Tenebrio molitor larva protein (TMP) is a highly promising new sustainable insect protein source. However, the single-phase gel has the defects of poor elasticity and loose structure, which significantly limits its application. This study systematically investigated the regulation mechanism of structure, rheological properties and physicochemical properties of TMP gel of different concentrations of transglutaminase (TGase) and chitosan (CS). The results showed that the addition of TGase at 1.5% CS could effectively improve the microstructure and macroscopic properties of the composite gels, and all gels exhibited typical elastic solid behavior. When the concentration of TGase was 80 U/g, the composite gel exhibited the best gel strength and anti-deformation ability. Its gel hardness (197.89 g), creep recovery rate (80.83%) and water retention capacity (40.22%) all reached the highest values. Fourier transform infrared spectroscopy (FTIR) results further revealed that the mechanism by which TGase and CS enhance the properties of TMP gels lies in the synergistic effect between the covalent isopeptide bonds catalyzed by TGase and the noncovalent interactions strengthened by CS. This synergistic effect induces an ordered transition in the secondary structure of proteins, resulting in the formation of a denser, more stable, and more regularly arranged gel network structure. In conclusion, this study elucidated the molecular mechanism by which TGase and CS synergistically drive the reconfiguration of the TMP gel network, and clarified the intrinsic relationship between performance enhancement and structural evolution. This provides a solid theoretical basis for the texture optimization, performance regulation, and industrial application of insect-based functional gels.

Protein-based gels are central structural elements in fermented foods, but their formation during lactic acid bacteria (LAB) fermentation cannot be adequately explained by acidification alone. Although pH reduction and isoelectric aggregation initiate gelation in many systems, the final network architecture and functionality are also governed by exopolysaccharide (EPS) production, proteolysis, ionic interactions and the initial colloidal state of the protein matrix. This review reinterprets LAB fermentation-driven protein gelation using a strain-metabolite-protein colloidal state-gel functionality framework. Within this framework, strain-specific traits determine acidification kinetics, EPS yield and structure, proteolytic activity and ionic microenvironment; these factors collectively modulate protein charge, conformational stability, hydrophobic exposure, peptide formation, ion bridging and protein-polysaccharide compatibility. Importantly, the same mechanism may produce opposite outcomes depending on the matrix: EPS can reinforce networks by bridging and pore filling but may also promote incompatibility or phase separation; controlled or limited proteolysis can expose reactive sites, generate crosslinkable peptides and enhance network formation, whereas excessive hydrolysis weakens network continuity; divalent ions can strengthen gels through bridging but may induce coarse aggregation when unbalanced. We further compare dairy, plant, meat and microbial protein systems to identify matrix-dependent control targets, including acidification rate, endpoint pH, EPS molecular features, degree of hydrolysis, ionic strength, fermentation temperature and fermentation duration. Finally, we highlight current knowledge gaps, particularly the lack of standardised quantitative reporting and predictive models linking microbial metabolism, colloidal transitions and gel functionality. This review provides a mechanistic basis for rational starter selection and process design in fermented protein gel systems.

Mycotoxins pose great risks to global food safety and human public health. Traditional instrumental detection suffers from high equipment costs and complicated procedures, whereas natural enzyme-based rapid assays are restricted by poor structural stability and excessive production costs. These drawbacks greatly limit their practical application in routine food monitoring. Combining unique nanostructural features and intrinsic enzyme-mimicking activity, nanozymes exhibit superior stability and adjustable catalytic properties, emerging as advanced functional materials for mycotoxin analysis. Accordingly, nanozyme-based biosensors have become a rapidly developing research hotspot. This review comprehensively summarizes five-year research advances of four mainstream nanozyme categories. Multi-dimensional regulation of structures, surface properties and chemical compositions can effectively improve their catalytic performance. Based on biorecognition, catalytic signal regulation and quantitative output, colorimetric, fluorescent and electrochemical biosensing platforms are well established for ultra-sensitive detection of typical mycotoxins, with detection limits reaching picogram and femtogram levels. Future directions include rational nanozyme design, sensing innovation, intelligent detection and industrial translation, which will facilitate full-chain mycotoxin monitoring and strengthen food safety management.

