volatile compounds of beef patties stored both aerobically and under modified atmosphere packaging for 15 days at 4 degrees C. The antioxidant and antimicrobial effects of the OE were compared to those of sulfite. Four formulations were elaborated according to the antioxidant and dose used: without antioxidant, C; 300 mg potassium metabisulfite/kg product, S; 150 mg OE/kg product, OE1; and 250 mg of OE/kg product, OE2. The parameters analyzed were pH, water activity, color, lipid oxidation (TBARS and volatile organic compounds: hexanal, 2-pentyl-furan, 1-pentanol, 2,3-octanedione and Nonanal, 1-octen-2-ol) and total viable counts. The OE delayed the loss of the bright red color of the patties and reduced the lipid oxidation in both types of packaging compared to the control patty. Sulfite was the most effective antioxidant for inhibition of the total viable counts. An OE could be used as a natural antioxidant to delay the lipid oxidation of meat without negatively affecting its physicochemical properties.

Comparative analysis of characteristic volatile compounds in Chinese traditional smoked chicken (specialty poultry products) from different regions by headspace-gas chromatography-ion mobility spectrometry.[Pubmed:33248636]

Poult Sci. 2020 Dec;99(12):7192-7201.

This article presents investigation of the flavor profile on 5 different regional Chinese smoked chicken samples using gas chromatography-ion mobility spectrometry analysis methods. Five batches of samples were obtained over the course of 6 mo. A total of 34 flavor substances were identified in the 5 smoked chicken samples, including 10 aldehydes, 7 alcohols, 4 ketones, 2 hydrocarbons, 3 heterocyclic compounds, 4 esters, 2 ethers, and 2 phenolic compounds. The whole spectral fingerprint visually displayed flavor differences and relations in 5 types of smoked chicken with local characteristics. Moreover, the orthogonal projections to latent structures discriminant analysis model revealed that these samples could be separately classified into 5 groups. Multivariate statistical analysis showed that 20 chemicals with higher Variable Importance for the Projection values were the key contributors to the differences of flavor in these 5 kinds of smoked chicken. N-Nonanal, heptanal, n-Nonanal, heptanal, furfurol, and hexanal were the main common flavor compounds in the 5 types of Chinese smoked chicken, whereas linalool, alpha-terpineol, 1,8-cineole, and anethole were the main characteristic flavor compounds of Goubangzi chicken (No. 1); gamma-butyrolactone, 2-acetylfuran, 2-methoxyphenol, 2-acetylpyrrole, and limonene were determined as the key flavor compounds of Liaocheng chicken (No. 2); the concentration of octanal and n-Nonanal was higher in Tangqiao chicken (No. 3); butyl acetate was the key contributor to the flavor compounds of Jinshan chicken (No. 4). 2-Heptanone and 2-pentylfuran had a high correlation with Zhuozishan chicken (No. 5). The different raw materials and ingredients used, especially the method of preparation and cultural differences, in different regions of the country in China were the main reasons leading to the similarities and differences of volatile compounds in the 5 kinds of Chinese traditional smoked chicken.

An environmental air sampler to evaluate personal exposure to volatile organic compounds.[Pubmed:33205787]

Analyst. 2020 Nov 18.

A micro fabricated chip-based wearable air sampler was used to monitor the personnel exposure of volatile chemical concentrations in microenvironments. Six teenagers participated in this study and 14 volatile organic compounds (VOCs) including naphthalene, 3-decen-1-ol, hexanal, Nonanal, methyl salicylate and limonene gave the highest abundance during routine daily activity. VOC exposure associated with daily activities and the location showed strong agreements with two of the participant's results. One of these subjects had the highest exposure to methyl salicylate that was supported by the use of a topical analgesic balm containing this compound. Environmental based air quality monitoring followed by the personnel exposure studies provided additional evidence associated to the main locations where the participants traveled. Toluene concentrations observed at a gas station were exceptionally high, with the highest amount observed at 1213.1 ng m-3. One subject had the highest exposure to toluene and the GPS data showed clear evidence of activities neighboring a gas station. This study shows that this wearable air sampler has potential applications including hazardous VOC exposure monitoring in occupational hazard assessment for certain professions, for example in industries that involve direct handling of petroleum products.

Comparative Analysis of Rapeseed Oils Prepared by Three Different Methods.[Pubmed:33177280]

J Oleo Sci. 2020 Dec 1;69(12):1641-1648.

