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Fermented golden pompano (Trachinotus ovatus) has a distinctive flavor, but the key flavor compounds and aroma profiles remains unclear. Thus, a molecular sensory science approach was used to investigate flavor and key aromatic compounds. The fermentation process enhanced the overall flavor, as evidenced by sensory evaluation and electronic nose (E-nose) analyses. A total of 48 aroma compounds were identified at different fermentation stages. Among them, 11 key aroma compounds were identified by flavor dilution (FD) factors ≥8 and odor activity values (OAVs) ≥ 1. Aroma recombination model successfully reproduces the characteristic floral and fruity aromas of fermented golden pompano. Omission experiments identified hexanal, decanal, 1-octen-3-ol, limonene, and isovaleric acid as significant contributors to the overall aroma profile. This study elucidates flavor dynamic modulation and key aromatic compounds during golden pompano fermentation, to provide a theoretical reference for the targeting process regulation of the product., Competing Interests: Declaration of competing interest We declare that we do not have any commercial or associative interest that represents a conflict of interest in connection with the work submitted., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Agar production is accompanied by a large amount of wastewater, which threatens the ecological environment and wastes biomass resources. The high-value utilization of biomass resources in wastewater is one of the key factors in wastewater treatment. We investigated the conversion process and antifungal mechanism of large molecule polysaccharides in wastewater into small molecule substances with antifungal activity through anaerobic fermentation. The results indicated that anaerobic fermentation of GAW achieved inhibition rates of 91.06 % and 88.94 % against Alternaria alternata and Alternaria spp. 16S rDNA sequencing and metabolomics revealed that dominant species such as Blautia, Agathobacter and Sphingomonas converted polysaccharide into phenolic acids like procyanidin C and columbidin. These substances disrupted the integrity of fungal cells, leading to their death. The preparation of composite antifungal agents using fermentation products effectively inhibited cherry tomato spoilage and toxin production. This study provided reliable technical support for the reuse of seaweed waste resources., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Complex microbial metabolism is key to the unique flavor formation of Chinese fermented mandarin fish (Siniperca chuatsi). However, the association between microorganisms and production of specific flavor components during fermentation is unclear. In this study, headspace-solid-phase microextraction-gas chromatography -mass spectrometry was performed to identify flavor components in fermented samples of S. chuatsi, and high-throughput sequencing of 16S rRNA was conducted to identify the diversity and succession of microbial communities. A correlation network model was adopted to predict the relationship between key microorganisms and flavor formation. The results revealed alcohols, nitrogen compounds, aldehydes, and esters as the main flavor components, and three microbial genera (Psychrilyobacter, Fusobacterium, and Acidaminococcus) were closely associated with the production of these components. These microorganisms contributed to formation of characteristic flavor substances such as linalool, trimethylamine, indole, and Geranyl acetate. This study improves the understanding of different roles of microorganisms in flavor formation during mandarin fish fermentation., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Fungal infection has become a major threat to crop loss and affects food safety. The waste water from agar processing industries extraction has a number of active substances, which could be further transformed by microorganisms to synthesize antifungal active substances. In this study, Bacillus subtilis was used to ferment the waste water from agar processing industries extraction to analyze the antifungal activity of the fermentation broth on Alternaria alternata and Alternaria spp. Results showed that 25% of the fermentation broth was the most effective in inhibited A. alternata and Alternaria spp., with fungal inhibition rates of 99.9% and 96.1%, respectively, and a minimum inhibitory concentration (MIC) was 0.156 μg/mL. Metabolomic analysis showed that flavonoid polyphenols such as coniferyl aldehyde, glycycoumarin, glycitin, and procyanidin A1 may enhance the inhibitory activity against the two pathogenic fungal strains. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that polyphenols involved in the biosynthesis pathways of isoflavonoid and phenylpropanoid were upregulated after fermentation. The laser confocal microscopy analyses and cell conductivity showed that the cytoplasm of fungi treated with fermentation broth was destroyed. This study provides a research basis for the development of new natural antifungal agents and rational use of seaweed agar waste. Key points: • Bacillus subtilis fermented waste water has antifungal activity • Bacillus subtilis could transform active substances in waste water • Waste water is a potential raw material for producing antifungal agents [ABSTRACT FROM AUTHOR]

Regular consumption of fish promotes sustainable health while reducing negative environmental impacts. Fermentation has long been used for preserving perishable foods, including fish. Fermented fish products are popular consumer foods of historical and cultural significance owing to their abundant essential nutrients and distinct flavor. This review discusses the recent scientific progress on fermented fish, especially the involved flavor formation processes, microbial metabolic activities, and interconnected biochemical pathways (e.g., enzymatic/non‐enzymatic reactions associated with lipids, proteins, and their interactions). The multiple roles of fermentation in preservation of fish, development of desirable flavors, and production of health‐promoting nutrients and bioactive substances are also discussed. Finally, prospects for further studies on fermented fish are proposed, including the need of monitoring microorganisms, along with the precise control of a fermentation process to transform the traditional fermented fish to novel, flavorful, healthy, and affordable products for modern consumers. Microbial‐enabled innovative fermented fish products that consider both flavor and health benefits are expected to become a significant segment in global food markets. The integration of multi‐omics technologies, biotechnology‐based approaches (including synthetic biology and metabolic engineering) and sensory and consumer sciences, is crucial for technological innovations related to fermented fish. The findings of this review will provide guidance on future development of new or improved fermented fish products through regulating microbial metabolic processes and enzymatic activities. [ABSTRACT FROM AUTHOR]

