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The growing interest in vegetable proteins, namely those derived from lupins, has raised concerns over potential safety risks associated with these food products. Lupin serves as the main host for the mycotoxin-producing fungus called Diaporthe toxica. This species, which is associated with animal diseases, has been scarcely characterized. Recently, phomopsin-A (PHO-A), the main mycotoxin produced by D. toxica, was found to be harmful to humans. Therefore, this study aimed at characterizing D. toxica growth and spore formation both in vitro and on lupin samples. In addition, the production of PHO-A and alkaloids was investigated on lupin beans by using three different inoculation methods. Particularly, growth and spore production were evaluated on different media, while PHO-A and alkaloid production were determined by means of µSPE extraction followed by UHPLC-MS/MS and HPLC-MS/MS, respectively. The results have demonstrated differences in growth on different media, with potato and oat-flakes-based media being the best options. Conversely, D. toxica was not able to produce spores on agar media, but only on lupin beans. Moreover, a thorough analysis of PHO-A production revealed an increase over time, reaching values up to 1082.17 ppm after 21 days on artificially rehydrated samples. On the other side, the analysis of alkaloids revealed impressive results, as this species produced great quantities of the quinolizidine alkaloids (QA) that are normally present in lupin seeds such as lupanine, sparteine, multiflorine, and hydroxylupanine. On balance, considering these results, different metabolic pathways were demonstrated in D. toxica, which are not adequately described in the existing literature. These data are of paramount importance to deepen the knowledge about a fungal species that is important to ensure the safety of lupin and lupin-based products.

Phomopsin A (PHO-A), a potent mycotoxin produced by the pathogenic fungus Diaporthe toxica, is a growing international concern due to the high toxicity and prevalence in lupin plants, a vital source of food and feed. This hexapeptide mycotoxin has raised health concerns for both animals and humans, prompting regulatory bodies to set maximum allowable levels in lupin products.Different analytical methods have been developed for PHO-A detection, including Enzyme-Linked Immuno-Sorbent Assay (ELISA) and high-performance liquid chromatography (HPLC) coupled with different detectors; they often lack sensitivity and selectivity required to meet maximum regulatory limits (MRL). In this work, we present a robust and sensitive method for PHO-A quantification and determination, developed using ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS).This method incorporates a selective clean-up step using Micro Solid Phase Extraction (µ-SPE) to efficiently purify samples, ensuring a rapid, efficient, and selective recovery of PHO-A from the complex lupin matrix. The clean-up step not only helps in achieving lower detection limits but also minimizes matrix effects and contamination. The proposed method was validated following international guidelines, demonstrating reliable recovery, matrix effects, linearity, accuracy, and precision.Additionally, this method was successfully applied to artificially contaminated Lupinus albus L. samples, confirming the suitability for assessing PHO-A contamination. This analytical approach fills a critical gap in the literature by providing a specific, sensitive, and selective method for PHO-A analysis, contributing to the safety of lupin products and field monitoring.

Biofilms represent an evolutionary form of life, which translates from life in free-living cells to a community lifestyle. In natural habitats, biofilms are a multispecies complex, where synergies or antagonisms can be established. For example, Listeria monocytogenes and Pseudomonas fluorescens are associated with a dual-species biofilm that is widespread in dairy plants. In food plants, multiple strategies are devised to control biofilms, including natural compounds such as essential oils (EOs). In this respect, this study evaluated the effectiveness of Thymbra capitata (L.) Cav. EO and Cinnamomum zeylanicum (CEO) against a dual-species biofilm of L. monocytogenes and P. fluorescens, mimicking dairy process conditions. Based on Minimum Inhibitory Concentrations results, the EOs concentration (10 µL/mL) was chosen for the antibiofilm assay at 12°C on polystyrene (PS), and stainless steel surfaces for 168 h, using a Ricotta-based model system as culture medium. Biofilm biomass was assessed by crystal violet staining, and the planktonic and sessile cells were quantified in terms of Log CFU/cm2. Results showed that CEO displayed the greatest antibiofilm activity, reducing significantly (P

The increased resistance of bacteria to antimicrobials, as well as the growing interest in innovative and sustainable alternatives to traditional food additives, are driving research towards the use of natural food preservatives. Among these, hydrolates (HYs) have gained attention as “mild” alternatives to conventional antimicrobial compounds. In this study, the response of L. monocytogenes ATCC 7644 exposed to increasing concentrations of Coridothymus capitatus HY (CHY) for 1 h at 37 °C was evaluated by means of Phenotype Microarray, modelling the kinetic data obtained by inoculating control and treated cells into GEN III microplates, after CHY removal. The results revealed differences concerning the growth dynamics in environmental conditions commonly encountered in food processing environments (different carbon sources, pH 6.0, pH 5.0, 1–8% NaCl). More specifically, for treated cells, the lag phase was extended, the growth rate was slowed down and, in most cases, the maximum concentration was diminished, suggesting the persistence of stress even after CHY removal. Confocal Laser Scanner Microscopy evidenced a diffuse aggregation and suffering of the treated cells, as a response to the stress encountered. In conclusion, the treatment with HY caused a stressing effect that persisted after its removal. The results suggest the potential of CHY application to control L. monocytogenes in food environments.