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The study aimed to evaluate the effect of digestion and gut microbiota interactions on beetroot ketchup formulations, focusing on the release of polyphenols, bioaccessibility, and microbial interactions on gut microbiota with polyphenols. Tested ketchup samples were evaluated using the TNO Gastro-Intestinal Model 1 (TIM-1) simulated upper part of the gastrointestinal tract and the TNO Gastro-Intestinal Model 2 (TIM-2) simulated colon system. The results showed that fermentation of ketchup with Lactobacillus johnsonii K4, increased the release of bioactive compounds during digestion, with higher polyphenol recoveries observed in fermented samples. In particular, a fermented sample has higher recovery percentages for most of the phenolic acids, flavonoids, and betalains. However, some polyphenolic compounds were degraded during fermentation, suggesting a dynamic process of polyphenol metabolism in the gut environment. The study highlights the potential of fermented foods, such as beetroot ketchup, enriched with polyphenols and beneficial bacteria, to promote gut health and overall well-being., 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 The Authors. Published by Elsevier Ltd.. All rights reserved.)

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.)

This study demonstrates that the co-inoculation with Lactiplantibacillus plantarum, Pichia fermentans and Staphylococcus saprophyticus accelerates catfish frame fish sauce fermentation. Over a 3-day period, significant changes occurred in physicochemical properties, microbial profiles, flavor compounds, and metabolomic spectra. Notable increases in acidity coupled with decreases in glucose underscored the robust environmental adaptability of the employed microorganisms. A reduction in total amino acids, alongside a rise in umami amino acids, suggested flavor enhancement. GC-MS analysis identified 40 key volatile compounds, with esters and aldehydes crucial for aroma development. UPLC-QTOF-MS-based untargeted analysis identified 934 metabolites, with 377 differential metabolites being vital (VIP > 1.5, P < 0.05), including amino acids, peptides, organic acids, nucleic acids, and fatty acids. Metabolites linked to amino acid metabolism, particularly phenylalanine and arginine, were associated with fermentation duration. These findings offer a theoretical basis for optimizing flavor and quality in fish sauces from fish by-products through accelerated fermentation., 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.)

This study utilized metabolomics and metagenomics to investigate the microbial composition and functions in low- and high-salt Chinese horse bean-chili pastes (CHCPs). The results showed that 25 key metabolites were identified to distinguish the flavor attributes between the two samples. Leuconostoc was identified as the dominant microbiota in low-salt CHCP, while Pantoea prevailed in the high-salt CHCP. Compared to traditional high-salt fermentation, low-salt and inoculated fermentation promoted the increase in the relative abundances of Companionlactobacillus, Levilactobacillus, Tetragenococcus, Zygosaccharomyces and Wickerhamiella as well as the enrichment of carbohydrate and amino acid metabolic pathways, which contributed to the enhancement of characteristic flavor compounds. Further metabolic pathway reconstruction elucidated 21 potential microbial genera associated with the formation of key metabolites, such as Leuconostoc, Levilactobacillus, Pantoea, and Pectobacterium. This study may provide insights for optimizing the fermentation process and improving the flavor quality of low-salt CHCP and similar fermentation products. KEYWORDS: Low-salt fermentation Hight-salt fermentation Chinese horse-bean chili paste Flavor formation Metabolomics Metagenomics., 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.)

The unique flavors of fermented foods significantly influence consumer purchasing choices, prompting widespread scientific interest in the flavor development process. Fermented rice and wheat foods are known for their unique flavors and they occupy an important place in the global diet. Many of these are produced on an industrial scale using starter cultures, whereas others rely on spontaneous fermentation, homemade production, or traditional activities. Microorganisms are key in shaping the sensory properties of fermented products through different metabolic pathways, thus earning the title "the essence of fermentation." Therefore, this study systematically summarizes the key microbial communities and their interactions that contribute positively to iconic fermented rice and wheat foods, such as steamed bread, bread, Mifen, and rice wine. This study revealed the mechanism by which these core microbial communities affect flavor and revealed the strategies of core microorganisms and related enzymes to enhance flavor during fermentation., 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. We confirm that there are no financial, personal, or professional interests that could potentially bias our research findings or influence the interpretation of the results presented in the manuscript. Additionally, we have not received any financial support, grants, or other forms of compensation that could be perceived as influencing the objectivity of our research. Furthermore, we declare that there are no relationships or affiliations with any organizations, companies, or individuals that could pose a conflict of interest for the content of the manuscript. We affirm that this Declaration of Interest accurately reflects our commitment to transparency and integrity in research, and we stand by the authenticity and impartiality of the findings reported in the manuscript., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Yancaigao, a distinctive fermented condiment indigenous to Southwest China, imparts unique sour flavor profile to various culinary applications. This study investigated the organic acid profile, volatile flavor constitutes, and microbial community of two fermented and six blended Yancaigao samples. Organic acid analysis revealed that lactic acid (86.51-117.28 mg/g) was the predominant organic acid in fermented Yancaigao, accounting for 97.40-98.08 % of total organic acids. It was significantly higher than those observed in blended Yancaigao (1.92-13.91 mg/kg). Headspace-solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) analysis identified 88 volatile compounds, mainly encompassing acids (10), alcohols (23), aldehydes (19), ketones (13), esters (5), pyrazines (4), ethers (2), olefins (2), benzene (1), and sulfide (1). Lactic acid, 2,3-butanediol, dimethyl trisulfide, 1-octen-3-one, and dimethyl disulfide were determined to be key aroma compounds of the eight Yancaigao samples, based on odor activity value and Orthogonal partial least squares-discriminant analysis (OPLS-DA). Notably, trans-α,α-5-trimethyl-5-vinyltetrahydro-2-furanmethanol and 2,3-pentanedione were exclusively detected in fermented Yancaigao. Microbial community analysis revealed that Pseudomonas (43.37 %) and Methyloversatilis (14.03 %) were the dominant microorganisms, indicating potential microbial contamination. This study could provide valuable insights for quality evaluation and integrated development of traditional fermented Yancaigao., 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.)

Health-promoting foods have become increasingly popular due to intensified consumer interest and awareness of illnesses. There is a global market for apple fruits, which are affordable, nutritious, tasty, and produced in large quantities for direct consumption as well as food processing to make derived products. The food matrix of apples is suitable for fermentation, besides containing a high amount of phenolics and polyphenols. Fermentation of apples is one of the most common methods of preserving apple fruit and its byproducts. With different fermentation techniques, apple fruit can be used to make a wide range of products, such as fermented apple juice, cider, liqueurs, apple cider, apple vinegar and fermented apple solids, because it is not only a low-cost and simple method of processing the fruit, but it can also sometimes increase the bioavailability of nutrients and the levels of components that can improve health and sensory quality. To understand the health benefits of food products and how the fermentation process impacts polyphenols, it is also crucial to observe the effects of digestion on polyphenol bioaccessibility. Polyphenolic profile changes can be observed via both in vitro and in vivo digestion methods; however, in vitro digestion methods have the advantage of observing every step of gastrointestinal track effects and have less cost as well. In this review, the polyphenolic profile, processing impact, and bioaccessibility of apple-fermented products is assessed, with most available studies showing polyphenol profiles and bioaccessibility in apple varieties and fermented apple products.

