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In the light of the problem of antibiotic resistance, the use of combined alternative therapies in combatting bacteria-related disorders has gained popularity. Bacteriophages are one element implemented in new combination therapy. Stevia rebaudiana is known to have antimicrobial activity and regarded as potentially having a synergistic effect with bacteriophages. Therefore, possible interactions of lytic bacteriophages (MS2, T4 and Phi6) with acetone and methanol S. rebaudiana extracts (SRa and SRm) in the bacterial environment were examined.

The goal of this research was to analyse the synergistic effect between selected plant extracts with zinc oxide particles, and zinc stearate. The influence of ZnO on the antimicrobial effectiveness of the selected extracts was confirmed in previous research carried out by the authors. However, the impact of zinc stearate on extract activity has yet to be analysed. The aim was to cover PLA films with active coatings based on hydroxy-propyl-methyl-cellulose (HPMC), or/and ethyl cellulose (EC) containing plant extracts and ZnO which has a synergistic effect. An additional aim was to use a CO2 extract of raspberry seed (RSE) with zinc stearate as active additives within the coatings. An examination of the antimicrobial properties (against Staphylococcus aureus, Escherichia coli, Bacillus subtilis, Pseudomonas syringae and Φ6 bacteriophage) of the covered films, as well as an investigation of layer presence with regards to PLA morphology (SEM, ATR-FTIR analysis) was carried out. The research work that was performed indicated that black chokeberry extract (ChE) and zinc oxide particles were effective against S. aureus, P. syringae and B. subtilis strains. In addition, the ChE with zinc stearate (ZnSt) was active against all analysed strains. The HPMC with ChE and ZnO as additives had antimicrobial properties against S. aureus, P. syringae and E. coli strains. The ChE was found to inhibit the growth of all of the analysed bacterial strains. When considering the coatings based on EC with the CO2 extract of raspberry seed (RSE) and ZnO, it was noted that they were only active against Gram-negative bacteria. The results of the experiments confirmed that AC1 (EC with RSE with ZnO) and AC2 (EC with RSE with ZnSt) coatings were not active against a phi6 bacteriophage. The HPMC coating containing the AC3 layer (ChE and ZnO) eliminated Φ6 particles, confirming its antiviral properties. In addition, the presence of the active (AC1, AC2 and AC3) coatings was confirmed by SEM and FTIR analysis. [ABSTRACT FROM AUTHOR]

The aim of the presented work was to functionalize a blend based on polyhydroxyalkanoate (PHA): poly(hydroxybutyrate (PHB) with poly(lactic acid) (PLA) and a mixture of three selected herb extracts, namely, Hypericum L., Urtica L. and Chelidonium L., (E), zinc oxide (ZnO) and a combined system (EZnO), produced via extrusion. Before processing with bioresin, the natural modifiers were characterized using thermal analysis, FTIR and antimicrobial tests. The results revealed interactions between the extracts and the filler, leading to higher thermal stability in EZnO than when using E alone. Moreover, the mixture of extracts exhibited antimicrobial properties toward both Gram-negative (S. aureus) as well as Gram-positive bacteria (E. coli). Modified regranulates were transformed into films by cast extrusion. The influence of the additives on thermal (DSC, TGA and OIT), mechanical, barrier (WVTR and OTR), morphological (FTIR) and optical properties was investigated. The EZnO additive had the highest impact on the mechanical, barrier (OTR and WVTR) and optical properties of the bioresin. The microbial test results revealed that PHA-EZnO exhibited higher activity than PHA-ZnO and PHA-E and also reduced the number of S. aureus, E. coli and C. albicans cells. The findings confirmed the synergistic effect between the additive components. Modified polyester films did not eliminate the phi6 bacteriophage particles completely, but they did decrease their number, confirming moderate antiviral effectiveness. [ABSTRACT FROM AUTHOR]

