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In this study, a novel antimicrobial formula that incorporates Listeria bacteriophage P100 and silver nanoparticles into an alginate matrix was successfully developed. Paper coated with the antimicrobial formula inhibited the growth of Listeria monocytogenes. The effects of alginate concentration on the formation of silver nanoparticles, silver concentration on the infectivity of phages, and of low alginate concentrations on the sustained release of silver and phages were explored. The highest antimicrobial activity of the alginate–silver coating was achieved with an alginate concentration of 1%. Adding phage P100 (109 PFU/mL) into the alginate–silver coating led to a synergic effect that resulted in a 5-log reduction in L. monocytogenes. A bioactive paper was then developed by coating a base paper with the antimicrobial formula at different coating weights, followed by infrared drying. The higher coating weight was a crucial factor for the maintenance of phage infectivity throughout the coating and drying processes. Phages incorporated into the alginate matrix remained functional even after high-temperature infrared drying. Taken together, an optimized coating matrix is critical in improving the antimicrobial performance of bioactive paper as well as maintaining phage infectivity during the paper manufacturing process.

Fluorescence is well-known nowadays as one of the most efficient anti-counterfeiting techniques. Zinc oxide quantum dots (ZnOQds) are exceptionally fluorescence when exposed to ultraviolet (UV) light, which makes them a candidate for anti-counterfeiting printing. The resulting anti-counterfeiting papers are sustainable and resistance against organic dyes. In this work, ZnOQds were prepared via a green method and characterized under UV–visible spectroscopy, along with microscopic observations by transmission electron microscopy (TEM) and crystallography by X-ray diffraction (XRD). Formation of ZnOQds nanocrystals with an average partials size of 7.3 nm was approved. Additionally, double-layers sheets were prepared at two loading concentrations of ZnOQds, namely 0.5 and 1 (wt./v) and underwent characterization using a topographical surface study via field emission scanning electron microscopy (FE-SEM). Hybrid sheets were mechanically more stable compared to single-layer paper and likewise polymer film. Moreover, aging simulation approved a high stability for hybrid sheets. Particularly, the photoluminescence emission affirmed anti-aging character of hybrid paper for more than 25 years. The hybrid sheets also showed a broad range of antimicrobial activity.

Here, we designed paper sheets coated with chitosan, bacterial cellulose (nanofibers), and ZnO with boosted antibacterial and mechanical activity. We investigated the compositions, with ZnO exhibiting two different sizes/shapes: (1) rods and (2) irregular sphere-like particles. The proposed processing of bacterial cellulose resulted in the formation of nanofibers. Antimicrobial behavior was tested using E. coli ATCC® 25922™ following the ASTM E2149-13a standard. The mechanical properties of the paper sheets were measured by comparing tearing resistance, tensile strength, and bursting strength according to the ISO 5270 standard. The results showed an increased antibacterial response (assigned to the combination of chitosan and ZnO, independent of its shape and size) and boosted mechanical properties. Therefore, the proposed composition is an interesting multifunctional mixture for coatings in food packaging applications.

In this study, a novel antimicrobial formula that incorporates Listeria bacteriophage P100 and silver nanoparticles into an alginate matrix was successfully developed. Paper coated with the antimicrobial formula inhibited the growth of Listeria monocytogenes. The effects of alginate concentration on the formation of silver nanoparticles, silver concentration on the infectivity of phages, and of low alginate concentrations on the sustained release of silver and phages were explored. The highest antimicrobial activity of the alginate–silver coating was achieved with an alginate concentration of 1%. Adding phage P100 (109 PFU/mL) into the alginate–silver coating led to a synergic effect that resulted in a 5-log reduction in L. monocytogenes. A bioactive paper was then developed by coating a base paper with the antimicrobial formula at different coating weights, followed by infrared drying. The higher coating weight was a crucial factor for the maintenance of phage infectivity throughout the coating and drying processes. Phages incorporated into the alginate matrix remained functional even after high-temperature infrared drying. Taken together, an optimized coating matrix is critical in improving the antimicrobial performance of bioactive paper as well as maintaining phage infectivity during the paper manufacturing process. [ABSTRACT FROM AUTHOR]

One of the main problems faced by libraries, archives and collectors is the mold degradation of the paper-based documents, books, artworks etc. Microfungi (molds) emerge in regular storage conditions of such items (humidity, usually over 50%, and temperatures under 21 °C). If the removal of the visible mycelium is relatively easy, there is always the problem of the subsequent appearance of mold as the spores remain trapped in the cellulosic, fibrillary texture, which acts as a net. Moreover, due to improper hand hygiene bacteria contamination, old books could represent a source of biohazard, being colonized with human pathogens. An easy and accessible method of decontamination, which could offer long term protection is therefore needed. Here, we present a facile use of the ZnO nanopowders as antimicrobial agents, suitable for cellulose-based products, conferring an extended antibacterial and anti-microfungal effect. The proposed method does not adversely impact on the quality of the cellulose documents and could be efficiently used for biodegradation protection.

