Perilla seed hulls are a promising but underutilized source of dietary fiber, yet little is known about how pretreatment-induced structural changes in soluble dietary fiber (SDF) derived from these hulls affect its functionality in cereal dough. This study compared SDF extracted from untreated, ultra-high-pressure (UHP)-pretreated, cellulase-pretreated, and sequentially UHP–cellulase-pretreated perilla seed hulls and evaluated their structural, physicochemical, and dough-modifying properties. The combined treatment increased the SDF content of the hull material from 3.71% to 8.63% and decreased insoluble dietary fiber from 55.74% to 50.37%. Relative to untreated SDF, the resulting UCPSDF had a lower apparent molecular weight (2442 vs. 2788 Da), a smaller mean particle size (2.76 vs. 3.62 μm), a lower glucose proportion, and higher arabinose and acidic monosaccharide proportions. FTIR, XRD, SEM, and thermal analyses indicated retention of the principal polysaccharide and cellulose-I signatures, accompanied by changes in structural characteristics and a looser, more porous morphology. UCPSDF also showed the highest water-holding and swelling capacities. At 6% supplementation, UCPSDF produced the strongest elastic response in wheat–corn composite dough, significantly increased springiness (0.59–0.72) and cohesiveness (0.64–0.76), increased the combined amide I-derived α-helix and β-sheet proportion of dough proteins from 53.93% to 66.82%, and reduced the T23 relaxation time from 297.86 to 81.23 ms. These findings indicate that sequential UHP–cellulase pretreatment improves the measured SDF content and hydration functionality of perilla seed hull SDF and supports its use as a dough-structuring ingredient in wheat–corn composite foods.
Game meat is increasingly discussed as a nutrient-rich alternative source of animal protein, although its consumption remains constrained by limited availability, consumer familiarity, and practical or perceptual barriers. This study assessed attitudes, knowledge, perceptions, and consumption behaviours related to game meat among respondents recruited through an online convenience survey in Romania. Following exclusion of three respondents who did not meet the predefined age criterion, 640 participants were included in the analysis. Data were analysed using descriptive and inferential statistics, multiple correspondence analysis (MCA) with exploratory clustering, and multivariable binary logistic regression. Overall, 75.8% of respondents (95% CI [72.3–78.9]) reported having previously consumed game meat, although consumption was predominantly infrequent. Having family members or friends involved in hunting showed the strongest adjusted association with previous consumption (OR = 4.81, 95% CI [2.59–8.94]), while older age and higher self-rated information were also associated with higher adjusted odds of previous consumption. Exploratory MCA-based clustering suggested three broad respondent profiles characterised by differing levels of familiarity, previous consumption, purchasing knowledge, and perceptions of game meat. Among non-consumers, 50.0% reported willingness to try game meat in the future, although the corresponding multivariable model had limited explanatory power. The principal reported barriers among non-consumers were lack of opportunity (63.2%), discomfort with the idea of eating wild animals (43.4%), and ethical concerns regarding hunting (34.2%). These findings highlight potential considerations for producers, retailers, and policy makers, including market accessibility, consumer information, culinary guidance, and transparent communication regarding product origin and safety. Given the young, student-dominated convenience sample, the findings primarily reflect the perspectives of younger, highly educated respondents in Romania.
Oilseed meal, the primary by-product of oil extraction, is rich in protein, dietary fiber, and minerals, offering significant development potential. However, its application in high-value feed and food is severely restricted due to anti-nutritional factors, leading to resource waste and environmental issues. Solid-state fermentation (SSF) provides a green and efficient approach for the high-value utilization of oilseed meal. This review comprehensively discusses the entire process of strain selection, fermentation strategies, and application of active products in the SSF of oilseed meal. Regarding strain selection, Bacillus spp. degrade macromolecular proteins and inhibit microbial contamination through protease and antimicrobial peptide production. Lactobacillus spp. enhance flavor and safety by producing acids and flavor compounds. Aspergillus spp. decompose cell walls and degrade phytate using their cellulase and phytase systems. For fermentation strategies, mixed fermentation achieves functional complementarity, enzyme–fungus synergy enhances substrate conversion, segmented fermentation optimizes the microbial environment, and physical field assistance boosts enzyme activity, collectively improving fermentation efficiency and nutritional quality. In product applications, fermented oilseed meal serves as both high-quality protein feed and a source of functional peptides and active polysaccharides with antioxidant and immunomodulatory activities, showing potential for functional foods and biomedicine. In conclusion, SSF technology effectively degrades anti-nutritional factors, improving the nutritional value and adding value to oilseed meal, thus representing a key strategy for resource conversion. Future efforts should prioritize high-performance strain selection, intelligent process monitoring, and green preparation of active products to promote industrial application and sustainable development.
