Comparative Analysis of Flavor, Taste, and Volatile Organic Compounds in Opossum Shrimp Paste during Long-Term Natural Fermentation Using E-Nose, E-Tongue, and HS-SPME-GC-MS

Metabolomics, E-tongue and HS-SPME-GC-MS reveal the smoking process of Prunus mume: Changes in flavor and chemical compositions

Smoked Prunus mume (SPM), known as Wumei, experiences remarkable alterations in flavor and chemical composition. However, no research has reported on the smoking process. In this study, the changes of flavor and chemical compositions were analyzed via E-tongue, metabolomics, and HS-SPME-GC-MS during the smoking process. Results showed that significant changes in the basic parameters and electronic sense were observed during the smoking process. 85 volatile organic compounds (VOCs) were identified, and 124 metabolites were significantly differentially regulated during the smoking process. Metabolic pathway analysis showed that 20 pathways in SPM, especially phenylpropanoid biosynthesis, are related to smoking process. A number of key substances were identified by Mantel test that may have caused the electrosensory changes in SPM. These findings revealed that the changes characterization of flavor and chemical compositions in SPM during the smoking process, which will help to better understand the formation mechanism of flavor and metabolites.

Correlation between quality change and hydrogen sulfide in aquatic product: Detection of hydrogen sulfide and its potential applications using bigeye tuna (Thunnus obesus) model during cold storage

Hydrogen sulfide (H2S) is an metabolic product of tuna during the spoilage, and relationship between H2S and tuna quality has not been specifically studied. This study detected changes in H2S content, H2S precursor substances, and related enzymes based on the formation pathway of H2S. H2S content increased of tuna resulted in significant increases in contents of cystathionine β-synthase, cystathionine γ-lyase, 3-mercapto pyruvate sulfotransferase, cysteine aminotransferase and methionine, while content of cysteine decreased which provided H2S formation. Cysteine and methionine metabolism, sulfur metabolism and histidine metabolism were metabolic pathways to assess H2S accumulation. Canonical correlation analysis showed that H2S content was significantly correlated with total volatile base nitrogen, total viable count (p < 0.05). This study elucidates the universality of H2S as an index for assessing seafood quality, utilizing quality indicators and modeling. Our findings offer a theoretical foundation and potential practical applications for improving the quality control of aquatic products.

Evaluation of flavor characteristics in Chinese wheat flour paste using electronic-nose, electronic-tongue, and headspace-gas chromatography-ion mobility spectrometry at different fermentation stages

BACKGROUND

Wheat flour paste is a typical Chinese fermented food, valued for its distinct flavors and health benefits. However, evidence regarding volatile organic compounds (VOCs) in Chinese wheat flour paste is limited. This study aims to examine the effect of fermentation on the VOCs and their physicochemical properties. Chinese wheat flour paste fermented at different stages was characterized using headspace gas chromatography ion-mobility spectrometry (HS-GC-IMS) with an electronic nose (E-nose) and an electronic tongue (E-tongue).

RESULTS

The results revealed that around 76 VOCs were found in Chinese wheat flour paste from all stages of fermentation. These included esters, alcohols, aldehydes, ketones, acids, furans, and pyrazines. The E-tongue and E-nose analyses also showed high responses for saltiness, umami, WIW, and W5S. The fermentation process changed the color of the wheat flour paste, and the taste, and smell parameters. Principal component analysis (PCA) showed that taste parameters were positively associated with the volatile flavor profile detected in wheat flour paste. Partial least squares discriminant analysis also identified 28 VOCs as distinct flavor metabolites across fermentation stages.

CONCLUSION

At the 'after ripening' (AR) and 'sterilization' (S) stages of wheat flour paste fermentation there were strong umami and salty flavors, with minimal sour and sweet notes in comparison with the other stages. These stages were characterized by elevated terpene concentrations, inorganic sulfides, and key flavor enhancers such as 2-hexanol and propyl sulfide. Headspace gas chromatography ion-mobility spectrometry and E-nose technologies are recommended for a more precise assessment of volatile changes during fermentation. The findings indicate that the 'sterilization' stage of wheat flour paste fermentation is optimal for achieving the required flavor profile. © 2024 Society of Chemical Industry.