The importance of nonconventional yeasts has increasingly been highlighted, particularly for aroma formation in fermented foods. Here, we performed de novo whole-genome sequencing of Wickerhamomyces subpelliculosus , which produces a variety of volatile flavor compounds, leading to the identification of the alcohol acyltransferase (AATase) family of genes. The genome of W. subpelliculosus contains seven AATase genes, encoding alcohol- O -acetyltransferases (ATFs) and ethanol acetyltransferase 1 (EAT1) for acetate ester formation, along with ethanol hexanoyl transferase 1 (EHT1) for ethyl ester formation. Among five ATF homologues, only WsATF5 showed acetyltransferase activity toward myriocin, a structural analogue of sphingosine. In contrast, heterologous expression of WsEHT1 and WsEAT1 in Saccharomyces cerevisiae promoted the production of ethyl decanoate and ethyl acetate, respectively, supporting their AATase activity. The enzymatic activity analyses revealed the additional alcoholysis activity of WsEAT1 and the thioesterase activity of WsEHT1. Subcellular localization analysis indicated that WsEAT1 was localized in the mitochondria, WsEHT1 in the endoplasmic reticulum and lipid droplets (LDs), and WsATF5 in the LDs. The novel W. subpelliculosus AATases could be usefully applied to produce flavor components in various food industries.

N -Lactoyl-phenylalanine (Lac-Phe) is a metabolite known for its appetite-suppressing and antiobesity properties, while phenyllactic acid (PLA) is recognized for its antibacterial activity. Both metabolites are derived from phenylalanine and lactic acid metabolism through peptidase and dehydrogenase activities. The aim of this study was to investigate the production of Lac-Phe and PLA in kimchi, focusing on the role of lactic acid bacteria (LAB). Ultrahigh performance liquid chromatography coupled with time-of-flight mass spectrometry was used to quantify these metabolites in homemade and commercial kimchi. Lac-Phe and PLA were detected in both kimchi sample types. Various genera, including Lactobacillus , Leuconostoc , and Weissella, were evaluated for Lac-Phe and PLA production. LAB strains exhibiting high Lac-Phe production generally showed lower PLA production, indicating an inverse relationship between these two metabolites. Analysis of dipeptidase sequences revealed that the presence of carnosine dipeptidase 2 (CNDP2)-like M20 metallopeptidase is crucial for Lac-Phe production in LAB. Additionally, phenylalanine was identified as a major factor for both Lac-Phe and PLA production, whereas lactic acid supplementation did not significantly affect their production levels.

Rusip is a spontaneously fermented anchovy product originating from Bangka Belitung province in Indonesia, used as umami seasoning. This study investigated the characteristics of rusip and its umami fractions to reveal umami peptides in rusip. Six commercial rusip samples from Bangka were analyzed for their proximate composition, pH, total titratable acids, NaCl, total sugars, free glutamic acid, nucleotide (adenosine monophosphate), and total amino acid composition. Umami taste intensity of water-soluble extracts (WSE) was analyzed by a sensory panel. Total plate count and total lactic acid bacteria were also analyzed to assess the microbial variations between the samples. Stepwise ultrafiltration on the highest umami intensity WSE was conducted to obtain three fractions: >5 kDa, 3-5 kDa, and <3 kDa, followed by chromatography fractionation of fraction <3 kDa by Sephadex G-15 gel to acquire umami fractions (F1-F4). Protein (28.94%-44.53% dry weight basis [db]) and NaCl (30.86%-55.73% db) were the major solids of rusip. Concentrations of free glutamic acid (5.79%-8.99% db) in rusip are related with umami intensities of WSE. F1 was the umami fraction with its residual umami amino acids higher than its free ones; therefore, F1 was also a peptide fraction. It contained peptides of 3-12 residues within the highest relative area. Their sequences contained those of umami peptides listed in BIOPEP database. Some of these peptides were also associated with bioactivities. This information could broaden the insight of umami peptides and their bioactivities in fermented foods. PRACTICAL APPLICATION: Rusip is used as a source of umami ingredient in food. The characteristics of product quality of rusip were reported in this study. In addition, the chemical and sensory characteristics as well as peptides of its umami fraction were also described. This information is important for the exploration of umami peptides from fish fermented products., (© 2024 Institute of Food Technologists.)

Kimchi is a traditional Korean dish made from fermenting vegetables. The fermentation process is crucial for enhancing its quality and flavor during storage. Approaches such as hyperspectral imaging (HSI) and chemometrics (PLS, partial least square; SVR, support vector regression) including principal component analysis (PCA), and 2-dimensional correlation spectroscopy (2D-COS) can detect key physical and chemical components and changes in total soluble solids (TSS), pH, titratable acidity (TA), salinity, and lactic acid bacteria (LAB). Multivariate analytical models were developed to predict the quality properties using full and characteristic wavelengths and preprocessed data. The results showed that the ratio of prediction to deviation (RPD) values of the PLS prediction model constructed using the full wavelengths of TSS, salinity, pH, TA, and LAB were 1.57, 2.33, 2.79, 2.91, and 2.73, respectively. The Savitzky Golay 1st derivative preprocessed SVR model established based on characteristic wavelengths (951, 1020, 1139, 1174, 1216, 1321, and 1384 nm) extracted by PCA and a 2D-COS matrix showed the best results and increased efficiency in predicting pH (R p 2  = 0.9166, RPD = 3.281) and the number of LAB (R p 2  = 0.8488, RPD = 2.466). Additionally, the visualization process accurately illustrated the distribution of various quality indicators of kimchi across different periods. These results demonstrate that our proposed HSI strategy successfully assessed the degree of kimchi fermentation., 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 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Red yeast rice (RYR) as a traditional fermented food produced by inoculation of the Monascus genus into steamed rice through solid-state fermentation, has been used intensively for thousands of years in China. Herein, we investigated the flavor profiles, metabolites and quality characteristics of RYR produced by mix fermentation with lactic acid bacteria (LAB) using the headspace solid phase microextraction gas chromatography-mass spectrometry (HS-SPME-GCMS) approach integrated with ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS). 56 volatile organic compounds (VOCs) and 1287 non-volatile metabolites were identified and classified into eight classes, the inoculation of Lactiplantibacillus plantarum (LP) and Limosilactobacillus fermentum (LF) increased VOCs and enhanced the flavor characteristics of RYR, with LP being the more significant. The KEGG pathway enrichment analysis revealed that most of the differential metabolites were enriched in amino acid metabolism when integrating volatile and non-volatile omics data, meanwhile, the addition of LAB promoted the metabolism of amino acid, alcohols, fatty acid and some flavonoids, in particular, amino acid metabolism was almost upregulated in the LP group. Therefore, this study highlights the tremendous potential of LAB in improving the flavor quality of RYR. This study provides novel insights into RYR fermentation processes and establishes a theoretical foundation for developing and applying new RYR products., 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.)

The jaboticaba is a fruit with a highly promising chemical profile for producing fermented products with biological activity. In this context, evaluating pre-fermentative maceration techniques in jaboticaba fermentations is essential to optimize the extraction of phenolic compounds and other metabolites of interest, imparting antioxidant characteristics to the product and offering potential health benefits. This study evaluated the impact of two pre-fermentative maceration techniques on the phenolic composition, bioaccessibility, and biological activities (α-amylase, α-glucosidase, and ACE inhibition) of alcoholic and acetic fermented products from jaboticaba. Three treatments were performed: one without pre-fermentative maceration and two with maceration, one cold (4 °C for 24 h) and the other thermal maceration (50 °C until 16 °Brix). The resulting musts were subjected to alcoholic and acetic fermentation. The results showed that the fermented products obtained after thermal maceration had higher concentrations of phenolic compounds, with ellagic acid (5393.78 µg/L) standing out for thealcoholic beverage and 2.5-DHBA (1552.33 µg/L) and 3.4-DHB (863.15 µg/L) acids for the vinegar. Regarding bioaccessibility, both pre-fermentative maceration techniques contributed to more bioaccessible compounds (with indices above 20 %) compared to the samples without maceration. A more significant inhibition of α-amylase and α-glucosidase was observed in the samples subjected to thermal maceration, along with notable ACE inhibition. Additionally, the sensitivity of E. coli, S. aureus, L. monocytogenes, and S. Enteritidis to the fermented jaboticaba products was verified, with distinct sensitivity patterns for each type of bacteria. In summary, this study offers a new perspective for valorizing fermented jaboticaba products through pre-fermentative techniques, enriching the understanding of this technique and its potential nutritional and bioactive contributions., 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.)

