Unique Volatile Organic Compounds Research Articles

Identification on Key Volatiles Contributed to Oviposition Preference of Plodia interpunctella (Hübner, 1813) (Lepidoptera: Pyralidae) from High and Normal Oleic Varieties of Peanut.

The Indian meal moth, Plodia interpunctella (Hübner, 1813) (Lepidoptera: Pyralidae), a primary stored peanut insect pest, exhibited a significant difference in oviposition preference among normal-oleic peanuts (NOPs) and high-oleic peanuts (HOPs). Identifying key volatile organic compounds (VOCs) that are attractive or repellent to P. interpunctella is of great significance for the ecological management of pests. The profiles and contents of VOCs among NOP and HOP varieties were measured and compared, and key bioactive VOCs were further confirmed via an electroantennogram (EAG) analysis, as well as behavioral responses in Y-tube olfactometer and wind tunnel bioassays. Females prefer to lay eggs on NOP varieties more than on HOP ones. Acetophenone, nonanal, decanal, dodecane, 2,5-dimethylbenzaldehyde, and 4-ethyl-benzaldehy derived from tested peanuts elicited stronger antennal EAG responses. The results of the Y-tube olfactometer and wind tunnel bioassay showed that the relative high levels of nonanal, dodecane, and unique VOC acetophenone in NOP varieties have a significant attraction to P. interpunctella. Conversely, 4-ethyl-benzaldehyde and the unique VOC 2,5-dimethyl-benzaldehyde commonly found in HOP varieties exhibit notable repellent effects on P. interpunctella. These VOCs could contribute to the development of attractants or repellents derived from special peanut varieties for pest management.

Harvest Initiated Volatile Organic Compound Emissions from In-Field Tall Wheatgrass.

While crop and grassland usage continues to increase, the full diversity of plant-specific volatile organic compounds (VOCs) emitted from these ecosystems, including their implications for atmospheric chemistry and carbon cycling, remains poorly understood. It is particularly important to investigate VOCs in the context of potential biofuels: aside from the implications of large-scale land use, harvest may shift both the flux and speciation of emitted VOCs. To this point, we evaluate the diversity of VOCs emitted both pre and postharvest from "Alkar" tall wheatgrass (Thinopyrum ponticum), a candidate biofuel that exhibits greater tolerance to frost and saline land compared to other grass varieties. Mature plants grown under field conditions (n = 6) were sampled for VOCs both pre- and postharvest (October 2022). Via hierarchical clustering of emitted VOCs from each plant, we observe distinct "volatilomes" (diversity of VOCs) specific to the pre- and postharvest conditions despite plant-to-plant variability. In total, 50 VOCs were found to be unique to the postharvest tall wheatgrass volatilome, and these unique VOCs constituted a significant portion (26%) of total postharvest signal. While green leaf volatiles (GLVs) dominate the speciation of postharvest emissions (e.g., 54% of unique postharvest VOC signal was due to 1-penten-3-ol), we demonstrate novel postharvest VOCs from tall wheatgrass that are under characterized in the context of carbon cycling and atmospheric chemistry (e.g., 3-octanone). Continuing evaluations will quantitatively investigate tall wheatgrass VOC fluxes, better informing the feasibility and environmental impact of tall wheatgrass as a biofuel.

Combining Targeted Metabolomics with Untargeted Volatilomics for Unraveling the Impact of Sprouting on the Volatiles and Aroma of False Flax (Camelina sativa) Cold-Pressed Oil.

Sprouting of stored oilseeds due to improper storage can lead to quality defects of cold-pressed oils obtained from them. This study aimed to evaluate the effect of seed sprouting on volatile organic compounds (VOCs), aroma-active compounds, and the content of nonvolatile metabolites in cold-pressed false flax oil obtained from sprouted seeds. In this study, 88 unique VOCs were detected in sprouted oils, whereas only 42 were found in the control oils. The control oils were characterized by a higher abundance of alcohols, while all other groups of compounds were associated with sprouted seeds. The formation of many VOCs was reflected in changes in the nonvolatile precursors. Fifteen aroma-active compounds were identified in sprouted oil, with five compounds playing a significant role (FD ≥ 128) in aroma formation. The presented approach allowed identification of differences caused by seed sprouting, resulting in oils with a much stronger aroma and a richer profile of VOCs due to intensive metabolic changes. The origin of many VOCs can be explained by alterations in the content of nonvolatile metabolites.