Spontaneous fermentation is a critical processing step that determines the taste quality of fermented mandarin fish (Siniperca chuatsi). Here, untargeted metabolomics using ultra-high-performance liquid chromatography coupled with Q Exactive tandem mass spectrometry was employed to characterize the taste-related metabolite profiles during the fermentation of mandarin fish. The results demonstrated that the taste profiles of mandarin fish at different stages of fermentation could be distinguished using an electronic tongue technique. Sixty-two metabolites, including amino acids, small peptides, fatty acids, alkaloids, and organic acids, were identified in fermented mandarin fish samples. Additional quantitative analysis of amino acids revealed glutamic acid and aspartic acid as significant contributors to the fresh flavor. Furthermore, the Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis revealed that amino acid metabolism was the dominant pathway throughout the fermentation process. This study provides a scientific and theoretical reference for the targeted regulation of the quality of fermented mandarin fish. [ABSTRACT FROM AUTHOR]

The main objective of this work was to investigate the effects of bacterial community and free amino acids on the content of biogenic amines in Yu-lu during fermentation. Four major biogenic amines (histamine, tyramine, cadaverine, and putrescine) were identified, and the content of tyramine was positively correlated with histamine (R value = 0.9113). Aspartic acid, glutamic acid, histidine, leucine, and lysine were the dominant free amino acids. 16S rRNA sequencing showed that the composition of the bacterial community changed significantly during fermentation of Yu-lu. Principal component analysis revealed the crucial links between microbial community and biogenic amines. For example, Halanaerobium was probably associated with the formation of putrescine, while Halomonas might be associated with the degradation of biogenic amines at the end of fermentation of Yu-lu. This study provided a detailed evaluation of the Yu-lu fermentation process, enabling development of better strategies for biogenic amine control in fish sauce. [ABSTRACT FROM AUTHOR]

[Display omitted] • Glutamate, alanine, and leucine were the main free amino acids identified. • Six major amino acid metabolizing microbial genera were associated with most flavor compounds. • Halobacterium and Clostridium were core microbiota and amino acid metabolizers. • This study revealed the distribution of amino acid metabolic during golden pomfret fermentation. Golden pomfret (Trachinotus ovatus) is an important farmed fish in Asia, often consumed following salting and natural microbial fermentation. Flavor development in fermented foods depends on the metabolism of fermenting microbes, especially amino acid metabolism. However, the microbes involved in golden pomfret fermentation and the mechanism by which they regulate flavor development are largely unknown. Accordingly, in this study, we investigated the microbial community and volatile and non-volatile compounds during the traditional fermentation of golden pomfret, focusing on amino acid metabolism. Thirty-five volatile compounds were detected. Glutamate, alanine, and leucine were the main amino acids responsible for the development of the characteristic taste of fermented golden pomfret. Metagenomic analyses were performed, and microbial genes for amino acid metabolism were functionally annotated, revealing the underlying mechanisms of flavor development during fish fermentation. Halobacterium , Clostridium , Natrinema , Alkalibacillus , Natrialba , and Vibrio were the dominant microbial genera with a major contribution to amino acid metabolism during fermentation and were strongly correlated with the majority of volatile compounds. The study provides a theoretical reference for the mechanism of flavor formation and important information on the microbial sources of volatile compounds derived from amino acids. [ABSTRACT FROM AUTHOR]

• The alteration in lipid of golden pomfret during fermentation was determined. • LC–MS-based lipidomics showed a total of 998 lipids belonging to six classes. • Fermentation time was a critical variable affecting golden pomfret's lipid profile. • Glycerophospholipid metabolism is the critical metabolic pathways. • Our results provided insight into alterations in golden pomfret during fermentation. Fermented golden pomfret (a popular marine fish product) is prepared via spontaneous fermentation. However, no comprehensive analysis has been reported on its lipid composition and metabolism. Herein, UHPLC-MS/MS-based untargeted lipidomic analysis identified 998 lipids (six classes; 29 subclasses) in fermented golden pomfret, including glycerolipids (47.70%) and glycerophospholipids (32.06%). As fermentation proceeded, triglyceride and diglyceride contents increased and subsequently decreased, while that of poly-unsaturated fatty acid-containing lipids increased (including those with docosahexaenoic acid, eicosapentaenoic acid, and docosapentaenoic acid). Pathway enrichment analysis identified seven lipid-related metabolic pathways, with the glycerophospholipid pathway found to be the most pertinent. Moreover, the decreased abundance of phosphatidylethanolamines and phosphatidylcholines during fermentation results from their high unsaturated fatty acid (FA) content. Indeed, essential FA contents increase following fermentation, due to their occurrence as glycerolipid side chains. Collectively, the results of this study provide a theoretical reference for optimizing the quality of fermented fish products. [ABSTRACT FROM AUTHOR]