Sour bamboo shoots are a traditional fermented delicacy that has garnered appreciation both domestically and internationally. This study investigates the intricate dynamics of microbial communities and volatile flavor compounds primarily derived from salted and pickled bamboo shoots during the fermentation process of Phyllostachys purpurea (PP). The dynamics of microorganisms and volatile flavor compounds were thoroughly examined initially using conventional isolation and cultivation methods in conjunction with high-throughput sequencing (HTS), headspace solid-phase microextraction (HS-SPME), and gas chromatography-mass spectrometry (GC-MS). In addition, we analyzed the core microorganisms responsible for modulating the volatile flavor profile. Our findings revealed 60 volatile compounds, 14 of which were the predominant contributors to the aroma of fermented PP. This group primarily comprised alcohols, aldehydes, and olefins. Notably, our investigation identified Lactobacillus and Candida as the dominant microbial genera during the middle and late stages of fermentation. These two genera exert a significant influence on the formation of characteristic aromas. Furthermore, we discovered that acids, sugars, and proteins pivotally influence the succession of microorganisms. Specifically, acids and soluble sugars drove the transition of Lactococcus to Lactobacillus and Pediococcus, whereas soluble proteins facilitated fungal succession from Candida to Kazachstania and Issatchenkia. These insights shed light on the community structure and succession patterns of flavor compounds throughout the PP fermentation process. Ultimately, they provide a foundation for optimizing the fermentation process and ensuring quality control in the production of sour bamboo shoots., 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.)

Chinese traditional fermented sour meat has a unique flavor and nutritional value. The antioxidant activity of sour meat peptides is related to their molecular weights, amino acid compositions, and structural characteristics. Therefore, this study explores the relationships between them. The results indicate that sour meat peptides with molecular weights <1 kDa exhibit significant antioxidant properties both in vitro and in vivo. The smaller the molecular weights, the higher the content of typical amino acids with antioxidant activity (p <0.05), and the characteristic peaks of ultraviolet absorption decrease. The absorption peak at 284.5 nm blue-shifted, and the polarity of the microenvironment increased. The peak intensity and peak area of the Raman characteristic peaks of tyrosine residues and aliphatic amino acids were enhanced. In the secondary structure, there is a high content of β-turns and a low content of α-helix, which are closely related to the enhancement of antioxidant activity., 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.)

Background/Objectives : The increase in the older adult population worldwide and the need to switch to vegetal-origin protein consumption for environmental sustainability point to legumes and pseudocereals as alternative ingredients in new food formulations. This study aimed to assess the impact of food structure and fungal fermentation on the digestibility of new food prototypes made with quinoa and/or lentil flours addressed to older adults. Methods : Four gels and six breads were elaborated and subjected to mechanical analysis and simulated gastrointestinal in vitro digestion. Then, proteolysis, lipolysis, and amylolysis were analysed. Results : Gels made with fermented quinoa or lentil flours exhibited less hardness and required less force, suggesting better adequacy for mastication. In terms of digestibility, using fermented flours led to increased proteolysis and reduced starch hydrolysis. Conclusions : Our results support future studies in the field aimed at supplying older adults with adapted foods to satisfy their nutritional needs to prevent sarcopenia and other health issues.

Baechu-kimchi is a traditional vegetable fermented food using kimchi cabbage (Brassica rapa) as the main ingredient. A wide variety of ingredients can be used in kimchi depending on the specific region and even household. Although there have been a lot of studies examining various aspects of kimchi, there has been limited research on kimchi with added fish as a minor ingredient. Therefore, in the present work we aimed to assess changes in the volatile compounds of baechu-kimchi with the addition of seafood used as minor ingredients of kimchi. Sulfur compounds were the most commonly detected volatile compounds; 9 categories of volatile components were detected in total. Altogether, 30 sulfur compounds were detected, and among them, five sulfur compounds: (E)-1-(methyltrisulfanyl)prop-1-ene, 1-(methyldisulfanyl)-1-methylsulfanylpropane, (methyltetrasulfanyl)methane, 1-(methyldisulfanyl)-1-[(E)-prop-1-enyl]sulfanylpropane, and 1,1-bis(methyldisulfanyl)propane, were found only in jogi-added kimchi, thus confirming the influence of jogi addition. Principal component analysis revealed clear distinctions in the volatile compounds as a result of jogi addition as fermentation progressed. Moreover, when confirming the correlation with microbial populations, it was evident that the differentiation in volatile compounds was more attributable to jogi addition than microbial impact. In conclusion, the addition of jogi to baechu-kimchi led to an abundance of volatile compounds by the 20th day of fermentation., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Lee et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Black chokeberry (Aronia melanocarpa (Michx.) Elliott) is recognized for its potential health benefits, largely attributed to its high phenolic content. However, many phenolic compounds possess a low bioavailability, potentially limiting their beneficial effects. Fermentation of chokeberry has been proposed as a method to improve bioavailability, bioactive composition, sensory qualities, and nutritional value. This systematic review provides an overview of fermented chokeberry products, including compound composition, sensory attributes, and health benefits observed in in vivo and in vitro studies. While sensory evaluations highlighted diverse flavour profiles and acceptability, human intervention studies suggested potential benefits for glucose-dependent insulinotropic peptide increase. Animal models indicated anti-obesity and immunomodulatory properties, while in vitro studies demonstrate antioxidant, anti-melanogenesis, and anti-diabetic effects. Despite some promising findings in human and animal trials, challenges such as participant adherence and dosing inconsistencies force further protocol improvements. Through continuous scientific research, fermented chokeberry products may emerge as functional foods contributing to human health., 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 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Tempe, a fermented soybean food rich in polyphenols including isoflavones, is valued for its health benefits, notably its antioxidants. Concerns about glyphosate residues in crops have led to increased demand for organic soy products, including tempe. The study aimed to investigate the metabolomic profiles of tempe and its bioactive potentials prior to and following in vitro simulated gastrointestinal digestion. Conventional soybean (CS), conventional tempe (CT), conventional tempe digesta (CTD), organic soybean (OS), organic tempe (OT) and organic tempe digesta (OTD) were analysed for various assays. The study observed a significant decrease in the total phenolic and flavonoid levels for conventional and organic samples in tempe extracts (CT, OT) compared to tempe digesta (CTD, OTD). Organic tempe digesta has a higher total phenolic content (CTD = 22.55 µg GAE/g, OTD = 41.36 µg GAE/g) and flavonoid content (CTD = 4.64 µg QE/g, OTD = 10.06 µg QE/g) compared to conventional tempe digesta. However, there is a significant difference in the bioaccessibility of phenolic (CT = 74.77 %, OT = 59.20 %) and flavonoid (CT = 49.4 %, OT = 57.52 %) in both organic and conventional tempe. Tempe consistently surpasses soybean in antioxidant assays such as DPPH, ABTS, and FRAP. Organic tempe digesta exhibits the most elevated levels of antioxidants. Using GNPS and the SIRIUS database, 34 metabolites were annotated according to the criteria of having a VIP score > 1.5, a log2(FC) > 1, and a p-value < 0.05. From the list, 26 metabolites demonstrated a positive correlation with antioxidant activity, DPPH, and FRAP. Molecular networking enables the visualization of 12 prominent isoflavones, namely daidzein, daidzin, genistein, genistin, glycitein, glycitin, 6″-O-malonyldaidzin, 6″-O-acetylgenistin, 6″-O-acetyldaidzin, and 7,8,4'-trihydroxyisoflavone. Interestingly, aglycone isoflavones are abundant in organic tempe digesta while glycoside isoflavones are abundant in organic and conventional soybeans. Overall, the findings indicate that tempe digesta exhibits distinct metabolic patterns and bioactive potentials., 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.)