Flavoured rapeseed oils prepared using traditional technologies (oils A and B) and a fragrant rapeseed oil obtained using an enzymatic Maillard reaction (oil C) were analysed to show that oil C featured basic indicators and a fatty acid composition similar to those of traditional oils while exhibiting a higher comprehensive sensory evaluation score. Volatile component, odour activity value (OAV), and relative odour activity value (ROAV) analyses revealed that oil C had an elevated content of pyrazines (20.83%) and aldehydes (38.15%), which resulted in stronger charred and caramel flavours. The aroma of oil C was directly impacted by 3-methylbutyraldehyde (OAV > 1) and was modified by 3-methylthiopropionaldehyde and Nonanal (RAOV > 1 in both cases). Thus, the developed technology was found to be well suited for the production of novel and safe fragrant rapeseed oil.

The volatile flavor compounds of Shanghai smoked fish as a special delicacy.[Pubmed:33171537]

J Food Biochem. 2020 Nov 10:e13553.

In this work, the effects of substrates on volatile flavor compounds of Shanghai smoked fish (SSF) from grass carp was investigated by head space-solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) by changing the ratios of soy sauce (15%-25%) to white sugar (10%-20%) and replacing white sugar with reducing sugar (glucose, fructose, and ribose). The results showed the key volatile flavor compounds (ROAV >/= 1) of SSF were 2,4-decadienal, p-xylene, Nonanal, and 1-octen-3-ol with the relative contents of 10.33, 1.14, 4.84, and 1.76%, respectively. Furthermore, the existence of soy sauce had an enhancing role in the production of pyrazines, but no significant difference in white sugar. The contents of isovaleraldehyde and benzeneacetaldehyde were increased when white sugar was replaced with glucose, octanol, and 2-pentyl furan for fructose, no obvious difference in ribose. Moreover, the optimal ratios of soaking solutions were 20% soy sauce and 15% white sugar based on the scoring method of sensory evaluation. This study will provide a theoretical basis for the formation of volatile flavor compounds of SSF. PRACTICAL APPLICATIONS: Grass carp usually grows in freshwater such as pond or lake, but bacteria with earthy smell are easily attached to plankton such as diatom and cyanobacteria leading to the accumulation of bad odor substances through the food chain. Shanghai smoked fish (SSF) deeply loved by public is a traditional special dish with crispy crust and delicious taste. The attractive flavor of grass carp could be increased with the help of the Maillard reaction (MR) and seasonings. Therefore, the effect of the MR on the volatile flavor compounds of SSF was investigated by HS-SPME-GC/MS in this work. A detailed study on the volatile flavor compounds of Shanghai smoked fish could not only enrich the theoretical knowledge of flavor chemistry of freshwater fish, but have a profound contribution to the development of freshwater fish processing techniques.

Variation and mitigation of musty, septic, chemical, grassy, fishy odors and corresponding odorants in a full-scale drinking water treatment plant with advanced treatments.[Pubmed:33162163]

Chemosphere. 2020 Oct 22:128691.

Ozone and biological activated carbon (BAC) are known to be effective at removing odors in drinking water. However, the specific variations in complex odors and odorants along the course of advanced treatments in full-scale drinking water treatment plants (DWTP) have remained unclear. In this paper, the migration of odors and odorants through pre-ozonation, sedimentation, post-ozonation, and BAC treatment processes were studied from January to December 2019 in a DWTP. The results indicated that septic, musty, and chemical odors with intensities of 6-6.7, 6-7.5, 4-5 could be removed by both ozonation and BAC, while grassy, fishy odors with intensities of 3.3-4.8, 2.3-5.8 could not be removed until the BAC step. Twenty-four odorants identified in raw water were classified as musty (2-methylisoborneol, geosmin), chemical (e.g. indane, eucalyptol), septic (e.g. dimethyl disulfide, pentanethiol), fishy (2,4-decadienal) and grassy (Nonanal, decanal) odor compounds. It is noteworthy that eleven additional odorants were produced after ozonation; in addition, the concentrations of fishy and grassy odorants were increased after ozonation, and the concentrations of musty, septic, fishy, and grassy odorants were increased after sedimentation, suggesting that sedimentation and ozonation should be carefully managed. BAC was the most effective at removing the above odorants simultaneously. This study would be helpful for providing more insights into the migration of odorants along treatment processes and understanding the mitigation of odors in DWTPs using raw waters with complex odors.

