Kombucha is a globally popular fermented beverage valued for its health-promoting properties, yet its traditional production is often hindered by slow and inconsistent fermentation kinetics. Non-thermal technologies, such as low-intensity Pulsed Electric Fields (PEF), offer a promising strategy to stimulate microbial activity without compromising product quality. This study investigated the application of low-intensity PEF to stimulate and accelerate kombucha fermentation. Seven PEF treatment conditions were screened to identify optimal parameters for inducing reversible electroporation in the Symbiotic Culture of Bacteria and Yeast (SCOBY). The most promising condition (1.14 kV/cm, 100 pulses, 17.78 kJ/kg) was evaluated over a 14-day period against an untreated control. Results demonstrated that optimised PEF treatment significantly accelerated microbial proliferation, with lactic acid bacteria and yeast counts reaching up to 2.5 log units higher than the control during early fermentation. This enhanced metabolic activity drove accelerated substrate utilization, resulting in a threefold increase in acetic acid and a 2.9-fold increase in ethyl acetate by day 14. Furthermore, PEF treatment positively modulated the volatile organic compound profile by enriching fruity esters and extending the enzymatic biotransformation of tea-derived polyphenols, preserving the beverage's high antioxidant capacity. In conclusion, low-intensity PEF serves as a promising lab-scale, precision tool capable of significantly modulate specific fermentation kinetics (sugar consumption and key metabolites production) while modifying its aromatic profile and preserving its nutritional and functional attributes.
Integrating environmental, economic, and hazard dimensions from early design stages is crucial for safer and more sustainable bioprocesses. Hop flowers (Humulus lupulus), rich in bioactive compounds, are suitable for extraction using green solvents and mild techniques. This study evaluated process configurations for extracting antioxidant compounds from hop flowers using ultrasound-assisted extraction (UAE) and pressurized liquid extraction (PLE) with water, aqueous ethanol, and natural deep eutectic solvents (NADES). Laboratory data were scaled up and modelled in SuperPro Designer® for mass and energy balances. Nine PLE scenarios combined three solvents and three extraction temperatures, while three UAE scenarios were evaluated at 25 °C. A cradle-to-gate life cycle assessment using Environmental Footprint (EF) 3.1 and a techno-economic analysis were conducted. Total phenolic recovery ranged from 13.23 to 34.95 kg GA eq per 1000 kg of hops for PLE and from 8.81 to 17.04 kg GA eq per 1000 kg of hops for UAE. PLE with aqueous ethanol at 100 °C (PLE-5) provided the best balance between environmental performance and economic viability, with 34.31 kg GA eq per 1000 kg of hops, a unit production cost of US$80.23/kg, an ROI of 80.39%, and a payback period of 1.24 years. In contrast, aqueous UAE showed a favorable environmental profile but a unit production cost of US$407.13/kg and an ROI of −13.00%. The representative NADES-based PLE configuration (PLE-8) was economically viable but showed higher EF 3.1 impacts due to upstream burdens associated with choline chloride and glucose. These results support PLE-5 as the most suitable option from an SSbD perspective.
Magnetic field promoted the formation of a more continuous and uniform gluten network in dough enriched with 40% potato pulp (DPP). To elucidate the mechanisms, the gluten fractions (gliadin and glutenin) were individually investigated. Magnetic field treatment improved the rheological and mechanical properties of gluten fractions. Increased fluorescence intensity and decreased surface hydrophobicity, suggesting that protein unfolding occurred after magnetic field treatment. Additionally, magnetic field increased hydrogen bonding by 68% in gliadin and 27.69% in glutenin, leading to conformational changes and gluten matrix rearrangement. Magnetic field decreased the content of sulfhydryl groups in the gluten fractions by 19.32–45.06%, while the disulfide bonds and surface hydrophobicity increased by 31.71–37.58% and 17.81–48.35%, respectively. Besides, magnetic field suppressed the depolymerization of gluten aggregates, thereby increasing the proportion of ordered secondary structures (β-sheet and α-helix) and enhancing thermal properties. These changes resulted in more compact and homogeneous structures in both fractions, attributed to the rearrangement of intermolecular disulfide bonds. This study offers underlying mechanism of magnetic field for regulating gluten polymerization in dough products.
