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ABSTRACT Crocus 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. [ABSTRACT FROM AUTHOR]

Fermentation is critical for producing high‐quality cocoa, yet its kinetics and resulting chemical and sensory outcomes are poorly understood and thus difficult to manage. Cocoa sweatings (CS), the liquid runoff produced early during fermentation and typically drained off, may beneficially affect fermentation outcome when added back into the fermenting mass. Here, we report how back‐addition of CS affects composition and sensory perception of roasted cocoa liquor after 5, 6, and 7 days of fermentation. Cocoa liquor (= 100% chocolate) made from beans fermented for 5 days with the addition of CS were similar in sensory perception to those fermented for 7 days without added CS. Twenty‐one flavor compounds showed similar patterns to the sensory results: In the beans fermented with CS, these compounds remained at similar levels after 5, 6, and 7 days of fermentation, while the same compounds significantly changed in the samples fermented conventionally, without CS addition. These results suggest a link between changes in flavor composition and sensory differences in roasted cocoa. Future work is needed to reveal the mechanism of flavor stabilization throughout fermentation resulting from the back‐addition of CS. Practical Application: Roasted cocoa liquor fermented with cocoa sweating (CS) is sensorily similar when fermented for 5 or 7 days and produces cocoa that is sensorily similar to traditionally fermented cocoa in shorter time (5 days vs. 7 days). The addition of CS seems to stabilize 21 flavor compounds throughout fermentation mimicking changes in sensory perception. The back‐addition of CS could help standardize cocoa fermentation as indicated by more consistent temperature evolution. [ABSTRACT FROM AUTHOR]

The volatile components of Stropharia rugosoannulata and Tricholoma lobayense were analyzed by mass spectrometry, and the relative contents of each component were determined by the internal standard method. In Stropharia rugosoannulata, 58 volatile components were identified, including 10 alcohols, 14 esters, 9 aldehydes, 5 ketones, 1 phenol, 3 alkanes, 4 amines, 5 acids, 1 furan, 1 pyrazine, 1 olefin, 1 oxime, 1 pyrazole, and 2 other components. Among them, the most abundant volatile component was hexanal (1655.40 ng/g), followed by pentanoic acid (1503.10 ng/g) and phenylethyl alcohol (1215.94 ng/g). In Tricholoma lobayense, 68 volatile components were identified, including 17 aldehydes, 11 ketones, 8 acids, 10 esters, 5 alcohols, 1 phenol, 2 furans, 4 alkanes, 1 alkene, 1 oxime, 1 pyrazole, 1 amine, and 6 other components. Among them, the most abundant volatile component was benzaldehyde (2190.67 ng/g), followed by hexanal (1708.81 ng/g) and furan, 2-pentyl- (838.45 ng/g). There were 21 common volatile components between the two different edible fungi, including 7 aldehydes, 5 esters, 3 ketones, 2 alcohols, 2 acids, 1 oxime, and 1 furan. [ABSTRACT FROM AUTHOR]

In order to study the key flavor characteristics and the influence of oxidation degree of oil on warmed-over flavor of pre-prepared steamed pork with preserved vegetable. The volatile flavor compounds and taste indexes of different brands of pre-prepared steamed pork with preserved vegetable were quantitatively detected by headspace-solid phase micro- extraction-gas chromatography-mass spectrometry and electronic tongue. The key flavor factors of pre-prepared steamed pork with preserved vegetable were screened and analyzed by odor activity value (OAV) and principal component analysis. Acid value, peroxide value and TBA value were used to analyze the oxidation degree of oil and warmed-over flavor of different brands of pre-prepared steamed pork with preserved vegetable. Results showed that a total of 85 volatile compounds were identified from 7 kinds of pre-prepared steamed pork with preserved vegetable, including 16 alkanes, 19 terpenes, 7 alcohols, 22 aldehydes, 3 ketones, 13 esters, 3 phenols and 2 others. A total of 23 key volatile compounds were screened by OAV, and the substances with OAV>10 were 1-octene-3-ol, hexanal, heptanal, octanal, nonanal, (E,E)-2,4- nonadienal, capric aldehyde, (E)-2-decenal, (E,E)-2,4-decenal and 1-octene-3-ketone, which were the key flavor substances for pre-prepared steamed pork with preserved vegetable. The results of electronic tongue and overripe taste evaluation showed that the taste of 7 kinds of pre-prepared steamed pork with preserved vegetable were mainly salty, umami and aftertaste. Its overripe taste mainly presented linseed oil taste and rancidity taste. The oil oxidation indexes of 7 kinds of pre-prepared steamed pork with preserved vegetable were higher and the differences were significant (P<0.05). The correlation analysis showed that the main factors that produce warmed-over flavor were (E)-2-decenal, 2-heptanone, nonylaldehyde, 1-octene-3-ketone, (E,E)-2,4-decenal, hexal, pentaldehyde, heptanal, (E)-2-heptenal and octanal, which were positively correlated with acid value, peroxide value and TBA value. In summary, the key flavor factors of the 7 kinds of pre-prepared steamed pork with preserved vegetable were related to overcooked taste, and it was speculated that the overcooked taste of pre-prepared steamed pork with preserved vegetable was related to the higher oxidation degree of oil. The key flavor factors, electronic tongue and overripe taste evaluation indexes obtained in this study provide the basis for the establishment of flavor quality system and overripe taste control of pre-prepared steamed pork with preserved vegetable. [ABSTRACT FROM AUTHOR]

To explore the characteristics of and variations in aroma components across different plum varieties and maturity stages, this study employed headspace solid-phase microextraction combined with gas chromatography–mass spectrometry (HS-SPME-GC-MS). This method was used to systematically analyze the aroma components of 12 early-maturing, 15 medium-maturing, and 11 late-maturing plum varieties. The variations in volatile components among these three germplasm types were then compared using multivariate statistical methods. The examination revealed that 138 aromatic components were meticulously identified and quantified, such as 26 aldehydes, 63 esters, 13 ketones, 30 alcohols, and six other compounds. Thirteen main aroma compounds including acetic acid hexyl ester, (Z)-3-hexen-1-ol acetate, hexanal, 1-hexanol, 3-hexenal, butanoic acid butyl ester, (E)-2-hexen-1-ol, hexanoic acid butyl ester, propanoic acid butyl ester, (E)-2-hexenal, L-.alpha.-terpineol, (Z)-2-hexen-1-ol acetate, and 1-butanol were considered dominant. The orthogonal partial least squares discriminant analysis (OPLS-DA) combined with variable importance projection (VIP) results showed that 24 differential aroma compounds were screened out from 38 varieties of plum fruits based on their differences in aroma components, which can be used to distinguish plum fruits at different ripening times. Twenty-four aroma-contributing compounds were identified based on their odor activity values (OAVs). Among these, 14 key aroma components with OAVs ≥ 10 were highlighted. In summary, the aroma compounds of early- and late-maturing plum germplasm exhibited rich diversity, with significant differences in aroma components between plums of varying maturity and germplasm. These differences can serve as indicators for identifying different plum germplasm. [ABSTRACT FROM AUTHOR]

Tea standard samples are the benchmark for tea product quality control. Understanding the inherent differences in Chinese national standards for Lapsang Souchong black tea of different grades is crucial for the scientific development of tea standardization work. In this study, Lapsang Souchong black tea of different grades that meet Chinese national standards was selected as the research object. The aroma characteristics were comprehensively analyzed through sensory evaluation, electronic nose, and HS-SPME-GC-MS (headspace solid-phase microextraction gas chromatography–mass spectrometry). The findings indicate that the higher-grade Lapsang Souchong has a higher evaluation score. The results of electronic nose analysis indicate that the volatiles with differences in tea of different grades were mainly terpenoids and nitrogen oxides. The results of HS-SPME-GC-MS analysis show that the odor characteristics of the super-grade samples are mainly floral and fruity, and these substances mainly include D-Limonene, 3,7-dimethyl-1,6-octadien-3-ol and 3-Hydroxymandelic acid, and ethyl ester. The primary aroma characteristics of the first-grade samples are floral, sweet, woody, and green, with key contributing compounds including 2-Furanmethanol, 1-Octen-3-ol, and 5-ethenyltetrahydro-α,α,5-trimethyl-cis-, 4,5-di-epi-aristolochene. The main aroma characteristics of the second-grade samples are green, herbal scent, and fruity, and the main substances include 3,7-dimethyl-1,6-octadien-3-ol, 2,3-dimethylthiophene, Dihydroactinidiolide, and Naphthalene-1-methyl-7-(1-methylethyl)-. It is worth noting that the second-grade samples contain a large amount of phenolic substances, which are related to the smoking process during processing. This study lays a solid foundation for the preparation of tea standard samples and the construction of the tea standard system. [ABSTRACT FROM AUTHOR]