Evaluation of the sensitization potential of volatile and semi-volatile organic compounds using the direct peptide reactivity assay.[Pubmed:33132246]

J Toxicol Sci. 2020;45(11):725-735.

The purpose of this study was to evaluate the sensitization potential of 82 compounds classified as volatile and/or semi-volatile organic compounds using the direct peptide reactivity assay (DPRA), given that these chemical compounds have been detected frequently and at high concentrations in a national survey of Japanese indoor air pollution and other studies. The skin sensitization potential of 81 of these compounds was evaluable in our study; one compound co-eluted with cysteine peptide and was therefore not evaluable. Twenty-five of the evaluated compounds were classified as positive. Although all glycols and plasticizers detected frequently and at high concentrations in a national survey of Japanese indoor air pollution were negative, hexanal and Nonanal, which are found in fragrances and building materials, tested positive. Monoethanolamine and 1,3-butanediol, which cause clinical contact dermatitis, and several compounds reported to have weak sensitization potential in animal studies, were classified as negative. Thus, it was considered that compounds with weak sensitization potential were evaluated as negative in the DPRA. Although the sensitization potential of the formaldehyde-releasing preservative bronopol has been attributed to the release of formaldehyde (a well-known contact allergen) by its degradation, its degradation products-bromonitromethane and 2-bromoethanol-were classified as positive, indicating that these degradation products also exhibit sensitization potential. The compounds that tested positive in this study should be comprehensively assessed through multiple toxicity and epidemiological studies.

Nonanal Stimulates Growth Factors via Cyclic Adenosine Monophosphate (cAMP) Signaling in Human Hair Follicle Dermal Papilla Cells.[Pubmed:33126774]

Int J Mol Sci. 2020 Oct 28;21(21). pii: ijms21218054.

Human hair follicle dermal papilla cells (DPCs) are a specialized population of cells located in the hair follicles and regulate hair growth and development, particularly by releasing numerous growth factors in response to various physiological conditions. In the present study, we aimed to test whether Nonanal, a scent compound from plants, stimulated growth factors in DPCs and to delineate the underlying mechanisms involved. We found that Nonanal promoted DPC proliferation in a dose-dependent manner. Meanwhile, it also increased the intracellular cyclic adenosine monophosphate (cAMP) levels and the expression of various growth factor genes such as vascular endothelial growth factor, keratinocyte growth factor, and insulin-like growth factor 1. Furthermore, Nonanal treatment stimulated DPC migration. Notably, the benefits of Nonanal use were abrogated by cAMP inhibition. Our results reveal the potential of Nonanal in preventing hair loss and suggest that its effects are cAMP-mediated in DPCs.

Biobased Aldehydes from Fatty Epoxides through Thermal Cleavage of beta-Hydroxy Hydroperoxides*.[Pubmed:33125173]

ChemSusChem. 2020 Oct 30.

The ring-opening of epoxidized methyl oleate by aqueous H2 O2 has been studied using tungsten and molybdenum catalysts to form the corresponding fatty beta-hydroxy hydroperoxides. It was found that tungstic acid and phosphotungstic acid gave the highest selectivities (92-93 %) towards the formation of the desired products, thus limiting the formation of the corresponding fatty 1,2-diols. The optimized conditions were applied to a range of fatty epoxides to give the corresponding fatty beta-hydroxy hydroperoxides with 30-80 % isolated yields (8 examples). These species were fully characterized by (1) H and (13) C NMR spectroscopy and HPLC-HRMS, and their stability was studied by differential scanning calorimetry. The thermal cleavage of the beta-hydroxy hydroperoxide derived from methyl oleate was studied both in batch and flow conditions. It was found that the thermal cleavage in flow conditions gave the highest selectivity towards the formation of aldehydes with limited amounts of byproducts. The aldehydes were both formed with 68 % GC yield, and Nonanal and methyl 9-oxononanoate were isolated with 57 and 55 % yield, respectively. Advantageously, the overall process does not require large excess of H2 O2 and only generates water as a byproduct.

Aged fragrance formed during the post-fermentation process of dark tea at an industrial scale.[Pubmed:33097332]

Food Chem. 2020 Sep 24:128175.

