This study investigated the effects of cold plasma treatments with air (80% N2, 20% O2), pure CO₂, and a 1:1 air–CO₂ mixture on the techno-functional properties of soy protein isolate. Treatments were applied to protein dispersions (16% w/v in distilled water) for 30 min at a gas flow rate of 2 SLPM and a voltage of 160 V. FTIR spectroscopy was used to assess plasma-induced alterations in the secondary structure of SPI, and key techno-functional properties were studied, including solubility, foaming, water- and oil-holding capacities and emulsifying capacity. Gel strength, syneresis and rheological behaviour were also evaluated. Air plasma treatments increased the random coil structure and improved solubility and foaming properties. In addition, air plasma treatments created a more oxidative environment due to reactive species, evidenced by increased values of oxidation–reduction potential. On the other hand, CO₂ plasmas favoured β-sheet enrichment and increased water-holding capacity. All plasma treatments yielded gels with higher strength, lower syneresis and increased resistance to deformation (higher G′, G″ and complex viscosity). Overall, the results highlight that gas composition is a key factor in modulating plasma-induced techno-functional modifications of soy protein.

The consumption of edible seaweed as a sustainable food source is increasing; however, their complex composition and diverse commercial formats pose significant challenges for the detection of pathogens, specifically human enteric viruses. Standardized methods, such as ISO 15216-1:2017 and FDA/BAM, are available for detecting and quantifying viral contamination in a diversity of food matrices, which is crucial to guarantee food safety and implement routine monitoring efforts. However, these methodologies demonstrated limited efficiency when applied to complex food samples, and information on their analytical performance is not available for edible seaweed, yet. In this study, three viral concentration protocols based on ISO or FDA/BAM procedures were comparatively assessed for their analytical performance in detecting human norovirus genogroups I and II (HuNoV GI and GII), hepatitis A virus (HAV), and human astrovirus (HAstV) in three edible seaweed species (Codium spp., Ulva lactuca, and Himanthalia elongata). Among assessed protocols, FDA/BAM method exhibited the highest sensitivity (LoD50% = 5.0 ± 0.8 log GC/25 g) and recovery efficiency (2.2-10.9%), significantly outperforming the alternatively tested ISO-based methods. In addition, the best-performing method was employed to conduct a pilot assessment of viral contamination in commercial seaweeds sold in different formats (fresh, dried, and powdered). The sampling campaign resulted in Ulva lactuca (3/15; 20.0%) and Sargassum muticum (1/15; 6.7%) contaminated with HuNoV GII RNA. Overall, these findings emphasise the need for sensitive and standardized detection methods for enteric viruses in complex food matrices, such as seaweeds.

Plasma treatment is an emerging non-thermal technology for modifying the functional and structural properties of starches, offering a promising alternative to conventional treatments. This study investigates the effect of plasma exposure (20 and 40 min) on rice varieties, Basmati and Japonica, in different forms: whole grain, flour and starch in comparison with commercial rice starch (CS). Results indicated that plasma exposure significantly reduced moisture content in Basmati variety experienced faster drying with short treatment time (20 min), however prolonged exposure (≥40 min) led to similar moisture losses across varieties. Colour variation increased with treatment time in grains and flours compared to starch which showed minimal changes, particularly in Japonica samples. Results of pasting profiles showed variety and matrix dependent effect. Plasma-treated Japonica grains and flours exhibited higher peak and breakdown viscosities, indicating lower stability, while Basmati grains and flours maintained more stable pasting profiles. In starches, Basmati starch and Japonica starch exhibited increased peak and breakdown viscosities with moderate plasma exposure (20 min), whereas in CS structural weakening was observed after prolonged treatment (40 min), that was confirmed by reduced crystallinity, and loss of gel-forming capacity. The hydration properties such as water absorption index, swelling power and water holding capacity were improved drastically in flour samples compared to other forms in both the varieties. Overall, plasma treatment induced surface-driven modifications improving hydration properties, emphasizing its potential application in tailoring the functional characteristics for the production of rice-based ingredients.