[Display omitted] • Volatile compounds dynamics were clarified by E-nose and GC-IMS during fermentation. • Aroma differences could be detected by P30/2, P30/1, PA/2 and T30/1 in E-nose. • GC-IMS identified 31 volatile compounds in fermented golden pomfret. • BP-ANN model could effectively predict the fermentation stages of samples. • Fermentation process significantly affected the profile of volatile compound types. Fermented golden pomfret (Trachinotus ovatus) is appreciated by local consumers owing to its distinct flavor. Electronic nose (E-nose) and gas chromatography-ion mobility spectrometry (GC-IMS) technologies were used to analyze the changes in volatile compounds responsible for evolution of the golden pomfret odor profile during fermentation. Forty-five ion peaks were detected using GC-IMS. Although aldehydes represented the major initial volatile compound group, their levels decreased as fermentation proceeded. Between 3 and 15 days, increased levels of esters contributed to a stable volatile organic compounds profile. After 18 days, high levels of indole and pyrazines were detected. Eleven key volatile compounds were screened based on partial least squares discriminant analysis (PLS-DA). Back propagation artificial neural network (BP-ANN) predicted the fermentation stage enabling the development of better strategies to regulate golden pomfret fermentation. This study provided a theoretical basis for real-time monitoring and quality control of Chinese fermented golden pomfet. [ABSTRACT FROM AUTHOR]

Fermentation causes changes in fish texture, nevertheless, the mechanism of protein involvement in this process of textural changes are unknown. We investigated changes in the tissue microstructure and texture, combined with a multidimensional fusion strategy to characterized the oxidative degradation properties of myofibrillar proteins, and analyzed the protein expression using label-free quantitative proteomics. Muscle protein hydrolysis, increased oxidation levels, and changes in spatial conformation were observed in the fish texture and microstructure during fermentation. We identified 664 proteins and screened 330 differentially proteins. The weighted protein co-expression network model screening yielded a total of 38 key potential proteins associated with textural changes. Characteristic proteins at important nodes, which were mainly structural proteins and metabolic enzymes, were identified using protein-protein interaction network analysis. These results reveal a relationship between proteins and textural characteristics and provide a theoretical basis for improving the quality control of fermented marine fish. • Significant changes in the texture and microstructure of fermented golden pompano. • Muscle protein hydrolysis and increased oxidation levels were observed. • Thirty-eight key differential expressed proteins were highly correlated with texture. • Potential protein markers for textural were identified. [ABSTRACT FROM AUTHOR]

• Metabolite changes in fish sauce during fermentation were studied by UPLC-Q/TOF-MS. • Forty-six metabolites were identified as key chemical components of fish sauce. • Aspartic acid and glutamic acid play a part in the umami taste of fish sauce. • Specific metabolites were primarily associated with amino acid metabolism. Spontaneous fermentation is a critical step in the processing of high-quality fish sauce. In this study, a comparative UHPLC-Q/TOF-MS-based metabolomics approach combining equivalent-quantification and the taste activity value (TAV) was used, for the first time, to evaluate the taste qualities and characterize metabolite profiles in Chinese fish sauce during fermentation. A total of 22,816 metabolite ion features were extracted from fish sauce samples. Forty-six metabolites, including amino acids, small peptides, organic acids, amines, carbohydrates, and nucleic acids, were identified as key chemical components of fish sauce. In addition, absolute quantification and TAV showed that aspartic acid and glutamic acid exert an important influence on the umami taste of fish sauce. Specific metabolites were primarily associated with amino acid metabolism, particularly alterations in arginine and proline metabolism. This study identifies chemical components and provides novel insights into the taste quality of fish sauce due to fermentation. [ABSTRACT FROM AUTHOR]

• Twelve volatile compounds were identified as key flavor components in fish sauce. • Correlations of volatile compounds and microbiota were explored by O2PLS analysis. • Metabolism of five key microbial genera lead to the flavor formation of fish sauce. • Microbial metabolic network reveals flavor formation of fish sauce. Complex microbial metabolism is the basis for flavor formation in traditional fish sauce. To guide the targeted regulation of production quality, we used molecular sensory and metagenomics analyses to determine dynamic changes in volatile flavor compounds and microbial communities of fish sauce as fermentation progressed. In total, 56 volatile compounds were identified; of these, 3-methylthiopropanal had the highest average odor activity value. Twelve volatile compounds, key for fish sauce flavor development, were identified. Bidirectional orthogonal partial least squares analysis was applied to investigate the correlation between microorganisms and flavor substances. Five microbial genera including Halanaerobium , Halomonas , Tetragenococcus , Halococcus and Candidat us Frackibacter constituted the core microbial flora responsible for flavor formation. The microbial metabolic pathways degraded raw materials into primary metabolites, such as glucose, amino acids, and fatty acids. This study provides novel insights into the flavor formation mechanism of traditional fish sauce fermentation. [ABSTRACT FROM AUTHOR]