Yam (Dioscorea spp.) stands as a critical crop in tropical and subtropical regions, contributing significantly to food security, rural livelihoods, and cultural food systems. Beyond its traditional role as a subsistence crop, yam represents a biologically complex and agro-industrially strategic resource, characterized by substantial species diversity, nutritional richness, and functional versatility. This review provides an integrated synthesis of current knowledge on Dioscorea spp., with particular emphasis on D. alata, D. rotundata, and D. cayenensis. It examines their origin and domestication, global and regional production systems, agronomic requirements, morphological and genetic diversity, and chemical composition. Special attention is given to the nutritional profile of yam tubers, including starch, dietary fiber, proteins, vitamins, and minerals, as well as to their diverse array of bioactive compounds such as steroidal saponins, diosgenin, polyphenols, flavonoids, tannins, alkaloids, and dioscorin that underpin both functional and health-related properties. The review also addresses antinutritional factors and highlights the critical role of processing in mitigating potential toxicological effects while preserving or enhancing nutritional and bioactive value. Furthermore, emerging industrial applications of yam flour, starch, and phytochemicals are discussed, alongside current challenges and research opportunities for crop valorization, particularly in the Colombian context. Overall, this review highlights the potential of yam as a multifunctional crop and emphasizes the need for interdisciplinary strategies to advance its sustainable production, processing, and utilization in future agri-food systems.
Encapsulation and coating approaches have become important tools in modern food systems for improving the stability, functionality, sensory quality, processability, and controlled delivery of bioactive and sensitive food ingredients. Their widespread adoption has enabled the incorporation of functional compounds into diverse food products while enhancing product quality, shelf life, and manufacturing performance. However, successful implementation depends not only on the encapsulation or coating strategy itself but also on the interactions among ingredient properties, carrier materials, food matrices, processing conditions, storage environments, and intended release behavior. Whereas recent reviews have mainly focused on specific encapsulation methods, carrier systems, industrial implementation, sensory functions, or regulatory aspects separately, this review integrates scientific publications and patent literature to examine method and system selection from food-engineering, formulation, processing, and industrial perspectives. Conventional processing and formulation approaches, including spray drying, freeze drying, coacervation, ionic gelation, emulsion-based encapsulation, and fluidized-bed coating, remain widely used, while established carrier systems such as liposomes and cyclodextrin inclusion complexes continue to support ingredient protection and delivery. Emerging carrier systems, including nanoemulsions, nanoliposomes, lipid nanoparticles, and hybrid multilayer structures, together with fabrication methods such as electrospraying and microfluidics, provide greater control over carrier architecture and release behavior but continue to face challenges related to manufacturing scalability, production throughput, storage stability, production cost, regulatory acceptance, and validation under industrial processing conditions. Although patent activity demonstrates continuing development of processing methods and carrier designs, patent publications alone do not establish commercial manufacture, market adoption, or industrial implementation. Across food applications, encapsulation improves ingredient protection, oxidation stability, sensory quality, dispersibility, controlled release, and process compatibility. By integrating research evidence with patent literature, this review further shows that recent progress is characterized primarily by application-driven refinement of carrier systems and fabrication methods rather than replacement of established approaches. Pet food is discussed as a representative specialized food application illustrating how encapsulation and coating strategies require adaptation to product format, processing severity, storage stability, palatability, and species-specific digestive requirements. Overall, this review highlights application-oriented food-engineering principles for selecting encapsulation methods and carrier systems suitable for industrial food applications.
