The current spreading of nanomaterial applications supports the search for further possible functions of theses diminutive particles. The antibacterial potentiality of zinc oxide (ZnO) nanoparticles (NPs), compared with conventional ZnO powder, against nine bacterial strains, mostly foodborne including pathogens, was evaluated using qualitative and quantitative assays. ZnO NP was more efficient as antibacterial agent than powder. Gram‐positive bacteria were generally more sensitive to ZnO than Gram negatives. The exposure of Salmonella typhimurium and Staphylococcus aureus to their relevant minimal inhibitory concentrations from ZnO NP reduced the cell number to zero within 8 and 4 h, respectively. Scanning electron micrographs of the treated bacteria with NPs exhibited that the disruptive effect of ZnO on S. aureus was vigorous as all treated cells were completely exploded or lysed after only 4 h from exposure. Promising results of ZnO NP antibacterial activity suggest its usage in food systems as preservative agent after further required investigations and risk assessments. PRACTICAL APPLICATIONS Foodborne pathogen invasion is still a recurrent serious problem facing researchers and food industry overseers. The introduction of novel powerful antimicrobial agents is of great importance for the control of pathogenic bacteria, especially antibiotic‐resistant strains. Zinc oxide (ZnO) nanoparticle (NP) could be one of these potential alternatives. This study focused on ZnO NP because of its increasing presence in many marketable products and that supports its application in food industries as a reasonably safe agent. The demonstrated antibacterial activity of ZnO NP recommends its possible application in the food preservation field; otherwise it can be applied as a potent sanitizing agent for disinfecting and sterilizing food industry equipment and containers against the attack and contamination with foodborne pathogenic bacteria.

Natural derivatives could be recommended as powerful antifungal alternatives to protect citrus fruits from postharvest fungal decay.

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Background Citrus production and trading are seriously affected by fungal decays worldwide; the green mold infection by Penicillium digitatum could be the most disastrous. The substitutions of chemical and synthetic fungicides with effectual natural alternatives are global demands; plant extract from pomegranates peels (PPE), biosynthesized selenium nanoparticles with PPE (PPE/SeNPs) and chitosan nanoparticles (NCT) were suggested as efficacious fungicidal agents/nanocomposites to control P. digitatum strains. Method PPE from Punica granatum was extracted and employed directly for synthesizing SeNPs, whereas NCT was produced using ionic gelation method of chitosan extracted from white prawn (Fenneropenaeus indicus) shells. The physiochemical, biochemical and structural characterization of generated molecules were conducted using infra-red spectroscopy, particles’ size (Ps) and charge assessment and electron microscopes imaging. Antifungal potentialities were investigated in vitro and in infected fruits with P. digitatum by applying NCT nanocomposites-based edible coating. Results The synthesis of PPE-synthesized SeNPs and NCT was successfully achieved, the molecular bonding in synthesized agents/composites were proved with infrared spectroscopy to have both biochemical and physical interactions. The nanoparticles had 82.72, 9.41 and 85.17 nm mean diameters for NCT, PPE/SeNPs and NCT/PPE/SeNPs nanocomposites, respectively. The nanoparticles had homogenous spherical shapes and good distribution attributes. The entire agents/nanocomposites exhibited potent fungicidal potentialities toward P. digitatum isolates; NCT/PPE/SeNPs nanocomposite was the most forceful and significantly exceeded the fungicidal action of standard fungicide. The direct treatment of fungal mycelia with NCT/PPE/SeNPs nanocomposite led to remarkable lysis and deformations of P. digitatum hyphae within 12 h of treatment. The coating of infected orange with NCT-based edible coatings reduced the green mold infection signs by 91.7, 95.4 and 100%, for NCT, NCT/PPE and NCT/PPE/SeNPs based coating solutions, respectively. Conclusions NCT, PPE-synthesized SeNPs, and their innovative nanocomposites NCT/PPE/SeNPs are convincingly recommended for formulating effectual antifungal and edible coatings to eliminate postharvest fungal pathogen, both with protection from their invasion or with destructing their existing infections. Graphical Abstract

BackgroundAcetaminophen (APAP)-induced toxicity is a predominant cause of acute hepatic and renal failure. In both humans and rodents toxicity begins with a reactive metabolite that binds to proteins. This leads to mitochondrial dysfunction and nuclear DNA fragmentation resulting in necrotic cell death. Pleurotus ostreatus (an edible oyster mushroom) is well recognized as a flavourful food, as well as a medicinal supplement. In the present study, we evaluated the role of Pleurotus ostreatus in the protection against APAP-induced hepato-renal toxicity. We also explored the mechanism by which Pleurotus ostreatus exerts its effects.MethodsNinety adult male Swiss albino mice were divided into three groups (30 mice/group). Mice were offered normal diet (control and APAP groups), or diet supplemented with 10% Pleurotus ostreatus (APAP + Pleurotus ostreatus) for 10 days. Mice were either treated with vehicle (control group, single intra-peritoneal injection.), or APAP (APAP and APAP + Pleurotus ostreatus groups, single intra-peritoneal injection, 500 mg/kg), 24 hours after the last meal.ResultsAPAP increased serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST) glutamate dehydrogenase (GDH), creatinine, blood urea nitrogen (BUN), urinary kidney injury molecule-1 (KIM-1), and hepatic and renal malondialdehyde (MDA) content. APAP decreased hepatic and renal glutathione (GSH) content, as well as glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) activities. Supplementation with Pleurotus ostreatus significantly reduced APAP-induced elevated levels of ALT, AST, GDH, creatinine, BUN, KIM-1and MDA, while GSH level, and GSH-Px and SOD activities were significantly increased. Our findings were further validated by histopathology; treatment with Pleurotus ostreatus significantly decreased APAP-induced cell necrosis in liver and kidney tissues.ConclusionsWe report here that the antioxidant effect of Pleurotus ostreatus opposes mitochondrial dysfunction and oxidative stress accompanying APAP over-dose, with subsequent clinically beneficial effects on liver and kidney tissues.