This study aimed to develop industrial exposure assessment models to determine the contamination level of Bacillus cereus in soy-based beverages formulated from raw materials (soy flour and soy protein) decontaminated by using cold plasma technology. The assessment comprised two stages: i) cold plasma sanitization of raw materials and ii) subsequent storage under cold chain break conditions (20 °C) of beverages formulated by using the sanitized raw material. B. cereus spores were inoculated into the raw materials and treated with synthetic air plasma (0.80 mbar, 300 W) at varying exposure times. Inactivation curves were modeled using the Weibull distribution function. To assess the growth, the Baranyi and Roberts model was used incorporating data from previous studies. The modular industrial exposure assessment models were used to perform Monte Carlo simulations including different initial contamination levels (102 to 104 CFU/g) and two plasma performance criteria (1 and 2 log reductions). Although all units remained contaminated, plasma treatment prevented B. cereus from reaching the infective dose in the formulated beverages with sanitized raw material, in all evaluated scenarios. Conversely, drinks formulated with untreated raw materials exceeded that infective dose at the highest contamination level. Consequently, cold plasma was found to be useful for the sanitization of raw materials used for formulate beverages, maintaining a safe level of B. cereus under cold chain break conditions. Cold plasma could be integrated into a hurdle technology approach to enhance food safety standards.

Antimicrobial resistance (AMR) remains a major public health concern, being the agri-food chain crucial in the emergence and dissemination of resistant pathogens such as Salmonella Typhimurium. Effective hygienization is key to prevent access of AMR bacteria into the agri-food chain. In this work, we investigated the consequences of ciprofloxacin (CIP) resistance acquisition in S. Typhimurium on tolerance to emerging non-thermal preservation technologies, including pulsed electric fields (PEF), ultraviolet C irradiation (UV-C) and high hydrostatic pressure (HHP). We focused on a CIP-resistant S. Typhimurium variant (SeTRV1) previously shown to exhibit crossprotection to thermal treatments. While no significant differences were observed following PEF treatments, UV-C and HHP susceptibility was significantly reduced, resulting in survival increases ranging from approximately 32- to 2000-fold. We confirmed that a mutation in rpoD was the primary contributor to these phenotypes and associated with transcriptional changes in selected stress- and AMR-related genes, as determined by RTqPCR. Virulence assessment using Galleria mellonella larvae revealed compensatory and divergent phenotypes associated with different mutations, ranging from reduced to enhanced virulence. Additional CIP-resistant variants harboring distinct mutations were subsequently evaluated, revealing that although PEF tolerance remained unaffected, several variants exhibited decreased susceptibility to UV-C, potentially linked to optimized DNA topology and enhanced oxidative stress responses. Overall, this study identifies rpoD as key driver of crossprotection to UV-C and HHP and highlights mutation-specific roles of ramR and cyaA in modulating UV-C tolerance and virulence, as well as gyrA/gyrB in increasing UV-C tolerance, with implications for food safety risk assessment in minimally processed foods.

Bacillus cereus is a foodborne pathogen whose spores can withstand pasteurization, posing a risk to food safety, particularly in soy-based beverages where its presence has been frequently reported. The aim of this study was to evaluate the efficacy of cold plasma as a disinfection technology for B. cereus contaminated soybean flour and soy protein isolate (SPI), as well as to assess its combined effect with nanoemulsified D-limonene, a well-known antimicrobial compound, to inhibit/reduce the growth of B. cereus in simulated soy drinks. Soybean flour and SPI inoculated with B. cereus spores were exposed to cold plasma treatment with synthetic air (20 % O2 and 80 % N2) at 80 Pa and 300 W for 30 min. Subsequently, these treated matrices were used to simulate soy beverages. Afterwards, remaining spores were germinated (80 degrees C, 10 min) and a 0.05 mol/L D-limonene nanoemulsion was added to the beverages. The viability of B. cereus was then monitored under different storage conditions (30 degrees C and 20 degrees C for 24 h, and 10 degrees C for 10 days). Cold plasma treatment reduced the spore load in soy-based matrices by approximately 1 log cycle and significantly slowed B. cereus growth after the lag phase at 20 degrees C and 30 degrees C. While D-limonene had no effect on B. cereus growth in beverages made with soy flour, it exhibited a bacteriostatic action in SPI drinks, suggesting a potential strategy to enhance food safety.