Although aged fragrance is the most outstanding quality characteristic of dark tea, its formation still is not much clear. Thus, the volatiles of Qingzhuan tea (QZT) during the whole post-fermentation process were investigated at an industrial scale. The results showed that most of volatiles increased during pile-fermentation of QZT and weakened during aging storage, but some new volatiles were produced through aging storage. Hexanal, (E)-2-hexenal, (E)-2-decenal, 2,6,6-trimethyl-1-cyclohexene-1-carboxaldehyde, heptanal, (E)-2-octenal, (R)-5,6,7,7a-tetrahydro-4,4,7a-trimethyl-2(4H)-benzofuranone, ionone, 2-heptanone, 3-ethyl-4-methyl-1H-pyrrole-2,5-dione, (R,S)-5-ethyl-6-methyl-3-hepten-2-one, cis-5-ethenyltetrahydro-5-trimethyl-2-furanmethanol, and linalool generated by pile-fermentation should be the basic volatiles of aged fragrance in QZT, and 4-(2,4,4-trimethyl-cyclohexa-1,5-dienyl)-but-3-en-2-one, 6-methyl-5-heptene-2-one, safranal, guaiene, trans-2-(2-propynyloxy)-cyclohexanol, Nonanal, and 4-(2,6,6-trimethyl-1-cyclohexen-1-yl)-2-butanone formed during aging storage should be the transformed volatiles of aged fragrance in QZT, which together constitute the characteristic components of aged fragrance. Notably, 4-(2,6,6-trimethyl-1-cyclohexen-1-yl)-2-butanone, 6-methyl-5-heptene-2-one, and safranal were selected as the key volatiles of QZT. These results contribute to understand better the formation of agedfragrance in dark tea.

Key aroma compounds of Chinese dry-cured Spanish mackerel (Scomberomorus niphonius) and their potential metabolic mechanisms.[Pubmed:33097327]

Food Chem. 2020 Oct 16:128381.

The key aroma compounds of six commercially available dry-cured Spanish mackerel (Scomberomorus niphonius, DCSM) were identified using electronic nose (E-nose), gas chromatography-olfactometry (GC-O), and two-dimensional gas chromatography-time-of-flight mass spectrometry (GC x GC-TOFMS). A total of 38-55 aroma compounds were identified, and 21-26 of them, which presented high flavor dilution factors based on aroma extract dilution analysis, were quantified. Lastly, 9-14 key aroma compounds with high odor-active value, including 3-methyl-1-butanal, octanal, 1-octen-3-ol, Nonanal, cis-4-decenal, ethyl caproate, (E)-2-octenal, (Z)-2-nonenal decanal, 3-methyl-1-butanol, 1-heptanol, 3-octanone, 2-octanol, and 6-methyl-5-hepten-2-one, were identified as the key aroma contributors in DCSM. Results also indicated that a longer dry-curing time would promote the generation of aroma compounds. The metabolism analysis implied that the auto-oxidation/oxidation of unsaturated fatty acids, such as oleic and linoleic acid, and the enzymatic degradation of l-leucine might be potential metabolic mechanisms.

Volatile organic compounds (VOCs) for the non-invasive detection of pancreatic cancer from urine.[Pubmed:33076134]

Talanta. 2021 Jan 1;221:121604.

Pancreatic ductal adenocarcinoma (PDAC) is a particularly challenging cancer, with very low 5-year survival rates. This low survival rate is linked to late stage diagnosis, associated with the lack of approved biomarkers. One approach that is receiving considerable attention is the use of volatile organic compounds (VOCs) that emanate from biological waste as biomarkers for disease. In this study, we used urine as our biological matrix and two VOC analysis platforms: gas chromatography - ion mobility spectrometry (GC-IMS) and GC time-of-flight mass spectrometry (GC-TOF-MS). We measured the urinary headspace of samples from patients with PDAC, chronic pancreatitis (CP) and healthy controls. In total, 123 samples were tested from these groups. Results indicate that both GC-IMS and GC-TOF-MS were able to discriminate PDAC from healthy controls with high confidence and an AUC (area under the curve) in excess of 0.85. However, both methods struggled to separate CP from PDAC, with the best result of AUC 0.58. This indicates that both conditions produce similar biomarkers in the urinary headspace. Chemical identification suggests that 2,6-dimethyl-octane, Nonanal, 4-ethyl-1,2-dimethyl-benzene and 2-pentanone play an important role in separating these groups. Therefore, both techniques validate this approach in identifying subjects for further investigation in a clinical setting.