Application of multiple dynamic sensory techniques to N-lauroyl amino acids: Exposing the relationship between taste-enhancing properties and chemical structure

This study investigated the taste enhancing effects of N-lauroyl amino acids, including N-lauroyl-phenylalanine, N-lauroyl-tryptophan and N-lauroyl-tyrosine. Sensory results obtained through TDS, TCATA, and TI assessments indicated that all N-Lau-AAs significantly increased the umami intensity and duration of solutions such as simulated chicken broth. Moreover, these compounds masked bitter taste, with LTR showing the most pronounced reduction of bitterness. LP had the effect of enhancing saltiness, whereas LTR and LTY diminished saltiness. Structural analysis revealed a correlation between the chemical structure of N-Lau-AAs and their sensory properties. The presence of carbon‑carbon double bond (CC) was positively correlated with umami intensity and negatively correlated with bitter and salty parameters. Phenolic hydroxyl groups (OH) were negatively correlated with umami intensity and positively correlated with a decrease in bitterness intensity and duration. Overall, this study provides valuable insights into the taste enhancement potential of N-Lau-AAs as taste enhancers in the food industry.

Impact of Enzyme-Microbe Combined Fermentation on the Safety and Quality of Soy Paste Fermented with Grass Carp By-Products

Freshwater fish processing produces 30-70% nutrient-rich by-products, often discarded or undervalued. Grass carp by-products, rich in protein, offer potential as raw materials for fermented seasonings. This study explores the use of these by-products-specifically, minced fish and fish skin-in soybean fermentation to evaluate their effects on the quality of the resulting seasonings. Tetragenococcus halophilus was used as a starter culture alongside food-grade protease to assess their combined impact on the safety and flavor of soy fish paste and soy fish skin paste. The findings revealed that natural fermentation resulted in higher protein hydrolysis in soy fish skin paste compared to soy fish paste. Across all fermentation conditions, amino acid nitrogen levels increased, while total volatile basic nitrogen levels decreased in both pastes, indicating improved quality. Additionally, microbial fermentation significantly reduced biogenic amine content in soy fish paste, enhancing safety. Enzymatic fermentation further enriched the flavor of both pastes by boosting key compounds such as 2-methylbutanal and ethyl acetate. Notably, enzyme-microbe co-fermentation harnessed the strengths of both methods, achieving improved safety and enhanced flavor profiles while elevating overall product quality. These findings suggest a promising way to transform freshwater fish by-products into high-value condiments, advancing sustainable food processing.

Correlation between physicochemical properties, flavor characteristics and microbial community structure in Dushan shrimp sour paste

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.

Characterizing the flavor profiles of Linjiangsi broad bean (Vicia faba L.) paste using bionic sensory and multivariate statistics analyses based on ripening time and fermentation environment

The flavor profile of Linjiangsi broad bean paste (LBBP) is significantly influenced by fermentation environment and ripening time. This study aims to investigate the flavor of outdoor-treated (OT) and indoor-treated (IT) LBBP. Gas chromatography-mass spectrometry, electronic-nose, and electronic-tongue, combined with multivariate statistical analyses, were employed to identify the characteristic flavor profiles of OT and IT LBBP in ripening periods of one and three years. Overall, 95 volatile organic compounds (VOCs) were identified. Relative odor activity values and multivariate statistical analysis indicated that nine VOCs were responsible for the flavor differences. The most abundant VOCs in OT were aldehydes, providing caramel and nutty flavors, whereas the most abundant compounds in IT were esters, contributing fruity flavors to LBBP. Notably, three years of ripening significantly intensified the characteristic flavors of both OT and IT. These findings may elucidate the ripening time and fermentation environment effect on LBBP characteristic flavor profiles.

Effects of 'bask in sunlight and dewed at night' on the formation of fermented flavor in shrimp paste after maturation

The purpose of the study was to illustrate the roles of three primary indexes, namely sunlight, ventilation and stirring, in the 'bask in sunlight and dewed at night' technique on the quality of shrimp paste, through a laboratory-scale design. The results showed that changes in the post-ripening fermentation conditions, especially sunlight, was instrumental in the physicochemical properties of the shrimp paste. E-nose and SPME-GC-MS were employed to assess the volatile flavor of post-ripening fermentation. A total of 29 key volatile aroma components played a crucial role in the development of post-ripening flavor in shrimp paste with or without sunlight. Lipidomic analysis revealed that sunlight promoted the oxidative degradation of FA, resulting in the production of a diverse range of flavor compounds that imparted the unique aroma of shrimp paste. The findings of this study will establish a theoretical basic for better control of the post-ripening fermentation of traditional shrimp paste.