The extraction of bioactive natural compounds is crucial to the pharmaceutical, food, and cosmetic industries, but it often entails high energy consumption, greenhouse gas emissions, and environmental impacts associated with solvent use. Life Cycle Assessment (LCA) provides a structured approach to identify environmental hotspots and evaluate trade-offs across solvent use, energy demand, and process scale-up. This review adopts a life-cycle perspective to examine the environmental impacts from upstream stages, including agriculture, raw material processing, and transportation, to extraction, waste management, and end-of-life treatment. Extraction technologies, including microwave-assisted, ultrasound-assisted, solvent-based, pressurized liquid, and high-voltage electrical discharge methods, are compared in terms of environmental performance and process efficiency. Solvent selection is highlighted as a critical factor, with a focus on the balance between extraction yield and sustainability across water, organic, and deep eutectic solvents. The integration of LCA with simulation tools, such as SuperPro Designer and Aspen Plus, is also reviewed for its potential to support scaling-up decisions and resource optimization. Although current LCA studies provide valuable insights, gaps remain in addressing energy constraints, waste flows, and real-world implementation. Advancing sustainable extraction requires a combination of system-level design, data-driven modeling, and circular resource utilization.

Background Color is a core sensory attribute and grading standard for soy sauce, influencing consumer preference and market value. As the industry moves toward standardization, understanding color formation has become a key research focus. Existing studies often examine single fermentation steps, overlooking the coupling among raw material degradation, microbial metabolism, and Maillard reaction. Scope and methods This review comprehensively retrieved, screened and synthesized literature from major international databases and elaborated color formation via three pathways: koji enzymolysis, microbial pigment synthesis, and Maillard reaction. Key findings and conclusions Aspergillus oryzae 3.042 and A. sojae 3.495 secrete proteases, cellulase, and xylanase, yielding free amino acids and reducing sugars. Salt-tolerant yeasts like Sporidiobolus pararoseus produce carotenoids via the MVA pathway, while Monascus generates yellow, orange, and red pigments, optimizing soy sauce chromaticity. Melanoidins over 30 kDa are the main contributors to reddish-brown color. We propose a precursor–pigment–melanoidin framework, wherein enzymatic degradation supplies intermediates for subsequent microbial and Maillard reactions, with microbial pigments and melanoidins jointly determining final appearance. At present, several limitations remain in soy sauce color formation, including incomplete structural characterization of melanoidins, unclear interactions among precursors, pigment-producing microbes, and Maillard products, and limited control over harmful by-products. Microbial pigment stability is poor under complex conditions, and Monascus safety risks (e.g., citrinin) persist. Fermentation variability due to dynamic microbial succession and physicochemical fluctuations leads to inconsistent color (A420, CIE L*a*b* × values), while regulatory constraints on natural pigments hinder standardization. Addressing these requires improved strain selection, enhanced process control, and robust safety monitoring.

Background Fatty acid metabolism critically affects the flavor complexity, nutritional value, and safety of soy sauce. However, existing studies remain fragmented and lack an integrated framework covering lipid biotransformation, microbial regulation, enzymatic catalysis, and multifunctional effects. Scope and methods In accordance with the PRISMA 2020 guidelines, this systematic review synthesizes high-quality literature (2000–2025) from Chinese and international databases. An integrated “lipid composition–microbial interaction–enzymatic regulation–flavor function” framework is constructed through mechanistic deconstruction and comparative analysis. Key findings and conclusions Raw soybean and wheat lipids—mainly triglycerides and phospholipids—are rich in unsaturated fatty acids, along with minor sterols. Microbial enzymes (lipases, lipoxygenases, esterases) drive four pathways: hydrolysis, β-oxidation/oxidative cleavage (yielding methyl ketones and C6–C9 aldehydes), sterol modification, and esterification. These processes temporally generate layered flavors—fresh top notes, rich middle notes, and mellow aftertastes. This review first establishes an integrated framework linking lipids, microbes, enzymes, flavor, and function, revealing fatty acid metabolism as central to both taste complexity and health benefits, thus guiding functional soy sauce development. Fatty acid derivatives exhibit antibacterial activity, modulate gut microbiota composition, and exert hepatoprotective effects through AMPK/mTOR-mediated signaling pathways. This integrated mechanistic framework identifies key metabolic nodes and regulatory targets, providing new research insights and technical support for precise regulation of fermentation, enhancement of flavor stability, development of functional products, and promotion of sustainable industrial innovation. Current challenges include fragmented pathway networks, unquantified flavor thresholds, and industrial instability. Future priorities focus on multiomics integration, AI-driven prediction, and microencapsulation to enable intelligent and sustainable upgrading.

