Barbara Speranza

Listeria monocytogenes is one of the most challenging foodborne pathogens for its psychrotrophic nature as well as the ability to grow under a wide range of environmental conditions; thus, food producers and regulatory agencies always search for new strategies to reduce the risk. In this context, predictive microbiology represents a valuable tool for supporting risk assessment and food safety management. This study investigated the time required for a 2-log increase in L. monocytogenes population (t₁₀₀) as an integrated time-to-threshold endpoint and developed a simulation-derived modeling framework combining outputs from the Food Spoilage and Safety Predictor (FSSP) and Pathogen Modeling Program (PMP). After a preliminary analysis based on DoE (Design of Experiments) theory, the dataset was expanded with 300 additional simulations and used to compare different modeling approaches (e.g., nonlinear models and Random Forest regression). The optimized Random Forest showed the best internal predictive performance; temperature and NaCl were the dominant predictors, followed by nitrite and pH, whereas simulation source and initial inoculum showed lower additional contributions. A separate FSSP-specific analysis showed that the inclusion of lactic acid, an input variable of this tool, did not improve the predictive performance of the model. Concerning the accuracy of the model, it is worth mentioning that error increases for high t₁₀₀ values and near the boundaries of the represented environmental space. Nevertheless, t₁₀₀ provides a useful integrated endpoint for combining heterogeneous simulated growth responses. However, the proposed model should be regarded as a simulation-derived metamodel whose performance has been assessed only by an internal cross-validation. Independent validation through challenge tests in representative food matrices is required before its applicability to practical food-safety decision making.

This study investigated the development of a novel ready-to-eat vegetable product based on glasswort from the Apulia region, combining nutritional characterization, natural preservation strategies, and consumer acceptance evaluation. Fresh samples showed a total phenol content of 2648 mg GAE 100 g⁻¹ dw and a total flavonoid content of 413 mg QE 100 g⁻¹ dw. Despite a moderate reduction in phenolic compounds following blanching (~40% and ~26% for total phenols and flavonoids, respectively), substantial levels of bioactive compounds were retained. Blanching also reduced oxalate content (~53%) and increased calcium concentration, suggesting improved mineral bioavailability in the processed product.The RTE-VP was preserved using thyme essential oil (T) and grapefruit seed extract (GFSE) under ordinary atmosphere and modified atmosphere packaging (MAP), and subjected to a microbiological challenge test with Pseudomonas fluorescens and Enterobacter agglomerans at 4°C and 15°C. GFSE demonstrated superior antimicrobial activity, and the combination of MAP and GFSE proved the most effective strategy, maintaining bacterial loads below 5 log CFU g⁻¹ over 90 days at 4°C. Both antimicrobials effectively reduced yellowing during storage. A consumer survey (n = 129) revealed high willingness to try the product (82.2%) and strong interest.

Soil salinization threatens global agricultural productivity, making halotolerant plant growth promoting bacteria (PGPB) crucial for sustainable farming in marginal areas. This study isolated and characterized PGPB from perennial glasswort ( Arthrocaulon macrostachyum ) collected at two sites in Margherita di Savoia, Apulia (Italy), during spring 2023. From rhizosphere and endosphere samples, 110 bacterial isolates (100 rhizobacteria, 10 endophytes) were obtained and characterized. Functional screening revealed: 18 isolates (16%) capable of phosphate solubilization, 25 isolates (23%) for silicon solubilization, 20 isolates (18%) producing indole acetic acid, 34 isolates (31%) producing siderophores, and 50 isolates (45%) demonstrating salt tolerance above 10% NaCl, with 28 isolates (25%) tolerating concentrations up to 17.5%. Using RAPD-PCR differentiation and Principal Component Analysis of PGPB traits, three promising halotolerant candidates were selected: Pseudomonas sp. (105S), Bacillus safensis (80S), and Peribacillus frigotolerans (114S), each exhibiting complementary plant growth promoting characteristics. These isolates represent valuable candidates for future field validation as biofertilizers in salt-affected agricultural systems.

Almond skin is an abundant by-product of almond processing and is recognized for its rich content of dietary fiber, polyphenols, and unsaturated fatty acids along with potential health benefits. This study aimed to evaluate the nutritional composition, prebiotic potential, and microbiota modulation properties of dehydrated almond skin, including its use in 3D-printed functional biscuits. Nutritional analysis revealed high dietary fiber (62.6%) and substantial antioxidant capacity linked to polyphenols. Almond skin supplementation with a concentration ranging from 2.5% to 5.0% significantly enhanced the viability of various probiotic strains during storage, extending their shelf life. Two biscuit formulations, with and without almond skin, were produced and subjected to simulated gastrointestinal digestion (INFOGEST protocol) followed by in vitro fermentation using a minimal gut microbiota model (Bifidobacterium longum, Lactobacillus rhamnosus, Bacteroides caccae, Escherichia coli, Segatella copri, and Clostridioides difficile). Results demonstrated that biscuit enriched with almond skin selectively promoted the growth of beneficial bacteria such as B. longum and L. rhamnosus (from 6.9 to 8.5 log cfu/mL and from 7.8 to 9.0 log cfu/mL, respectively) while suppressing pathogens including C. difficile and E. coli. Moreover, enriched biscuits retained higher polyphenol content and exhibited a favorable macronutrient profile. These findings support the valorization of almond skin as a sustainable functional ingredient offering prebiotic effects and probiotic viability protection, with promising applications in personalized nutrition and gut health management. Further in vivo studies and clinical trials are necessary to confirm these effects and optimize formulations for commercial use.