Influencing the starch postprandial glycemia via interventions that are sourced from natural plant materials has gained attention recently. Amylose present in starch is reported to form complexes with small ligands such as gallic acid (GA) through a conformational change that are digested slowly and contribute to the formation of resistant starch. In this study, the molecular interactions, multi-scale structure and in vitro digestion properties of normal neat rice starch and rice starch-GA composites (2, 5 % w/v) obtained either by high hydrostatic pressure (HHP) or thermal (T) treatment were compared. The multi-scale structure changes experienced by the rice starch gels (neat and composite) during simulated oro-gastrointestinal (OGIT) digestion were also characterised. Overall, formation of the V-7 type inclusion complex was demonstrated in the composite gels processed by HHP and T, although the main molecular interactions found in the composites were non-inclusion complexes. Sample A-GA-5-HHP formed gels with a unique microstructure, whilst also displaying a significant increase of the resistant starch fraction (similar to 13 %) and a large decrease of the rapidly digestible starch fraction than A-GA-5-T (p < 0.05). The lower digestibility in A-GA-5-HHP was attributed to increased molecular interactions between amylose and GA, as suggested by the greater intensity peak at 3520 cm(-1) in the FTIR, and the downfield chemical shifts (0.12 ppm) in the C-13 NMR spectra. Our findings indicate that HHP gelatinisation of starch-GA composites represents a promising approach for the design of novel starch-based systems with distinct microstructure and digestion characteristics.

Alginate is a dietary polysaccharide that is known to support the growth of particular gut-associated bacteria, including members of the Bacteroides genus. However, there is limited understanding of how key physicochemical characteristics of partially depolymerised alginate fractions affect the growth of various Bacteroidetes strains. In this study, the growth profile of Bacteroides thetaiotaomicron VPI-5482, Bacteroides cellulosilyticus WH2 and Dysgonomonas mossii DSMZ22836 on alginate fractions (Mw = 17-58 kDa) with different mannuronic and guluronic ratios (M/G ratio = 0.27-1.14) depolymerised by high hydrostatic pressures (HHP), pulsed electric fields (PEF) and H2O2-based treatments was screened. The tested strains were able to grow in the HHP, PEF and H2O2 treated samples. Growth of Bacteroides sp. was significantly affected by the physicochemical properties of the alginate substrates. The lower the Mw of the samples the faster the growth for the three strains investigated (p <0.05, r =-0.7757). Higher M/G ratios significantly enhanced the growth of B. thetaiotaomicron VPI-5482 (p < 0.05, r = 0.9685). Finally, D. mossii DSMZ22836 was found to employ three enzymes (Aly, GH88, GH92) to degrade the low Mw alginate fractions. This study advances the understanding of strain-specific interactions of three glycan degraders in the presence of various low Mw alginate fractions.

Rice bran (RB) is a by-product with limited application due to technological constraints. Enhancing its technological functionality as potential food ingredient will improve the sustainability of rice production. The aim was to study the impact of enzymatic and thermal treatments on defatted rice bran using six distinct commercial enzymes (carbohydrases and proteases) and dry heating by evaluating its technological, nutritional and functional properties. Enzymatic treatment increased up to 208% the soluble dietary fiber content (8.19 g/100 g) of defatted RB. Moreover, the solvent retention capacity, including water, oil, sodium carbonate, and sucrose, exhibited a noteworthy increase across all treatments (p < 0.05). Bran color changed after treatments, increasing its luminosity (L*) and decreasing the value of a* in all cases, but b* decreased when treated with protein-acting enzymes while increased with carbohydrate-acting enzymes. Proteases played a pivotal role in reducing particle size and forming gels requiring minimal force for application. Microscopic analysis revealed that carbohydrases-treated samples exhibited prominent cell wall breakage, while protease-treated ones showed a gel-like surface with less distinct protein bodies and layered walls. These comprehensive study sheds new transformations brought about by these enzymatic interventions, offering valuable insights into the optimization of rice bran functionality.