Optimization Co-Culture of Monascus purpureus and Saccharomyces cerevisiae on Selenium-Enriched Lentinus edodes for Increased Monacolin K Production.

Selenium-enriched Lentinus edodes (SL) is a kind of edible fungi rich in organic selenium and nutrients. Monascus purpureus with high monacolin K (MK) production and Saccharomyces cerevisiae were selected as the fermentation strains. A single-factor experiment and response surface methodology were conducted to optimize the production conditions for MK with higher contents from selenium-enriched Lentinus edodes fermentation (SLF). Furthermore, we investigated the nutritional components, antioxidant capacities, and volatile organic compounds (VOCs) of SLF. The MK content in the fermentation was 2.42 mg/g under optimal fermentation conditions. The organic selenium content of SLF was 7.22 mg/kg, accounting for 98% of the total selenium content. Moreover, the contents of total sugars, proteins, amino acids, reducing sugars, crude fiber, fat, and ash in SLF were increased by 9%, 23%, 23%, 94%, 38%, 44%, and 25%, respectively. The antioxidant test results demonstrated that 1.0 mg/mL of SLF exhibited scavenging capacities of 40%, 70%, and 79% for DPPH, ABTS, and hydroxyl radicals, respectively. Using gas chromatography-ion mobility spectrometry technology, 34 unique VOCs were identified in SLF, with esters, alcohols, and ketones being the main components of its aroma. This study showed that fungal fermentation provides a theoretical reference for enhancing the nutritional value of SL.

Early asymptomatic prediction of potato soft rot disease using phytohormone-induced volatile biomarkers.

Potatoes (Solanum tuberosum L.) are one of the world's major staple crops. In stored potatoes, Pectobacterium carotovorum subsp carotovorum causes soft rot. As a result of the rapid spread of the disease during post-harvest storage, potato production suffers huge losses. By detecting disease early and controlling it promptly, losses can be minimized. The profile of volatiles of plants can be altered by phytopathogens. Identifying unique volatile organic compounds (VOCs) as biomarkers for early disease detection has attracted considerable research attention. This study compared the VOC profiles of healthy and soft rot inoculated potatoes (cv. "Kufri Pukhraj") over a time course using gas chromatography-mass spectrometry (GC-MS). It was found that there was a differential emission of 27 VOCs between healthy non-inoculated potatoes and soft rot inoculated potatoes. Among 27 VOCs, only five (1-octen-3-ol, 2-methylisoborneol, 3-octanone, 1,4-dimethyladamantane, and 2-methyl-2-bornene) were found exclusively in soft rot inoculated potatoes, suggesting them potential biomarker for non-destructive prediction of soft rot disease in potatoes. Reactive oxygen species (H2O2) and phytohormone methyl-jasmonate (MeJa) levels increased transiently on infection with soft rot. The analysis of the primary metabolism of soft rot infected tubers at three different stages suggests metabolic reprogramming that occurs at the early stage of infection, possibly leading to biomarker volatile emission. Based on these results, it appears that the initial potato-soft rot bacteria interaction initiates metabolic reprogramming mainly through H2O2 and the MeJa signalling pathway. In asymptomatic potatoes, these biomarkers may be promising candidates for non-destructive detection of soft rot at an early stage. These biomarkers can be used to develop an e-nose sensor to predict soft rot in the future.

Unravelling the importance of seed roasting for oil quality by the non-targeted volatilomics and targeted metabolomics of cold-pressed false flax (Camelina sativa L.) oil and press cakes

False flax (Camelina sativa L.), known as camelina, is an ancient oil plant that has gathered renewed interest. In this study, a comprehensive analysis encompassing nontargeted volatilomics and targeted, quantitative metabolomics performed for cold-pressed oil and press cake and was integrated with sensory analysis of cold-pressed camelina oil and the effect of seed roasting was evaluated.Roasting in general resulted in the formation of 22 new volatile organic compounds (VOCs) in oil, while roasting at 140 and 180 °C resulted in the formation of 12 and 124 unique VOCs, respectively. Roasting notably influenced the profile of primary and secondary metabolites in both oil and press cakes, as well as volatilome and aroma of cold-pressed camelina oil. Many VOCs can be attributed to thermal degradation of primary and secondary metabolites. Roasting intensified the flavour of cold-pressed camelina oil, enhancing the perception of notes formed through the Maillard reaction.

