The aim of this work was to study the interaction of corrugated and plastic materials with pathogenic and spoiling microorganisms frequently associated to fresh produce. The effect of the two packaging materials on the survival during the storage of microorganisms belonging to the species Escherichia coli, Listeria monocytogenes, Salmonella enteritidis, Saccharomyces cerevisiae, Lactobacillus plantarum, Pseudomonas fluorescens, and Aspergillus flavus was studied through traditional plate counting and scanning electron microscopy (SEM). The results obtained showed that cardboard materials, if correctly stored, reduced the potential of packaging to cross-contaminate food due to a faster viability loss by spoilage and pathogenic microorganisms compared to the plastic ones. In fact, the cell loads of the pathogenic species considered decreased over time independently on the inoculation level and packaging material used. However, the superficial viability losses were significantly faster in cardboard compared to plastic materials. The same behavior was observed for the spoilage microorganisms considered. The SEM microphotographs indicate that the reduction of superficial contamination on cardboard surfaces was due to the entrapping of the microbial cells within the fibers and the pores of this material. In addition, SEM data showed that the entrapped cells were subjected to more or less rapid lyses, depending on the species, due to the absence of water and nutrients, with the exception of molds. The latter spoilers were able to proliferate inside the cardboard fibers only when the absorption of water was not prevented during the storage. In conclusion, the findings of this work showed the reduction of cross-contamination potential of corrugated compared to plastic packaging materials used in fruit and vegetable sector. However, the findings outlined the importance of hygiene and low humidity during cardboard storage to prevent the mold growth on packaging.

The floc-forming ability of flocculent strains of Zygosaccharomyces bailii and Z. fermentati, isolated from musts, was tested for susceptibility to proteinase and sugar treatments. Z. fermentati was found highly resistant to the proteolytic enzymes tested, whereas Z. baili was only trypsin-resistant. The inhibition of flocculation by sugars distinguished two types: in Z. fermentati flocculation was completely inhibited by mannose, in Z. bailli by various sugars. By SEM observation, the cell surface of Zygosaccharomyces revealed the presence of a column structure, resulting from fusion of vesicles present on the cell surface.

Physicochemical parameters, microbiota, and sensory profile of 13 samples of ‘Nduja, a typical sausage from Calabria, Southern Italy, were determined. The chemical composition is characterized by a wide variability, confirming the differences between the producers' recipes. A common feature is the presence of fibers and sugars due to the addition of pepper (about 25%). The presence of sugars in the ripened product confirms that the fermentations were incomplete, as evidenced by the low counts of lactic acid bacteria and coagulase negative cocci. No spoilage bacteria were found. It has been verified that the pepper limit microbial growth, lowering pH and Aw in the mixture, so that Nduja may be considered a meat preserve, not a fermented sausage. Total biogenic amines content was <200 mg/kg, mainly cadaverine, histamine, and tyramine. Finally, as regards the sensory aspect, a trained panel identified 12 specific descriptors. Practical applications Although ‘Nduja is produced artisanally and in a circumscribed area, having followed the migratory flows of Calabrian people it is known and diffused worldwide. Despite this diffusion, however, studies of the chemical composition, the microbiological, and the sensory characteristics are poor. This study provides information about the chemical and microbiological composition of different samples of ‘Nduja. The safety aspects, due to the massive addition of peppers, have also been verified. These traits are useful for producers who must guarantee a safe product to consumers. This paper is the first to show the sensory aspects of ‘Nduja in detail, creating a specific sensory profile with proper descriptors. All this information could help in drafting a protocol for Community Protected Geographical Indication when required.