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

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

Featured Application: Featured Application: This study provides a comprehensive analysis of the impact of various vinification techniques, including prolonged maceration, pre-fermentation heating, and barrel aging, on the volatile aroma profile and sensory characteristics of Teran red wine. Teran (Vitis vinifera L.) is the most widespread red autochthonous variety in Istria, traditionally grown in the north Adriatic area, including the Croatian Istria viticultural subregion. As a key grapevine variety in viticulture across these regions, understanding the impact of the investigated techniques is crucial for enhancing its unique characteristics and market value. These insights can be directly applied by winemakers to optimize and tailor wine production processes, enhancing desirable aroma attributes and sensory qualities to meet specific market demands. The findings offer practical guidelines for producing wines with distinct and appealing aromatic profiles, aiding in product differentiation and improving overall wine quality. This study investigates the effect of prolonged maceration, pre-fermentation heating, and barrel aging on the volatile aroma profile and sensory characteristics of Teran wine. The vinification processes included a control treatment (7-day maceration, TM7-Y; Y—young wine), 10-day maceration (TM10-Y), 21-day post-fermentation maceration (TM21-Y), and 48-h pre-fermentation heating at 45 °C followed by 8-day maceration (TPHT-Y). All wines were then aged in oak barrels for six months, resulting in TM7-A, TM10-A, TM21-A, and TPHT-A wines (A—aged wine). Volatile compounds were extracted using headspace solid-phase microextraction (HS-SPME) and analyzed by gas chromatography/mass spectrometry (GC/MS), while sensory profiles were evaluated using quantitative descriptive analysis (QDA). TPHT-Y and TM21-Y treatments reduced several groups of free volatile compounds while enhancing sensory properties, with TM21-Y wines notably exhibiting pronounced dried fruit notes, likely due to high β-damascenone concentrations. Conversely, TM10-Y and TM7-Y treatments resulted in significantly higher concentrations of the most volatile aroma compounds. Aging in oak barrels significantly increased the levels of particular free volatile compounds like C13-norisoprenoids, volatile phenols, furans, and lactones. It also enhanced sensory quality, with fruity aromas prominent across all treatments, and TM21-A and TPHT-A wines showing strong dried fruit, jam, and liqueur notes. This study offers valuable insights into tailoring wine aromas and sensory attributes through specific vinification techniques, contributing to a more refined approach to optimizing wine production. In conclusion, the findings highlight the importance of maceration and aging techniques in developing complex and desirable wine profiles, offering practical guidance for improving Teran wine quality. [ABSTRACT FROM AUTHOR]

The aim of this study was to identify the aromatic compounds present in different apple varieties and to gain insights into the changes in the aromatic compounds during ripening. Three apple varieties ("Red Astrachan", "Ning Qiu", and "Golden Delicious") at different stages of ripening were selected for this study; their peel and pulp were analyzed via headspace solid-phase microextraction (HS-SPME)–gas chromatography–mass spectrometry (HS-SPME-GC-MS), and 30 volatile compounds were identified. The samples' differences were analyzed using heat map cluster analysis, principal component analysis (PCA), and an independent samples t-test. The results showed that the content of aromatic compounds in the peel was higher than that in the pulp. The relative content of esters in the aromatic compounds of the three apple varieties followed the order of pulp > peel and "Ning Qiu" > "Golden Delicious" > "Red Astrachan". This suggests that "Ning Qiu" combines the advantages of its parents in terms of its aroma content. The highest concentrations of aroma compounds in "Red Astrachan" and "Ning Qiu" accumulate before the ripening stage, and care should be taken to choose an appropriate harvesting time according to the different needs during production. The main compounds of "Red Astrachan" are aldehydes and C8 esters, while those of "Ning Qiu" and "Golden Delicious" are alkenes and esters. After analyzing the relative odor activity values (rOAVs) of key volatile compounds and their aroma descriptors during the harvest period, acetic acid pentyl ester, butanoic acid hexyl ester, hexanoic acid hexyl ester, and 2-ethyl-1-Hexanol were found to contribute the most to the overall flavor of the peel and pulp. "Ning Qiu" combines the parental advantages of the concentrated peel of "Red Astrachan" and the astringent pulp of "Golden Delicious", with compounds in its composition that give a pleasing aroma. Mature "Ning Qiu" fruits have a more intense aroma and fruity flavor. The development of flavor-specific varieties has provided the theoretical basis for future research in molecular hybridization, molecular-assisted breeding, and the molecular biology of apple flavor synthesis and metabolism. [ABSTRACT FROM AUTHOR]

Rosa roxburghii (R. roxburghii), native to the southwest provinces of China, is a fruit crop of important economic value in Guizhou Province. However, the changes in fruit quality and flavor during R. roxburghii fruit ripening have remained unknown. Here, this study investigated the changes of seven active components and volatile organic compounds (VOCs) during the ripening of the R. roxburghii fruit at five different ripening stages including 45, 65, 75, 90, and 105 days after anthesis. The results indicated that during the ripening process, the levels of total acid, vitamin C, and soluble sugar significantly increased (p < 0.05), while the levels of total flavonoids, superoxide dismutase (SOD), and soluble tannin significantly decreased (p < 0.05). Additionally, the content of total phenol exhibited a trend of first decreasing significantly and then increasing significantly (p < 0.05). A total of 145 VOCs were detected by HS-SPME-GC-MS at five mature stages, primarily consisting of aldehydes, alcohols, esters, and alkenes. As R. roxburghii matured, both the diversity and total quantity of VOCs in the fruit increased, with a notable rise in the contents of acids, ketones, and alkenes. By calculating the ROAV values of these VOCs, 53 key substances were identified, which included aromas such as fruit, citrus, green, caramel, grass, flower, sweet, soap, wood, and fat notes. The aromas of citrus, caramel, sweet, and wood were predominantly concentrated in the later stages of R. roxburghii fruit ripening. Cluster heatmap analysis revealed distinct distribution patterns of VOCs across five different maturity stages, serving as characteristic chemical fingerprints for each stage. Notably, stages IV and V were primarily characterized by a dominance of alkenes. OPLS-DA analysis categorized the ripening process of R. roxburghii fruit into three segments: the first segment encompassed the initial three stages (I, II, and III), the second segment corresponded to the fourth stage (IV), and the third segment pertained to the fifth stage (V). Following the variable importance in projection (VIP) > 1 criterion, a total of 30 key differential VOCs were identified across the five stages, predominantly comprising ester compounds, which significantly influenced the aroma profiles of R. roxburghii fruit. By integrating the VIP > 1 and ROAV > 1 criteria, 21 differential VOCs were further identified as key contributors to the aroma changes in R. roxburghii fruit during the ripening process. This study provided data on the changes in quality and aroma of R. roxburghii fruit during ripening and laid the foundation for the investigation of the mechanism of compound accumulation during ripening. [ABSTRACT FROM AUTHOR]