Nowadays, thanks to nanotechnological progress, which itself guides us more and more closely toward not only the efficient design of innovative nanomaterials or nanostructures, but to the improvement of their functionality, we benefit from an important asset in the battle against pathogenic illnesses. Herein, we report a versatile biocompatible plasmonic nanoplatform based on a Whatman paper incorporating positively-charged gold nanospherical particles via the immersion approach. The morphological characterization of the as-engineered-plasmonic paper was examined by SEM (scanning electron microscopy) and HRTEM (high-resolution transmission electron microscopy) investigations, while its surface chemical modification with a synthetic polypeptide, specifically RRWHRWWRR-NH2 (P2), was proved by monitoring the plasmonic response of loaded gold nanospheres and the emission signal of P2 via fluorescence spectroscopy. The as-functionalized plasmonic paper is non-cytotoxic towards BJ fibroblast human cells at bactericidal concentrations. Finally, the antimicrobial activity of the P2-functionalized plasmonic paper on both planktonic bacteria and biofilms was tested against two reference strains: Gram-positive Bacteria, i.e., Staphylococcus aureus and the Gram-negative Bacteria, i.e., Escherichia coli, determining microbial inhibition of up to 100% for planktonic bacteria. In line with the above presented nanoplatform’s proper design, followed by their functionalization with active antimicrobial peptides, new roads can be open for determining antibiotic-free treatments against different relevant pathogens.

The study investigates four paper-based materials designed for short-time wrapping of meat products by determining morpho-structure, capillary-hydroscopic, barrier and antibacterial properties, wettability and migration into food simulants. The paper-based materials are coded as RO, SP, IT and SLO. RO and SLO samples exhibit the best barrier properties against water vapors. The low solubility and contact angles of RO, IT and SLO in A simulant (distilled water) make them suitable for aqueous food storage. The extremely high solubility of SP and SLO in simulant B (acetic acid) shows that wax and hydrophobized starch, respectively are carried by the acidic media, thus these agents are unlikely to coat the paper designed to package acidic food. SLO inhibits E. coli, Salmonella enterica, Lysteria monocytogenes, Pseudomonas aeruginosa and fluorescens. Polyethylene coated on RO and IT surface and wax impregnated on SP have a lower antimicrobial activity in comparison with hydrophobized starch coated on SLO. [ABSTRACT FROM AUTHOR]

This study used a plant-based antimicrobial agent (Trachyspermum ammi or Ajowan essential oil) to develop a water-based coating emulsion with polyvinyl alcohol as a binder. The emulsion was spray-coated onto the packaging paper to achieve antimicrobial properties and prevent disease transmission during the e-commerce supply chain. The coated papers were studied for their morphological, chemical, mechanical, barrier, and antimicrobial behaviors. The presence of Ajowan oil on coated paper was confirmed by infrared spectroscopy and surface morphology. In parallel, the time-bound release of volatile Ajowan oil from the coated papers was demonstrated when stored in a controlled environment using UV–vis spectroscopy. Both bending stiffness and tear strength significantly increased for coated papers due to the presence of polyvinyl alcohol in the coating, whereas the high concentration of oil resulted slight decrease in tensile and burst strength of coated papers. Finally, the antimicrobial activity of coated paper was checked against S. aureus and E. coli at different concentrations of Ajowan oil in coating and was found to be effective for 10 days. The coated papers also showed remarkable antimicrobial activity when tested against all unknown microbes on bare human hands. [Display omitted] • A water-based antimicrobial coating emulsion was developed for paper packaging. • Ajowan essential oil was utilized as an antimicrobial agent with PVA as a binder. • The coated paper showed antimicrobial properties against E. coli and S. aureus. • The coated paper showed antimicrobial activity against unknown microbes in human hands. [ABSTRACT FROM AUTHOR]

