Filomena Nazzaro

Biofilms in food-processing environments present multifaceted challenges for food safety, quality, and public health. These microbial communities, forming on a variety of surfaces within food-processing facilities, are responsible for persistent contamination, increased tolerance to cleaning and disinfection, and the transmission of spoilage organisms and pathogens. This review provides a comprehensive overview of current knowledge on the formation, ecological organization, persistence, and impact of mixed-species biofilms in food systems, emphasizing their central role in contamination control and food safety management. While recent advances in analytical technologies have improved our understanding of their complexity and resilience, significant knowledge gaps remain regarding their behavior under real-world industrial conditions. The review highlights the limitations of traditional eradication-based approaches and discusses innovative strategies for monitoring, controlling, and preventing biofilm-associated risks in modern food production systems.

Citrus processing by-products represent a sustainable source of bioactive plant complexes with potential applications in intestinal health. This study investigated the effects of standardized food-grade orange (OE) and lemon (LE) pomace extracts and their simulated gastrointestinal digestates (DIGs) on intestinal epithelial responses and selected probiotic strains. Caco-2 cells were used to assess cytotoxicity, epithelial wound closure, and, in differentiated monolayers challenged with lipopolysaccharide (LPS), extracellular levels of SOD2, catalase, Nrf2, IL-6, IL-8, TNF-α, and IL-1β. In parallel, the effects of OE, LE, and their corresponding DIGs on the growth and cell-surface hydrophobicity of four probiotic lactic acid bacteria were evaluated. OE and LE DIGs were non-cytotoxic and promoted epithelial wound closure in a concentration- and time-dependent manner. In LPS-challenged monolayers, both DIGs counteracted alterations in extracellular oxidative stress-related proteins and reduced pro-inflammatory cytokine levels without affecting cell viability. OE and LE also produced strain-dependent effects on probiotic growth and cell-surface hydrophobicity, which were modified by gastrointestinal digestion. Overall, these findings extend previous evidence on the intestinal bioactivity of Citrus pomace-derived plant complexes and support their further investigation as sustainable food-grade ingredients for gut health applications.

Interpretable-by-design architectures, such as Concept-Bottleneck Models (CBMs), are essential for trustworthy AI under regulations like the EU AI Act. While classical CBMs rely on costly expert labels, recent automated methods use vision–language models for concept discovery. However, whether automation preserves interpretability remains an open question. We systematically evaluate four automated methods (LF-CBMs, LaBo, PCBMs, and VLG-CBMs) against an expert-supervised CBM using fine-grained binary classification (Amanita muscaria vs. Boletus edulis) from the FungiTastic dataset. Although automated methods match expert accuracy, they systematically fail with regard to two key interpretability requirements: concept atomicity and instance-level grounding. Specifically, automated concepts conflate multiple morphological properties, yield scores ungrounded in visual evidence, and produce biologically implausible class-concept associations; a specific failure mode, cross-class contamination, is one that the expert-supervised vocabulary avoids by construction, though expert supervision remains subject to its own annotation and validation risks. We characterize four distinct failure modes across these architectures, concluding that automated concept discovery cannot yet substitute domain expert supervision in safety-critical tasks where explanation fidelity is a functional requirement alongside predictive accuracy.

Agricultural and horticultural by-products represent an underexploited source of valuable bioactive compounds that can contribute to the development of more sustainable production systems. This study investigated the chemical composition and biological activities of the essential oil obtained from the horticultural byproducts of Artemisia dracunculus. The waste aerial biomass was subjected to steam distillation, and the essential oil was characterized by gas chromatography–mass spectrometry. Its antioxidant, α-amylase and α-glucosidase inhibitory, phytotoxic, antibacterial, and antibiofilm activities were subsequently evaluated. The essential oil was characterized as an estragole-rich chemotype (70.17%), with trans-β-ocimene and cis-β-ocimene as other main constituents. The essential oil showed moderate antioxidant activity and measurable enzyme inhibitory activity and, despite showing limited effects on seed germination, it significantly inhibited radical elongation in selected plant species. Furthermore, it demonstrated excellent antibiofilm activity, significantly reducing the metabolic activity of mature cells of bacteria associated with biofilm formation: Listeria monocytogenes, Pseudomonas aeruginosa, Escherichia coli, Acinetobacter baumannii, Klebsiella pneumoniae and Staphylococcus aureus. The results demonstrate how horticultural by-products from A. dracunculus maintain a chemical profile comparable to conventional plant material and represent a valuable source of bioactive compounds with promising potential for sustainable agri-food applications.

