Integration of E-tongue, GC-IMS and chemometrics for unraveling the disparities in volatile profiles of optimized jujube craft beers.

To investigate the impact of varying steaming durations on the flavor characteristics of mutton and carrot stuffing, dynamic changes in volatile organic compounds (VOCs) and fatty acids were analyzed using solid-phase micro-extraction gas chromatography-mass spectrometry (SPME-GC-MS) and gas chromatography-ion mobility spectrometry (GC-IMS). The results revealed a total of 116 VOCs identified throughout the steaming process, with 73 detected by GC-MS and 44 by GC-IMS. Notably, VOC concentrations were significantly higher at 18-24 min compared to 8-16 min. Additionally, a GC-IMS fingerprint was developed to assess the distribution of VOCs during steaming. Orthogonal partial least squares discriminant analysis (OPLS-DA) indicated that 11 compounds, such as ethyl caprylate (B3), linalyl acetate (B6), and 1-nonanal (C1), significantly influenced the flavor characteristics of the mutton and carrot filling. Further analysis demonstrated that stearic acid content reached its lowest point at 20-22 min of steaming, while n-6 and n-3 series polyunsaturated fatty acids (PUFAs) and the ratio of polyunsaturated fatty acids to saturated fatty acids (P/S) peaked at this time.

This study evaluated the volatile organic compounds (VOCs) and taste properties of Gorgon Euryale seeds processed by five methods (steaming, boiling, microwaving, roasting, and stir-frying) using electronic tongue (E-tongue), electronic nose (E-nose), gas chromatography-mass spectrometry (GC-MS), and gas chromatography-ion mobility spectrometry (GC-IMS). A total of 44 and 40 VOCs were identified by GC-MS and GC-IMS, respectively. Pyrazines (2-ethyl-3,5-dimethylpyrazine, 2,3-diethyl-5-methylpyrazine) and furans (2-pentylfuran, 2-ethylfuran) played a major role in the baked aroma characteristics of roasted and stir-fried Gorgon Euryale seeds. Six and seven marker compounds were identified by Orthogonal Partial Least Square Discriminant Analysis (OPLS-DA) models for GC-MS and GC-IMS based on 12 VOCs with odor activity value>1 and 18 VOCs with relative odor activity value>0.1, respectively. OPLS-DA and principal component analysis score plots of the E-tongue and E-nose demonstrated that samples could be effectively distinguished in terms of flavor. This research provides a comprehensive basis for evaluating the impact of processing methods on the changes in flavor of Gorgon Euryale seeds. PRACTICAL APPLICATION: This work demonstrates that the use of E-tongue, E-nose, HS-SPME-GC-MS, and GC-IMS has the capability to thoroughly analyze the flavor profile of Gorgon Euryale seeds at both macro and micro levels. This approach effectively distinguishes Gorgon Euryale products subjected to different processing treatments and provides a reliable reference for evaluating and identifying the flavor quality of Gorgon Euryale seeds.

Huanglongbing (HLB) is caused by “Candidatus Liberibacter asiaticus” and is spread by citrus psyllids. It is a highly damaging and infectious disease of citrus for which there is no reliable treatment. Timely detection and removal of diseased trees is an effective strategy to control HLB. Various citrus cultivars infected with HLB exhibit distinct symptoms, posing a challenge to generalize HLB detection methods across multiple cultivars. Volatile organic compounds (VOCs) in HLB‐infected leaves from cultivars grown in different regions were comprehensively analysed by gas chromatography–mass spectrometry (GC‐MS) and gas chromatography‐ion mobility spectrometry (GC‐IMS), aiming to establish a new generalized HLB detection method applicable to a range of citrus cultivars. The changes in VOCs were analysed in leaves of four citrus cultivars after infection with HLB. The results showed that there was a similar response to HLB infection in different citrus cultivars, and this response was reflected in both the concentration and type of VOCs. By combining GC‐MS and GC‐IMS with orthogonal partial least squares discriminant analysis (OPLS‐DA) model, the accurate identification of the HLB infection status of different citrus cultivars was achieved, with the prediction indices reaching 0.994 for GC‐MS and 0.972 for GC‐IMS. In addition, 27 compounds were identified that were significantly different between citrus cultivars affected by HLB and healthy plants. This study provides valuable insights into the changes in VOCs in citrus cultivars after HLB infection and lays the theoretical foundation for VOC‐based HLB detection strategies.

