The aim of this study was to obtain membranes with antimicrobial activity presenting a complex sandwich-type structure. The outer layers are comprised of poly(methyl methacrylate) membranes, whereas the inner active layer consists of a modified commercial membrane to achieve antimicrobial properties. This activity arises due to the presence of silver nanoparticles in a material with a hybrid composition deposited on a commercial membrane. This hybrid material consists of polymer colloids and multiwall carbon nanotubes used for both the stabilization of the active layer by the interconnections of the polymer particles and as active component. The filtration tests revealed a good stability of the materials and an increased hydrophilicity of the hybrid membranes. The antimicrobial properties have been evaluated using Staphylococcus aureus and Escherichia coli, and have been correlated with the content and migration rate of silver ions.

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Taking into consideration the circular economy context, from cereal production and processing result by-products and residues which can be transformed into the new raw materials. Straw, husks, brans, flours, bread waste, confectionary waste, so on, can be re-used using different processes such as: extraction, fermentation, microorganism cultivation, for obtaining added value products. These new products obtained can be: biofuels, enzymes, biodegradable material food contact, single cell protein, bio-adsorbent, nanoparticles, bio alcohol, bioactive compounds like fibres, phytochemicals, minerals, so on. This paper is a short review regarding sharing knowledge and good practices in implementing circular economy within food systems, specifically, cereal supply chain.

Plasmonic silver film was directly generated on a variety of substrates through a facile and environmentally friendly method, which involves a UV-photoreduction process without any reducing or stabilizing agent and requiring no thermal step. Topcoated films of unprotected silver nanoparticles (3-11 nm) were generated from hydroalcoholic AgNO 3 solution and directly on glass substrates or food packaging plastic wraps, low density polyethylene film, and polyvinyl chloride. The natural antibacterial activity of the material was evaluated. The correlation between silver migration and antimicrobial activity of silver-functionalized substrates against pure strains of gram-negative bacteria (Escherichia coli) and gram-positive bacteria (Staphylococcus aureus) was demonstrated. By way of illustration, food plastic wraps top-coated in this way exhibited a high antibacterial activity. The metal nanoparticle film obtained in this way was characterized and the influence of several parameters (fluence, exposure, silver nitrate concentration, and nature of the free radicals generator) on their formation was studied. Moreover, by shaping the actinic beam with an appropriate device, it is very easy to pattern the brown yellow silver nanofilm or to print messages in plain text.

PLA-based composites containing CF in the range 0 to 10 wt. % were prepared by melt mixing technique. The prepared composites were investigated in terms of processability, chemical structure (by Attenuated total reflectance - Fourier Transform Infrared - ATR-FT-IR analysis), thermal (Differential Scanning Calorimetry - DSC), optical properties (using UV-Vis spectrometry), barrier and migration in distilled water. Also, the behaviour of PLA based composites at sterilization was performed by examination the changes in their chemical structure. This study shows the feasibility of improving of PLA properties by using cellulose fibres, designed for flexible food packaging.

Preventing and controlling the spread of multidrug-resistant (MDR) bacteria implicated in healthcare-associated infections is the greatest challenge of the health systems. In recent decades, research has shown the need for passive antibacterial protection of surfaces in order to reduce the microbial load and microbial biofilm development, frequently associated with transmission of infections. The aim of the present study is to analyze the efficiency of photocatalytic antimicrobial protection methods of surfaces using the new photocatalytic paint activated by light in the visible spectrum. The new composition is characterized by a wide range of analytical methods, such as UV-VIS spectroscopy, electron microscopy (SEM), X-ray powder diffraction (PXRD) or X-ray photoelectron spectroscopy (XPS). The photocatalytic activity in the UV-A was compared with the one in the visible light spectrum using an internal method developed on the basis of DIN 52980: 2008-10 standard and ISO 10678—2010 standard. Migration of metal ions in the composition was tested based on SR EN1186-3: 2003 standard. The new photocatalytic antimicrobial method uses a type of photocatalytic paint that is active in the visible spectral range and generates reactive oxygen species with inhibitory effect against all tested microbial strains.

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Heavy metals are elements who exist naturally in the environment, but rapid urbanization and industrialization led to increased levels of these metals. These metals can reach the human body through food, water or air, where they have the property to accumulate in various tissues and organs for long periods of time and to produce serious effects on certain organs and the proper functioning of the body. Studies have also shown that heavy metals can have important effects, including on plants or animals. Their toxicity is dependent on factors such as dose, route of exposure, time of exposure, level of concentration, as well as age, gender, genetics, and nutritional status of exposed individuals. There is a growing interest from researchers to detect various physical, physical-chemical or microbiological methods to reduce or eliminate the presence of these metals, especially from surface or wastewater, which are mainly responsible for food contamination. This chapter present the main characteristics of heavy metals, the sources of contamination of exposure, as well as their toxicity on some environmental segments and especially on living organisms.