Background Lactic acid bacteria (LAB) are core microorganisms in fermented foods. Indole derivatives, such as indole-3-lactic acid (ILA), indole-3-acetic acid (IAA), and indole-3-propionic acid (IPA), produced via tryptophan metabolism, significantly contribute to food flavor, quality, and health functions. Traditional research has focused on LAB organic acid metabolism, while systematic understanding of the biosynthesis pathways, regulatory mechanisms of indole derivatives, and their role in the "fermented food-human health" connection remains limited. Scope and Methods This review systematically consolidates LAB strain (primarily Lactobacillus and Bifidobacterium) producing indole derivatives in fermented foods. It elucidates their synthetic pathways (including transamination, decarboxylation, and oxidative deamination) and key regulatory enzymes (e.g., ArAT, ILDH, TDC), analyzes the molecular mechanisms behind their bioactivities particularly via the Aryl hydrocarbon receptor (AhR) pathway, and explores their application potential in modulating fermented food quality. Key Findings and Conclusions LAB convert tryptophan into diverse indole derivatives through multiple pathways, with synthesis efficiency showing significant strain specificity. These compounds are widely present in foods, contributing unique flavors and extending shelf life. They also exhibit multiple physiological functions: ILA and IPA exert anti-inflammatory and antioxidant effects by activating AhR; IPA is associated with improved insulin sensitivity and neuroprotection; IAld helps maintain intestinal barrier integrity. However, challenges remain, including incomplete elucidation of pathways, unclear structure-activity relationships, and low industrial yield. Future research should employ multi-omics integration, synthetic biology tools, and fermentation optimization to decipher metabolic networks and develop functional foods or precision probiotics based on high-yield strains, fully realizing the health-promoting potential of indole derivatives.

Reduced-salt soy sauce often exhibits excessive acidity and residual bitterness. To mitigate these defects, N-propionyl-L-tryptophan (NPr-Trp), N-propionyl-L-tyrosine (NPr-Tyr), and N-propionyl-L-phenylalanine (NPr-Phe) were synthesized using an optimized thermal route. NPr-Trp achieved the highest yield (25.36%), consistent with its lowest calculated activation barrier for thermal synthesis (ΔG‡ = 102.9 kJ·mol-1). Sensory evaluation showed that NPr-Trp reduced sourness (38%) and bitterness (31%) in reduced-salt soy sauce while enhancing umami and kokumi; similar effects were observed for NPr-Tyr and NPr-Phe. Docking simulations suggest that these derivatives may suppress sourness by stabilizing OTOP1 in a closed state and may reduce bitterness by occluding TAS2R binding pockets. Additionally, computational screening suggests that the propionyl (C3) chain provides an optimized hydrophobic motif for receptor anchoring. Collectively, these findings support the use of N-propionyl aromatic amino acids as effective taste modulators to improve the flavor quality of low-sodium fermented foods.

Low-salt soy sauce (LSS) supports healthier diets but suffers flavor defects compared with high-salt and koikuchi soy sauce (HSS, KSS). In this study, an XGBoost-SHAP-MMVec model integrating a sensory-volatiles-microbiota triomics data set was developed to guide LSS flavor enhancement. Quantitative descriptive analysis and olfactometry identified 6-sensory terms and 29-odor active volatiles. XGBoost-SHAP (accuracy >0.90) revealed contributors: sauce (furanones), rancid (linear fatty aldehydes), fruit (short-chain ethyl and acetate esters), roast (3-methylpyrazine derivatives), flower (norisoprenoids), and grain (Ehrlich-derived aldehydes), confirmed by recombination/omission tests. Microbiota profiling identified 12-microbiota (with abundance and co-occurrence connectivity advantages), which were used for MMVec training to reveal volatiles-microbiota associations. A five-genus consortium (Lactiplantibacillus, Staphylococcus, Bacillus, Zygosaccharomyces, Aspergillus) capturing three soy sauce flavor profiles was confirmed by fermentation trials. Model-guided optimization yielded the enhanced LSS retained grain and flower aromas while incorporating HSS-like sauce and KSS-like roast and fruity signatures. This research demonstrates a strategy for targeted flavor enhancement in fermented foods.