This study employed headspace solid phase micro‐extraction gas chromatography mass spectrometry (HS‐SPME‐GC–MS) coupled with multivariate statistical analysis to identify volatile markers in various levels of Zhenjiang Aromatic Vinegar (ZAV). A full range of 40 volatile organic compounds (VOCs) were identified and categorized into acids, alcohols, esters, aldehydes, ketones, heterocyclic compounds and others. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) demonstrated a clear clustering effect among different levels of ZAV, indicating distinct volatile characteristics at the relative content level. Furthermore, using Orthogonal partial least squares discrimination analysis (OPLS‐DA), 20 significant volatile organic compounds (VOCs) were identified as markers for distinguishing between the various levels of ZAV. To differentiate among the levels of ZAV, two volatile compounds, acetic acid and n‐hexanol, were identified as characteristic volatile compounds using a combination of Venn diagram, analysis of variance (ANOVA) and boxplot analysis. The results showed notable variations in VOCs among ZAV samples of different grades. Acetic acid and n‐hexanol can serve as reliable markers for grade distinction, providing valuable technical and theoretical support for the production and quality control of ZAV. [ABSTRACT FROM AUTHOR]

BACKGROUND: Although microorganisms are the main cause of spoilage in prepared beef steaks, very few deep spoilage mechanisms have been reported so far. Aiming to unravel the mechanisms during 12 days of storage at 4 °C affecting the quality of prepared beef steak, the present study investigated the changes in microbial dynamic community using a combined high‐throughput sequencing combined and bioinformatics. In addition, gas chromatography‐mass spectrometry combined with multivariate statistical analysis was utilized to identify marker candidates for prepared steaks. Furthermore, cloud platform analysis was applied to determine prepared beef steak spoilage, including the relationship between microbiological and physicochemical indicators and volatile compounds. RESULTS: The results showed that the dominant groups of Pseudomonas, Brochothrix thermosphacta, Lactobacillus and Lactococcus caused the spoilage of prepared beef steak, which are strongly associated with significant changes in physicochemical properties and volatile organic compounds (furan‐2‐pentyl‐, pentanal, 1‐octanol, 1‐nonanol and dimethyl sulfide). Metabolic pathways were proposed, among which lipid metabolism and amino acid metabolism were most abundant. CONCLUSION: The present study is helpful with respect to further understanding the relationship between spoilage microorganisms and the quality of prepared beef steak, and provides a reference for investigating the spoilage mechanism of dominant spoilage bacteria and how to extend the shelf life of meat products. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

In order to study the key flavor characteristics and the influence of oxidation degree of oil on warmed-over flavor of pre-prepared steamed pork with preserved vegetable. The volatile flavor compounds and taste indexes of different brands of pre-prepared steamed pork with preserved vegetable were quantitatively detected by headspace-solid phase microextraction-gas chromatography-mass spectrometry and electronic tongue. The key flavor factors of pre-prepared steamed pork with preserved vegetable were screened and analyzed by odor activity value (OAV) and principal component analysis. Acid value, peroxide value and TBA value were used to analyze the oxidation degree of oil and warmed-over flavor of different brands of pre-prepared steamed pork with preserved vegetable. Results showed that a total of 85 volatile compounds were identified from 7 kinds of pre-prepared steamed pork with preserved vegetable, including 16 alkanes, 19 terpenes, 7 alcohols, 22 aldehydes, 3 ketones, 13 esters, 3 phenols and 2 others. A total of 23 key volatile compounds were screened by OAV, and the substances with OAV>10 were 1-octene-3-ol, hexanal, heptanal, octanal, nonanal, (E,E)-2,4-nonadienal, capric aldehyde, (E)-2-decenal, (E,E)-2,4-decenal and 1-octene-3-ketone, which were the key flavor substances for pre-prepared steamed pork with preserved vegetable. The results of electronic tongue and overripe taste evaluation showed that the taste of 7 kinds of pre-prepared steamed pork with preserved vegetable were mainly salty, umami and aftertaste. Its overripe taste mainly presented linseed oil taste and rancidity taste. The oil oxidation indexes of 7 kinds of pre-prepared steamed pork with preserved vegetable were higher and the differences were significant (P

To explore the differences in the quality and volatiles of 10 kinds of commercial butter hotpot base, the basic physicochemical indexes of hotpot base were determined. The volatiles of hotpot base were further analyzed by headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) and headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS) in this study. The physicochemical indexes analysis results showed that the 10 kinds of commercially available butter hot pot base, samples N4 and N7 had higher amino acid nitrogen content, samples N1, N2 and N3 had higher fat content, and sample N6 had higher protein and total acid content. The HS-SPME-GC-MS analysis results indicated that a total of 107 volatiles were identified in 10 kinds of commercial butter hotpot base, and 15 key differentiated volatiles including hinokiene, γ-pinene, terpinolene and linalool could be used to differentiate the spicy butter hotpot base from the mellow, saucy, and cumin butter hotpot bases. The orthogonal partial least-squares discrimination analysis (OPLS-DA) results showed that the volatiles content in the N1 sample was higher than that in the N4, N5, N7, N8 and N9 samples among the six spicy butter hotpot bases. In the mellow, saucy and cumin butter hotpot base, the volatiles content in the N2 sample was higher than that in the N3 and N10. The HS-GC-IMS results showed that γ-butyrolactone and ethyl 3-methylthiopropionate were the characteristic volatiles of the N2 sample, isobutyl acetate and ethyl butyrate were the characteristic volatiles in the N4, N6, and N10 samples, and 2-hexenal and 2,6-trimethylpyridine were the characteristic volatiles of the N4, N5, and N10 samples. These results indicated that 10 kinds of the commercial butter hotpot base had different characteristic fingerprints.

Fixation is a necessary tea processing step that affects the quality of tea, including its aroma. However, there are no guidelines to follow whether the Cyclocarya paliurus leaves need to be fixated to produce tea. The aim of this study was to determine the volatile metabolites in fixated and unfixated C. paliuru s tea by gas chromatography-mass spectrometry in order to identify the volatile compounds that differentiate them and establish the key aroma compounds. Compared with the unfixated tea, the fixated tea had higher contents of amines, phenols, nitrogen compounds, ether, alcohol, terpenoids, ester and aromatics. A total of 147 metabolites that differentiated both types of teas were identified using principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA). Among them, 22 and 25 volatile compounds of teas processed without and with fixation, respectively, had relative odor activity values greater than 1. These metabolites had green, fruity, sweet, woody, herbal, floral, fresh, spicy, earthy and waxy odor. This study showed that fixation technology improved the quality of C. paliurus tea, which provided the basis for the production of C. paliurus tea, and promoted the standardization of the preparation technology of C. paliurus tea.

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

Steamed bread is a traditional staple food in China, and it has gradually become loved by people all over the world because of its healthy production methods. With the improvement in people's living standards, the light flavor of steamed bread fermented by single yeast cannot meet people's needs. Multi-strain co-fermentation is a feasible way to improve the flavor of steamed bread. Here, the dynamic change profiles of volatile substances in steamed bread co-fermented by Saccharomyces cerevisiae SQJ20 and Wickerhamomyces anomalus GZJ2 were analyzed using the electronic nose (E-nose) and headspace solid-phase microextraction combined with gas chromatography–mass spectrometry (HS-SPME-GC-MS). The five detectors of the E-nose rapidly detected the changes in volatile substances in different dough or steamed bread with the highest response value in co-fermented dough. A total of 236 volatile substances were detected in all the samples using HS-SPME-GC-MS, and alcohols were the most variable component, especially Phenylethyl alcohol. Significantly, more alcohols and esters were upregulated in co-fermented dough, and the addition of W. anomalus GZJ2 improved the key volatile aroma compounds of steamed bread using the relative odor activity value method (ROAV), especially the aldehydes and alcohols. Moreover, these key volatile aroma compounds can be quickly distinguished using the W2S detector of the E-nose, which can be used for the rapid detection of aroma components in steamed bread. [ABSTRACT FROM AUTHOR]