Brewer’s spent grain (BSG) is the primary by-product of the brewing industry and a low-cost lignocellulosic resource rich in phenolics, proteins, and arabinoxylans (AXs). Conventional recovery methods using acids, alkalis, and organic solvents often involve energy-intensive processes, generate hazardous waste, and limit food-grade applications. This review critically examines the evolution of extraction methodologies for BSG bioactives, highlighting the potential of deep eutectic solvents (DES) as sustainable alternatives. Key factors such as solvent chemistry (polarity, pH, and water content) influence bioactives’ recovery and selectivity. Process intensification techniques such as ultrasound, microwave, and pressurised liquid extraction enhance efficiency by reducing extraction time and temperature. The review assesses how various processes modify the structure–function properties of BSG bioactives, including antioxidant activity, protein functionality, and rheological behaviour. A significant finding is that DES research has primarily focused on single compounds, while integrated DES biorefineries for comprehensive valorisation remain underexplored. Future research should therefore prioritise integrated process design that balances recovery, structural preservation, functionality, and sustainability to support scalable, near-zero-waste BSG valorisation for food and nutraceutical applications.
Saline and alkali aquaculture offers a sustainable strategy to alleviate pressure on freshwater resources and ecologically ameliorate saline and alkali environments; however, information regarding the quality of aquatic products from such conditions remains scarce. This study evaluated the nutritional components, color, texture, and flavor profiles of grass carp cultured under three representative saline and alkali conditions in China: carbonate (CB), chloride (CR), and sulfate (SF), with a freshwater-cultured grass carp (Ctenopharyngodon idellus) serving as a control (CK). The results obtained in our study showed that the CB group exhibited the lowest muscle water content (68.96 ± 0.04%). Crude fat and sodium levels were significantly elevated in all treatment groups compared to the CK group (p < 0.05). Conversely, the CK group displayed superior springiness and higher concentrations of geosmin, adenine, and uracil. Notably, the CR group exhibited the highest L* and whiteness values, whereas the CB and SF groups possessed significantly higher collagen content and enriched EPA and DHA levels. These findings demonstrate that saline and alkali conditions distinctly modulate the nutritional and flavor profiles of grass carp, highlighting their potential for producing value-added aquatic products under saline and alkali conditions.
American oak is widely used in enology, but its interactions with white wine and the role of wood properties remain poorly understood. In this study, oxygen dynamics and changes in the phenolic composition of wines made from the Verdejo, Albillo, Rufete, and Puesta en Cruz varieties were evaluated over 35 days of contact with toasted pieces from two Quercus alba wood samples with contrasting grain widths. Untreated control wines and a model wine treated separately with each wood were also included. Wood density and impregnation were determined, dissolved-oxygen partial pressure was monitored noninvasively, and routine enological parameters, spectrophotometric indices, and low-molecular-weight phenolic compounds were analyzed in the final wines. Contact with wood modified the net dissolved-oxygen profiles, although the relative effects of the two contrasting wood samples depended on the wine matrix. The fine-grain wood tested showed greater impregnation and generally produced higher phenolic indices, larger changes in color, and higher concentrations of several wood-derived compounds. Overall, the results show that the properties of the two wood samples and wine composition jointly shape the response of white wines to oak contact.
Listeria monocytogenes is a concern in low-moisture foods because it can survive prolonged dry storage conditions and exhibit increased heat resistance at low water activity (aw). This study evaluated the survival and thermal resistance of L. monocytogenes in peanut butter powder and whole egg powder equilibrated to approximately 0.25 and 0.45 aw. Inoculated powders were stored at 22 °C for 16 months, followed by thermal treatment at 75 and 80 °C. Log-linear, biphasic, and Weibull models were compared using goodness-of-fit metrics and information criteria. Weibull scale parameters (δ) were calculated from replicate-level fits. During storage, L. monocytogenes persisted longer at 0.25 aw than at 0.45 aw in both matrices. In peanut butter powder, populations declined from 8.48 to 2.70 log CFU/g at 0.45 aw and from 8.89 to 3.64 log CFU/g at 0.25 aw after 16 months. In whole egg powder, populations decreased from 8.25 log CFU/g to nondetectable levels by month 15 at 0.45 aw, whereas 4.62 log CFU/g remained after 16 months at 0.25 aw. Nonlinear models generally outperformed the log-linear model. The largest modeled time to the first 1-log reduction (δ) occurred at 75 °C and 0.25 aw in whole egg powder (18.28 min; 95% CI: 16.34–20.45) and peanut butter powder (13.38 min; 95% CI: 9.18–19.52). Lower aw enhanced both long-term survival and thermal resistance of L. monocytogenes, demonstrating the importance of aw- and matrix-specific validation of thermal processes for low-moisture foods.