Effect of thermosonication on the bioactive peptide profile, volatile compounds, and fatty acid profile of Minas Frescal cheese

This study investigated the effect of thermosonication (TS) of milk on the bioactive peptide profile, fatty acid composition, and volatile compounds of Minas Frescal cheese. Five cheese formulations were prepared: raw milk (Control), pasteurized milk (High-Temperature Short-Time or HTST) (72–75 °C/15 s), and milk treated by TS at nominal powers of 160 W (TS160), 400 W (TS400), and 640 W (TS640). The fatty acid profile and health indices did not change significantly after HTST or TS. TS, mainly TS400 treatment, increased the number of bioactive peptides with antihypertensive, antioxidant, immunomodulatory, and antimicrobial activities and promoted the formation of unique volatile organic compounds, mainly from the ester and fatty acid groups. In conclusion, TS can be considered by the dairy industry as an interesting alternative for manufacturing Minas Frescal cheese, resulting in products with greater functional potential and unique volatile compounds and keeping the fatty acid profile unchanged.

Analysis of unique volatile organic compounds in “Mianhua” made from wheat planted in arid alkaline land

Hebei Province's Huanghua “Mianhua” is a province intangible cultural property made from arid alkaline wheat (AAW). This study aims to assess how different soil conditions affect the volatile organic compounds (VOCs) of “Mianhua” and identify distinct VOCs for land type discrimination. These findings will guide future research on AAW products, enhancing their processing and utilization. 51 VOCs in “Mianhua” from wheat samples grown in arid alkaline land and general land in Huanghua were analyzed by Gas Chromatography-Ion Mobility Spectrometry (GC-IMS). The result of ANOVA, VOC fingerprint, T test, and OPLS-DA revealed VOCs differences based on planting environments. According to multivariate variance contribution rate analysis, most VOCs were more affected by the variety. Land type significantly influenced (E)-2-heptenal (75.3%), Butanol (60.6%), Propyl acetate (60.0%), ethyl pentanoate (45.5%), and ethyl acetate (44.4%). LDA progressively identified Butanol as the characteristic VOC to distinguish “Mianhua” between it made from AAW and general wheat (GW), with a classification accuracy of 75%.

Effects of the coculture of Pediococcus pentosaceus and Saccharomyces cerevisiae with different leavening ability on the quality and volatile organic compounds of Chinese steamed bread

Pediococcus pentosaceus has a promising potential to improve the quality and flavor of Chinese steamed bread (CSB), but its synergistic effect with Saccharomyces cerevisiae is still unclear. In this study, P. pentosaceus was cocultured with three S. cerevisiae isolates separately, which had different leavening ability. The times required for the fermentation of dough by 2 times the volume of S. cerevisiae isolates ACX 0089, ACX 0490 and ACX 0078 were 46, 88 and 120 min, respectively. The results showed that the leavening ability of S. cerevisiae had a significant impact on the quality of CSBs. Compared other S. cerevisiae isolates, the ACX 0490 cocultured with P. pentosaceus increased the contents of bound water and free water in CSB, decreased the content of semibound water, and produced larger and regular porosity, thus endowed a greater specific volume and softer texture. A total of 36 volatile organic compounds (VOCs) were found in CSBs, with alcohols accounting for the main component. The coculture of P. pentosaceus with the intermediate leavening ability of S. cerevisiae ACX 0490 produced the highest proportion of esters among all CSBs. Moreover, S. cerevisiae ACX 0490 endowed the CSB unique VOCs, including cyclodecanol, ethylacetate, and 3,5-dimethylbenzaldehyde. The results of sensory evaluation also showed that S. cerevisiae ACX0490 cocultured CSB obtained the highest scores among all the test samples. The results provided a reference for selecting S. cerevisiae isolates with different leavening ability and the combination of P. pentosaceus to achieve the best quality and flavor of CSB.

Brazilian indigenous nonstarter lactic acid bacteria enhance the diversification of volatile compounds in short-aged cheese.