Scirpophaga incertulas Walker (Lepidoptera: Crambidae, yellow stem borer, YSB) is a monophagous insect pest that causes significant yield loss in rice (Oryza staiva L.). Semiochemical based pest management is being sought as an alternate to chemical pesticides to reduce pesticide footprints. We hypothesized differential release of volatiles from host rice and two companion non-host weeds, Echinochloa colona and Echinochloa crus-galli could be responsible for oviposition and biology of YSB and these chemicals could be used for YSB management. Number of eggs laid, and number of larvae hatched were significantly higher in rice plant as compared to weeds. YSB could only form dead hearts in rice plants. YSB significantly preferred host-plant volatiles compared to the non-host plants both in choice and no-choice tests in an Y-tube olfactometer. 2-Hexenal, hexanal, 2,4-hexadienal, benzaldehyde, nonanal, methyl salicylate and decanal were found in the leaf volatolomes of both the host and non-host plants in HS-SPME-GC-MS (Headspace-Solid phase micro extraction-Gas chromatography-Mass spectrometer). Pentene-3-one, 2-pentyl furan, 2,4-heptadienal, 2-octenal, 2-octenol and menthol were present only in the non-host plants. Fourteen rice unique compounds were also detected. The built-in PCA (Principal Component Analysis) and PLS-DA (Partial least squares-discriminant analysis) analysis in the MS-DIAL tool showed that the volatiles emitted from TN1 formed a cluster distinct from Echinochloa spp. and 2-octenal was identified as a unique compound. Olfactometer bioassays using synthetic compounds showed that rice unique compounds, like xylene, hexanal served as attractants whereas non-host unique compounds, like 2-pentylfuran, 2-octenal acted as repellent. The results indicate that the rice unique compounds xylene, hexanal along with other volatile compounds could be responsible for higher preference of YSB towards rice plants. Similarly, the non-host unique compounds 2-pentylfuran, 2-octenal could possibly be responsible for lower preference and defence against YSB. These compounds could be utilised for devising traps for YSB monitoring and management. [ABSTRACT FROM AUTHOR]

This work used headspace solid-phase microextraction with gas chromatography–mass spectrometry (HS-SPME-GC–MS) to analyze the volatile components of hydrosols of Citrus × aurantium 'Daidai' and Citrus × aurantium L. dried buds (CAVAs and CADBs) by immersion and ultrasound–microwave synergistic-assisted steam distillation. The results show that a total of 106 volatiles were detected in hydrosols, mainly alcohols, alkenes, and esters, and the high content components of hydrosols were linalool, α-terpineol, and trans-geraniol. In terms of variety, the total and unique components of CAVA hydrosols were much higher than those of CADB hydrosols; the relative contents of 13 components of CAVA hydrosols were greater than those of CADB hydrosols, with geranyl acetate up to 15-fold; all hydrosols had a citrus, floral, and woody aroma. From the pretreatment, more volatile components were retained in the immersion; the relative contents of linalool and α-terpineol were increased by the ultrasound–microwave procedure; and the ultrasound–microwave procedure was favorable for the stimulation of the aroma of CAVA hydrosols, but it diminished the aroma of the CADB hydrosols. This study provides theoretical support for in-depth exploration based on the medicine food homology properties of CAVA and for improving the utilization rate of waste resources. [ABSTRACT FROM AUTHOR]

Introduction: Fengxiangxing Huairang Daqu (FHD) is one of the major types of Daqu in China. However, the relationship between the microbial community structure at different stages, the changes in the sensory characteristics, fermentation characteristics, volatiles, the most critical process point, and the quality formation of FHD is not clear. Methods: Based on microscopic characterization, PacBio SMRT sequencing, and HS-SPME-GC-MS volatile metabolite analysis revealed the relationship between FHD quality formation and the dynamics of Qupi. Results: The results showed that the 12th day of the culture was the most critical process point, highlighting the most significant differences in microbial community structure, sensory characteristics, fermentation characteristics, and flavor substances. Bacillus licheniformis (43.25%), Saccharopolyspora rectivirgula (35.05%), Thermoascus aurantiacus (76.51%), Aspergillus amstelodami (10.81%), and Saccharomycopsis fibuligera (8.88%) were the dominant species in FHD. S. fibuligera, A. amstelodami, and T. aurantiacus were associated with the snow-white color of the FHD epidermis, the yellow color of the interior, and the gray-white color, respectively. The abundance of T. aurantiacus, A. amstelodami, B. licheniformis, and S. rectivirgula was positively associated with the esterifying power and liquefying power of FHD. The abundance of T. aurantiacus and A. amstelodami was positively correlated with the saccharifying power of FHD. The abundance of S. fibuligera was positively related to the fermenting power of FHD. A total of 248 volatiles were detected in Qupi, mainly including alcohols, esters, aldehydes, and ketones. Of them, eleven volatiles had a significant effect on the flavor of Qupi, such as 1-butanol-3-methyl-, hydrazinecarboxamide, ethanol, phenylethyl alcohol, ethyl acetate, 2-octanone, 1-octen-3-ol, formic acid-hexyl ester, (E)-2-octen-1-ol, ethyl hexanoate, and 2(3H)-furanone-dihydro-5-pentyl-. The abundance of B. licheniformis, S. rectivirgula, T. aurantiacus, and S. fibuligera was positively correlated with the alcohols, aromatic compounds, and phenols in FHD. The abundance of S. fibuligera was positively correlated with the acids, esters, and hydrocarbons in FHD. Discussion: These results indicate important theoretical basis and technical support for controllable adjustment of FHD microbial community structure, stable control of FHD quality, and precise, effective, and large-scale guidance of FHD production. [ABSTRACT FROM AUTHOR]

Vacuum freeze drying (VFD) combined with thermal drying can solve the defects of vacuum freeze-dried chives, such as faint flavor, unpleasant color, and taste. However, the mechanisms for enhancing flavor, reducing lightness, and improving taste through combined drying remain to be explored. In this study, the effects of vacuum freeze drying combined with hot air drying, vacuum freeze drying combined with infrared hot air drying, and vacuum freeze drying combined with catalytic infrared drying (VFD-CIRD) on the flavor and quality characteristics of chive leaves and stems were investigated. The results demonstrated that VFD-CIRD had the richest flavor, attributed to the key aromas hydroxyacetone and 2-ethyl-6-methylpyrazine. Combined drying eliminated the wax layer on the surface of chive leaves, which reduced lightness. Furthermore, VFD-CIRD could degrade phenolic compounds in chives, thereby reducing the bitterness. VFD-CIRD has the potential to become the basis for the industrial production of high-quality dried chives. [ABSTRACT FROM AUTHOR]

[Objectives] The paper aimed to investigate the characteristic aroma components of black tea from the main production areas in Jiangsu Province and distinguish the key difference components in different main production areas. [Methods] The aroma composition of representative Jiangsu black tea samples from the main production areas was analyzed using electronic nose (E-nose) and headspace solid phase microextraction gas chromatography mass spectrometry (HS-SPME-GC-MS) technology. [Results] The electronic nose analysis showed that terpenoids and aromatic ring substances were the main volatile components in the aroma of Jiangsu black tea, and the contents of alcohols, ketones, aldehydes, sulfur components and terpenoids were significantly higher in Yixing production area than those in Jurong and Jintan production areas. HS-SPME-GC-MS analysis showed that alcohols were the volatile compounds with the highest proportion in all Jiangsu black teas, accounting for 62.06%-75.66% of the total volatile. With relative odor activity value (ROAV) greater than 1.00 as the criterion, a total of 12 key aroma presenting substances were screened out, and linalool, geraniol, citral, trans-ẞ-ionone, decanal, dimethyl sulfide might be the most critical aroma components in Jiangsu black tea (ROAV>10.00). Orthogonal partial least squares discriminant analysis (OPLS-DA) showed that there were some differences between the aroma components of black tea from different production areas. Seven variance components were screened using variable importance in projection (VIP) values greater than 1.00 as a criterion. Among them, 2-methyl-butanal and phenylacetaldehyde in fruity aroma and trans-linalool oxide (furans) in woody aroma were the key aroma components that distinguished the Jintan production area from Yixing and Jurong production areas, and cis-jasmone in floral aroma was the key aroma component that distinguished the Jurong production area from the Jintan and Yixing production areas, which were the key factor causing the aroma difference among production areas. In addition, the ratio of geraniol to linalool content in the main production areas of Jiangsu black tea was about 1:1, which was presumed to be one of the important reasons for the difference between Jiangsu black tea and other famous black teas. [Conclusions] In this study, the characteristic aroma components of Jiangsu black tea were clarified by combining HS-SPME-GC-MS and electronic nose technology, and the different aroma components of Jiangsu black tea from different production areas were explored, and the results laid a foundation for enriching the aroma theory of black tea in China. [ABSTRACT FROM AUTHOR]