Evaluating the influence of high-temperature sterilization and pasteurization on volatile organic compounds in tomato stewed beef brisket: An analysis using gas chromatography-ion mobility spectrometry and multivariate statistical visualization

Characterization of the effect of different cooking methods on volatile compounds in fish cakes using a combination of GC–MS and GC-IMS

Fat has a great impact on the meat product flavor, which is influenced by cooking time. This study explored the effect of different steaming times on the fat flavor of pork belly. A total of 14 aldehydes, 11 ketones, 6 esters, 4 alcohols, and 1 acid volatile compounds were identified through gas chromatography ion mobility spectrometry (GC-IMS). The relative odor activity value (ROAV) combined with the principal component analysis (PCA) method showed that the aroma of pork belly fat was considerably different under different steaming times. The quantity of key volatile compounds with ROAV ≥ 1, namely, heptanal, ethyl hexanoate, 2-methylbutanal-m, 3-methylbutanal, ethyl acetate, and 2, 3-butanedione increased considerably in the fat after steaming. The fat gives rise to two key volatile compounds, hexanal-d and 1-heptanol, after steaming for 30 min. Similarly, ethyl formate and 3-hydroxy-2-butanone were obtained as the key volatile compounds after steaming for 180 min. PRACTICAL APPLICATIONS: Pork belly is the main ingredient of Chinese traditional dishes such as Dongpo's pork and braised pork in brown sauce. When heated for extended periods of time, the high fat content of pork belly gives rise to important precursors that influence the flavor characteristics of these dishes. However, studies comparing the diversities of volatile compounds in pork belly fat exposed to different heating times are sparse. To address this gap in literature, this study identified the flavor components of pork belly fat exposed to different heating times. The data from this study can act as a framework for further flavor research on pork belly products.

Ambient volatile organic compound (VOC) concentrations around a petrochemical complex and a petroleum refinery

This study investigates the carotenoid and volatile compositions of one sample of lupin oil (Lupinus angustifolius) and five samples of lupin oil flavored with aromatic herbs, namely, basil, chives, rosemary, sage, and thyme. Flavored oils are obtained by macerating lupin oil with the herbs for 15 days, in the dark at 15 ± 1 °C. Overall 11 carotenoids are identified by HPLC‐DAD‐MS‐(APCI). (all‐E)‐Lutein and β‐carotene are the most abundant. Thyme flavored oil results the richest in carotenoids, with a cumulative carotenoid content of 195 ± 13 μg mL−1. Volatile organic compounds are detected by HS‐SPME‐GC/MS analysis. Overall, 50 aroma compounds are determined, with alcohols, furans, and terpenoids being the most abundant classes. Chives flavored oil is the only sample to provide organosulfur compounds. Qualitatively, terpenoids are responsible for great differences among the samples, since unique terpenoid profiles are observed, for example, isoterpinolene is detected only in sage flavored oil, β‐myrcene in rosemary flavored oil, and thymol in thyme flavored oil. The relative odor activity value (ROAV) is determined and employed to evaluate the contributions of the single compounds to the overall odor. The compounds with the greatest odor activity are 3‐hexen‐1‐ol, hexanal, α‐pinene, eucalyptol, and 2‐pentylfuran.Practical Applications: Aromatic herbs have been traditionally used to enhance the flavor of food. The effects of herbs addition on lupin products has not been investigated yet. Additionally, this is the first study that explores some quality characteristics of commercial lupin oil. Data indicate that the maceration of lupin oil with aromatic herbs has limited effects on the content of total carotenoids, nonetheless, it modifies markedly the composition and relative proportions of the volatile organic compounds, and likely the overall aromas. Consumers are generally not familiar with the culinary use of lupin oil, nevertheless, the aromatization with herbs could increase its use. Lupin oil results rich in carotenoids. This is useful information for the production of functional products with healthy properties. Lupin oil can be recommended as a carotenoid‐rich product and as an alternative to more traditional table oils. Data from this study can contribute to the economic valorization of lupin oil.This study assesses the effects of the maceration of lupin oil with aromatic herbs, e.g., basil, chives, rosemary, sage, and thyme on the content of volatile organic compounds, and investigates the carotenoid profile of the flavored oils. Flavored oils are prepared by macerating lupin oil with the herbs (6% w/w) for 15 days, in the dark at 15 ± 1°C. Plain lupin oil and basil, chives, and thyme flavored oils are relatively rich in 2‐pentylfuran, whereas rosemary flavored oil is abundant in α‐pinene. (all‐E)‐Lutein is the predominant carotenoid in all the experimental oils, followed by β‐carotene.