Background: Microbiota succession determines the flavor and quality of fermented foods. Quantitative PCR-based quantitative microbiome profiling (QMP) has been applied broadly for microbial analysis from absolute abundance perspectives, transforming microbiota ratios into counts by normalizing 16S ribosomal RNA (16S rRNA) gene sequencing data with gene copies quantified by quantitative PCR. However, the application of QMP in fermented foods is still limited., Results: QMP elucidated microbial succession of Taiwanese pickled cabbage. In the spontaneous first-round fermentation (FR), the 16S rRNA gene copies of total bacteria increased from 6.1 to 10 log copies mL -1 . The dominant lactic acid bacteria genera were successively Lactococcus, Leuconostoc and Lactiplantibacillus. Despite the decrease in the proportion of Lactococcus during the succession, the absolute abundance of Lactococcus still increased. In the backslopping second-round fermentation (SR), the total bacteria 16S rRNA gene copies increased from 7.6 to 9.9 log copies mL -1 . The addition of backslopping starter and vinegar rapidly led to a homogenous microbial community dominated by Lactiplantibacillus. The proportion of Lactiplantibacillus remained consistently around 90% during SR, whereas its absolute abundance exhibited a continuous increase. In SR without vinegar, Leuconostoc consistently dominated the fermentation., Conclusion: The present study highlights that compositional analysis would misinterpret microbial dynamics, whereas QMP reflected the real succession profiles and unveiled the essential role of vinegar in promoting Lactiplantibacillus dominance in backslopping fermentation of Taiwanese pickled cabbage. Quantitative microbiome profiling (QMP) was found to be a more promising approach for the detailed observation of microbiome succession in food fermentation compared to compositional analysis. © 2024 Society of Chemical Industry., (© 2024 Society of Chemical Industry.)

Temperature is an important driving force that shapes the texture of fermented vegetables through driving the molecular distribution and microbial invasion between the liquid phase (brine) and the solid phase (vegetables) during fermentation. The objective of this study was to investigate the texture softening by investigating firmness, microstructure, physicochemical properties, molecular distribution and microbial community between brine and vegetables of Paocai as affected by fermentation temperatures of 10 °C, 20 °C and 30 °C. Results demonstrated that, compared with 10 °C and 30 °C, 20 °C attenuated softening of Paocai by restraining microbial invasion and suppressing pectinolysis. Moreover, at 20 °C, a balanced molecular distribution and microbial community were achieved between vegetables and brine, thus accomplishing acid-production fermentation. By contrast, 10 °C and 30 °C promoted nonfermentative microbial genera, retarding fermentation. This study provided an understanding of the divergent influence of temperature on quality formation of fermented vegetables during fermentation., 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.)

Douchi is traditional Chinese condiment. In this study, electronic sense, GC-IMS and metabolomics were combined to analyse the changes in flavour profiles and metabolites of Yangjiang douchi at different fermentation stages. The results showed that umami was the primary taste characteristic of douchi. Aldehydes, esters, and ketones representing the predominant flavour compounds. Metabolomic analysis identified 13 compounds as key differential metabolites, which were mainly enriched in the arachidonic acid metabolic pathway in lipid metabolism. The correlation analysis indicated that heptanal, hexanal, phenyl acetaldehyde, benzene acetaldehyde and abhexone may be the key aroma substances during fermentation. The major free fatty acids that may act as key flavour precursors are palmitic acid, oleic acid and linoleic acid. This study provides a scientific basis for the industrial regulation of Yangjiang douchi fermentation., 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.)

This study aimed to improve the quality of fermented fish Zaoyu by inoculating different starters (Chuzhai starter, Aroma starter and Sweetness starter), and examining the role of key microorganisms. High-throughput sequencing showed the microbial composition of Aroma starter was similar to Sweetness starter, but both were different from Chuzhai starter. Compared to traditional fermentation, inoculated fermentation with Aroma starter and Sweetness starter strengthened the color of Zaoyu by Maillard reaction and softened the muscle by degrading muscle fibers, endomysium and epicardium. Additionally, the taste and odor of Zaoyu were obviously improved, because the proportion of sweet, umami and aroma compounds increased by 2.51 %, 7.09 %, and 22.94 %, respectively. Correlation analysis combined with metabolic functions showed key microorganisms, such as Trichococcus, Rhizopus, Saccharomycopsis, Saccharomyces, etc., improved the quality mainly by promoting sugar production and conversion, and protein degradation. Overall, Aroma starter and Sweetness starter were superior in improving the quality of Zaoyu., 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.)

White colony-forming yeast (WCFY) forms white colonies on kimchi during fermentation, causing off-flavors and quality deterioration, which are significantly damaging to kimchi industry. To study its impact, kimchi samples were inoculated with representative WCFYs (Candida sake, Debaryomyces hansenii, Kazachstania servazzii, and Pichia kudriavzevii) and monitored for 50 days at 15 °C using high-throughput DNA sequencing and gas chromatography/mass spectrometry. Dominant bacteria at the end of fermentation were Companilactobacillus and Latilactobacillus in the control and WCFY-inoculated samples, respectively. The fungal communities of control sample remained stable, whereas those for WCFY-inoculated samples showed Kazachstania or Pichia dominance. Metabolite analysis revealed significant increases in glycerol, erythritol, and myo-inositol in WCFY-inoculated samples. Correlation analysis showed that Lactococcus and Weissella were negatively correlated with Kazachstania. This study underscores ecological role of WCFYs in kimchi fermentation, particularly their impact on microbial communities and metabolites, suggesting the need for strategies that control WCFY growth to improve kimchi quality., 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.)

Suantangzi is a fermented corn food product with Manchu characteristics from Liaoning Province, China. To analyze the microbial diversity and flavor compounds in Suantangzi dough, this study utilized high-throughput sequencing of the 16S rRNA and internal transcribed spacer regions, high-performance liquid chromatography, and gas chromatography time-of-flight mass spectrometry. Spearman correlation analysis and random forest model were conducted to investigate the correlation between the dominant genera and flavor compounds. A total of 267 and 123 bacterial and fungal genera, respectively, were identified. Flavor compound analysis identified 7 and 156 organic acids and other flavor compounds, respectively, and partial least squares discriminant analysis was used to screen 22 differential flavor compounds. Additionally, Paucilactobacillus, Pediococcus, and Tausonia genera were speculated to produce different flavors in Suantangzi dough made in different regions. These findings provide a theoretical foundation for microbial community dynamics and the formation of key flavor compounds in Suantangzi dough., 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.)

Reducing nitrites tends to increase the accumulation of hazardous biogenic amines (BAs) in Chinese fermented sausages (CFSs). Gallic acid (GA) has emerged as a potential alternative to reduce nitrite usage and control BAs. This study explored how GA inhibits BAs and nitrosamines accumulation in reduced-nitrite CFSs. Results demonstrated that combining 0.05% (w/w) GA with reduced nitrite effectively curbed BAs and N-nitrosodimethylamine, decreasing total BA from 271.48 to 125.46 mg/kg. Fifty-one metabolites associated with the metabolism of BAs and N-nitrosodimethylamine were identified. GA boosted Lactococcus while reducing spoilage bacteria and Macrococcus. This dual regulation suppressed BAs and dimethylamine accumulation by regulating amino acids and trimethylamine pathways. Consequently, GA achieved an 89.86% reduction in N-nitrosodimethylamine by decreasing the key precursors like putrescine, dimethylamine, and nitrite. These findings offer new insights into utilizing GA and similar plant polyphenols to manage BAs and nitrosamines in meat products with reduced nitrite usage., 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.)