Fibrillated egg white protein (FEWP) has promising emulsifying functionality, whereas excessive association may restrict the organization of freshly prepared emulsions. This study examined the concentration-dependent effects of γ-cyclodextrin (γ-CD; 0.5%, 1%, and 2%, w/v) on 3% (w/v) FEWP dispersions and the resulting oil-in-water emulsions. Relative to native egg white protein (NEWP), redispersed FEWP showed a smaller apparent hydrodynamic diameter (36.56 vs. 371.97 nm). γ-CD caused only minor changes in particle size and a non-monotonic intrinsic-fluorescence response. Among the γ-CD levels tested, 1% produced the highest intrinsic fluorescence intensity, emulsifying activity index (2.56 m2/g), and emulsion stability index (207.87 min). In the observed microscopic fields, this formulation contained fewer conspicuous large droplets and a visually more uniform spatial distribution than the other FEWP-γ-CD formulations. It also moderated progressive microscopic immobilization and maintained elastic-dominated, shear-thinning, and partially recoverable behavior. Increasing γ-CD to 2% reduced emulsifying performance and bulk structural connectivity. Thus, 1% γ-CD provided the most favorable combination of short-term emulsifying and rheological properties among the concentrations examined.
Food safety and quality analysis is shifting from laboratory-based end-point testing toward faster, lower-volume and matrix-adapted on-site decision-making. Near-infrared (NIR), visible-near-infrared (Vis-NIR), hyperspectral, Raman, surface-enhanced Raman scattering (SERS), fluorescence, colorimetric and terahertz approaches, together with impedance time-series readout, provide complementary information on composition, molecular vibrations, spatial distribution, reaction outputs, or electrical responses. In real foods, however, lipids, proteins, sugars, salts, pigments, particles and native fluorescence can alter spectral baselines, mass transfer and model stability. The value of microfluidics is therefore not limited to miniaturization but lies in organizing filtration, homogenization, splitting, mixing, extraction, enrichment, reaction, and readout positions into a controllable sample-to-signal workflow. This review first distinguishes chemical hazards, biological hazards, authenticity issues, and quality changes according to target and matrix characteristics, and then compares the functional boundaries of continuous-flow, paper-based, droplet, digital-hybrid and enrichment-oriented chips. It further analyses how microfluidics affects detection time, sample and reagent consumption, sensitivity, selectivity, repeatability, portability and cross-matrix applicability through spectral interfaces, signal enhancement, labelled and label-free detection, chemometrics, and machine learning. Representative applications involving pesticides, mycotoxins, pathogens, antibiotics, heavy metals, adulterants, oxidation products, and freshness indicators in real foods are discussed within a unified chain linking chip architecture, spectral signal generation and decision models. Finally, requirements for translation are proposed in terms of standard and real samples, chip-to-chip variation, external model validation, data traceability and scalable manufacturing, providing an operational framework for the joint design of broad-spectrum spectroscopic technologies and microfluidic systems.