The goal of this study was to analyze the antifungal and antiviral activity of coatings based on Formitopsis betulina, Verbascum L. and Uncaria tomentosa extracts with ZnO nanoparticles as active compounds. The other purpose was to investigate the impact of polypropylene bags coated with the obtained antiviral/antifungal coatings on the microbial quality/purity of strawberries. The results of this study showed that the analyzed coatings inhibited Candida albicans growth completely. They did not inhibit the growth of Fusarium oxysporum, but they decreased its number. Additionally, all layers demonstrated a high activity against the Φ 6 bacteriophage particles. Analyzing the microbial purity of the strawberries after storage, it was noticed that the modified bags with Verbascum L. (ZnVL) and F. betulina (ZnFb) extracts and the addition of the nano ZnO had a significant effect on the decrease of the total count and on the number of yeast and mold. After 144 h of storage of the strawberries, the ZnVL coating was found to be more effective than the ZnFb layer. However, after 216 h of storage, ZnVL was more active against yeast and mold, but the packaging covered with the ZnFb coating was more effective against bacteria. [ABSTRACT FROM AUTHOR]

The goal of this work was to improve the barrier properties of selected papers against water, grease and oil or gases (water vapor and oxygen) by covering them with biodegradable commercial coating carriers based on cellulose nanocrystals (CNCs) and polyvinyl alcohol (PVOH). The aim was also to obtain cellulose recyclable packaging materials with improved barrier characteristics. The properties of paper coatings based on CNCs and PVOH were characterized. Various paper coating techniques (flexographic printing, rotogravure printing and blade printing) were evaluated with respect to the final properties of the surface-modified paper with different starting grammages (40 g/m2, 70 g/m2, 100 g/m2). Functional properties, such as the barrier against oxygen, water vapor, water and grease; mechanical properties; and seal characterization of coated paper were examined. The results of this study demonstrated that the covering of the paper may improve the water, grease and oil barrier and that the best results were obtained for Gerstar 70 g/m2 coated with J12 coatings using the flexographic technique. [ABSTRACT FROM AUTHOR]

Introduction: Recently, interest in essential oils used in natural medicine, has been increasing. Essential oils are still being tested for their potential uses as an alternative remedies for the treatment of many infectious diseases.

The temperature has a significant effect on cathepsin activity, but the effect of temperature on the ripening of marinades, and the formation of protein hydrolysis products, is less studied than other technological factors. The results of this study showed that herring marinated at 2 °C showed a higher mass yield, but lower non-protein nitrogen (NPN), peptides, and free amino acid fraction content, than after marinating at 7 and 12 °C. The higher temperature increased the free amino acid content the most, and decreased the hardness, as measured via sensory assessment, of the marinated meat. This was confirmed by the hardness measurement in the texture profile analysis. The highest activity of cathepsins D and B in the meat was found at 7 °C, while cathepsin L was found at 2 °C. Increasing the temperature by 10 °C increased the diffusion/loss of nitrogenous substances from the meat to the brine by 36%. The meat and brine showed high antioxidant activity, which depended on the marinating temperature, and originated mainly from the 5–10 or <5 kDa fraction. The meat had a higher ABTS (2,2′-azinobis-3-ethylbenzothiazoline-6-sulfonate) activity than the brine, opposite to the DPPH (2,2-diphenyl-1-picrylhydrazyl radical) activity, while the FRAP (Ferric Reducing Antioxidant Power) capacity was similar for meat and brine. The fractionation of the meat and brine extracts increased the antioxidant potential of FRAP and ABTS only for the brine. The most hydrophobic peptides were released during marinating at 7 °C. The meat and brine were dominated by 2–4 kDa peptides, followed by 4–6 and 0.5–2 kDa. The higher temperature favored a higher proportion of <4 kDa than >4 kDa peptides in the brine. [ABSTRACT FROM AUTHOR]