Latilactobacillus sakei is an important bacterial species used as a starter culture for fermented foods; however, two subspecies within this species exhibit different properties in the foods. Matrix-assisted laser desorption/ionization-time of flight mass spectrometer (MALDI-TOF MS) is the gold standard for microbial fingerprinting. However, the resolution power is down to the species level. This study was to combine MALDI-TOF mass spectra and machine learning to develop a new method to identify two L. sakei subspecies ( L. sakei subsp. sakei and L. sakei subsp. carnosus ) and non- L . sakei species. Totally, 227 strains were collected, with 908 spectra obtained via on- and off-plate protein extraction. Only 68.7% of strains were correctly identified at the subspecies level in the Biotyper database; however, a high level of performance was observed from the machine learning models. Partial least squares-discriminant analysis (PLS-DA), principal component analysis-K-nearest neighbor (PCA-KNN), and support vector machine (SVM) demonstrated 0.823, 0.914, and 0.903 accuracies, respectively, whereas the random forest (RF) achieved an accuracy of 0.954, with an area under the receiver operating characteristic (AUROC) curve of 0.99, outperforming the other algorithms in distinguishing the subspecies. The machine learning proved to be a promising technique for the rapid and high-resolution classification of L. sakei subspecies using MALDI-TOF MS., Importance: Latilactobacillus sakei plays a significant role in the realm of food bacteria. One particular subspecies of L. sakei is employed as a protective agent during food fermentation, whereas another strain is responsible for food spoilage. Hence, it is crucial to precisely differentiate between the two subspecies of L. sakei . In this study, machine learning models based on protein mass peaks were developed for the first time to distinguish L. sakei subspecies. Furthermore, the efficacy of three commonly used machine learning algorithms for microbial classification was evaluated. Our results provide the foundation for future research on developing machine learning models for the classification of microbial species or subspecies. In addition, the developed model can be used in the food industry to monitor L. sakei subspecies in fermented foods in a time- and cost-effective method for food quality and safety., Competing Interests: The authors declare no conflict of interest.

The diet in early life is essential for the growth and intestinal health later in life. However, beneficial effects of a diet enriched in branched short-chain fatty acids (BSCFAs) for infants are ambiguous. This study aimed to develop a novel fermented protein food, enriched with BSCFAs and assess the effects of dry and wet ferment products on young pig development, nutrient absorption, intestinal barrier function, and gut microbiota and metabolites. A total of 18 young pigs were randomly assigned to three groups. The dry corn gluten-wheat bran mixture (DFCGW) and wet corn gluten-wheat bran mixture (WFCGW) were utilized as replacements for 10% soybean meal in the basal diet. Our results exhibited that the WFCGW diet significantly increased the growth performance of young pigs, enhanced the expression of tight junction proteins, and regulated associated cytokines expression in the colonic mucosa. Simultaneously, the WFCGW diet led to elevated levels of colonic isobutyric and isovaleric acid, as well as the activation of GPR41 and GPR109A. Furthermore, more potential probiotics including Lactobacillus , Megasphaera , and Lachnospiraceae&#95;ND3007&#95;group were enriched in the WFCGW group and positively associated with the beneficial metabolites such as 5-hydroxyindole-3-acetic acid. Differential metabolite KEGG pathway analysis suggested that WFCGW might exert gut health benefits by modulating tryptophan metabolism. In addition, the WFCGW diet significantly increased ghrelin concentrations in serum and hypothalamus and promoted the appetite of young pigs by activating hypothalamic NPY/AGRP neurons. This study extends the knowledge of BSCFAs and provides a reference for the fermented food application in the infant diet.

The goal of this study was to create a fermented probiotic fruit puree for lactose-intolerant people, vegetarians, and infants over 6 months old. Fermented fruit purees were developed using apples, peaches, and bananas with lactic acid bacteria (LAB) strains: Lactobacillus plantarum subsp. plantarum (S5), Lactobacillus fermentum strain w8 (S10), and Lactobacillus pentosus strain ml104 (S14). Different fruit puree formulations were produced using three strains, two inoculation ratios (4% and 5%), and two fermentation durations (24  and 48 h). The physicochemical parameters (pH, total soluble solids, and color), total phenols content (TPC), total antioxidant capacity, bacterial viability, volatile aroma profile (VAP), and individual phenolic compound profile of fruit puree fermented for both 24  and 48 h were compared with the unfermented (control) purees. The results of VAP were evaluated via PROMETHEE and cluster analysis. Time of fermentation and bacterial cultures at varied concentrations improved color values of samples (L*, a*, and b*) compared to controls. The level of bioactive compounds in several samples (S10 and S14) decreased after fermentation in contrast to S5 samples. The bacterial population in the samples ranged from ∼7.00 to 9.50 log CFU/g after 48-h fermentation. The fruit puree samples exhibited the presence of two different phenolic compounds and a total of 17 distinct volatile aroma compounds. The control sample scored highest for aromatic components in PROMETHEE, while S14-II was the most unique sample in cluster analysis. In conclusion, fermented probiotic fruit puree shown high promise as a carrier for live probiotics, and the fermentation process boosted the nutritional content of the fruit puree., (© 2024 The Author(s). Journal of Food Science published by Wiley Periodicals LLC on behalf of Institute of Food Technologists.)

Ingestion of fermented foods impacts human immune function, yet the bioactive food components underlying these effects are not understood. Here, we interrogated whether fermented food bioactivity relates to microbial metabolites derived from aromatic amino acids, termed aryl-lactates. Using targeted metabolomics, we established the presence of aryl-lactates in commercially available fermented foods. After pinpointing fermented food-associated lactic acid bacteria that produce high levels of aryl-lactates, we identified fermentation conditions to increase aryl-lactate production in food matrices up to 5 × 10 3 fold vs. standard fermentation conditions. Using ex vivo reporter assays, we found that food matrix conditions optimized for aryl-lactate production exhibited enhanced agonist activity for the human aryl-hydrocarbon receptor (AhR) as compared to standard fermentation conditions and commercial products. Reduced microbial-induced AhR activity has emerged as a hallmark of many chronic inflammatory diseases, thus we envision strategies to enhance AhR bioactivity of fermented foods to be leveraged to improve human health., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: If there are other authors, they 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 The Authors. Published by Elsevier Ltd.. All rights reserved.)

The control of excess biogenic amines (BAs) is crucial for the sustainable development of fermented foods. This study aimed to screen endogenous functional strains in Doubanjiang with the capacity to degrade BAs and to elucidate their application potential. Pediococcus acidilactici L-9 (PA), which was confirmed as a safe strain by phenotypic and genotypic analyses, exhibited an efficient degradation ability on BAs, particularly regarding tyramine. Notably, the degradation of tyramine was maintained at 24.03-50.60% at different temperatures (20-40 °C), pH values (4.0-9.0), and NaCl concentrations (3-18%, w/v). Additionally, genomic data revealed the presence of the laccase-coding gene, which was demonstrated to play a pivotal role in BA degradation by heterologous expression. Further, molecular docking results indicated that the degradation of BA by laccase is closely linked to the electron transfer pathway formed by the substrate and key amino acid residues. Finally, the degradation of tyramine by PA remained within the range of 8.19-64.19% under the simulated system with 6-12% salinity. This study provided valuable insights into the safety of PA and its potential degradation capacity on BAs, particularly in mitigating tyramine accumulation, which could improve the quality of Doubanjiang and other fermented foods.

Fermented foods have been a component of the human diet since ancient times, including live bacteria employed to restore gut health, contributing to the frontline of functional food progression. Human concern about the harmful consequences of possible contaminants has increased significantly as their toxicity, carcinogenicity, and teratogenicity have become more publicized. In order to take preventive measures, it is essential to correctly identify and define the implications of contaminants and toxins in human health and intestinal microbiota balance for preventing or diagnosing epidemics before they cause damage. The longer food chain that results from urbanization and underreporting of diseases makes it harder to correlate contaminated food to disease, which in turn presents challenges to improving food safety. This research aims to present the potential physical, chemical, and microbiological pollutants and toxins found in fermented products and their effects on human health. The scope tackles various categories of fermented foods, such as dairy products, alcoholic and nonalcoholic beverages, fermented meat products, traditional bakery products, and fermented cereals and vegetables. Furthermore, it examines specific control processes such as rigorous sanitation protocols, advanced packaging technologies, regulatory harmonization, and decontamination methodologies used to prevent the release of contaminants from fermented foods. Future viewpoints and opportunities are briefly mentioned in the conclusion., (© 2024 The Author(s). Comprehensive Reviews in Food Science and Food Safety published by Wiley Periodicals LLC on behalf of Institute of Food Technologists.)