Information asymmetry in aquatic product markets heightens consumers’ perceived food safety risks. Using basa fish as the focal product, this study examined how public opinion content influences purchase intention through perceived benefits and perceived sacrifices, and whether regulatory focus moderates these effects. Based on a scenario experiment, prior basa fish consumers were randomly assigned to positive, balanced, or negative video conditions; the final per-protocol sample comprised 742 participants. Baseline-adjusted analyses showed that positive content produced the highest perceived benefits and purchase intention and the lowest perceived sacrifices, balanced content produced intermediate responses, and negative content produced the least favorable responses. Significant indirect effects operated through perceived benefits and perceived sacrifices. Regulatory focus produced selective moderation: among more promotion-oriented consumers, the positive-versus-negative and balanced-versus-negative advantages in perceived benefits, and the balanced-versus-negative reduction in perceived sacrifices, were greater; among more prevention-oriented consumers, the balanced-versus-negative advantage in purchase intention was greater. These findings clarify how complete public opinion message packages shape consumer evaluations and provide guidance for aquatic product communication and market governance.
Ideal food safety communication provides timely evidence-based information for consumers to protect themselves from foodborne illnesses. We investigated if information sources (experts providing factual information vs. social media influencers (SMIs) providing misinformation), cognitive, affective, and sociodemographic factors influenced participants’ intentions to adhere to food safety practices for raw chicken, a high-risk food. In a quasi-experimental, cross-sectional survey, 727 U.S. adults watched videos about raw chicken food safety from an expert, SMI, or a control. Structural model A explained 56.6% of the variance in intentions. Compared to the control, expert and SMI sources had direct, negative effects on intentions. Experts were associated with greater perceived threat for consuming raw chicken compared to SMI and control videos. Perceived threat and efficacy had significant indirect effects on intentions. Structural model B explained 47.6% of the variance in intentions. Knowledge, trust in science, trust in information source, counterarguing, and sociodemographic factors were insignificant moderators. Food safety communicators should provide clear information about the risks of consuming raw or undercooked chicken and actionable guidance for consumers to avoid foodborne illnesses. Audience segmentation analysis may be an important next step to identify consumer groups and tailor food safety messages to specific consumer needs.
Chinese yam (Dioscorea spp.) is widely used as food and traditional medicine, but varietal differences may affect dried yam slice quality. This study compared ten Chinese yam varieties, examined relationships between raw-material quality indicators and dried yam slice quality, and evaluated hyperspectral imaging for rapid assessment before processing. Significant varietal differences were observed in reducing sugar content, total phenolic content, and texture properties (p < 0.05), and trait–quality relationships were variety-dependent. Spectral preprocessing, variable selection, and regression modelling were used to predict the reference values of reducing sugar content and total phenolic content obtained using the specified analytical procedures, together with fresh-slice hardness. The best models combined principal component analysis with decision tree regression (PCA-DTR), competitive adaptive reweighted sampling with partial least squares regression (CARS-PLSR), and CARS with random forest regression (CARS-RFR), respectively. Prediction-set coefficients of determination (RP2) were 0.9891, 0.9335, and 0.9314, with root mean square errors of prediction (RMSEP) of 0.0981%, 0.0905 mg gallic acid equivalents/100 g dry weight, and 130.3973 gf, and residual predictive deviation (RPD) values of 9.7535, 3.9438, and 3.8820, respectively. These results support hyperspectral imaging with chemometrics for rapid assessment and selection of yam raw materials for dried yam slice processing.
Food is lost and wasted at different points in the food supply chain, causing serious environmental, social and economic implications. School lunches are a significant source of food waste at the consumption stage. This study, undertaken in the framework of the Interreg Central Europe project ‘foodCIRCUS’, investigates food preparation, consumption, and waste generation in six educational institutions (three primary schools and three kindergartens) in Wrocław, Poland. Monitoring was done during five consecutive days in each institution (October–December 2024), covering food produced and eaten as well as unserved food, serving leftovers, and plate waste for the main lunch components (soup, protein, starch, and vegetables). The main results give an overall amount of food waste of 236 g/meal planned, with a wastage level of 45%. This is higher than values reported in the literature and higher than the commonly cited global estimate of approximately 30% across the entire food supply chain. Most of the wastage occurred as plate waste (27% of the total food prepared), whereas unserved food constitutes 18%. Primary schools show higher levels of unserved food due to variability in meal uptake, whereas kindergartens show higher plate waste. Vegetables and certain starch-based dishes (groats) have the highest wastage levels. It can be concluded that both operational and behavioral factors cause food waste in school canteens. The national nutrition guidelines lead to a consistent overproduction of food in kindergartens and primary schools, both with their own kitchens and served by catering companies. Reduction strategies should focus on behavioral approaches such as nudging or awareness-raising and operational optimization (e.g., improved forecasting and portion control), as well as redistribution approaches for surplus. The national nutrition guidelines should be interpreted and implemented less strictly. Each pupil should be given the chance to eat portions according to the amounts based on the guidelines, but this does not mean that these amounts have to be prepared for all the pupils potentially attending lunch (as for many it is not their only nutrition source).