By employing headspace solid‑phase microextraction gas chromatography–mass spec‑ trometry (HS‑SPME‑GC‑MS), this study displayed the compositional changes in volatile organic compounds (VOCs) in Tricholoma matsutake samples subjected to hot‑air drying (HAD) and vac‑ uum freeze‑drying (VFD) processes from their fresh samples. A total of 99 VOCs were detected, including 2 acids, 10 aldehydes, 10 alcohols, 13 esters, 12 ketones, 24 alkanes, 14 olefins, 7 aromatic hydrocarbons, and 7 heterocyclic compounds. Notably, the drying process led to a decrease in most alcohols and aldehydes, but an increase in esters, ketones, acids, alkanes, olefins, aromatic, and het‑ erocyclic compounds. Venn diagram (Venn), principal component analysis (PCA), and partial least squares‑discriminant analysis (PLS‑DA) analyses enabled an easy and rapid distinction between the VOC profiles of T. matsutake subjected to different drying methods. Among the identified VOCs, 30 were designated as marker VOCs indicative of the employed drying process. And the VFD method was more capable of preserving the VOCs of fresh T. matsutake samples than the HAD method. Ben‑ zaldehyde, 1‑Octen‑3‑ol, 3‑Octanol, and (E)‑2‑Octen‑1‑ol were identified as markers for FRESH T. matsutake. Conversely, (E)‑3‑Hexene, lavender lactone, and α‑Pinene were associated with VFD T. matsutake. For HAD T. matsutake, olefins, pyrazine, and esters, particularly ocimene, 2,5‑Dimethyl‑ pyrazine, and methyl cinnamate, significantly contributed to its particularities. The results from this present study can provide a practical guidance for the quality and flavor control of volatile organic compounds in preciously fungal fruiting bodies by using drying processes. [ABSTRACT FROM AUTHOR]

Hemerocallis L. possesses abundant germplasm resources and holds significant value in terms of ornamental, edible, and medicinal aspects. However, the quality characteristics vary significantly depending on different varieties. Selection of a high-quality variety with a characteristic aroma can increase the economic value of Hemerocallis flowers. The analytic hierarchy process (AHP) is an effective decision-making method for comparing and evaluating multiple characteristic dimensions. By applying AHP, the aromatic character of 60 varieties of Hemerocallis flowers were analyzed and evaluated in the present study. Headspace solid-phase microextraction gas chromatography–mass spectrometry (HS-SPME-GC-MS) was employed to identify volatile components in Hemerocallis flowers. Thirteen volatile components were found to contribute to the aroma of Hemerocallis flowers, which helps in assessing their potential applications in essential oil, aromatherapy, and medical treatment. These components include 2-phenylethanol, geraniol, linalool, nonanal, decanal, (E)-β-ocimene, α-farnesene, indole, nerolidol, 3-furanmethanol, 3-carene, benzaldehyde and benzenemethanol. The varieties with better aromatic potential can be selected from a large amount of data using an AHP model. This study provides a comprehensive understanding of the characteristics of the aroma components in Hemerocallis flowers, offers guidance for breeding, and enhances the economic value of Hemerocallis flowers. [ABSTRACT FROM AUTHOR]

In this study, E-nose, HS-GC-IMS, and HS-SPME-GC–MS technologies were used to evaluate the flavor characteristics of the pileus and stipe of Boletus edulis from eight origins. 23 key Volatile organic compounds (VOCs) with odor activity values (OAVs) > 1 were identified, and 19 aroma types have been identified in Boletus edulis at the same time. Vegetable and earthy were defined as the dominant aroma types for all pileus and stipe samples. Balsamic and musty were the main and characteristic aroma types for the pileus. The highest concentrations of VOCs in the pileus and stipe were originated from Chuxiong Prefecture and Aba Prefecture, respectively. 19 and 16 key VOCs were detected Chuxiong pileus and Aba stipe, respectively, and Methional was the decisive compound that influenced the vegetable aroma type. The results of this study could be helpful for flavor identification and application of pileus and stipe from Boletus edulis.

Dushan shrimp sour paste (DSSP), a traditional Guizhou condiment, and its unique flavor is determined by the fermentation microbiota. However, the relationship between the microbiota structure and its flavor remains unclear. This study identified 116 volatile flavor compounds using electronic nose and headspace solid-phase microextraction-gas chromatography mass spectrometry (HS-SPME-GC–MS) techniques, of which 19 were considered as key flavor compounds, mainly consisting of 13 esters and 1 alcohol. High-throughput sequencing technique, the bacterial community structure of nine groups of DSSPs was determined. Further analysis revealed Vagococcus, Lactococcus, and Tepidimicrobium as key bacteria involved in flavor formation. This study contributes to our understanding of the relationship between bacterial communities and the flavor formation, and provides guidance for screening starter culture that enhance the flavor of DSSP in industrial production.

Pheretima is a popular healthy food, but Pheretima and related foods have specific stenchy odor, especially after decocting or warm soaking, the odor is intense, resulting in nausea and vomiting. This indicates that the release of stenchy odor components is intensified when Pheretima was exposed to hot water. It is urgent to study the composition and release pattern of the stenchy odor components of Pheretima. In this study, a series of samples with different odors were prepared by the combination of SFE-CO2 and warm soaking. The results showed that the fishy and smoky odor of Pheretima were heavier, attributed to the components such as dimethyl trisulfide, TMA, and guaiacol. When Pheretima was exposed to hot water, the fishy odor increased sharply. Dimethyl trisulfide and TMA were the key odor components, especially the exposure of TMA increased by 2∼3 times after warm soaking. The volatilization rate of n-hexanal, TMA, dimethyl trisulfide and other components was found to be highly volatile, and the volatilization rate at 75 °C was 2.5 times that at room temperature. This study proved for the first time that stenchy odor substances include two categories: water-soluble and liposoluble. And found that the water-soluble odor components accelerate their exposure and volatilization in warm water, which is the scientific principle of “Pheretima smells worse exposed to water”.

This study aims to analyze the differences in flavor compounds of potatoes from various varieties and regions, as well as to explore the impact of soil elements on starch content in potatoes. Headspace solid-phase micro-extraction/gas chromatography–mass spectrometry (HS-SPME-GC–MS) was employed to identify volatile flavor compounds in 18 potatoes representing 4 different varieties from 5 different regions. The relative odor activity (rOAV) was utilized for principal component analysis to establish a comprehensive scoring model for potato volatile flavor compounds. In addition, the starch and amylose content of the potatoes were determined using enzymatic methods, and the correlation between soil elements and starch content in Dingxi potatoes was analyzed. The results indicated that the flavor scores for the samples “DX-DP,” “DX-LS,” “NM-XY,” “JB-LS,” “ZB-XS,” and “GY-LS” were 15.184, 14.500, 13.992, −4.62, −7.199 and − 9.525, respectively, with “DX-DP” exhibiting the highest flavor score (15.184) and starch content (15.21 %). This study demonstrated that the overall quality of potatoes from Dingxi was superior, particularly for “DX-DP”. Further analysis revealed that potato starch content was positively correlated with soil potassium and negatively correlated with total nitrogen and pH. In conclusion, this study provides insights into the relationship between potato genotypes and soil environments, offering valuable guidance for potato land selection and cultivation practices.