The main goal of the work was to create an internal coating based on super critical CO2 extracts of raspberry seeds, pomegranate seeds and rosemary that could be active against chosen bacterial strains. Additionally, the synergistic effect of these substances in the coating were then analysed. The next goal of the work was to demonstrate the antiviral activity of the coatings against phi6 bacteriophage particles (airborne viruses surrogate). The results of the study indicated that three coatings containing a mixture of extracts showed bacteriolytic activity against S. aureus cells and bacteriostatic activity against E. coli and B. subtilis strains. Two coatings showed bacteriolytic activity against a P. syringae strain. As a result of the experiments, a synergistic effect was noted in the active additives/compounds in the coatings. These coatings may be used as internal coatings for packaging films to extend the shelf life of selected food products. All seven coatings may also be used as external coatings with antiviral activity, as these coatings demonstrated significant effects on the phi6 phage, selected as a surrogate for airborne viruses, e.g., coronaviruses. It could be concluded that coatings I–VII will also show antiviral effects on SARS-CoV-2 particles. [ABSTRACT FROM AUTHOR]

The growing market demand for plant raw materials with improved biological value promotes the extensive search for new elicitors and biostimulants. Gellan gum derivatives may enhance plant growth and development, but have never been used under stress conditions. Perilla (Perilla frutescens, Lamiaceae) is a source of valuable bioproducts for the pharmaceutical, cosmetic, and food industries. However, there is not much information on the use of biostimulators in perilla cultivation. In this work we investigated the effects of oligo-gellan and salt (100 mM NaCl) on the yield and quality of red perilla (P. frutescens var. crispa f. purpurea) leaves. Plants grown under stress showed inhibited growth, smaller biomass, their leaves contained less nitrogen, phosphorus, potassium, total polyphenol and total anthocyanins, and accumulated considerably more sodium than control plants. Treatment with oligo-gellan under non-saline conditions stimulated plant growth and the fresh weight content of the above-ground parts, enhanced the accumulation of nitrogen, potassium, magnesium and total polyphenols, and increased antioxidant activity as assessed by DPPH and ABTS assays. Oligo-gellan applied under saline conditions clearly alleviated the stress effects by limiting the loss of biomass, macronutrients, and total polyphenols. Additionally, plants pretreated with oligo-gellan and then exposed to 100 mM NaCl accumulated less sodium, produced greater amounts of photosynthetic pigments, and had greater antioxidant activity than NaCl-stressed plants. Irrespective of the experimental treatment, 50% extract effectively inhibited growth of Escherichia coli and Staphylococcus aureus. Both microorganisms were the least affected by 25% extract obtained from plants untreated with either NaCl or oligo-gellan. In conclusion, oligo-gellan promoted plant growth and enhanced the quality of red perilla leaves and efficiently alleviated the negative effects of salt stress. [ABSTRACT FROM AUTHOR]

The aim of this study was to cover biopolymeric packaging films based on PLA/PHBV blend with a functional composite coating (to retain their ecological character) and to investigate their antimicrobial properties before and after UV irradiation. As an active coating, the carrier hydroxypropyl methyl cellulose (HPMC), as well as its modified form with Achillea millefolium L., Hippophae rhamnoides L., and Hypericum L. extract (E) and a combined system based on the extracts and nano-ZnO (EZ), was used to obtain active formulations. Additionally, film surface morphology (SEM, FTIR-ATR) and color (CIELab scale) analysis of the pre- and post-UV-treatment samples were performed. The results confirmed that the E and EZ-modified films exhibited antibacterial properties, but they were not effective against phage phi6. Q-SUN irradiation led to a decrease in the activity of E coating against Staphylococcus aureus , Pseudomonas syringae , and Candida albicans . In this case, the effectiveness of EZ against C. albicans at 24 h and 72 h UV irradiation decreased. However, the irradiation boosted the antiviral effectiveness of the EZ layer. SEM micrographs of the film surface showed that UV treatment did not significantly influence the native film morphology, but it had an impact on the coated film. FTIR analysis results showed that the coatings based on HPMC altered the IR absorption of the nonpolar groups of the biopolyester material. The applied coatings only marginally affected film color changes and increased their yellowness after UV irradiation, whereas a composite layer of nano-ZnO limited these changes.