Moisture content is an important indicator of grain storage safety, processing quality, and circulation efficiency. However, the performance of near-infrared spectroscopy (NIRS) models is affected by differences in grain crops, sample morphologies, preprocessing strategies, feature selection methods, and regression models, and the adaptation relationships among these factors remain insufficiently understood. In this study, soybean, maize, and wheat samples with whole-grain and powder morphologies were investigated to reveal the method adaptation patterns of NIRS-based moisture prediction under consistent experimental conditions. Spectra in the range of 900–1700 nm were collected, and 54 analytical pathways were established by combining six preprocessing strategies, three feature selection algorithms (SPA, CARS, and UVE), and three regression models (PLSR, SVR, and RF). The results showed that representative optimal pathways achieved Rp values above 0.9730 for powder samples and above 0.9587 for whole-grain samples. Different grain crops and sample morphologies exhibited distinct analytical pathway preferences, indicating that appropriate analytical strategies should be selected according to specific detection objects. Spectral variation analysis further demonstrated higher spectral variability in whole-grain samples than in powder samples. This study provides insights into the selection of suitable NIRS analytical strategies for grain moisture prediction and quality assessment.
Starch modification through physical processing represents a promising “green” strategy to enhance food functionality and nutritional quality while meeting clean-label demands. This review offers a critical overview of the structural and nutritional impacts of physical modifications coupled with an exploratory use of artificial intelligence (AI)-assisted literature for screening and mining. Focused on literature published between 2001 and 2026, a traditional human-led systematic search identifies eligible studies that examined the effects of three major commercially relevant modification techniques—annealing (ANN), heat–moisture treatment (HMT), and autoclaving—on rapidly digestible starch (RDS), slowly digestible starch (SDS), and resistant starch (RS), with emphasis on resistant starch type III (RS3). Among the evaluated techniques, autoclaving, particularly when followed by retrogradation, appears to offer the greatest potential for increasing RS relative to the original native starch. However, its effectiveness is strongly dependent on the raw material, with substantial gains arising from its amylose content, while waxy starches may show little improvement or even a reduction in RS. ANN tends to produce milder and more variable effects, often shifting starch from RDS toward SDS. HMT generally reduces RDS and increases SDS, making it a promising approach for attenuating glycemic responses. However, the extent of these changes can vary substantially depending on the starch source, amylose content, moisture level, and processing temperature. Overall, the work revisits the potential of physical processing as an avenue for starch engineering while underlining a pressing need for standardized workflows, harmonized methodologies, and unified protocols for quantification of starch digestibility, namely, of RS levels. Lastly, the review exemplifies AI can accelerate preliminary literature identification and synthesis yet highlights gaps in AI aptitudes for independent quantitative integration that still maintains a need for thorough human-driven validation.
Myofibrillar protein (MP) emulsion systems tend to be unstable, leading to loss of water and oil from the emulsion gel. Thus, improvements in MP emulsification ability are needed to enhance the quality of meat products. The effects of different added concentrations of locust bean gum (LBG) (0–5 mg/g) on the emulsion gel performance of bovine MP were studied. LBG can act on myosin to stretch the spatial structure of the protein and thus improve the thermal stability of the emulsion. LBG can enhance the hydrophobicity of the MP emulsion gel molecules, allowing greater combination of the oil phase with protein, optimizing the protein’s secondary structure, and promoting greater order and uniformity in the network structure of the MP emulsion gel. LBG imparts better texture characteristics and water retention properties to MP emulsion gels. Compared with a control group, adding 5 mg/g LBG can increase the hardness of an MP emulsion from 23.11 g to 65.91 g, springiness from 0.74 to 0.82, and water holding capacity from 59.45% to 93.24%. This study provides a reference for improving the quality of beef protein-based food emulsion gel.