There is growing interest in using autochthonous lactic acid bacteria (LAB) that provide unique sensory characteristics to dairy products without affecting their safety and quality. This work studied the capacity of three Brazilian indigenous nonstarter LABs (NSLAB) to produce biogenic amines (BAs) and evaluated their effect on the volatile organic compounds (VOCs), microbial LAB communities, and physicochemical profile of short-aged cheese. Initially, the strain's potential for biosynthesis of BAs was assessed by PCR and in vitro assays. Then, a pilot-scale cheese was produced, including the NSLAB, and the microbial and VOC profiles were analyzed after 25 and 45 days of ripening. As a results, the strains did not present genes related to relevant BAs and did not produce them in vitro. During cheese ripening, the Lactococci counts were reduced, probably in the production of alcohols and acid compounds by the NSLAB. Each strain produces a unique VOC profile that changes over the ripening time without the main VOCs related to rancid or old cheese. Particularly, the use of the strain Lacticaseibacillus. paracasei ItalPN16 resulted in production of ester compounds with fruity notes. Thus, indigenous NSLAB could be a valuable tool for the enhancement and diversification of flavor in short-aged cheese.

Abstract 4433: Secondary electrospray ionization mass spectrometry for volatile analysis of lung cancer

Abstract Lung cancer remains a leading cause of cancer-related mortality globally, necessitating innovative approaches for early detection and improved understanding of its metabolic landscape and consequences. Secondary Electrospray Ionization Mass Spectrometry (SESI-MS), an innovative analytical technique, has emerged as a powerful tool for the analysis of volatile organic compounds (VOCs) associated with various diseases, from metabolic disorders to bacterial infections. In this proof-of-concept study, we first utilized SESI-MS analyses of four representative lung cancer cells of both non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC) to demonstrate its capability to profile VOCs released by lung cancer cells. The technique allows for real-time, non-invasive analysis of the headspace above cultured cells, enabling the detection of unique VOC signatures associated with different lung cancer subtypes. Meanwhile, SESI-MS also facilitated the discrimination specific cells based on distinct VOC patterns. Furthermore, we also performed cisplatin treatment experiments and observed the metabolic signature shift post drug treatment. These results collectively offered potential applications in early diagnosis and personalized treatment strategies. Next, we continued with in vivo investigations to further extend the utility of SESI-MS in lung cancer research. Animal models, mimicking human lung cancer pathophysiology, have been subjected to SESI-MS analysis to identify volatile biomarkers indicative of tumor development and progression. Several representative cancer drug treatments were performed to the lung cancer mice model, and the drug-induced responses were also monitored via SESI-MS breath analyses. The in vivo SESI-MS approach detected many interesting breath VOC features that could provide valuable insights into the dynamic changes in VOC profiles during various stages of lung cancer, and therefore has the potential to offer a deeper understanding of the disease's metabolic alterations and potential avenues for targeted therapeutic interventions. In conclusion, SESI-MS-based volatile analysis presents a robust and versatile approach for investigating lung cancer, and our ongoing work has the potential to bridge the gap between in vitro and in vivo models for better translational research outcomes. The detection of unique VOC signatures associated with lung cancer cells and tumors holds significant promise for early detection, subtype classification, and monitoring of treatment responses. As technology continues to advance, SESI-MS stands poised to play a pivotal role in transforming the landscape of lung cancer diagnostics and research. Citation Format: Jiangjiang (Chris) Zhu, Fouad Choueiry. Secondary electrospray ionization mass spectrometry for volatile analysis of lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4433.

A nondestructive asymptomatic early disease prediction method employing ROS-induced differential volatile emissions from dry rot-infected potatoes