Black tea, a widely popular non-alcoholic beverage, is renowned for its unique aroma and has attracted significant attention due to its complex composition. However, the chemical profile of Iranian tea remains largely unexplored. In this research, black tea samples from key tea cultivation regions in four geographical areas in northern Iran were firstly analyzed using headspace solid-phase microextraction followed by gas chromatography–mass spectrometry (HS-SPME-GC–MS) to separate, identify, and quantify their volatile organic compounds. Subsequently, employing a robust investigative strategy, we utilized for the first time the well-known multivariate curve resolution-alternating least square (MCR-ALS) method as a deconvolution technique to analyze the complex GC–MS peak clusters of tea samples. This approach effectively addressed challenges such as severe baseline drifts, overlapping peaks, and background noise, enabling the identification of minor components responsible for the distinct flavors and tastes across various samples. The MCR-ALS technique significantly improved the resolution of spectral and elution profiles, enabling both qualitative and semi-quantitative analysis of tea constituents. Qualitative analysis involved comparing resolved peak profiles to theoretical spectra, along with retention indices, while semi-quantification was conducted using the overall volume integration (OVI) approach for volatile compounds, providing a more accurate correlation between peak areas and concentrations. The application of chemometric tools in GC–MS analysis increased the number of recognized components in four tea samples, expanding from 54 to 256 components, all with concentrations exceeding 0.1 %. Among them, 32 volatile compounds were present in every tea sample. Hydrocarbons (including alkenes, alkanes, cycloalkanes, monoterpenes and sesquiterpenes), esters and alcohols were the three major chemical classes, comprising 78 % of the total relative content of volatile compounds. Analyzing black teas from four distinct regions revealed variations not only in their volatile components but also in their relative proportions. This integrated approach provides a comprehensive understanding of the volatile chemical profiles in Iranian black teas, enhances knowledge about their unique characteristics across diverse geographical origin, and lays the groundwork for quality improvement.

The chemical compositions and volatile profiles of wax gourd seed oil (WGSO), watermelon seed oil (WSO), pumpkin seed oil (PSO), cucumber seed oil (CSO), and bitter gourd seed oil (BGSO) were comparatively explored for the first time. All oils complied with standards for physicochemical properties and BGSO had the highest phenolic content. Their mineral levels varied significantly. The fatty acid composition of WGSO, WSO, PSO, and CSO was similar, predominantly linoleic acid. Whereas BGSO exhibited a distinct fatty acid profile with 55.38 % α-eleostearic acid. All samples were rich in tocopherols and squalene, with WSO having the highest total tocopherol content and PSO having the highest squalene content. HS-GC–IMS and HS-SPME-GC–MS detected 118 and 67 VOCs, respectively, primarily consisting of aliphatic aldehydes, alcohols, esters, and ketones. Principal component analysis confirmed that BGSO had the most distinctive volatile characteristics, while the other four seed oils shared similar VOC profiles.

To enhance comprehension of the impact of mixed fermentation using Torulaspora delbrueckii Bio-119667 (TD) on the aroma composition of Munage grape base-wine (MGBW), we analysed the aroma composition of MGBW using HS-SPME-GC-MS widely targeted metabolomics. The levels of volatile aroma components, including terpenes, higher alcohols, aldehydes, heterocyclic compounds, and esters, were significantly higher in MGBW produced by mixed fermentation compared to the pure Saccharomyces yeast control fermentation. The study found that the content of esters increased by 26.3% after mixed fermentation, indicating the contribution of TD to the formation of ester flavour components during the fermentation of MGBW. After analysing aroma activity values, we discovered that 49 out of 115 esters (25.5% of the total) significantly contributed to the aroma profile of MGBW (rOAV > 1). Of these esters, 16 were identified as key aroma compounds (rOAV > 1, VIP > 1) produced by mixed fermentation with the participation of TD. This finding further supports the contribution of TD to the improvement of MGBW's aroma composition. This study reveals the role of non-Saccharomyces yeast strain Torulaspora delbrueckii Bio-119667 in improving the aroma composition of MGBW produced by mixed culture fermentation and the biosynthetic pathways of key aroma components therein. [ABSTRACT FROM AUTHOR]

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Headspace solid-phase microextraction, combined with gas chromatography–mass spectrometry and partial least squares discriminant analysis, was adopted to study the rule of change in volatile organic compounds (VOCs) for domestic and imported fishmeal during storage with different freshness grades. The results showed that 318 kinds of VOCs were detected in domestic fishmeal, while 194 VOCs were detected in imported fishmeal. The total relative content of VOCs increased with storage time, among which acids and nitrogen-containing compounds increased significantly, esters and ketones increased slightly, and phenolic and ether compounds were detected only in domestic fishmeal. Regarding the volatile base nitrogen, acid value, pH value, and mold counts as freshness indexes, the freshness indexes were significantly correlated with nine kinds of VOCs (p < 0.05) through the correlation analysis. Among them, volatile base nitrogen had a significant correlation with VOCs containing nitrogen, acid value with VOCs containing carboxyl group and hydrocarbons, pH value with acids which could be used to adjust pH value, and mold counts with part of acids adjusting pH value and VOCs containing nitrogen. Due to the fact that the value of all freshness indexes increased with freshness degradation during storage, based on volatile base nitrogen and acid value, the fishmeal was divided into three freshness grades, superior freshness, corrupting, and completely corrupted. By using partial least squares discriminant analysis, this study revealed the differences in flavor of the domestic and imported fishmeal during storage with different freshness grades, and it identified four common characteristic VOCs, namely ethoxyquinoline, 6,7,8,9-tetrahydro-3H-benzo[e]indole-1,2-dione, hexadecanoic acid, and heptadecane, produced by the fishmeal samples during storage, as well as the characteristic VOCs of fishmeal at each freshness grade. [ABSTRACT FROM AUTHOR]

Volatile organic compounds (VOCs) play a significant role in influencing the flavor quality of cherry tomatoes (Solanum lycopersicum var. cerasiforme). The scarcity of systematic analysis of VOCs in cherry tomatoes can be attributed to the constraints imposed by detection technology and other contributing factors. In this study, the cherry tomato cultivar var. 'Zheyingfen1' was chosen due to its abundant fruit flavor. Two detection technology platforms, namely the commonly employed headspace solid-phase microextraction—gas chromatography–mass spectrometry (HS-SPME-GC-MS) and the most advanced headspace solid-phase microextraction—full two-dimensional gas chromatography–time-of-flight mass spectrometry (HS-SPME-GC×GC-TOFMS), were employed in the analysis. The VOCs of cherry tomato cultivar var. 'Zheyingfen1' fruits at red ripening stage were detected. A combined total of 1544 VOCs were detected using the two aforementioned techniques. Specifically, 663 VOCs were identified by through the HS-SPME-GC-MS method, 1026 VOCs were identified by through the HS-SPME-GC×GC-TOFMS, and 145 VOCs were identified by both techniques. The identification of β-ionone and (E)-2-nonenal as the principal VOCs was substantiated through the application of the relative odor activity value (rOAV) calculation and subsequent analysis. Based on the varying contribution rates of rOAV, the analysis of sensory flavor characteristics revealed that cherry tomato cultivar var. 'Zheyingfen1' predominantly exhibited green and fatty attributes, accompanied by elements of fresh and floral flavor characteristics. In conclusion, our study conducted a comprehensive comparison of the disparities between these two methodologies in detecting VOCs in cherry tomato fruits. Additionally, we systematically analyzed the VOC composition and sensory flavor attributes of the cherry tomato cultivar var. 'Zheyingfen1'. This research serves as a significant point of reference for investigating the regulatory mechanisms underlying the development of volatile flavor quality in cherry tomatoes. [ABSTRACT FROM AUTHOR]

'Cuixiang' (Actinidia deliciosa) is recognized as a highly valued fruit with significant economic importance. Its distinctive and pleasant flavor sets it apart from other species of kiwifruit, contributing to its stellar reputation. However, the flavor profile of 'Cuixiang' kiwifruit is susceptible to change during storage, and the underlying mechanisms responsible for these changes have yet to be fully investigated. Herein, we conducted a comprehensive analysis of volatile profiles and transcriptome on 'Cuixiang' samples at different storage times, aiming to uncover the mechanism underlying the flavor biotransformation. A total of 63 volatiles were quantified by HS–SPME–GC–MS, of which 16 were identified as key compounds distinctive of aroma quality during storage by PLS-DA and OAV analysis. Besides, a total of 13,922 differentially expressed genes in fruits were identified and used to identify key candidate genes that may regulate volatiles during storage. The results of KEGG analysis showed that Achn072171, Achn270621, and Achn012241 were involved in the synthesis of key aroma compounds and verified by qRT-PCR. Weighted gene co-expression network analysis (WGCNA) showed that NAC and BHLH transcription factors were positively correlated with the expression of these genes. Our findings elucidate the underlying metabolic processes that regulate aroma during the storage of 'Cuixiang' kiwifruit, and the identification of key genes involved in flavor regulation presents promising targets for flavor regulation and quality assurance of 'Cuixiang' fruit. [ABSTRACT FROM AUTHOR]

