Cold plasma is a new technology of promising potential to use as a part of technological extraction lines constructed to implement green chemistry solutions or simply to reduce resources in solvent-based extraction lines. The present study was undertaken to verify the effect of nitrogen cold plasma pre-treatment conducted for 8 min (20 kHz) on the content of antioxidants, antioxidant activity, the profile of volatile compounds, microbial count, pH and color measured in herb extracts (12 herbs: Echinacea purpurea; Salvia officinalis; Urtica dioica; Polygonum aviculare; Vaccinium myrtillus; Taraxacum officinale; Hypericum perforatum; Achillea millefolium; Sanguisorba officinalis; Leonurus cardiaca; Ballota nigra; Andrographis paniculata) obtained with its usage. The surface morphology of extracted herbs was examined as well. Herbs used for extraction were ground and suspended in water before cold plasma treatment, which is a novel approach not studied before. Most plasma-treated extracts were characterized by a higher content of polyphenols (11 out of 12). Content of flavonoids and anthocyanins increased in four extracts and in the case of anthocyanins was significantly higher in comparison to control (up to 77%). The antioxidant activity measured at least by one method (ABTS, DPPH, FRAP) was also higher in nine plasma-treated solutions. Moreover, plasma decreased total aerobic bacteria, affected the color and increased pH of the extracts. The surface structure of the plant material after the extraction process was significantly damaged, which probably led to a higher extraction yield of bioactive compounds and in consequence to the higher antioxidant activity of extracts obtained with the cold plasma treatment.

Since the discovery of memristors, their application in computing systems utilizing multivalued logic and a neuromimetic approach is of great interest. A thin film device made of methylammonium bismuth iodide exhibits a wide variety of neuromorphic effects simultaneously, and is thus able to mimic synaptic behaviour and learning phenomena. Standard learning protocols, such as spike-timing dependent plasticity and spike-rate dependent plasticity might be further modulated via metaplasticity in order to amplify or alter changes in the synaptic weight. Moreover, transfer of information from short-term to long-term memory is observed. These effects show that the diversity of functions of memristive devices can be strongly affected by the pre-treatment of the sample. Modulation of the resistive switching amplitude is of great importance for the application of memristive elements in computational applications, as additional sub-states might be utilized in multi-valued logic systems and metaplasticity and memory consolidation will contribute to the development of more efficient bioinspired computational schemes.

Double-layered active films based on furcellaran (1st layer—FUR), chitosan, and gelatin hydrolysates (2nd layer—CHIT+HGEL) were successfully prepared. Bioactive ingredients were added to the 1st film layer: AgNPs, which were synthesized in situ with yerba mate extract; montmorillonite clay (MMT); and different loads of ethanolic curcumin (CUR) extract enriched with rosemary essential oil (REO). SEM images confirmed the presence of AgNPs with a size distribution of 94.96 ± 3.33 nm throughout the films, and AFM and SEM photos indicated that the higher substance concentrations had rougher and more porous film microstructures. However, the water vapor transmission rate was reduced only at the lowest load of this ingredient. Despite the tensile strength of the films having decreased, the incorporation of the compounds showed a tendency towards reducing the modulus of elasticity, resulting in a lower stiffness of the composites. The addition of CUR and AgNPs improved the UV light barrier properties of the materials. The presented films showed quick reactions to changes in the pH value (from orange to red along with an increase in pH from 2 to 10), which indicates their potential use as indicators for monitoring the freshness of food products. Composite No. 2 showed the highest antimicrobial potential, while none of the presented films showed an antifungal effect. Finally, the antioxidant activities of the films increased dramatically at higher AgNP and CUR loads, suggesting an outstanding potential for active food packaging applications.

To improve the quality of multi-layer film, four-layer films based on furcellaran and active ingredients: gelatin hydrolysate, curcumin, capsaicin, montmorillonite and AgNPs, were produced in an innovative manner. The films were characterised by SEM and AFM analysis. Along with an increase in the concentration of active ingredients, the structure of the film becomes less homogeneous, which may affect the functional properties. The objective of the study was to analyse changes in the functional properties of the newly-obtained films and to verify their potential as packaging materials for fish products. With the increase in active ingredient concentration, water properties also improved, but there were no noticeable significant effects on mechanical properties. For antioxidant properties, the obtained values were within 1.04-2.74 mM Trolox/mg (FRAP) and 7.67-40.49% (DPPH). The obtained multi-layer films were examined with regard to the shelf-life of salmon. For this purpose, salmon fillets were packed in films having good antioxidant and functional properties. The films were effective in microorganism growth inhibition responsible for fillet spoilage during storage. The microorganism number in the active film-stored samples was lower by 0.13 log CFU/g on day 12 versus the control. However, film application did not retard lipid oxidation in the salmon fillets. Nonetheless, the films show great potential as active packaging materials, extending the shelf-life of the packed foods.