Potatoes are a staple crop with many health benefits. Postharvest storage of potatoes takes a considerable amount of time. Potato dry rot is one of the most serious postharvest storage diseases, caused primarily by the fungus Fusarium sambucinum. It is possible to minimize losses if disease is detected early, which allows it to be controlled promptly. A phytopathogen infection can alter the volatile profile of plants. Identifying unique volatile organic compounds (VOCs) as biomarkers for early disease detection is an area of considerable research interest. In this study, we compared the VOC profiles of healthy and dry rot inoculated potatoes (cv. "Kufri Pukhraj") over a time course using gas chromatography-mass spectrometry (GC-MS). There were 29 differentially emitting VOCs between healthy and dry rot inoculated potatoes. Nevertheless, only four of these compounds (linalool tetrahydride, γ-muurolene, alloaromadendrene, and α-isomethyl ionone) were exclusively found in dry rot inoculated potatoes, and hence they were considered biomarkers. Furthermore, reactive oxygen species (ROS) levels were altered in potatoes that were inoculated with dry rot, suggesting a role for ROS signaling in differential VOC emissions. In the early stages of dry rot infection, when symptoms were barely visible, these four biomarker VOCs were robustly useful in distinguishing healthy and dry rot-infected potatoes. These novel biomarkers associated with this disease are promising candidates for non-destructive detection of dry rot in stored potatoes at an early asymptomatic stage. These biomarkers can be used to develop an e-nose sensor to predict dry rot in the future.

Species profile of volatile organic compounds emission and health risk assessment from typical indoor events in daycare centers

Daycare centers (DCCs) play an instrumental role in early childhood development, making them a significant indoor environment for a large number of children globally. Amidst routine DCC activities, young children are exposed to a myriad of volatile organic compounds (VOCs), potentially impacting their health. Therefore, this study aims to investigate the VOC emissions during typical DCCs activities and evaluate respective health risk assessments. Employing a full-scale experimental setup within a well-controlled climate chamber, research was conducted into VOC emissions during three typical DCC events: arts-and-crafts (painting, gluing, modeling), cleaning, and sleeping activities tied to mattresses. The research identified 96 distinct VOCs, grouped into twelve categories, from 20 different events examined. Each event exhibited a unique VOC fingerprint, pinpointing potential source tracers. Also, significant variations in VOC emissions from different events were demonstrated. For instance, under cool & dry conditions, acrylic painting recorded high total VOC concentrations of 808 μg/m3, whereas poster painting showed only 58 μg/m3. Given these disparities, the study emphasizes the critical need for carefully selecting arts-and-crafts materials and cleaning agents in DCCs to effectively reduce VOC exposure. It suggests ventilating new mattresses before use and regular mattress check-ups to mitigate VOCs exposure during naps. Importantly, it revealed that certain events resulted in VOC levels exceeding the 10−5 cancer risk thresholds for younger children. Specifically, tetrachloroethylene and styrene from used mattresses in cool & dry conditions, ethylene oxide from new mattresses in warm & humid conditions, and styrene, during sand modeling in both conditions, were the key compounds contributing to this risk. These findings highlight the critical need for age-specific health risk assessments in DCCs. This study highlights the significance of understanding the profiles of VOC emissions from indoor events in DCCs, emphasizing potential health implications and laying a solid foundation for future investigations in this field.

Effect of Natural Variation and Rootstock on Fruit Quality and Volatile Organic Compounds of ‘Kiyomi tangor’ (Citrus reticulata Blanco) Citrus

In this study, we compared the fruit quality and color of ‘Kiyomi’ (WT) and its mutant (MT) grafted on Ziyang xiangcheng (Cj) (WT/Cj, MT/Cj), and the MT grafted on Trifoliate orange (Pt) (MT/Pt). The differences in sugar, organic acid, flavonoids, phenols, and volatile substances of the three materials were also analyzed by high performance liquid chromatography (HPLC) and headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC–MS). The results showed significant differences in the appearance of WT/Cj, MT/Cj, and MT/Pt. MT/Pt, compared to WT/Cj, MT/Cj, had lower sugar, acid, phenol and flavonoid contents in the pulp. However, MT/Pt pulp was higher in vitamin C (VC), and the peel had significantly higher total phenol and flavonoid contents. In terms of pulp, WT/Cj had the greatest diversity of volatile organic compounds (VOCs). 4-methyl-1-pentanol was significantly higher in MT/Cj pulp, while MT/Pt pulp had a unique octanoic acid, methyl ester. VOCs were more diverse in the peels of the three materials. β-Myrcene and valencen were significantly higher in MT/Cj peels. In contrast, 16 unique VOCs were detected in MT/Pt, and D-limonene content was significantly higher than in WT/Cj and MT/Cj. The results suggest Trifoliate orange is a suitable rootstock for MT.