The fishy odor of fish oil, a popular nutritional supplement, affects its quality as well as consumer acceptance and eating experience. An objective or scientific method for analyzing fish oil's olfactory characteristics is still lacking. This study examined anchovy oil to develop qualitative and quantitative approaches for identifying fishy odor components. Multiple fish oil refining samples were analyzed using gas chromatography-ion mobility spectrometry (GC-IMS). Due to their significant alterations during fish oil refining, low threshold values, and distinct olfactory properties, the unsaturated aldehydes (E)-2-pentenal and (E,E)-2,4-heptadienal and the unsaturated ketone 1-penten-3-one may contribute to the fishy odor. Among the chemicals, (E,E)-2,4-heptadienal was chosen as the marker for developing a method to quantify fishy odor and analyze deodorization samples using headspace solid-phase micro-extraction gas chromatography-mass spectrometry (HS-SPME-GC-MS). The quantitative study of fishy odor in fish oil is a pioneering approach that can help improve quality assurance and refining process. [ABSTRACT FROM AUTHOR]

To investigate suitable processing methods for improve the flavor while maintaining quality, hellgrammites were subjected to fifteen different processing methods. The samples were tested by sensory evaluation and were analyzed using HS-SPME-GC–MS. The sensory evaluation revealed that five methods for head and chest removal, three wine-fried methods, and three vinegar-roasting methods significantly reduced the levels of hexanal (3129.05 ± 45.77 μg/kg) and heptanal (436.72 ± 7.42 μg/kg), compounds responsible for fishy and earthy flavors, compared to raw samples. The latter two methods exhibited increased aroma flavor. PCA and OPLS-DA analyses suggested that acids, alcohols, and esters played a crucial role in flavor modification. Notably, vinegar-roasting methods demonstrated the highest acid content and had a substantial impact on volatile compounds. Additionally, boiling methods effectively reduced the levels of hazardous compounds, such as toluene and 1,3-Dimethyl-benzene. However, other methods did not exhibit similar efficacy in reducing hazardous compounds. The accumulation of hazardous compounds showed a decreasing trend in the whole insect, head removal, and head and chest removal groups. Moreover, the relative odor activity value consistently identified aldehyde compounds, including hexanal and heptanal, as the main contributors to aroma. Overall, boiling and head and chest removal procedures were suggested as precautionary measures during the initial processing of hellgrammites-based food products. The vinegar-roasting and wine-fried methods could be employed to impart desired flavors, aligning with consumers' preferences. These findings lay the foundation for standardizing processing techniques and ensuring the quality control of products derived from hellgrammites. [ABSTRACT FROM AUTHOR]

In this study, we used fresh Oudemansiella raphanipes as raw materials and pre-treated through hot air drying (HD), infrared radiation drying (ID), and vacuum freeze drying (VD) to investigate the effects of different drying methods on the rehydration rate, appearance quality, microstructure, and volatile flavor components of the dried products, as well as to determine the physicochemical properties and bioactivities of the polysaccharides in the dried O. raphanipes. The results showed that the VD O. raphanipes had the highest rehydration rate and the least shrinkage in appearance, and it better maintained the original color of the gills, but their aroma was not as strong as that of the HD samples. The scanning electron microscopy results indicate that VD maintains a good porous structure in the tissue, while HD and ID exhibit varying degrees of shrinkage and collapse. Seventy-five common volatile substances were detected in the three dried samples, mainly alkanes, alcohols, and esters. The polysaccharides (PS-H, PS-I, and PS-V) extracted from the dried samples of these three species of O. raphanipes had similar infrared spectral features, indicating that their structures are basically consistent. The highest yield was obtained for PS-V, and the polysaccharide content and glucuronic acid content of PS-I were higher than those of the remaining two polysaccharides. In addition, PS-V also showed better antioxidant activity and inhibitory activity against α-glucosidase as well as α-amylase. In conclusion, among the above three drying methods, the quality of O. raphanipes obtained by vacuum freeze drying is the best, and this experiment provides a theoretical basis for the selection of drying methods for O. raphanipes. [ABSTRACT FROM AUTHOR]

Due to an outbreak of coronavirus spreading in recent years, there is an urgent need for effective, rapid, and non‐invasive diagnostics to detect and differentiate among patients who are infected and uninfected with SARS‐CoV‐2 for controlling the virus propagation. This study developed an alternative method for COVID‐19 screening from volatile analysis of metabolites mainly studied in sweat samples obtained from the populations in Bangkok, Thailand, during December 2020 to April 2022. A total of 140 collected samples; 70 positive confirmed COVID‐19 cases and another 70 negatives confirmed COVID‐19 cases were applied to be separated, detected, and identified as volatile organic compounds (VOCs)/odor occurring from SARS‐CoV‐2 infection body by the technique of Headspace solid‐phase microextraction gas chromatography‐mass spectrometry (HS‐SPME‐GC‐MS) together with principle component analysis (PCA), which allowed potential volatile markers of COVID‐19 such as pentadecane, nonanal, styrene, xylene, ethylbenzene, and 2‐ethylhexyl acrylate (up to 94 % accuracy, 93 % sensitivity, 96 % selectivity, and 94 % specificity), respectively, along with limit of detection in a range of 0.26–125 μg. The result was validated by comparison with the RT‐PCR results. [ABSTRACT FROM AUTHOR]

Matteuccia struthiopteris is one of the most globally consumed edible ferns and widely used in folk medicine. Reports mainly focus on young fronds and the rhizome which are common edible medicinal parts. However, there are few detailed reports on other parts. Therefore, the volatile components of different parts based on HS-SPME-GC-MS were identified, and total flavonoid contents, antioxidant activities and acetylcholinesterase inhibitory activities were compared in order to reveal the difference of volatile components and potential medicinal value of different parts. The results showed that total flavonoid contents, antioxidant activities and volatile components of different parts were obviously different. The crozier exhibited the strongest antioxidant activities, but only underground parts exhibited a dose-dependent inhibition potential against AChE. Common volatile compounds were furfural and 2-furancarboxaldehyde, 5-methyl-. In addition, it was found that some volatile components from adventitious root, trophophyll, sporophyll and petiole were important ingredients in food, cosmetics, industrial manufacturing and pharmaceutical applications. [ABSTRACT FROM AUTHOR]

Non-Saccharomyces (NSc) yeasts have great potential in improving wine qualities. In this study, two NSc and two Saccharomyces cerevisiae (Sc) samples were tested on their performance of mono-inoculated and composite culture in the fermentation of Chunjian citrus wine. The cell count, Brix degree, total sugar, total acidity, alcohol level, pH value, color intensity (CI), and tonality were determined to evaluate the contribution of NSc to the quality of citrus wine in the mixed fermentation. Volatile compounds were analyzed by HS-SPME-GC-MS, and sensory evaluation was carried out. During the 9-day fermentation, the mixed-culture wine exhibited a higher cell concentration than the pure culture. After the fermentation, mixed-culture wine specifically decreased the concentrations of unfavorable volatile compounds, such as isobutanol and octanoic acid, and increased favorable volatile compounds, including ethyl octanoate, ethyl decanoate, and phenylethyl acetate. The quality category of the citrus wine was improved compared with the Sc mono-inoculated wines, mainly in regard to aroma, retention, and sweetness. The study shows that the mixed fermentation of NSc and Sc has positive impacts on reducing alcohol level and total acidity and increasing CI. The present work demonstrates that the mixed fermentation of NSc and Sc has enormous beneficial impacts on improving the quality of citrus wine. [ABSTRACT FROM AUTHOR]