Introduction: The fatty acid composition and multifunctional biological activities of seed oils from Brassica juncea (L.) Czern. (Indian mustard), Passiflora edulis Sims (passion fruit), and Persea americana Mill. (avocado) were investigated. GC–MS analysis revealed distinct lipid profiles among the oils. Results and discussion: Avocado seed oil was dominated by oleic acid (92.37%), whereas Indian mustard oil contained high levels of erucic acid (48.23%) and α-linolenic acid (18.29%). Passion fruit seed oil was characterized by linoleic acid (54.03%), elaidic acid (20.04%), and stearic acid (15.85%). The unsaturated/saturated fatty acid ratio was highest in avocado oil (18.57), followed by Indian mustard (13.93) and passion fruit oil (3.81). Biological assays revealed differentiated functional properties. Passion fruit oil exhibited the strongest antioxidant activity, with a DPPH IC ₅₀ of 2.55 μg/mL and showed the highest butyrylcholinesterase inhibition (63.3%). Indian mustard oil demonstrated the greatest anti-arthritic activity (IC ₅₀ = 6.61 μg) and a high ABTS antioxidant capacity (5.18 μmol TE/g). Avocado oil displayed notable acetylcholinesterase inhibition (58.8%) and selective tyrosinase inhibitory activity (IC ₅₀ = 13.95 μg). Antibiofilm assays showed strain- and stage-dependent effects, with avocado oil producing a consistent inhibition of mature biofilm structure (77.80% against Listeria monocytogenes , and 68.76% against Pseudomonas aeruginosa ) and inhibitory activity against microbial sessile cells, reaching 47.93% against P. aeruginosa and 53.63% against Escherichia coli . All three oils positively influenced the growth of selected probiotic strains. Molecular docking, correlation analysis, and principal component analysis highlighted distinct relationships between fatty acid composition and biological activities, suggesting complementary functional profiles and application- specific potential. This study provides the first comparative evaluation of the fatty acid composition, enzyme inhibitory properties, antibiofilm activity, and probiotic-supporting effects of these three seed oils, highlighting their potential as multifunctional ingredients for food, nutraceutical, cosmetic, and health-related applications.

Agricultural and horticultural by-products represent an underexploited source of valuable bioactive compounds that can contribute to the development of more sustainable production systems. This study investigated the chemical composition and biological activities of the essential oil obtained from the horticultural byproducts of Artemisia dracunculus. The waste aerial biomass was subjected to steam distillation, and the essential oil was characterized by gas chromatography-mass spectrometry. Its antioxidant, α-amylase and α-glucosidase inhibitory, phytotoxic, antibacterial, and antibiofilm activities were subsequently evaluated. The essential oil was characterized as an estragole-rich chemotype (71.88%), with trans-β-ocimene and cis-β-ocimene as other main constituents. The essential oil showed moderate antioxidant activity and good enzyme inhibitory activity and, despite showing limited effects on seed germination, it significantly inhibited radical elongation in selected plant species. Furthermore, it demonstrated excellent antibiofilm activity, significantly reducing the metabolic activity of mature cells of bacteria associated with biofilm formation: Listeria monocytogenes, Pseudomonas aeruginosa, Escherichia coli and Staphylococcus aureus. The results demonstrate how horticultural by-products from A. dracunculus maintain a chemical profile comparable to conventional plant material and represent a valuable source of bioactive compounds with promising potential for sustainable agri-food applications.

This study aimed to characterize the chemical composition of essential oil (EO) obtained by hydrodistillation from leaves of Tunisian Pistacia lentiscus (yield: 0.18%) and to evaluate its antibiofilm, antioxidant, and enzyme‐inhibitory activities. The composition was determined by GC–MS and compared with other Tunisian EOs reported in the literature using multivariate analysis. The EO was rich in α‐pinene (19.95%) and terpinen‐4‐ol (15.49%). Antibiofilm activity was assessed by crystal violet and MTT assays against five bacterial strains (three Gram‐negative and two Gram‐positive), with Escherichia coli and Pseudomonas aeruginosa being the most sensitive. Enzyme inhibition was evaluated spectrophotometrically against cholinesterases, α‐glucosidase, and α‐amylase. Acetylcholinesterase showed the highest sensitivity (IC ₅₀ = 1.10 mg/mL). Overall, the EO represents a promising natural source of antibiofilm agents and enzyme inhibitors, with potential applications in the control of bacterial biofilms and in targeting enzymes relevant to metabolic and neurodegenerative disorders.