The demand for natural preservatives has increased interests in antimicrobial peptides (AMPs) from Lactiplantibacillus plantarum. Beyond ribosomal bacteriocins, its proteolytic system generates AMPs from food proteins, with activities ranging from low μg mL-1 (purified peptides) to mg mL-1 (crude hydrolysates). In this process, cell-envelope proteinases initiate protein cleavage, Opp/DtpT systems transport peptides, and intracellular peptidases produce active AMPs. These amphipathic, hydrophobic and basic residue-rich peptides primarily form membrane pores or target the mannose phosphotransferase receptor. Applications in fermented foods show promise for biopreservation, shelf-life extension, texture improvement, and nitrite reduction. However, industrial translation is limited by yield variability, matrix interference, high purification costs, and the need for strain-specific safety evaluation. Future advances require an integrated strategy combining omics, CRISPR-based metabolic engineering, and microencapsulation to optimize yield, stability, and delivery. This review provides a roadmap for engineering L. plantarum as a natural bio-preservative factory for safer, clean-label fermented foods.

4-Vinylguaiacol (4-VG) and 4-Ethylguaiacol (4-EG) are key aromatic compounds that contribute to the characteristic smoky and soy-like aromas of soybean paste, thereby influencing its overall flavor. 4-EG in soybean paste reached 13.76 mg/kg through the inoculation of two bacterial strains: Bacillus licheniformis, which promotes the production of 4-VG, and Wickerhamiella versatilis, which enhances the generation of 4-EG. The results indicated that the 4-VG produced by Bacillus licheniformis during fermentation can be converted into 4-EG by Wickerhamiella versatilis. Furthermore, Wickerhamiella versatilis promoted the development of ethyl ester flavors, which added sweet and fruity compounds to the soybean paste. Notably, the levels of alcohols and esters increased by 59 and 22 times, respectively, while the organic acid concentration increased by 1.5 times. This study underscored that both B. licheniformis and W. versatilis significantly enhance appealing smoky and fruity flavors through the production of 4-EG and aromatic compounds.

This study presents a comparative cradle-to-gate environmental and economic evaluation of nine synthetic routes for Molnupiravir (EIDD-2801), a broad-spectrum antiviral drug. Integrating Life Cycle Assessment (LCA) with Life Cycle Costing (LCC), we quantified the environmental impacts alongside capital and operational costs, net present costs, and break-even prices of each route. The results reveal significant variation across the schemes, with Schemes #1 and #2 exhibiting the highest impacts and costs due to intensive use of chloroform and diethyl ether, while Scheme #8 demonstrated the lowest impacts and costs, benefitting from higher batch output, greener solvents, and process intensification. Scenario analyses showed that solvent recovery improves sustainability only when high recovery rates are combined with clean electricity; otherwise, the additional energy demand may offset benefits. Scale-up analysis confirmed that higher production scales substantially reduce per-gram impacts and costs, supporting economies of scale. These findings highlight the critical role of solvent management, energy sourcing, the use of sustainability assessment at the earliest stages of innovation, and process design in aligning green chemistry with economic viability. The proposed integrated LCA-LCC framework provides transferable insights to guide sustainable pharmaceutical manufacturing and supports the development of evidence-based policy for greener antiviral drug production.