The development of new electrospinning technology offers enormous possibilities for creating next-generation active and intelligent food packaging that increases shelf life and monitors the quality and safety of packaged food products in real-time. This study introduces a novel active and intelligent packaging label based on poly(vinyl alcohol) (PVA) electrospun nanofibers incorporated with anthocyanin-rich Althaea officinalis extract (AOEX). The optimized nanofibers exhibited a uniform morphology (average diameter of 204.9 nm, expanding to 480.9 nm with AOEX loading) and significantly enhanced hydrophilicity (contact angle reduced to 47.6°–73.1°). Importantly, the incorporation of this new source of plant material into the mat gave rise to strong dose-dependent antioxidant and antibacterial activities against relevant foodborne pathogens, with an IC50 value of 375 ppm for the DPPH free radical. FTIR and thermal analyses confirmed the stable physical integration of bioactive compounds without structural degradation. The multifunctional label, applied on rainbow trout fillets stored at 4 °C, exhibited a multi-functional action. It extended shelf life by delaying the TVB-N threshold exceedance by 2.5 days and the TVC safety limit breach by 3 days compared to control samples, while allowing the real-time monitoring of fish freshness through a pH-triggered colorimetric response. For more precise quantification of the chromatic variations, a smartphone RGB analysis model was developed, allowing the early, non-destructive detection of the rejection zone before visible color changes. Therefore, this plant-derived nanofibrous system, combining active preservation and fast smartphone-aided intelligent monitoring, appears as a promising, and emerging technology for the next generation of seafood packaging.
This study evaluated the antimicrobial potential of Pulsed light (PL) exposure during wheat tempering to reduce Salmonella contamination. The preliminary screening of three non-thermal treatments (cold plasma, ultraviolet, and PL) showed that only PL achieved a ≥ 3 log CFU/g reduction under the evaluated conditions. Hard red spring wheat was inoculated with Salmonella enterica cocktail, tempered (17% moisture), and exposed to PL (0.164–0.329 J/cm2), and plating was performed on xylose-lysine deoxycholate (XLD) selective agar medium alone and XLD with a tryptic soy agar overlay (XLD + T) to account for the sub-lethally injured cells. A reduction of 4.217 ± 0.09 log CFU/g (XLD) and 3.915 ± 0.066 log CFU/g (XLD + T) was observed after 18 h of tempering, indicating 51.944 ± 10.551% sublethal injury-associated permeabilization. Non-linear models (Weibull and Geeraerd log-linear shoulder) provided better descriptive fits than the log-linear model, as indicated by higher R2 and lower RMSE across tempering times and recovery media. The Geeraerd log-linear shoulder model was selected as the primary kinetic model because it most frequently provided the lowest AIC and explicitly captured shoulder behavior. Similarly, Weibull β > 1 indicated an initial resistant phase at lower fluence, followed by more rapid microbial inactivation as fluence increased. The model predicted a 2-log reduction in Salmonella would require approximately 0.245–0.300 J/cm2 (60–73 s), depending on tempering time and recovery medium. Mechanistic assays conducted in cell suspension showed increased membrane permeability, cellular leakage, and loss of DNA integrity following PL exposure. The PL treatment at 0.329 J/cm2 (80 s) had a significant effect on wheat flour functionality. Particle size distribution and dough rheology remained nearly identical (p > 0.05). However, damaged starch, measured using the SDmatic method, increased significantly (p < 0.05) and was accompanied by changes in the bread's loaf volume, texture, and C-cell characteristics. These findings pave the way for using PL as a potential intervention to reduce Salmonella in wheat during tempering.
In this study, Lacticaseibacillus casei, a lactic acid-producing, non-ethanol-yielding bacterium, was used to ferment a non-alcoholic orange beverage (composed of 50% fruit content standardized with sucrose) to produce a postbiotic product. Thermosonication (TS) was evaluated and compared against conventional thermal inactivation (TH) at 50, 55, and 60 °C. The research focused on the influence of the reactor type (its material acoustic properties, spatial confinement, and operating frequency) on inactivation kinetics. While TH consistently followed linear first-order kinetics (Bigelow model), TS kinetics were influenced by the reactor's physical environment. In a confined stainless-steel chamber, TS induced a non-linear Weibull inactivation with a resistant “tailing” effect. This might be attributed to the material's high acoustic impedance mismatch and surface roughness, which are known in the literature to potentially promote standing waves and boundary attenuation. Conversely, transitioning to larger glass reactors is hypothesized to facilitate vigorous macroscopic acoustic streaming and homogeneous energy distribution. This yielded robust linear and highly predictable inactivation (R2 > 0.99), effectively mitigating the survival of subpopulations. The most efficient TS approach (glass reactor at 60 °C, 10 W/mL) achieved a D-value of 0.62 min, reducing processing time by 57% compared to thermal processing. Three optimized processing scenarios (isothermal, hybrid, and homogeneous TS) are proposed to ensure product safety. Ultimately, this study indicated that the reactor type (including its material acoustic properties, operating frequency, and topographical properties) might mitigate kinetic non-linearities, thereby establishing homogeneous thermosonication as a predictable and viable technology for the industrial scale-up of postbiotic production.