This study analyzed five essential oils derived from plants that, despite sharing the common “pepper”, belong to distinct genera and botanical families, which are increasingly recognized for their multifunctional bioactivities, including antioxidant, neuroprotective, and antimicrobial properties. In particular, five commercially available essential oils obtained from Pimenta dioica, Piper nigrum, Schinus molle, Schinus terebinthifolia, and Zanthoxylum armatum were chemically characterized and systematically evaluated for their biological potential. Gas chromatography–mass spectrometry analysis revealed distinct phytochemical profiles dominated by phenylpropanoids, monoterpenes, or oxygenated monoterpenes, which were further discriminated by multivariate statistical analysis. The essential oils were assessed in vitro for antioxidant capacity (DPPH and TEAC assays), anti-arthritic activity (protein denaturation inhibition), neuroprotective effects (acetylcholinesterase, butyrylcholinesterase, and tyrosinase inhibition), and antibiofilm activity against clinically relevant Gram-positive and Gram-negative bacteria. All oils exhibited measurable antioxidant and enzyme inhibitory activities, with P. dioica and P. nigrum showing the most balanced redox and neuroprotective profiles. Significant antibiofilm effects were observed during biofilm formation, while mature biofilms displayed strain- and oil-dependent susceptibility, highlighting differences between biomass reduction and metabolic inhibition. Overall, the results demonstrate that pepper-derived essential oils possess complementary and multi-target bioactivities strongly linked to their chemical composition, supporting their potential application as natural agents in food, pharmaceutical, and biomedical fields.

The valorization of agri-food residues is crucial for advancing circular bioeconomy strategies and mitigating environmental impacts. Turnip greens (Brassica rapa subsp. sylvestris) are a traditional vegetable cultivated in southern Italy. While the edible portions include flower sprouts, buds, and young leaves, the more leathery leaves and stems are typically discarded. These wastes represent valuable sources of compounds with antioxidant and antimicrobial potential. This study aims to develop the extraction of phenolic compounds from turnip green residues using two techniques: silent maceration and ultrasound-assisted extraction (UAE). Ethanol was selected over methanol as a food-safe alternative solvent, with preliminary tests confirming equivalent efficiency. A Design of Experiments (DoE) approach was applied to both leaves and stems to assess the effects of solvent composition, solvent-to-matrix ratio, and extraction time on Total Phenolic Content and Trolox Equivalent Antioxidant Capacity. DoE results identified UAE as the most effective method for stems, while for leaves, the solvent-to-dry-mass ratio was the key parameter. HPLC-DAD analysis was performed to identify and quantify the phenolic acids in selected extracts. The antibacterial activity of these extracts against biofilms of six pathogenic strains was evaluated using crystal violet and MTT assays, confirming efficacy in both biofilm formation and mature stages.

Microbial biofilms pose significant medical and industrial challenges due to their resistance to conventional antimicrobials, accounting for 40–80% of bacteria in various environments. This resistance primarily results from the extracellular polymeric matrix, a protective network of sugars, proteins, and other molecules produced by bacteria. The matrix restricts antibiotic penetration, facilitates microbial communication, and retains nutrients. Consequently, novel strategies to counteract biofilms are under investigation. Fatty acids have emerged as promising prebiotic agents, defined as substances that stimulate the growth of beneficial bacteria. These compounds can disrupt biofilm structure and increase microbial susceptibility to treatment. Short- and medium-chain fatty acids demonstrate direct antimicrobial activity and can alter microbial community composition, thereby inhibiting biofilm formation in several pathogens, including oral species. For instance, omega-3 fatty acids effectively inhibit Staphylococcus aureus and Pseudomonas aeruginosa biofilms through membrane disruption and quorum sensing (QS) inhibition. Additionally, long-chain fatty acids, particularly omega-3 and omega-6 polyunsaturated fatty acids, exhibit anti-inflammatory and antibacterial properties. This review synthesises current evidence on fatty acids as prebiotics, emphasising their mechanisms of action and therapeutic potential against drug-resistant biofilm-associated infections. Given the increasing prevalence of antimicrobial resistance, unsaturated and essential fatty acids rep-resent promising candidates for innovative biofilm-control strategies.