Agastache rugosa (Fisch. et Mey.) O. Ktze, also known as "Suhuoxiang" (SHX), has been cultivated for more than three hundred years as a valuable aromatic edible and medicinal plant in Jiangsu Province, China. The volatile compounds of SHX from various habitats were investigated by HS-SPME-GC-MS, detecting sixty-five chemical constituents with menthone, pulegone, and estragole being the major volatile compounds. Their relative contents showed various accumulation tendencies in different growth months by GC-MS, with the relative content of menthone gradually increasing, pulegone content decreasing, as well as estragole content climbing initially before declining. This tendency was supported by quantitative experiments using samples from various habitats, which also revealed that the full-bloom stages exhibited the highest total concentrations of menthone and pulegone. The volatile composition of SHX in various plant organs differed, with palmitic acid being the main volatile component of stems, while menthone and pulegone being the core volatile components of leaves and spikes, implying that leaves and spikes should be separated from the stem to obtain higher drug contents. The current findings provide new information for SHX cultivation and applications. [ABSTRACT FROM AUTHOR]

To expound on the correlation between the microorganism communities and the formation of off-odour in Xuanwei ham, the microorganism communities and volatile compounds were investigated in the biceps femoris (BF) and semimembranosus (SM) of Xuanwei ham with different quality grades (normal ham and spoiled ham). The single molecule real-time sequencing showed that differential bacteria and fungi were more varied in normal hams than in spoiled hams. Headspace solid-phase microextraction–gas chromatography (HS-SPME-GC-MS) results indicated that aldehydes and alcohols were significantly higher in spoiled hams than those in normal hams (p < 0.05). The off-odour of spoiled hams was dominated by ichthyic, malodourous, sweaty, putrid, sour, and unpleasant odours produced by compounds such as trimethylamine (SM: 13.05 μg/kg), hexanal (BF: 206.46 μg/kg), octanal (BF: 59.52 μg/kg), methanethiol (SM: 12.85 μg/kg), and valeric acid (BF: 15.08 μg/kg), which are positively correlated with Bacillus cereus, Bacillus subtilis, Bacillus licheniformis, Pseudomonas sp., Aspergillus ruber, and Moraxella osloensis. Furthermore, the physicochemical property and quality characteristics results showed that high moisture (BF: 56.32 g/100 g), pH (BF: 6.63), thiobarbituric acid reactive substances (TBARS) (SM: 1.98 MDA/kg), and low NaCl content (SM: 6.31%) were also responsible for the spoilage of hams with off-odour. This study provided a deep insight into the off-odour of Xuanwei ham from the perspective of microorganism communities and a theoretical basis for improving the flavour and overall quality of Xuanwei hams. [ABSTRACT FROM AUTHOR]

In order to investigate the dynamic changes of flavor compounds, Ultra Performance Liquid Chromatography Tandem Mass Spectrometry (UPLC-MS/MS) combined with Headspace Solid Phase Microextraction Gas Chromatography Mass Spectrometry (HS-SPME-GC–MS) was used to detect the metabolites in different drying processes. A total of 80 volatile compounds and 1319 non-volatile compounds were identified. The trend in the changes of C-8 compounds and sulfur-containing compounds were generally consistent with the trend of key enzyme activities. 479 differential metabolites were identified and revealed that metabolic profiles of compounds in Boletus edulis were altered with increased organic acids and derivatives and lipids and lipid-like molecules. Fatty acids and amino acids were transformed into volatile compounds under the action of enzymes, which played a significant role in the formation of the distinctive flavor of Boletus edulis. Our study provided a theoretical support for fully comprehending the formation mechanism of flavor from Boletus edulis during drying processes.

This study aimed to investigate the effects of germination and roasting on the flavor of quinoa. Firstly, the aroma of quinoa and germinated quinoa roasted under different conditions was analyzed using sensory evaluation and electronic nose (E-nose). Results showed that the best favorable aroma of quinoa and germinated quinoa was obtained when roasted at 160 °C for 15 min. Then, a total of 34 and 80 volatile organic compounds (VOCs) of quinoa and germinated quinoa roasted at 160 °C for 15 min were determined using headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS) and headspace solid-phase microextraction gas chromatography–mass spectrometry (HS-SPME-GC–MS), respectively. Germination and roasting effectively reduced the contents of VOCs that produced undesirable flavor. Moreover, germination improved the floral aromas, while roasting mainly produced caramel, cocoa, and roasted nut aromas of quinoa. This study indicated that germination and roasting treatments might serve as promising processing methods to improve the flavor of quinoa.

Hot air drying (HD), vacuum freeze drying (FD), and pilot-scale freeze drying (PSFD) are extensively used to prepare peach slices. However, the aroma of hot air drying and vacuum freeze-drying is yet to be addressed. In this study, HS-SPME-GC–MS was used to characterize and quantify the volatile compounds in peach slices. First, 33, 36, and 46 volatile compounds were identified and quantified in the HD, FD, and PSFD groups, respectively. PSFD is preferable to HD and FD in terms of the volatile compound types, content, and aroma profiles. PSFD was selected for subsequent permeation and dehydration experiments. The key aroma compounds with an OAV ≥ 1 were found in the PSFD30 group. GC-O analysis was conducted on the PSFD30 group, leading to the preliminary identification of 2-methylbutanal, pentanal, hexanal, 2-hexenal, phenylacetaldehyde, ethyl acetate, 2-methylbutyl acetate, ethyl lactate, linalool, methyl heptenone, and γ-octalactone as distinctive aromas in dried peach slices.

Composition and content of volatiles, the important factors in flavor formation of edible fungi, are affected by growth process. GC–MS was performed and a total of 102 volatiles were identified in Phallus impudicus. Almost all identified volatile compounds showed an obvious upward trend at four growth period, and reached the maximum at fourth stage (PIII), of which the transition from first stage (ZP) to second stage (PI) achieved a breakthrough for 88 volatile compounds from scratch. The PCA and HCA results showed that the four stages were completely separated and appeared different, among which third stage (PII) and PIII might be the two dramatic change nodes in aroma quality. In addition, the top 50 differential metabolites were screened by OPLS-DA and PLS-DA, and correlation analysis showed that 6-undecyl alcohol, α-terpine-7-al, 2, 4-decenol, and 2-cyano-2-ethyl-butanamide, might co-regulate the flavor formation of Phallus impudicus through synergistic action of other chemical components.

To explore the characteristics of and variations in aroma components across different plum varieties and maturity stages, this study employed headspace solid-phase microextraction combined with gas chromatography–mass spectrometry (HS-SPME-GC-MS). This method was used to systematically analyze the aroma components of 12 early-maturing, 15 medium-maturing, and 11 late-maturing plum varieties. The variations in volatile components among these three germplasm types were then compared using multivariate statistical methods. The examination revealed that 138 aromatic components were meticulously identified and quantified, such as 26 aldehydes, 63 esters, 13 ketones, 30 alcohols, and six other compounds. Thirteen main aroma compounds including acetic acid hexyl ester, (Z)-3-hexen-1-ol acetate, hexanal, 1-hexanol, 3-hexenal, butanoic acid butyl ester, (E)-2-hexen-1-ol, hexanoic acid butyl ester, propanoic acid butyl ester, (E)-2-hexenal, L-.alpha.-terpineol, (Z)-2-hexen-1-ol acetate, and 1-butanol were considered dominant. The orthogonal partial least squares discriminant analysis (OPLS-DA) combined with variable importance projection (VIP) results showed that 24 differential aroma compounds were screened out from 38 varieties of plum fruits based on their differences in aroma components, which can be used to distinguish plum fruits at different ripening times. Twenty-four aroma-contributing compounds were identified based on their odor activity values (OAVs). Among these, 14 key aroma components with OAVs ≥ 10 were highlighted. In summary, the aroma compounds of early- and late-maturing plum germplasm exhibited rich diversity, with significant differences in aroma components between plums of varying maturity and germplasm. These differences can serve as indicators for identifying different plum germplasm.