Evaluating the physical instability of protein dispersions is critical in food science and product development, yet current methods rely on subjective visual inspection or costly light-scattering instruments. These approaches provide only snapshots in time and offer limited temporal resolution. We present a robotic and computer vision system for automated assessment of the physical instability of protein dispersions across varying pH conditions. The system automates titration and pipetting tasks, while an optical camera continuously monitors up to ten samples stored in cuvettes. Captured images are analyzed with a Laplacian-based algorithm that enhances agglomerate visibility and quantifies instability through a single metric. The system was validated through acid titration of a 1% milk protein solution at 30 °C, successfully detecting both massive physico-chemical instability (aggregation) and subtle physical instability (sedimentation). The amount of added acid required to reach the instability point showed a 6% variation in the millimolar range, demonstrating high reproducibility across experiments. This cost-effective and scalable platform enables parallel analysis of up to ten samples, making it well suited for early-stage formulation screening. Beyond protein dispersions, the system could be extended to study more complex, multi-ingredient formulations. In addition, it can facilitate the generation of large, high-quality datasets to support the development of machine-learning models for formulation optimization.
Ultrasound-assisted extraction (UAE) was employed to recover bioactive compounds from avocado seeds and develop novel antifungal solutions for postharvest preservation of fresh mandarins. An UAE avocado seed extract (AVS) was evaluated as both a direct dip treatment and an active ingredient of biopolymer-based edible emulsions composed of carboxymethyl cellulose (CMC) or gum arabic (GA) matrices combined with eugenol (EU) and beeswax (BW). The influence of emulsion composition on antifungal performance, coating functionality, and mandarin quality during storage was investigated. Dip application of AVS aqueous solutions reduced the incidence of green and blue molds caused by Penicillium digitatum and Penicillium italicum by 60–70% on artificially inoculated ‘Orri’ mandarins either stored at 20 °C for 7 days or refrigerated at 5 °C for up to 4 weeks. Among coating emulsions, CMC + AVS + EU provided the best overall balance between disease control and fruit quality after 4 weeks at 5 °C followed by 1 week of shelf life at 20 °C. Although BW enhanced the barrier properties of the emulsions, it reduced their antifungal efficacy, showing that the formulation components govern the availability and functionality of incorporated bioactive compounds. These results prove the potential of UAE AVS as multifunctional ingredients for edible biopolymeric coating emulsions and highlight the importance of formulation design in optimizing the balance between barrier performance and biological activity. Further, this work advances the valorization of avocado processing by-products for reducing mandarin postharvest losses and synthetic fungicide dependence.
Sugarcane dry leaves (SDL) are underutilized in feed and food industries due to their dense lignocellulose and low digestibility, requiring bioconversion. Trichoderma erinaceum, secreting efficient cellulases, is a promising degrader, but traditional fermentation is prone to variability and contamination, while single strains are metabolically limited. Therefore, we introduced a synthetic microbial community and developed a two-phase sequential fermentation: aerobic phase with Trichoderma erinaceum for 5 days to hydrolyze cellulose, followed by anaerobic phase with Kluyveromyces marxianus, Lactiplantibacillus plantarum and Limosilactobacillus fermentum for 5 days to accumulate organic acids. After aerobic phase, group A (two-phase aerobic-anaerobic fermentation with consortium) reduced neutral detergent fiber (DM basis) by 3.91% and acid detergent fiber (DM basis) by 4.59% vs. control (CK). After anaerobic phase, crude protein increased by 10.49%, lactic acid (LA) by 18.65%, and acetic acid (AA) by 291.09% in group A. Metagenomics revealed that elevated LA during the aerobic phase coincided with K. marxianus enrichment, while LA/AA accumulation during the anaerobic phase accompanied Lentilactobacillus enrichment, and GH enrichment correlated with fiber degradation. Untargeted metabolomics revealed 3264 differential metabolites, including upregulated zosteric acid, 3-hydroxycinnamic acid, cyclo(Pro-Arg), and carquinostatin A, which were associated with antimicrobial, flavor, antioxidant and were positively correlated with Lentilactobacillus; 4-aminobutanoate accumulation was correlated with enhanced acid tolerance of Lentilactobacillus, thus indirectly promoting LA and AA production. Overall, this two-phase sequential solid-state fermentation combined with a synthetic microbial community effectively converts SDL into organic acid-rich biomass, offering a viable route for high-value feed and functional food ingredients within a circular bioeconomy.