The rheological, mechanical and structural properties of conventional and waxy rice starch-alginate composite gels formed by heat (90 +/- 1 degrees C, 20 min) and high hydrostatic pressure (500 MPa at 20 +/- 3 degrees C for 20 min) were investigated to explore the feasibility of these matrices as novel dysphagia-oriented foods. Amylose containing rice starch composite samples processed by HHP exhibited a rheological pattern typical of weaker networks with more fluid-like behaviour among all formulations (G' = 300-1200 Pa, tan delta = 0.10-0.20), which was considered favourable for dysphagia patients. HHP gelatinisation led to marked short-term retrogradation of normal starch gels, as reflected by the significantly higher values of gel firmness (72 +/- 4 g) (p < 0.05). However, this phenomenon was significantly attenuated by the presence of alginate (10-15 g) (p < 0.05). The texture profile analysis (TPA) parameters of all formulations were within the range recommended for texture-modified food products for dysphagia patients. HHP treatment indicated a positive effect on the long-range and short-range ordered structure of the composite gels, which was further confirmed by the SEM micrographs. The international dysphagia diet standardization initiative (IDDSI) tests indicated that only amylose-containing starch-alginate composites produced by HHP could be classified as level 5. These results provide insights into the potential benefits of utilising HHP to produce starch-alginate composites for the development of the novel soft gel-type dysphagia food matrices.

Cold plasma (CP) technology is a promising alternative to thermal treatments for the microbial decontamination of foods with low-water activity. The aim of this work is study the application of low-pressure CP (0.35 mbar) for the inactivation of Bacillus cereus in a soybean powder matrix using O₂ and synthetic air as ionizing gases. The parameters tested were an input power of 100, 200 and 300 W and an exposure time of 10 to 30 min. The excited reactive species formed were monitored by optical emission spectroscopy, and survival data were analyzed using the Weibull mathematical model. Treatments with both gases were effective in inactivating B. cereus. Air plasma resulted in a maximum 3.71-log reduction in bacterial counts at 300 W and 30 min, while O2 plasma showed the strongest inactivation ability, achieving levels higher than 5 log cycles at 300 W and > 25 min. This is likely due to the strong antimicrobial activity of oxygen-derived radicals together with carbon monoxide as an oxidation by-product. In addition, the Weibull distribution function accurately modeled the inactivation of B. cereus. Cold plasma technology is a promising approach for the decontamination of bacteria in low-water activity foods.

An exposure assessment model for industrial use has been developed by using kinetic data from inactivation and growth of Bacillus cereus spores. It can provide a valuable tool for estimating the concentration of B. cereus after a storage period of 24 h at a specified temperature (20 °C) and for an estimation of the percentage of contaminated portions according to the input data of the model. This model considers a rice-derived product that has undergone a standard cooking process at 95 °C for 20 min. According to the results, the presence of chitosan affects the final microbial load after storage, potentially serving as an additional control measure in the event of cold chain abuse or break. Chitosan's antimicrobial properties likely play a role in reducing microbial growth during storage, thereby contributing to enhanced food safety. In practical terms, this suggests that incorporating chitosan into food products, especially those susceptible to microbial contamination like rice derivatives, could help mitigate risks associated with temperature abuse or cold chain disruptions. By acting as a protective barrier against microbial proliferation, chitosan offers a preventive measure to maintain product quality and safety throughout the supply chain. Considering two scenarios, 104 or 107 as initial contamination the model estimated that the 55 and 100% of portions would be respectively contaminated, according to a Performance Criteria of 4 log reductions.

Berries contaminated with human norovirus (HuNoV) have been frequently identified as a cause of foodborne gastroenteritis. To prevent virus transmission while preserving sensory and quality parameters, non-thermal treatments, such as high-pressure processing (HPP), can be applied to the berries and products thereof. Here, strawberry purees contaminated with HuNoV genogroup I (GI.3[P13]) and II (GII.4 Sydney [P16]), along with murine norovirus (MNV) and Tulane virus (TV) serving as surrogates, were exposed to HPP at several pressuretime combinations. Virus inactivation was assessed by cell culture, including the novel human intestinal enteroids (HIE) model for HuNoVs. The infectivity results showed TV more resistant than MNV to HPP, as also confirmed by kinetic mathematical modelling. Results indicated that a holding pressure of 450 MPa and an exposure time of >= 5 min are reliable operational conditions for HPP process to successfully control viral contamination. In addition, the inactivation models deduced from MNV and TV viruses were challenged with experimental HuNoV GII.4 infectivity resulting in bias factors <1 for all treatment conditions. This finding validates the proposed models for the conservative estimation of HuNoV inactivation. Our work offers a blueprint for moving forward with inactivation studies using the HIE system, which provides useful practical information on optimum treatments for the best public health outcomes.