Background: The complex flavor profiles characteristics of fermented foods emerge through dynamic microbial interactions rather than individual microbial activities. While traditional research primarily focused on flavor compound identification and product enhancement, contemporary studies increasingly highlight the pivotal role of microbial community dynamics in flavor development. Scope and approach: This review explores the critical role of microbial interactions in fermented food flavor development, with three focal points: (1) microbial interaction types and their associated flavor compounds; (2) bidirectional regulation between microbial dynamics and flavor formation; and (3) applications of genome-scale metabolic modeling in elucidating these relationships. Key findings and conclusions: Cooperative metabolic exchange drives the formation of desirable flavor compounds and aromatic profiles, which remain underdeveloped in monoculture systems. Competitive interactions simultaneously suppress undesirable species, thereby eliminating off-flavor production while redirecting metabolic flux toward beneficial compounds. Quorum sensing mechanisms further regulate these processes by synchronizing population-wide gene expressions to optimize flavor biosynthesis through coordinated metabolic pathways. Biofilm formation creates specialized physicochemical microenvironments that enhance metabolic efficiency and facilitate flavor compound accumulation. Advanced analytical approaches, particularly genomescale metabolic modeling, have become indispensable tools for elucidating these complex interaction networks. A systems-level understanding of microbial community dynamics enables precise flavor engineering and quality enhancement in fermented foods, underscoring the necessity of ecological management strategies that transcend single-species optimization.

In this study, to increase the antimicrobial activity of chitosan, lysine was grafted onto chitosan, resulting in a novel derivative named double lysine-modified chitosan (DL-chitosan). The use of 1H NMR, FT-IR, SEM, TG and DTG analyses provided compelling evidence of the structure of the newly developed derivatives. The MICs of DL-chitosan ranged from 0.225 mg/mL to 0.300 mg/mL with a broad antibacterial spectrum, which were greater than unmodified chitosan. The SEM, TEM and PI staining analysis indicated its antimicrobial impact is the disruption of bacterial cell membrane. Moreover, DL-chitosan not only inhibited the growth of total bacteria in chicken meat during refrigerated but also increased the diversity and abundance of beneficial bacterial communities. The DL-chitosan can extend the shelf life of chicken meat during refrigeration, owning to the maintenance of the meat physicochemical attributes including pH, Drip loss, TVBN, and TBARS. Overall, DL-chitosan shows promise as a natural preservative.

Low-salt soy sauce  (LSS) supports healthier diets but suffers taste defects. Endogenous acid-acyl amino acids (AcAAs), β-citryl-l-glutamate  (Cit-Glu) and  N-lactoyl-l-phenylalanine  (Lac-Phe), may help restore taste. In this study, sensory functions and mechanisms of Cit-Glu and Lac-Phe were examined by sensory evaluation and molecular simulation, and their biosynthesis was traced using strain cultures and enzyme assays. Cit-Glu and Lac-Phe exhibited intrinsic umami thresholds (230 and  380  mg·L-1) and boosted kokumi through strong hydrogen bonds with hTAS1R1/hTAS1R3 and CaSR, while competitive binding to OTOP1 and hTAS2Rs suppressed sourness and bitterness. Co-fermenting of Lactiplantibacillus plantarum with Zygosaccharomyces rouxii produced these AcAAs via glutamate N-acetyltransferase (catalyzing acyl group transfer to Glu) and cytosolic nonspecific dipeptidase (catalyzing reverse hydrolysis). Microbiota intervention plus enzymatic strategies increased Cit-Glu and Lac-Phe to 2.25 and 0.87  mM in LSS, significantly reducing sourness and bitterness and enhancing umami and kokumi. These findings provide a practical strategy to optimize taste in sodium-reduced fermented foods.

Debaryomyces hansenii has demonstrated significant applications in the food industry because of its exceptional stress tolerance and capacity to produce various flavor compounds and enzymes. This review systematically analyzes the molecular networks that regulate its response to high salinity, extreme pH, temperature fluctuations, and oxidative stress. The HOG-MAPK pathway plays a crucial role in facilitating glycerol accumulation, while salt ions can further activate antioxidant defense systems and bidirectionally modulate carbon and nitrogen metabolic fluxes. Furthermore, Debaryomyces hansenii contributes essential flavor compounds through several mechanisms, including the synthesis of sugar alcohols, ferulic acid decarboxylation, protease/lipase-mediated protein-lipid hydrolysis, and amino acid Ehrlich conversion. Additionally, Debaryomyces hansenii exhibits promising potential applications in biocontrol, food preservation, and probiotic functionality. Thus, this review serves as a foundation for screening high-quality strains of Debaryomyces hansenii and provides a theoretical framework for future applications within the food industry.