Table olives are one of the most known fruit consumed as fermented food, being a fundamental component of the Mediterranean diet. Their production and consumption continue to increase globally and represent an important economic source for the producing countries. One of the most stimulating challenges for the future is the modernization of olive fermentation process. Besides the demand for more reproducible and safer production methods that could be able to reduce product losses and potential risks, producers and consumers are increasingly attracted by the final product characteristics and properties on human health. In this study, the contribution of microbial starters to table olives was fully described in terms of specific enzymatic and microbiological profiles, nutrient components, fermentation-derived compounds, and content of bioactive compounds. The use of microbial starters from different sources was tested considering their technological features and potential ability to improve the functional traits of fermented black table olives. For each fermentation assay, the effects of controlled temperature (kept at 20 °C constantly) versus not controlled environmental conditions (oscillating between 7 and 17 °C), as well as the consequences of the pasteurization treatment were tested on the final products. Starter-driven fermentation strategies seemed to increase both total phenolic content and total antioxidant activity. Herein, among all the tested microbial starters, we provide data indicating that two bacterial strains (Leuconostoc mesenteroides KT 5-1 and Lactiplantibacillus plantarum BC T3-35), and two yeast strains (Saccharomyces cerevisiae 10A and Debaryomyces hansenii A15-44) were the better ones related to enzyme activities, total phenolic content and antioxidant activity. We also demonstrated that the fermentation of black table olives under not controlled environmental temperature conditions was more promising than the controlled level of 20 °C constantly in terms of technological and functional properties considered in this study. Moreover, we confirmed that the pasteurization process had a role in enhancing the levels of antioxidant compounds., 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 The Authors. Published by Elsevier Ltd.. All rights reserved.)

In this study, flavor characteristics and dynamic change of Chinese traditional fermented fish sauce (Yu-lu) with different fermentation time (2, 4, 6, 8, and 12 months) were analyzed. The electronic nose analyses confirmed a notable flavor change in fish sauce samples from different stages. During the 12-months fermentation, the total volatile compounds in fish sauce increased from 3.9 mg/L to 13.53 mg/L. Acids, aldehydes, esters and phenols were the main aroma substances and their contents gradually increased during the fermentation process. The PCA of GC-MS and GC-IMS showed that fish sauce samples from different fermentation periods can be well distinguished. A total of 110 volatile compounds identified by GC-MS, and 102 volatile compounds were detected by GC-IMS. Among them, 13 compounds were identified by both GC-MS and GC-IMS. The most varieties (49) of volatiles appeared after 8 months of fermentation. The odor activity value (OAV) analysis showed that 10 volatile compounds were considered as characteristic flavor in traditional fish sauce. The variable influence on projections (VIPs) in PLS-DA models constructed by GC-MS and GC-IMS identified 5 and 10 volatile compounds as biomarkers, respectively. Our results revealed the dynamic changes of characteristic flavor in fish sauce in combination of GC-MS and GC-IMS, which provides theoretical basis for the production and flavor regulation of fish sauce., 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.)

Traditionally, dairy products have been the primary medium for delivering probiotics to humans. However, despite their numerous health benefits, such as nutrient supply and prevention and treatment of certain diseases, there are limitations to their use in many regions, including Africa. These limitations arise from allergens, lactose intolerance, hypercholesterolemia effects, the need for vegetarian options, cultural food taboos against milk, and religious beliefs. As a result, research efforts worldwide have focused on probiotics with health benefits. To address this issue, an integrative approach has been adopted, consolidating ideas and concepts from various studies. Researchers have explored different food matrices to determine their potential as probiotic carriers, specifically emphasizing cereals and cereal products. Studies have revealed that traditional African fermented cereal-based beverages show promise as probiotic carriers due to the presence of probiotic organisms involved in the fermentation process. This presents an opportunity to utilize African cereal beverages to deliver. This review paper provides comprehensive information on probiotics, including their sources, types, health benefits, and delivery vehicles. Specifically, it highlights the challenges and prospects for developing and consuming cereal-based probiotics in Africa. This opens up new avenues for providing probiotic benefits to a broader African population and contributes to the advancement of probiotic research and development in the region., 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. Published by Elsevier Ltd.)

Fermented plant-based products are rapidly gaining popularity. Jerusalem artichoke is a medicinal plant that can be used to make fermented beverages. Samples were subjected to pretreatment (ultrasound at 35 kHz for 2, 4, and 6 min, freezing at -80 °C and -17 °C) while an untreated sample was used as control. It was shown that all types of pretreatments did not lead to an increase in protein, solids, polyphenols, and carbohydrates compared to the control sample. The greatest decrease in the values of these indicators occurs when pre-freezing tubers are used for Jerusalem artichoke dispersion production. It was also found that samples frozen at -80 °C had a significantly higher concentration of Ca, Si, Mg, and P whereas untreated samples frozen at -17 °C had more Al, K, Cu, Sr, and Cr. The processing method can affect the sensory descriptors of Jerusalem artichoke tuber dispersions to different extents, but the preference was for the control sample without pre-treatment. The fermentation of Jerusalem artichoke tuber dispersions demonstrated that S. thermophilus induced the most rapid fermentation (pH 4.75 in 5 h). The highest antioxidant activity after fermentation (55.39% FRSA) was shown for L. acidophilus H9, while the highest % FRSA value during the storage period was for L. bulgaricus (67.5%) on day 5 after fermentation. The highest viability among all selected microorganisms was detected for L. bulgaricus, L. acidophilus AT-41, and B. coagulans MTCC 5856 with the increase in biomass content by 2.3, 2.27, and 2.12 log 10 CFU/ml after fermentation. According to the results of sensory evaluation using hybrid hedonic scale the best results were shown for samples fermented with L. bulgaricus., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Environmental-origin microbiota significantly influences Red Heart Qu (RH&#95;Qu) stratification, but their microbial migration and metabolic mechanisms remain unclear. Using high-throughput sequencing and metabolomics, we divided the stratification of RH&#95;Qu into three temperature-based stages. Phase I features rising temperatures, causing microbial proliferation and a two-layer division. Phase II, characterized by peak temperatures, sees the establishment of thermotolerant species like Bacillus, Thermoactinomyces, Rhodococcus, and Thermoascus, forming four distinct layers and markedly altering metabolite profiles. The Huo Quan (HQ), developing from the Pi Zhang (PZ), is driven by the tyrosine-melanin pathway and increased MRPs (Maillard reaction products). The Hong Xin evolves from the Rang, associated with the phenylalanine-coumarin pathway and QCs (Quinone Compounds) production. Phase III involves the stabilization of the microbial and metabolic profile as temperatures decline. These findings enhance our understanding of RH&#95;Qu stratification and offer guidance for quality control in its fermentation process., 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.)