Extended-spectrum β-lactamase genes in foodborne Salmonella enterica can disseminate through mobile multidrug-resistance platforms. IncHI2 plasmids are important resistance vehicles capable of carrying complex resistance regions and facilitating their horizontal transfer across diverse bacterial backgrounds, but the transfer and genomic organization of IncHI2 elements co-carrying blaLAP-2 and blaCTX-M-55 remain insufficiently characterized. This study investigated two multidrug-resistant foodborne isolates recovered in Shanghai in 2022: Salmonella Agona ST13 isolate Sal22C150 and Salmonella Havana ST1527 isolate Sal22P208. Antimicrobial susceptibility testing, whole-genome sequencing, conjugation, plasmid-retention analysis, comparative genomics, as well as strain- and plasmid-level phylogenetic analyses were performed. Both isolates exhibited broad antimicrobial resistance, including resistance to extended-spectrum cephalosporins. In both isolates, blaLAP-2 and blaCTX-M-55 co-transferred with the IncHI2 replicon to Escherichia coli J53 at frequencies of (4.95 ± 0.41) × 10−5 and (4.46 ± 0.42) × 10−6 transconjugants per donor cell, respectively. All tested plasmid markers remained detectable through 20 passages without antimicrobial selection. Complete assembly of Sal22P208 confirmed the location of the three β-lactamase genes on the 275,096 bp IncHI2 plasmid pSal22P208. The plasmid contained a conserved conjugative backbone and mosaic accessory regions carrying 15 antimicrobial-resistance determinants together with mercury- and tellurium-resistance loci. SNP-based analysis placed pSal22P208 within a closely related cluster containing six reference IncHI2 plasmids differing by fewer than 30 SNPs and recovered from Salmonella and E. coli of animal, food, and human origin, suggesting a broad distribution of this plasmid lineage across diverse bacterial and ecological backgrounds. Sal22P208 additionally contained a Tn3-associated chromosomal multidrug-resistance region between rpmJ and rpmE that shared extensive structural similarity with a region in Citrobacter braakii LBA3. These findings highlight the role of transferable IncHI2 resistance platforms in the horizontal dissemination and short-term post-transfer maintenance of linked resistance determinants, while chromosomally integrated resistance regions may provide an additional route for the accumulation and inheritance of multidrug resistance in foodborne Salmonella.
Rehmannia Radix is an important medicinal and edible plant resource in China. However, the production of paocai by fermenting Rehmannia Radix has rarely been reported. This study employed response surface methodology to optimize fermentation conditions, and investigated the changes in physicochemical properties, bioactive components, and metabolic profiles of paocai before and after fermentation. The optimal fermentation conditions were 5% salt, 9% sugar, and fermentation at 20 °C for 5 days. During the fermentation process, total acidity increased, pH decreased, and crispness and chewiness declined significantly, indicating a softer texture. Electronic tongue analysis demonstrated that fermentation decreased bitterness and astringency, while enhancing sourness, sweetness, and umami. Fermentation significantly increased total phenolic content, total flavonoid content, and antioxidant activity, with phenolic content increasing from 0.80 to 1.63 mg/g and flavonoid content increasing from 2.67 to 3.67 mg/g, while the contents of iridoid glycosides and phenylethanoid glycosides decreased significantly after fermentation. Untargeted metabolomics analysis identified 719 metabolites, of which 417 were differentially abundant metabolites, indicating that fermentation altered the metabolic profile of paocai. In conclusion, fermentation exerted a bidirectional regulatory effect: mitigating the bitterness and astringency of Rehmannia Radix paocai while improving its texture and flavor. This study not only developed the optimal fermentation process for Rehmannia Radix-based medicinal and edible products, but also provided the scientific basis for the sustainable processing and high-value utilization of Rehmannia Radix as a functional food.