ABSTRACTHeadspace solid-phase microextraction/gas chromatography–mass spectrometry (HS-SPME/GC–MS) analysis combined with ‘relative odour activity value (ROAV)’ was used to monitor changes in key volatile compounds in peanut oil, soybean oil, rapeseed oil, and linseed oil during ambient storage. Volatile composition and oxidation process were compared among edible oil samples. The differences in the volatile contents of edible oils led to their characteristic flavour. Aldehydes featured a relatively high content and low odour threshold and mainly contributed to the flavour of edible oils. The key flavour compounds included pentanal, hexanal, octanal, nonanal, trans-2-heptenal, and benzaldehyde, which are important oxidative degradation products of oleic acid and linoleic acid. The formation of key volatile oxidation compounds was affected by different oxidation processes during ambient storage. Certain aldehydes increased with oxidation level, whereas other aldehydes initially increased then decreased. Correlation analysis showed that the concentrations of several volatile compounds progressively increased during oxidation. The key volatile oxidation compounds formed during oil storage at ambient temperature are partly different from those generated at high temperatures. Volatile oxidation compounds can be a marker for monitoring the oxidation degree of edible oils during ambient storage.

Nosocomial infections caused by Escherichia coli (E. coli) may pose serious risks to patients, and early identification of pathogenic bacteria and drug sensitivity results can improve patient prognosis. In this study, we clarified the composition and relative content of volatile organic compounds (VOCs) generated by E. coli in tryptic soy broth (TSB) using gas chromatography-ion mobility spectrometry (GC-IMS). We explored whether imipenem (IPM) could be utilized to differentiate between carbapenem-sensitive E. coli (CSEC) and carbapenem-resistant E. coli (CREC). The results revealed that 36 VOCs (alcohols, aldehydes, acids, esters, ketones, pyrazines, heterocyclic compounds, and unknown compounds) were detected using GC-IMS. Besides, the results indicated that changes in the relative content of VOCs as well as changes in the signal intensity of fingerprints were able to assess the growth state of bacteria during bacterial growth and help identify E. coli. Lastly, under selective pressure of IPM, volatile fingerprints of E. coli could be employed as a model to distinguish CSEC from CREC strains.