Background: Yangjiang douchi (YD) is a traditional fermented soybean product, which is popular in Chinese cuisine for its unique flavor. However, due to its high salt content and unstable flavor, its competitiveness in the international market is gradually weakening. Microorganisms have a key role in the production process of YD because it is a fermented food but the effect of microorganisms on the volatile compounds of YD is also not currently clear., Results: In this paper, aroma compounds and microbial diversity in different fermentation stages of YD were analyzed using gas chromatography-mass spectrometry/olfactometry (GC-MS/O) and IlluminaMiseq system sequencing. A total of 78 aroma-active compounds were detected throughout the fermentation process and they influenced the formation of flavor in YD. Fungi flora were relatively single in YD, and bacteria were rich and varied. A total of 418 species of bacteria were present during fermentation, with unclassified&#95;Staphylococcus, Staphylococcus&#95;kloosii, and Bacillus&#95;velezensis&#95;Bacillus predominating. There were 25 species of fungi at the species level, and Aspergillus minisclerotigenes (OTU 4) played a dominant role in the whole fermentation process., Conclusion: Staphylococcus and Bacillus in the bacterial genus were strongly correlated with most flavor compounds detected, and A. minisclerotigenes in the fungi were more relevant to flavor compounds. This research provides a theoretical basis for the enhancement of the flavor of traditional fermented douchi in China. © 2024 Society of Chemical Industry., (© 2024 Society of Chemical Industry.)

Table olives are among the most popular fermented foods and cv. Chalkidiki green table olives are particularly popular in both Greek and international markets. This work aimed at comparatively investigating the effect of processing method on the production of Spanish-style and natural cv. Chalkidiki green olives during fermentation and 12-month storage in brines with different chloride salts composition (NaCl, KCl, CaCl 2 ) at industrial scale. All delivered products were safe with satisfactory color and texture characteristics. Employment of UPLC-HRMS revealed differences in metabolites' profile of polar extracts from olives and brines between the processing methods. Τhe application of alkali treatment drastically decreased the content of hydroxytyrosol and tyrosol in drupes, still an essential amount (1037-2012 and 385-885 mg/kg dry flesh, respectively) of these health-promoting phenolic compounds was retained in all products, even after storage. Noteworthy, fermentation of natural olives in brine (5 % NaCl) yielded in products with significantly lower Na levels in olive flesh (1.7 g/100 g), followed by Spanish-style olives fermented in low (4 %) and high (8 %) NaCl brines (2.7 and 5.2 g Na/100 g, respectively), supporting the efforts toward the establishment of table olives as functional food. Moreover, maslinic and oleanolic acids content was 1.5-2-fold higher in the natural table olives compared to the Spanish-style ones owing to the detrimental effect of alkali treatments. The processing method did not exert a differential effect on α-tocopherol content of olives. Sensory analysis indicated that all the final products were acceptable by consumers, with a slight preference for Spanish-style green olives fermented in brines with 50 % lower NaCl content. Present findings could be beneficial to the ongoing endeavor directed for the establishment of table olives as a source of bioactive compounds that concerns both industrial and scientific communities., 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.)

Laotan Suancai, a popular traditional Chinese fermented vegetable, is manufactured in the industry via four fermentation rounds. However, the differences in flavor quality of Laotan Suancai from the four fermentation rounds and the causes of this variation remain unclear. Metabolome analysis indicated that the different content of five taste compounds and 31 aroma compounds caused the differences in flavor quality among the variated fermentation rounds of Laotan Suancai. Amplicon sequencing indicated that the microbial succession exhibited a certain pattern during four fermentation rounds and further analysis unveiled that organic acids drove the microbiota shift to more acid-resistant populations. Spearman correlation analysis highlighted that seven core microbes may be involved in the formation of differential flavor and the corresponding metabolic pathways were reconstructed by function prediction. Our findings offer a novel perspective on comprehending the deterioration of flavor quality across the fermentation rounds of Laotan Suancai., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that influenced the work reported in this paper., (Copyright © 2023. Published by Elsevier Ltd.)

Starter cultures used during the fermentation of malt wort can increase the sensory characteristics of the resulting beverages. This study aimed to explore the aroma composition and flavor recognition of malt wort beverages fermented with lactic acid bacteria ( Levilactobacillus brevis WiKim0194) isolated from kimchi, using metabolomic profiling and electronic tongue and nose technologies. Four sugars and five organic acids were detected using high-performance liquid chromatography, with maltose and lactic acid present in the highest amounts. Additionally, e-tongue measurements showed a significant increase in the sourness (AHS), sweetness (ANS), and umami (NMS) sensors, whereas bitterness (SCS) significantly decreased. Furthermore, 20 key aroma compounds were identified using gas chromatography-mass spectrometry and 15 key aroma flavors were detected using an electronic nose. Vanillin, citronellol, and β-damascenone exhibited significant differences in the flavor profile of the beverage fermented by WiKim0194, which correlated with floral, fruity, and sweet notes. Therefore, we suggest that an appropriate starter culture can improve sensory characteristics and predict flavor development in malt wort beverages.

Single starter can hardly improve the volatile flavor of fermented fish surimi. In this study, the changes of volatile compounds (VCs) and microbial composition during cooperative fermentation of Latilactobacillus sakei and Pediococcus acidilactici were studied by headspace solid-phase microextraction gas chromatography-mass spectrometry and 16S rRNA gene high-throughput sequencing. During cooperative fermentation, most VCs and the abundance of Latilactobacillus and Lactococcus significantly increased, while Pediococcus, Acinetobacter, and Macrococcus obviously decreased. After evaluation of correlation and abundance of each genus, Latilactobacillus and Lactococcus possessed the highest influence on the formation of volatile flavor during cooperative fermentation. Compared with the natural fermentation, cooperative fermentation with starters significantly enhanced most of pleasant core VCs (odor activity value≥1), but inhibited the production of trimethylamine and methanethiol, mainly resulting from the absolutely highest influence of Latilactobacillus. Cooperative fermentation of starters is an effective method to improve the volatile flavor in the fermented tilapia surimi., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Hui Huang reports was provided by National Key Research and Development Program of China. Hui Huang reports was provided by Earmarked fund for CARS. Shengjun Chen reports was provided by Science and Technology Program of Guangzhou of China. Jun Li reports was provided by Key Platform Project of Guangdong Provincial Department of Education. Yongqiang Zhao reports was provided by Central Public-interest Scientific Institution Basal Research Fund, CAFS. Chunsheng Li reports was provided by Central Public-interest Scientific Institution Basal Research Fund, South China Sea Fisheries Research Institute, CAFS. If there are other authors, they 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.)

Due to the reports describing virulent and multidrug resistant enterococci, their use has become a topic of controversy despite most of them being safe and commonly used in traditionally fermented foods worldwide. We have characterized Enterococcus lactis SF68, a probiotic strain approved by the European Food Safety Authority (EFSA) for use in food and feed, and find that it has a remarkable potential in food fermentations. Genome analysis revealed the potential of SF68 to metabolize a multitude of carbohydrates, including lactose and sucrose, which was substantiated experimentally. Bacteriocin biosynthesis clusters were identified and SF68 was found to display a strong inhibitory effect against Listeria monocytogenes . Fermentation-wise, E. lactis SF68 was remarkably like Lactococcus lactis and displayed a clear mixed-acid shift on slowly fermented sugars. SF68 could produce the butter aroma compounds, acetoin and diacetyl, the production of which was enhanced under aerated conditions in a strain deficient in lactate dehydrogenase activity. Overall, E. lactis SF68 was found to be versatile, with a broad carbohydrate utilization capacity, a capacity for producing bacteriocins, and an ability to grow at elevated temperatures. This is key to eliminating pathogenic and spoilage microorganisms that are frequently associated with fermented foods.

Lactobacilli fermentation possesses special nutritional and health values to food, especially in improving diseases related to the gut microbiota such as osteoporosis risk. Previous research indicates that lactobacilli-fermented foods have the potential to enhance the bone mineral density (BMD), as suggested by some clinical studies. Nonetheless, there is currently a lack of comprehensive summaries of the effects and potential mechanisms of lactobacilli-fermented foods on BMD. This review summarizes findings from preclinical and clinical studies, revealing that lactobacilli possess the potential to mitigate age-related and secondary factor-induced bone loss. Furthermore, these findings imply that lactobacilli are likely mediated through the modulation of bone remodeling via gut inflammation-related pathways. Additionally, lactobacilli fermentation may augment calcium accessibility through directly promoting calcium absorption or modifying food constituents. Considering the escalating global health challenge of bone-related issues among the elderly population, this review may offer a valuable reference for the development of food strategies aimed at preventing osteoporosis.