To provide a novel strategy for the development of soy sauce with an improved flavor profile but without gluten, soybean meal was employed as the sole material for fermentation by Aspergillus niger and Aspergillus oryzae. SEM, FTIR, GC-MS, peptide omics and molecular docking were used to analyze flavor characteristics and flavor peptide formation in different combinations. The Aspergillus niger and Aspergillus oryzae groups stand out and presented 3.62-fold increases in alcohol, phenol, and ketone contents in soy sauce compared with Aspergillus oryzae alone; the contents of umami and sweet free amino acids increased by 12.66 %, with the highest content compared with Aspergillus niger; furthermore, Aspergillus niger promoted a 173.7 % increase in the Pro content of the soy sauce compared with Aspergillus oryzae alone, which influenced the amino acid distribution and overall flavor. Thus, the cofermentation of Aspergillus niger and Aspergillus oryzae provides an option for the development of soy sauce.

Pseudomonas aeruginosa infection has become a widespread problem in patients with cystic fibrosis (CF). A safe and effective manufacturing method is required to produce antibiotic dry powder inhalations (DPIs) which can be effectively delivered to treat lung infections. In this study, an excipient-free tobramycin inhalable powder was prepared using spray freeze-drying (SFD) method. The mass median aerodynamic diameters (MMAD) of optimized inhalable powder prepared by SFD was 1.30 µm, and the fine particle fractions (FPF) reached 83.31%. In both in vitro and in vivo safety and activity studies, the inhalable powder showed excellent safety performance at both animal and cellular levels, with a minimum inhibitory concentration (MIC) of 0.5 μg/mL. Compared with intravenous injection, inhalation of excipient-free tobramycin inhalable powder had a better effect in the infected mouse model because of its amorphous state. This study demonstrates that excipient-free tobramycin inhalable powder with good delivery and deposition performance can be successfully obtained using the SFD method. Inhalation of excipient-free tobramycin inhalable powder has the potential to be a promising strategy for treating pulmonary infections caused by P. aeruginosa in patients with CF.

Two unique oleaginous strains, Sporidiobolus pararoseus and Rhodotorula mucilaginosa, were identified during soy sauce fermentation. Both strains demonstrated robust growth under extreme conditions (15 % NaCl, pH 5, 3 % ethanol). Lipidomics revealed 689 and 678 lipid species in S. pararoseus and R. mucilaginosa, with 671 shared components. Among the common components, Triglyceride (TG, 180 species), Diglyceride (DG, 72 species), and Ceramides (Cer, 52 species) were significantly enriched, directly participating in the biosynthesis of characteristic aroma substances by releasing fatty acids with chain lengths of C14-C18. GC-MS analysis showed 1.25- and 1.20-fold increases in long-chain fatty acid esters compared to traditional fermentation. These esters contributed to fat flavor formation and enrichment in defatted soybean sauce fermentation. The findings provide a theoretical basis for developing tailored strains to regulate lipid-derived aroma profiles in fermented soybean products.

Soy sauce, a traditional condiment, derives its characteristic smoky aroma from 4-vinylguaiacol (4-VG) and 4-ethylguaiacol (4-EG), formed by yeast metabolism of ferulic acid (FA). However, controlling the production of these compounds remains challenging. This study isolated four yeasts from soy sauce: Starmerella etchellsii was identified as a key 4-VG producer (28.33 mg/L in monoculture), Wickerhamiella versatilis converted 4-VG to 4-EG, while Debaryomyces hansenii degraded FA/4-VG. Critically, Zygosaccharomyces rouxii showed no FA metabolic capability. Atmospheric and room temperature plasma (ARTP) mutagenesis of S. etchellsii generated mutant WQF-S15 with 86.2 % higher 4-VG yield (72.32 mg/L). Sequential inoculation of WQF-S15 followed by W. versatilis during soy sauce fermentation significantly elevated smoky compounds (4-EG: 26.90 mg/L) and optimized amino acid nitrogen to 0.98 g/100 mL. Sensory and chromatographic analyses confirmed enhanced caramel aroma in S15 + W(A) (4-hydroxy-2,5-dimethyl-3(2H)-furanone (HDMF) increased 3.04-fold vs. control), while W. versatilis enhanced ester complexity. Synergistic yeast action thus improved flavor quality.