This study investigated the effects of low-pressure cold plasma on the inactivation of Bacillus cereus vegetative cells and spores in an inert matrix (borosilicate glass slide) and in rice grains, using oxygen as ionization gas. Greater reductions in B. cereus counts were observed in vegetative cells rather than spores. The experimental data obtained show that both the power of the plasma treatment and the matrix proved to be determining factors in the inactivation of both the spores and vegetative cells of B. cereus. To characterize the inactivation of B. cereus, experimental data were accurately fitted to the Weibull model. A significant decrease in parameter “a”, representing resistance to treatment, was confirmed with treatment intensification. Furthermore, significant differences in the “a” value were observed between spores in inert and food matrices, suggesting the additional protective role of the food matrix for B. cereus spores. These results demonstrate the importance of considering matrix effects in plasma treatment to ensure the effective inactivation of pathogenic microorganisms, particularly in foods with low water activity, such as rice. This approach contributes to mitigating the impact of foodborne illnesses caused by pathogenic microorganisms.

The Bacillus cereus group represents a serious risk in powdered and amylaceous foodstuffs. Cold plasma (the fourth state of matter) is emerging as an alternative effective nonthermal technology for pasteurizing a wide range of matrices in solid, liquid, and powder form. The present study aims to evaluate the mechanisms involved in Bacillus cereus inactivation via cold plasma, focusing on (i) the technology’s ability to generate damage in cells (at the morphological and molecular levels) and (ii) studying the effectiveness of cold plasma in biofilm mitigation through the direct effect and inhibition of the biofilm-forming capacity of sublethally damaged cells post-treatment. Dielectric barrier discharge cold plasma (DBD-CP) technology was used to inactivate B. cereus, B. thuringiensis, and B. mycoides under plasma power settings of 100, 200, and 300 W and treatment times ranging from 1 to 10 min. Inactivation levels were achieved in 2–7 log10 cycles under the studied conditions. Percentages of sublethally damaged cells were observed in a range of 45–98%, specifically at treatment times below 7 min. The sublethally damaged cells showed poration, erosion, and loss of integrity at the superficial level. At the molecular level, proteins and DNA leakage were also observed for B. cereus but were minimal for B. mycoides. Biofilms formed by B. cereus were progressively disintegrated under the DBD-CP treatment. The greater the CP treatment intensity, the greater the tearing of the bacteria’s biofilm network. Additionally, cells sublethally damaged by DBD-CP were evaluated in terms of their biofilm-forming capacity. Significant losses in the damaged cells’ biofilm network density and aggregation capacity were observed when B. cereus was recovered after inactivation at 300 W for 7.5 min, compared with the untreated cells. These results provide new insights into the future of tailored DBD-CP design conditions for both the inactivation and biofilm reduction capacity of B. cereus sensu lato species, demonstrating the effectiveness of cold plasma and the risks associated with sublethal damage generation.

High-pressure processing (HPP) enhances food safety and shelf life by inactivating microorganisms and preserving food quality, yet its effectiveness in low-humidity environments has not been evaluated. This study investigated the effects of HPP at 500 MPa for 15 min across varying hydration levels (15, 30, 60, 77 %) on rice bran (RB), aiming to identify microbial effectiveness, besides techno-functional and physicochemical properties. HPP effectively reduced mesophilic bacteria, molds and yeast of RB at > 15 % hydration level, achieving reductions of up to 4 logarithmic cycles in the latter, nearing the detection limit of the method. However, it did not significantly impact spore inactivation. HPP treatment of ≥ 30 % hydrated RB induced particles aggregation and a honeycomb formation. The interaction between hydration and HPP treatment significantly affected the distribution of total dietary fibers, with an increase in soluble dietary fiber from 8.73 g/100 g to 11.03 g/100 g after HPP treatment at 15 % hydration level. Protein solubility was enhanced by hydration (15, 30 and 60 %), and peroxide values decreased after HPP treatment at low hydration (≤30 %) but increased when applied to high hydrated (>30 %) RB. Emulsifying activity decreased upon HPP treatment of highly hydrated RB (≥60 %), but more stable emulsions were achieved after HPP, regardless of the hydration level. Therefore, this study highlights the potential of HPP as a sustainable approach to enhance the utilization of rice bran in food applications, addressing existing knowledge gaps regarding its processing under different moisture conditions.