Elevated levels of biogenic amines (BAs) in fermented food can have negative effects on both the flavor and health. Mining enzymes that degrade BAs is an effective strategy for controlling their content. The study screened a strain of Lactobacillus hilgardii 1614 from fermented food system that can degrade BAs. The multiple copper oxidase genes LHMCO 1614 were successfully mined after the whole genome protein sequences of homologous strains were clustered and followed by homology modeling. The enzyme molecules can interact with BAs to stabilize composite structures for catalytic degradation, as shown by molecular docking results. Ingeniously, the kinetic data showed that purified LHMCO 1614 was less sensitive to the substrate inhibition of tyramine and phenylethylamine. The degradation rates of tyramine and phenylethylamine in huangjiu (18% vol) after adding LHMCO 1614 were 41.35 and 40.21%, respectively. Furthermore, LHMCO 1614 demonstrated universality in degrading tyramine and phenylethylamine present in other fermented foods as well. HS-SPME-GC-MS analysis revealed that, except for aldehydes, the addition of enzyme treatment did not significantly alter the levels of major flavor compounds in enzymatically treated fermented foods ( p > 0.05). This study presents an enzymatic approach for regulating tyramine and phenylethylamine levels in fermented foods with potential applications both targeted and universal.

The study investigated the effect of different sodium chloride (NaCl) concentrations (10%, 15%, and 20%) on the ripening fermentation of Pixian-Douban, a traditional fermented condiment. The results showed that NaCl affected the dynamics of physicochemical parameters, volatile components, fatty acids, amino metabolites, organic acids, and microbial composition, and their dynamic modes were different. After 253 days fermentation, the 10% NaCl Pixian-Douban had significantly (p < 0.05) higher levels of total organic acids (20,308.25 mg/kg), amino metabolites (28,144.96 mg/kg), and volatiles (3.36 mg/kg) compared to 15% and 20% NaCl Pixian-Douban. Notably, the possible health risk associated with high concentration of biogenic amines in 10% NaCl Pixian-Douban is of concern. Moreover, correlation analyses indicated that the effect of NaCl on the quality of Pixian-Douban may be mainly related to bacteria. This study deepens the knowledge about the role of NaCl in ripening fermentation of Pixian-Douban and contributes to develop low-NaCl Pixian-Douban product., 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.)

In recent years, numerous studies have demonstrated the significant potential of non-Saccharomyces yeasts in aroma generation during fermentation. In this study, 134 strains of yeast were isolated from traditional fermented foods. Subsequently, through primary and tertiary screening, 28 strains of aroma-producing non-Saccharomyces yeast were selected for beer brewing. Headspace-solid phase microextraction (HS-SPME) combined with gas chromatography-mass spectrometry (GC-MS) and chemometrics were employed to analyze the volatile flavor substances in beer samples fermented using these strains. Chemometric analysis revealed that distinct species of non-Saccharomyces yeast had a unique influence on beer aroma, with strains from the same genus producing more similar flavor profiles. Accordingly, 2,6-nonadienal, 1-pentanol, phenyl ethanol, isoamyl acetate, ethyl caprate, butyl butyrate, ethyl propionate, furfuryl alcohol, phenethyl acetate, ethyl butyrate, ethyl laurate, acetic acid, and 3-methyl-4 heptanone were identified as the key aroma compounds for distinguishing among different non-Saccharomyces yeast species. This work provides useful insights into the aroma-producing characteristics of different non-Saccharomyces yeasts to reference the targeted improvement of beer aroma., 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.)

Nowadays, the food industry is facing challenges due to the simultaneous rise in global warming, population, and food consumption. As the integration of synthetic biology and food science, novel synthetic foods have obtained high attention to address these issues. However, these novel foods may cause potential risks related to human health. Four types of novel synthetic foods, including plant-based foods, cultured meat, fermented foods, and microalgae-based foods, were reviewed in the study. The original food sources, consumer acceptance, advantages and disadvantages of these foods were discussed. Furthermore, potential risk factors, such as nutritional, biological, and chemical risk factors, associated with these foods were described and analyzed. Additionally, the current detection methods (e.g., enzyme-linked immunosorbent assay, biosensors, chromatography, polymerase chain reaction, isothermal amplification, and microfluidic technology) and processing technologies (e.g., microwave treatment, ohmic heating, steam explosion, high hydrostatic pressure, ultrasound, cold plasma, and supercritical carbon dioxide) were reviewed and discussed critically. Nonetheless, it is crucial to continue innovating and developing new detection and processing technologies to effectively evaluate these novel synthetic foods and ensure their safety. Finally, approaches to enhance the quality of these foods were briefly presented. It will provide insights into the development and management of novel synthetic foods for food industry., (© 2024 The Authors. Comprehensive Reviews in Food Science and Food Safety published by Wiley Periodicals LLC on behalf of Institute of Food Technologists.)

The aim of the present study was to provide a first characterization of lacto-fermented garlic manufactured by local small-scale artisanal producers in the Lower Silesia Region (Poland). The lacto-fermented garlic samples showed high nutritional features in terms of antioxidant activity. A total of 86 compounds, belonging to various chemical classes, were identified by headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC/MS). Most of these compounds belonged to six main classes, being sulfur compounds, esters and acetates, oxygenated monoterpenes, monoterpene hydrocarbons, and alcohols. Aldehydes, acids, ketones, furans, and phenols were also identified. In the analyzed samples, counts up to 8 log cfu g -1 were observed for lactic acid bacteria. Metataxonomic analysis revealed the presence of Levilactobacillus, Lactiplantibacillus, Latilactobacillus, Secundilactobacillus, Weissella, Leuconostoc, Lactococcus, Pediococcus, and Lacticaseibacillus among the major taxa. These results were confirmed by the isolation and characterization of viable lactic acid bacteria. Indeed, the presence of the closest relatives to Lacticaseibacillus casei group, Pediococcus parvulus, Levilactobacillus brevis, Levilactobacillus parabrevis, and Lactiplantibacillus plantarum group was observed. A good acidification performance in salty garlic-based medium was observed for all the isolates that, between 8 and 15 days of fermentation, reached pH values comprised between 4 and 3.5, depending on the tested species. Of note, 15 out of the 37 lactic acid bacteria isolates (Levilactobacillus parabrevis, Pediococcus parvulus, Lactiplantibacillus plantarum group, and Lacticaseibacillus casei group) showed the presence of the hdcA gene of Gram-positive bacteria encoding for histidine decarboxylase. Furthermore, for 8 out of the 37 isolates the in-vitro exopolysaccharides production was observed. No isolate showed inhibitory activity against the three Listeria innocua strains used as surrogate for Listeria monocytogenes., 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 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Kimchi cabbage, the key ingredient in kimchi, is cultivated year-round to meet high production demands. This study aimed to examine the effects of seasonal harvesting (spring, summer, fall, and winter) on the microbial and metabolic profiles of kimchi during 30 days of fermentation. Lactic acid bacteria distribution is notably influenced by seasonal variations, with Latilactobacillus dominant in fall-harvested kimchi group and Weissella prevailing in spring, summer, and winter. The microbial communities of spring and fall group exhibited similar profiles before fermentation, whereas the microbial communities and metabolic profiles of spring and summer group were similar after 30 days of fermentation. Seasonal disparities in metabolite concentrations, including glutamic acid, serine, and cytosine, persist throughout fermentation. This study provides a comprehensive understanding of the substantial impact of seasonal harvesting of kimchi cabbage on the microbial and metabolic characteristics of kimchi, providing valuable insights into producing kimchi with diverse qualities., 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.)