Characterization of flavor profile of Steamed beef with rice flour using gas chromatography-ion mobility spectrometry combined with intelligent sensory (Electronic nose and tongue)

The intelligent senses (Electronic nose and tongue), were combined with headspace gas chromatography-ion mobility spectrometry (HS-GC-IMS) and free amino acid were used in combination to determine the aroma and taste components during the processing of Chinese traditional dish Steamed beef with rice flour (SBD). The findings revealed that E-nose and E-tongue, could clearly distinguish and identify the aroma and taste of SBD. A total of 66 volatile substances and 19 free amino acids were identified by HS-GC-IMS and amino acid analyzer, respectively. The highest contribution to aroma in the production of SBD was alcohols, esters and aldehydes. Further analysis of relative odor activity showed that 3-Methylbutanol-D, 3-Methylbutanol-M and 3-Methylthio propanal is the marinating stage (T2) main aroma components. Ethyl 3-methylbutanoate-M and Ethyl 3-methylbutanoate-D were the main aroma components in the seasoning stage (T3). Additionally, the calculation of the taste activity value showed that Glutamic contributed significantly to the umami of SBD. Alanine was a representative taste component in the marinating stage (T2), while Proline, Aspartic, Lysine, Glutamic, Valine, Arginine, and Histidine were characteristic amino acids of the seasoning stage (T3). Consequently, this study offers valuable insights into the industrial-scale production and flavor regulation of SBD products.

BitterMasS: Predicting Bitterness from Mass Spectra

Bitter compounds are common in nature and among drugs. Previously, machine learning tools were developed to predict bitterness from the chemical structure. However, known structures are estimated to represent only 5-10% of the metabolome, and the rest remain unassigned or "dark". We present BitterMasS, a Random Forest classifier that was trained on 5414 experimental mass spectra of bitter and nonbitter compounds, achieving precision = 0.83 and recall = 0.90 for an internal test set. Next, the model was tested against spectra newly extracted from the literature 106 bitter and nonbitter compounds and for additional spectra measured for 26 compounds. For these external test cases, BitterMasS exhibited 67% precision and 93% recall for the first and 58% accuracy and 99% recall for the second. The spectrum-bitterness prediction strategy was more effective than the spectrum-structure-bitterness prediction strategy and covered more compounds. These encouraging results suggest that BitterMasS can be used to predict bitter compounds in the metabolome without the need for structural assignment of individual molecules. This may enable identification of bitter compounds from metabolomics analyses, for comparing potential bitterness levels obtained by different treatments of samples and for monitoring bitterness changes overtime.

Metabolomics and HS-SPME-GC-MS-based analysis of quality succession patterns and flavor characteristics changes during the fermentation of Lycium barbarum and Polygonatum cyrtonema compound wine

This work set out to investigate how the physicochemical markers, volatiles, and metabolomic characteristics of mixed fermented the fermentation of Lycium barbarum and Polygonatum cyrtonema compound wine (LPCW) from S. cerevisine RW and D. hansenii AS2.45 changed over the course of fermentation. HS-SPME-GC-MS combined with non-targeted metabolomics was used to follow up and monitor the fermentation process of LPCW. In total, 43 volatile chemical substances, mostly alcohols, esters, acids, carbonyl compounds, etc., were discovered in LPCW. After 30 days of fermentation, phenylethyl alcohol had increased to 3045.83 g/mL, giving off a rose-like fresh scent. The biosynthesis of valine, leucine, and isoleucine as well as the metabolism of alanine, aspartic acid, and glutamic acid were the major routes that led to the identification of 1385 non-volatile components in total. This study offers a theoretical foundation for industrial development and advances our knowledge of the fundamental mechanism underlying flavor generation during LPCW fermentation.

Integrated microbiome, metabolome and transcriptome profiling reveals the beneficial effects of fish oil and Bacillus subtilis jzxj-7 on mouse gut ecosystem