Characterization, reactivity, source apportionment, and potential source areas of ambient volatile organic compounds in a typical tropical city

Drivers and impacts of decreasing concentrations of atmospheric volatile organic compounds (VOCs) in Beijing during 2016–2020

Background: Air pollution is one of the biggest problems in the world, and it is generated by industrial production, vehicular flow and use of fossil fuels, leaving aside other important emission sources such as vegetation. The aim of this research is to quantify the emissions of natural volatile organic compounds produced by the forest species: Eucalyptus globulus L., Pinus radiata and Alnus acuminata in Riobamba, Ecuador. Methods: Identification of plant coverings in the years 2014 and 2017was performed using geographic information systems tools, complemented with the application of the Guenther model for the calculation of monoterpenes and other organic volatile compounds; thus, to analyze the relationship between meteorological variables and concentrations of volatile organic compounds and nitrogen dioxide per species. Results: Mathematical calculation of emissions in Riobamba showed that Eucalyptus globulus L. registered higher emissions in the years 2014-2017, followed by Pinus radiata and Alnus acuminata. These emissions are due to the vegetation cover covering each species. The analysis of volatile organic compounds in forest plantations in air is directly related to the emissions represented in the environment and correlated with the meteorological variables of temperature, global solar radiation and wind velocity. The proposed method manages to estimate concentrations of monoterpenes and volatile organic compounds for the two examined seasons, presenting the influence of the species introduced in this study such as Eucalyptus globulus L. and Pinus radiata, with a reduction in their emissions (less area found in the year 2017, with respect to 2014). However, the emission of Alnus acuminata can be quantified only in 2017, since in 2014 no records of this species were found. Conclusions: Volatile organic compound concentrations in the air are directly related to the emissions represented spatially and correlated with the meteorological variables of temperature, global solar radiation and wind velocity.

Background: Air pollution is one of the biggest problems in the world, and it is generated by industrial production, vehicular flow and use of fossil fuels, leaving aside other important emission sources such as vegetation. The aim of this research is to quantify the emissions of natural volatile organic compounds produced by the forest species: Eucalyptus globulus L., Pinus radiata and Alnus acuminata in Riobamba, Ecuador. Methods: Identification of plant coverings in the years 2014 and 2017was performed using geographic information systems tools, complemented with the application of the Guenther model for the calculation of monoterpenes and other organic volatile compounds; thus, to analyze the relationship between meteorological variables and concentrations of volatile organic compounds and nitrogen dioxide per species. Results: Mathematical calculation of emissions in Riobamba showed that Eucalyptus globulus L. registered higher emissions in the years 2014-2017, followed by Pinus radiata and Alnus acuminata. These emissions are due to the vegetation cover covering each species. The analysis of volatile organic compounds in forest plantations in air is directly related to the emissions represented in the environment and correlated with the meteorological variables of temperature, global solar radiation and wind velocity. The proposed method manages to estimate concentrations of monoterpenes and volatile organic compounds for the two examined seasons, presenting the influence of the species introduced in this study such as Eucalyptus globulus L. and Pinus radiata, with a reduction in their emissions (less area found in the year 2017, with respect to 2014). However, the emission of Alnus acuminata can be quantified only in 2017, since in 2014 no records of this species were found. Conclusions: Volatile organic compound concentrations in the air are directly related to the emissions represented spatially and correlated with the meteorological variables of temperature, global solar radiation and wind velocity.

Ammonia (NH3), temperature, moisture content, pH, pack depth, nutrient composition and concentration of odorous volatile organic compounds (VOC) were measured at 56 locations in each of four pens in two commercial beef deep-bedded mono-slope facilities (BDMF). Areas of high NH3 concentration occurred randomly throughout the pens. Ammonia concentration increased as pack and ambient air temperature increased. Concentration of VOC was highest in transition areas between the bedded pack and the concrete floor. Depth, moisture content, and pH of the bedded pack did not influence concentration of NH3 and VOC. Nutrient composition of the manure/bedding material in BDMF is similar to manure in open feedlots, except that in BDMF the volatile solids content is much higher. E. coli concentrations can occur at high levels in BDMF and vary with differences in ambient temperature. Priority should be given to NH3 and E. coli mitigation during hot months. However, locationspecific NH3 mitigation will not be effective due to the random distribution of NH3 in the pen. Frequent cleaning of the area surrounding the bedded pack should reduce VOC concentration.