Consumers are driving food production toward the use of natural preservatives and minimal processing technologies. Green tea extract (GTE) at low concentration could be combined with high pressure processing (HPP) for reduced treatment times and quality impact on foods in a hurdle concept for synergistic effects on foodborne viral pathogens, specifically human norovirus and hepatitis A virus (HAV). Viral inactivation by HPP (at 300, 400, and 500 MPa for 5 min) combined with 3.3 mg/mL aged-GTE was initially evaluated in buffer (PBS) against murine norovirus (MNV), a culturable human norovirus surrogate, and HAV. Furthermore, human norovirus inactivation was evaluated by the novel human intestinal enteroid system (HIE) and a capsid integrity binding assay (ISC-RT-qPCR). HPP treatment completely inhibits human norovirus GII.4 infectivity when applied at 500 MPa alone and at 400 MPa combined with aged-GTE. Additional experiments investigated the reduction of MNV and HAV infectivity in apple and horchata juices exposed to combined aged-GTE and HPP treatments. Results demonstrated that the addition of aged-GTE to the juices exposed to HPP significantly inactivated MNV and HAV at reduced holding pressure time. This synergistic effect of aged-GTE combined with HPP treatments represents a hurdle technology that could be exploited as a control measure to improve the food safety of beverages.

The antimicrobial potential of grape extract was assessed in cooked rice against Bacillus cereus. Grape extract efficacy was tested at 1, 5 and 10 mL/L, at pH 4.5, 5.5 and 6.5; and at incubation temperatures simulating different storage scenarios, specifically temperature abuse (10 degrees C), cool chain break (20 degrees C) and optimal B. cereus growth temperature (30 degrees C). Survival curves for grape extract concentration versus time were obtained. The results indicate that antimicrobial activity of grape extract was dependent on temperature, pH and grape extract concentration. A bactericidal effect of the grape extract was shown at concentration levels >= 5 mL/L at all temperatures and pHs studied. Inactivation curves of B. cereus under grape extract exposure were fitted to a Weibull distribution function for 5-10 mL/L grape extract concentration. Observations showed that the higher the incubation temperature and grape extract concentration, the lower the kinetic rate value. In other words, lower resistance of the microorganism to environmental conditions. The maximum inactivation level was 6 log10 cycles after 24 h of exposure at 10 mL/L of grape extract concentration and pH 4.5. Results indicate that the grape extract could be a good additional control measure for preventing Bacillus cereus growth in cooked rice during storage.

Rice due to its high carbohydrate content, is an ideal medium for Bacillus cereus growth, a spore-producing microorganism. The objective of this study was to determine the antimicrobial activity of a grape extract in combination with heat treatments and different pH against B. cereus spores in a rice solution. The survivor data obtained were fitted to the Weibull survival function, and the values of parameters a and b (scale and shape indexes, respectively) were determined. Results showed that the grape extract affected the survival of B. cereus spores at 90 °C and 95 °C, reaching greater logarithmic reductions in acidic pH values. This behaviour was reflected in a parameter of the Weibull survival function which decreased as the temperature increased and at acidic pH values. In addition, a secondary model was developed by relating the logarithm of a to the independent variables (temperature and pH). A global model relating B. cereus inactivation with temperature and pH was developed, and validated by calculating the accuracy factor. The results demonstrate the usefulness of grape extract as a by-product, which can be used as an additional control measure for rice, especially when combined with mild heat treatments and acidic pH values.

Despite the market expansion of plant-based beverages (PBB) there is limited information about what is driven the market and the nutritional status of the existing beverages. The objective was to identify the existing gaps in the PBB market with particular emphasis on their composition and nutritional value. PBB are mainly based on individual flour/powder and blends and sunflower oil is frequently present, besides gellan gum to stabilize the emulsion. In general, PBB are low calorie drinks (10–84 Kcal/ 100 mL), with low amount of saturated fat (0.1–1.90 g/ 100 mL) and fibers, and large variation in proteins (0.1–12 g/ 100 mL). The calcium fortification of PBB is comparable to the calcium levels of whole cow's milk, although the vitamin fortification is low. Analysis reveals that salt and oil reduction, as well as fibers enrichment might drive future innovations.