Air frying (AF) has emerged as a promising alternative to deep-fat frying (DFF) for producing tortilla chips with improved quality attributes. This study integrated real-time kinetics of mass and heat transfer, color development, and shrinkage with acrylamide formation, texture, and microstructural data obtained during AF (140–170 °C) and DFF (170 °C) processing of tortilla chips. Effective diffusivity coefficients increased with temperature from 1.22 × 10−9 to 3.84 × 10−9 m2/s, apparent thermal diffusivity from 2.04 × 10−10 to 8.63 × 10−9 m2/s, and the browning index rate constant (k) from 0.059 to 0.104 min−1. Arrhenius-type relationships for the effective moisture and apparent thermal diffusivity coefficients and the browning index yielded empirical equations with activation energies from 22.25 to 67.42 kJ/mol, supporting equipment design, process optimization, and preliminary industrial-scale estimations. AF at 170 °C for 15 min lowered acrylamide content 1.7-fold (37.59 μg/kg) relative to DFF for 2 min (64.57 μg/kg). Overcooking at 170 °C for 30 min produced a 7.3-fold increase in acrylamide content, from 34.07 to 247.17 μg/kg, compared with optimal AF conditions. Acrylamide content correlated strongly with the browning index through a second-order model (R2 = 0.97). Microstructural analysis revealed temperature-dependent starch gelatinization, crust formation, crack development, and fat distribution patterns. AF also had lower fat content (6.10%) than DFF (27.22%). Factorial design and principal component analysis integrated sixteen response variables, distinguishing optimal from overcooked conditions as distinct quality classes suitable for computer vision-based process control. Overall, AF tortilla chip processing yields superior quality and advantages over DFF. Industrial relevance The empirical Arrhenius equations derived for effective moisture diffusivity, apparent thermal diffusivity, and browning index provide preliminary baseline engineering data useful for understanding cooking kinetics and supporting future equipment design and scaling studies from laboratory to industrial scale. The 4.5-fold reduction in oil content and 7.3-fold reduction in acrylamide compared to DFF support AF as a viable industrial process for producing tortilla chips with improved nutritional characteristics. The integration of real-time thermographic and digital imaging with transport phenomena demonstrates the feasibility of implementing computer vision systems in AF equipment to prevent overcooking, control acrylamide formation, and ensure consistent product quality across household, restaurant, and industrial scales.
The impact of ultraviolet light-emitting diode (UV-LED) irradiation on the chemical and sensory properties of black peppercorns is investigated in this study. Samples were treated with 280-, 300-, and 365-nm light, as well as at 280 + 300 nm. Total phenolic content, antioxidant activity, phenolic compounds, volatiles, piperine, fatty acids, and tocopherols were analysed, followed by a sensory analysis. Chemical and instrumental analyses revealed moderate changes (up to 40%) in phenolic compounds, volatiles, fatty acids, and tocopherols, with the combined wavelength treatment often resulting in a greater deterioration, and agitation being the main driver for quality degradation. However, sensory evaluation showed no significant differences in colour, smell, or flavour, indicating that organoleptic properties remained unaffected. The findings suggest that UV-LEDs offer a valuable and feasible alternative to conventional heat and water vapour treatments, avoiding humidity-related issues whilst preserving the product's organoleptic integrity. UV-LEDs demonstrated potential for non-thermal spice treatment with minimal sensory impact.
Several studies have demonstrated the use of terahertz waves to estimate mass diffusion coefficients under transient conditions. Monitoring transient water content is recognized as a key parameter in many drying processes (e.g., wood, paper, etc.). However, accurate control of this physical quantity remains essential to ensure product quality and, in the case of food products, to extend shelf life. In this study, terahertz waves were employed to locally measure the water content in a cereal-based product, using a muffin as a case study. To characterize the spatial distribution of water within the product, the muffin was sliced into sections of equal thickness and scanned using a terahertz line camera. By comparing the transmitted signals obtained from the wet and dry samples, the local water content of each slice was determined. Stacking the resulting measurement planes provides an overall water-content distribution within the muffin.
Electrospraying is a process that uses an electric field to remove solvents from polymeric solutions, allowing the production of micro- and nanoscale particles. This technique is characterized by its non-thermal nature, which avoids thermal damage to treated materials. This method has not been employed as a dehydration approach in food processing, and its potential applications in this field have not yet been explored or studied in depth. In this study, electrospraying for the removal of water from reconstituted milk was evaluated, yielding promising results. The increase in the distance between the tip and the collector did not show significant effects on the size of the drops due to the interaction of two opposite effects: the decrease in the intensity of the electric field and the increase in the residence time. It was also observed that a larger diameter of the tip resulted in big drops, while a high fat content generated small drops due to the increase in viscosity and decrease in surface tension. The diameter of the droplets was reduced by decreasing the flow rate and/or increasing the concentration of total solids. Finally, electrospraying, at a low flow rate, eliminated water significantly (p < 0.05) without producing any significant effect on the structure of proteins (i.e., caseins and whey proteins). These findings open the way for novel research directions in the drying of high–value liquid foods, highlighting the potential of this technique for innovative applications within the food processing sector.