Machine-learning-assisted sensor array for detecting COVID-19 through simulated exhaled air

Reverse transcription polymerase chain reaction (RT-PCR), the primary test for COVID-19, requires complicated sample collection and several hours to obtain results. Breath test for exhaled volatile organic compounds (VOCs) has gained substantial research attention as a simple non-invasive and fast screening method. However, a unique VOC fingerprint as a potential prognostic biomarker is still unavailable. Accordingly, this study prepared simulated VOC gases to test the classification performance of a sensing system. The simulated VOC gases were selected according to the actual composition of the exhaled breath of patients with acute respiratory diseases, including COVID-19. Two sets of metal oxide sensor arrays, comprising eight commercial sensors and eight Advanced Institute of Science and Technology (AIST) laboratory-made sensors, were prepared to test their sensing ability for the simulated gases. The principal component analysis (PCA) results revealed that the AIST sensors had better sensing ability than the commercial sensors. Moreover, the recursive feature elimination cross-validation (RFECV) of random forest (RF) further confirmed the superiority of the AIST sensors over the commercial sensors. An artificial neural network (ANN) with excellent prediction performance for gas concentration was developed. This study provides a promising method for rapidly screening respiratory diseases.

Volatile organic compounds emitted by conventional and “green” cleaning products in the U.S. market

Exposure to cleaning products has been associated with harm to the respiratory system, neurotoxicity, harm to the reproductive system, and elevated risk of cancer, with greatest adverse impacts for workers exposed in an occupational setting. Social and consumer interest in cleaning products that are safer for health created a market category of “green” products defined here as products advertised as healthier, non-toxic, or free from harmful chemicals as well as products with a third-party certification for safety or environmental features. In the present study we examined the air quality impacts of cleaning products and air fresheners, measuring the number, concentrations, and emission factors of volatile organic compounds (VOCs) in an air chamber following product application. Across seven common product categories, 30 products were tested overall including 14 conventional, 9 identified as “green” with fragrance, and 7 identified as “green” and fragrance-free. A total of 530 unique VOCs were quantified with 205 additional VOCs detected below the limits of quantification. Of the quantifiable VOCs, 193 were considered hazardous according to either the California's Department of Toxic Substances Control Candidate Chemicals List or the European Chemical Agency's Classification and Labeling Inventory. The total concentration of VOCs and total emission factors across all products with detections ranged from below limits of detection to 18,708 μg/m3, 38,035 μg/g product and 3803 μg/application. Greater total concentration, total emission factors, and numbers of VOCs were generally observed in conventional cleaning products compared to products identified as “green”, particularly compared to fragrance-free products. A hazard index approach was utilized to assess relative risk from measured VOC emissions. The five products with the highest hazard indices were conventional products with emissions of 2-butoxyethanol, isopropanol, toluene and chloroform. Overall, this analysis suggests that the use of “green” cleaning products, especially fragrance-free products, may reduce exposure to VOC emissions.

Variation in ripe fruit volatiles across the tomato clade: an evolutionary framework for studying fruit scent diversity in a crop wild relative.

The scents of volatile organic compounds (VOCs) are an important component of ripe fleshy fruit attractiveness, yet their variation across closely related wild species is poorly understood. Phylogenetic patterns in these compounds and their biochemical pathways offer insight into the evolutionary drivers of fruit diversity, including whether scent can communicate an honest signal of nutrient content to animal dispersers. We assessed ripe fruit VOC content across the tomato clade (Solanum sect. Lycopersicon), with implications for crop improvement since these compounds are key components of tomato flavor. We analyzed ripe fruit volatiles from 13 species of wild tomato grown under common garden conditions. Interspecific variation in 66 compounds and their biochemical pathways was assessed in 32 accessions, with an accession-level phylogeny accounting for relatedness. Wild tomato species can be differentiated by their VOCs, with Solanum pennellii notably distinct. Phylogenetic conservatism exists to a limited extent. Major clade-wide patterns corresponded to divergence of the five colored-fruited species from the nine green-fruited species, particularly for nitrogen-containing compounds (higher in colored-fruited) and esters (higher in green-fruited), the latter appearing to signal a sugar reward. We established a framework for fruit scent evolution studies in a crop wild relative system, showing that each species in the tomato clade has a unique VOC profile. Differences between color groups align with fruit syndromes that could be driven by selection from frugivores. The evolution of colored fruits was accompanied by changes in biochemical pathways underlying esters and nitrogen-containing compounds, volatiles important to tomato flavor. This article is protected by copyright. All rights reserved.