The effects of fish oil (FO) and Bacillus subtilis jzxj-7 (JZXJ-7) on the colonic physiology, bacteria, metabolites, and gene expressions were studied in C57BL/6J mice. Co-administration of FO and JZXJ-7 was more beneficial than individual supplementation, as evidenced by improved growth performance, enhanced colon crypt depth and goblet cell numbers. FO + JZXJ-7 inhibited colonic fibrosis by downregulating fibrosis marker protein expression and upregulating occludin, claudin-2 and claudin-4 gene expressions. FO + JZXJ-7 ameliorated oxidative stress and inflammation by increasing catalase, superoxide dismutase, total anti-oxidation capacity, and reducing colon tumor necrosis factor (TNF)-α, interleukin (IL)-1β and IL-6 levels. Mechanistically, FO + JZXJ-7 modulated the colon micro-ecological environment by enriching Roseburia, Lachnospiraceae NK4B4, Faecalibaculum and Lactococcus and its derived short-chain fatty acids, and activating Ppara and Car1 mediated peroxisome proliferators-activated receptor (PPAR) and phosphatidylinositol 3 kinase/protein kinase B (PI3K/Akt) signaling. Overall, FO + JZXJ-7 may serve as a promising nutraceutical to improve health by boosting the growth of colonic beneficial bacteria, altering metabolic phenotype, and regulating gene expression.

Flavor profile and role of macromolecules in the flavor generation of shrimp meat and valorization of shrimp by-products as a source of flavor compounds: a review

Shrimps are a widely cultivated species among crustaceans worldwide due to their nutritional profile and delicacy. Because of their unique flavor, shrimp-based food products are gaining consumer demand, so there is a need to understand the flavor chemistry of shrimp meat. Further, the processing and macromolecules of shrimp meat play a significant role in flavor generation and suggest a focus on their research. However, shrimp processing generates a large amount of solid and liquid waste, creating disposal problems and environmental hazards. To overcome this, utilizing these waste products, a rich source of valuable flavor compounds is necessary. This review comprehensively discusses the nutritional aspects, flavor profile, and role of macromolecules in the flavor generation of shrimp meat. Besides, recent trends in analyzing the aroma profile of shrimp and the benefits of shrimp by-products as a source of flavor compounds have been addressed. The delicious flavor of shrimp meat is due to its volatile and nonvolatile flavor compounds. Proteins play a major role in the textural and flavor adsorption properties of shrimp meat-based products. Green extraction technologies, especially ultrasonication, are recommended for valorizing shrimp by-products as a source of flavor compounds, which have enormous applications in the food and flavor industries.

The Membrane Phospholipidomics Research of Oxidatively Damaged INS-1 Pancreatic Beta Cells Intervened by the Effective Constituents of Anemarrhenae Asphodeloides Rhizoma

The rhizoma of Anemarrhenae asphodeloides has a long history of hypoglycemic use in Chinese traditional medicine. In this article, 400 μmol/L H2 O2 induced normal INS-1 pancreatic beta cells to establish experimental model of oxidative damage. Quercetin was used as a positive drug, and mangiferin and its ethanolic extract were selected as therapeutic agents in an oxidative damage model to evaluate the ameliorative effect of the active ingredients of Anemarrhenae asphodeloides rhizoma on oxidative damage in INS-1 pancreatic β-cells. Building a qualitative analysis method of membrane phospholipids of INS-1 pancreatic beta cells and identified 82 phospholipids based on the UPLC/Q-TOF MS technology, which could provide a database for further statistics analysis. OPLS-DA was used to screen the phospholipid biomarkers from the raw data. Exploring the biological significances of these biomarkers, and discussing the toxic effect of the effective components of Anemarrhena asphodeloides rhizoma, on oxidatively damaged INS-1 pancreatic beta cell.

Characteristic flavor metabolic network of fish sauce microbiota with different fermentation processes based on metagenomics

This article purposed to discuss the connection between microbiota and characteristic flavor of different fish sauces (Natural fermentation (WQ), koji outdoor fermentation (YQ), heat preservation with enzyme (BWE), and heat preservation with koji (BWQ)) at the early (3 months) and late stage (7 months). A total of 117 flavor compounds were determined according to SPME-GC-MS analysis. O2PLS-DA and VIP values were used to reveal 15 and 28 flavor markers of different fish sauces at 3 and 7 M of fermentation. Further, the possible flavor formation pathways were analyzed using metagenomic sequencing, and the key microbes associated with flavor formation were identified at the genetic level. The top 10 genera related to flavor generation, such as Lactobacillus, Staphylococcus, Enterobacter, etc., appeared to play a prominent part in the flavor formation of fish sauce. The difference was that only BWQ and BWE groups could produce ethyl-alcohol through amino acid metabolism, while YQ, BWE and BWQ groups could generate phenylacetaldehyde through the transformation of Phe by α-ketoacid decarboxylase and aromatic amino acid transferase. Our research contributes to clarifying the various metabolic roles of microorganisms in the flavor generation of fish sauce.