This research examines how consumers perceive food safety, particularly emphasizing how social media are associated with perceptions and behaviors. An online cross‐sectional survey was conducted with a sample of Italian participants ( n = 505), evaluating, among others, sociodemographic factors, the frequency, and trust in social media usage. Logistic regression analyses were utilized to pinpoint predictors. As a second step, a focus group was done to analyze food safety items with a restricted number of participants. The findings indicated that younger individuals, those with lower educational levels and higher trust in social media, were associated with a higher likelihood of relying on influencers for food safety information. Gender disparities were noted, with women displaying greater susceptibility. In addition, qualitative responses indicated widespread confusion regarding food safety versus other notions like food security or healthy eating, underscoring ongoing gaps in consumer awareness. These results highlight the growing role of digital channels in shaping public comprehension of food safety and point out the necessity for more effective, focused communication strategies. Health organizations and institutions should consider engaging trustworthy online figures while promoting critical evaluation of food‐related content, particularly among vulnerable demographic groups.

A key area of research is the role played by the gut microbiota in the health of sheep during the early period of life; consequently, understanding its complexity may have significant implications for sheep farming. While factors such as diet, age, health status, and environmental conditions are crucial for determining the composition of the gut microbiota, there are very few summaries on the gut microbiota in early life and only a limited number of reviews considering the gut microbiota in adult (sheep) life. Accordingly, after a brief introduction to the generic qualitative and quantitative composition of the gut microbiota in sheep, this review focuses on its development in early life, with primary attention given to the rumen. It then provides an overview of factors that may modulate the microbiota, with a particular focus on prebiotics, probiotics, and synbiotics. The optimisation of these processes in sheep may enhance digestibility, immunity, and overall production efficiency. The review also highlights key challenges associated with the adoption of management strategies based on the integration of microbial approaches in modern livestock systems with the aim of enhancing animal welfare, sustainability, and production efficiency.

Plant growth-promoting bacteria (PGPB) could exert positive effects on plant growth and productivity; however, little is known about the effects of variables during the production of PGPB biomass and how they could affect the performances of these microorganisms. This study investigated the effects of pH, temperature, and culture age on the growth of promising PGPBstrains, Bacillus sp. 36M and Stenotrophomonas sp. 20P, isolated from the rhizosphere of durum wheat. A fractional factorial 2^k design was applied to evaluate bacterial growth under varying conditions (pH 5.0–7.5; 15–35 °C; 24–72 h precultures). Multifactorial ANOVA revealed that all independent variables and their interactions significantly affected cell concentration (p < 0.05). Bacillus sp. 36M exhibited optimal growth when inoculated from 24 h cultures and incubated under moderate conditions (15 °C, pH 7.5), whereas Stenotrophomonas sp. 20P showed higher viability with 72 h cultures. These results demonstrate that the inoculum physiological state is a critical determinant of PGPB stress tolerance and should be specifically optimized for each strain. The greater technological robustness of Stenotrophomonas sp. 20P suggests its suitability for biofertilizer formulations requiring extended shelf-life or application under variable environmental conditions. In conclusion, this work provides a quantitative framework for tailoring PGPB production protocols to maximize field performance in sustainable agriculture.

Beneficial bacteria adapted to hypersaline conditions represent a promising biotechnological tool for enhancing crop productivity in salt-affected agricultural systems, particularly as soil salinization constitutes an increasingly critical global challenge impacting extensive cultivated areas. Halotolerant Plant Growth Promoting Bacteria (PGPB) can stimulate plant growth by increasing soil carbon, nitrogen, and mineral availability and uptake. The present study aimed to isolate, characterize, and select potential halotolerant PGPB from Cakile maritima plants collected in two sites located in Margherita di Savoia, in Apulia. This coastal region harbors a unique and taxonomically diverse indigenous microbiota that remains largely unexplored, potentially serving as a valuable reservoir of beneficial microorganisms adapted to high salinity. Microbiological sampling was conducted in triplicate at three phenological stages (seeding, vegetative growth, and anthesis) of the plant’s life cycle in 2023. A total of 180 isolates (150 rhizobacteria and 30 endophytes) were recovered and characterized using morphological, biochemical, and molecular approaches. Halotolerant isolates exhibiting plant growth promoting traits, including phosphate and silicon solubilization, indole acetic acid and siderophore biosynthesis, ammonia production, and drought and salt tolerance, were selected and genotypically identified. The main result was the selection of three promising isolates (assigned to the genera Pantoea and Bacillus ) warranting further validation under field conditions.