The volatilome reveals microcystin concentration, microbial composition, and oxidative stress in a critical Oregon freshwater lake.

Toxins produced by cyanobacterial blooms in freshwater lakes are a serious public health problem. The conditions leading to toxin production are unpredictable, thereby requiring expensive sampling and monitoring programs globally. We explored the potential of volatile organic compounds (VOCs) to indicate microcystin presence and concentration and microbial community composition in Upper Klamath Lake, Oregon. Elastic net regularization regression selected 24 of 229 detected m/z + 1 values (corresponding to unique VOCs) in models predicting microcystin contamination. These models outperformed regression models based only on environmental parameters, including chlorophyll, pH, and temperature. Several m/z + 1 values selected by elastic net were putatively identified as saturated fatty aldehydes, which defend cyanobacteria against oxidative stress. Elastic net also identified unique sets of m/z + 1 values that predicted the relative abundance of the dominant bacterial phyla, classes, and cyanobacterial genera. VOCs appear to reveal the physiological status of cyanobacteria during toxic blooms and may be a key component of lake monitoring strategies. IMPORTANCE Harmful algal blooms are among the most significant threats to drinking water safety. Blooms dominated by cyanobacteria can produce potentially harmful toxins and, despite intensive research, toxin production remains unpredictable. We measured gaseous molecules in Upper Klamath Lake, Oregon, over 2 years and used them to predict the presence and concentration of the cyanotoxin, microcystin, and microbial community composition. Subsets of gaseous compounds were identified that are associated with microcystin production during oxidative stress, pointing to ecosystem-level interactions leading to microcystin contamination. Our approach shows potential for gaseous molecules to be harnessed in monitoring critical waterways.

Defect engineering of two-dimensional ultrathin Co3O4 nanosheets for wireless and high-performance monitoring of the sensing properties of volatile organic compounds

Volatile organic compounds (VOCs) as serious outdoor and indoor air pollutants have attracted great attention. Many detection technologies of VOCs have been investigated. However, it is challenging to develop an efficient and portable wireless sensor for monitoring VOCs. Here, we proposed a new strategy to obtain a high-performance VOC sensor based on two-dimensional Co3O4 nanosheets (NSs) with numerous oxygen vacancy defects. The Co3O4 NS-30 W sensor detected 200 ppm ethanol and exhibited a high response value (10.70) and fast response and recovery behavior (20 s and 17 s, respectively). The effect of oxygen vacancy defects on the sensitive properties was studied by theoretical calculations on the (110) plane of Co3O4. Furthermore, a unique VOC wireless sensor was fabricated in order to enable wireless early warning from multiple terminals and monitoring of alcohol in exhaled gas. The VOC sensor exhibited a promising potential for precisely monitoring the alcohol consumption of drivers.

Natural Variation Confers 'Aiyuan 38' Citrus Mutant a New Color and Unique Flavor.

Citrus exhibits unique nutritional values. Most citrus cultivars are derived from mutations. However, the effect of these mutations on fruit quality is unclear. We have previously found a yellowish bud mutant in the citrus cultivar 'Aiyuan 38'. Therefore, this study aimed to determine the effect of the mutation on fruit quality. 'Aiyuan 38' (WT) and a bud mutant variant (MT) were used to analyze variations in fruit color variation and flavor substances using colorimetric instruments, high-performance liquid chromatography (HPLC), headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS), and odor activity values (OAVs). The mutation in MT conferred yellowish characteristics to its peel. Although the differences in total sugar and acid content of the pulp were not statistically significant between WT and MT, the MT glucose content was significantly lower and the malic acid level was significantly higher. HS-SPME-GC-MS analysis revealed that the MT pulp released more types and contents of volatile organic compounds (VOCs) than the WT, whereas the opposite trend was observed for the peel. Analysis of the OAV revealed that the MT pulp contains 6 unique VOCs, whereas the peel contains only 1. This study provides a useful reference for the study of flavor substances associated with citrus bud mutations.