Herein, we fabricated a starch-based flexible coating for food packaging papers with excellent hydrophobicity and antimicrobial properties. FTIR (Fourier transform infrared) and XRD (X-ray diffraction) spectra revealed the homogeneous dispersion of the ZnO nanoparticles (NPs) in the composite film within 5% ZnO NP dosage. SEM (scanning electron microscope) and AFM (atomic force microscope) micrographs confirmed the increased roughness on the composite film with the increased dosages of ZnO NPs. Hydrophobic characteristics showed that dramatic enhancement was obtained in the values and stabilities of DCAs (dynamic contact angles) in the resultant film and coated paper. TG (thermogravimetry) results demonstrated the increased thermal stabilities of the composite films. Significantly, a decreased water vapor transmission rate was observed in the coated paper. When 20% guanidine-based starch and 2% CMC (carboxy methyl cellulose) was added, a flexible coating with excellent antimicrobial activity towards Escherichia coli can be obtained. Furthermore, the migration of ZnO NPs into the food simulants was well below the overall migration legislative limit. The resultant starch-based flexible composite film and coated paper established an effective approach to develop a green-based material for food packaging applications.

For this study, a paper impregnated with silver nanoparticles (AgNPs) was prepared. To prepare the substrates, aqueous suspensions of pulp fines, a side product from the paper production, were mixed with AgNP suspensions. The nanoparticle (NP) synthesis was then carried out via laser ablation of pure Ag in water. After the sheet formation process, the leaching of the AgNPs was determined to be low while the sheets exhibited antimicrobial activity toward Escherichia coli (E. coli).

Conjugated amino acid with nano-biodegradable polymer was applied as ecofriendly and edible coating. Polystyrene sulfate (PSS) was highly investigated with dynamic light scattering (DLS) to measure the particle size and over charge (zeta potential measurements) of nano-polymer system as well as the homogeny of particle distribution in presence and absence of Lysine mixture (AA). In addition, topographical structure of the coating was studied for PSS, AA and conjugated one as well as Fourier transform infrared (FTIR) and Differential Scanning Calorimetry (DSC). Antimicrobial test cleared that the prepared conjugate described as broad-spectrum antibacterial agent as well as antifungal with different concentrations. The hydrophilic active ingredient is absorbed into fiber, distributed homogenously and kept out the fiber loaded with antimicrobial properties over all areas. Tensile strength of the paper sheets coated with uni-layer 200 µ thickness presented good improving in physical and mechanical properties of coated paper sheets as well as gives more fiber condensation according to Scanning Electron Microscope (SEM) topography. [ABSTRACT FROM AUTHOR]

In this work, the effect of using Ag-doped TiO2 nanopigments on optical, mechanical and antimicrobial properties of coated paper was explored. Furthermore, the long-term antimicrobial activity of the coated paper was examined for up to 25 years. Titanium dioxide (TiO2) nanoparticles have been synthesized and doped with different percentages of Ag nanoparticles (Ag NPs) using a simple wet chemical approach. The Ag@TiO2 modified nanopigments were in the form of nanorods with an average size of about 20 nm as observed from TEM images. Increasing Ag content from 0.01 to 1.0% showed an increase in the mechanical properties of coated paper in terms of tensile, stretching, tensile energy absorption and burst while preserving the optical properties. Moreover, the antimicrobial inhibition activity increased with increasing the Ag content. The 1% Ag@TiO2 showed a long-lasting antimicrobial effect against Staphylococcus aureus (S. aureus) Gram-positive bacteria even after 25 years of ageing (93.4% inhibition). Investigation of reactive oxygen species (ROS) generation and reaction mechanism of antimicrobial activity over Ag/TiO2 under visible light is proposed. These results suggest that Ag/TiO2 NPs can be potentially used as a disinfection coating for paper and improving its mechanical properties. [ABSTRACT FROM AUTHOR]

Guanidinylated chitosan (GCS) was prepared by grafting guanidine oligomers onto chitosan under microwave irradiation. The structure of GCS characterized by FT-IR and 1H NMR verified the covalent bonding between the guanidine oligomers and chitosan; the effects of molar ratio, reaction temperature, and time were investigated and the degree of substitution of GCS reached a maximum of 25.5% under optimized conditions in this work. The resulting GCS showed significantly enhanced antimicrobial activities. The results obtained from the dynamic UV absorption of Escherichia coli (E. coli) and atomic force microscopy (AFM) revealed that the deactivation of E. coli by GCS was due to the destructing of the cell membrane and the prompt release of cytoplasm from the bacterial cells. The adsorption of GCS onto cellulose fibers and the antimicrobial efficiency of the hygiene papers with GCS were also investigated. Microwave irradiation as a green assisted method was applied to promote this reaction. This facile approach allowed chitosan to be guanidinylated without tedious preparation procedures and thus broadened its application as a biocompatible antimicrobial agent.

This study aims to investigate the antimicrobial activity of paper-based packaging materials including coriander (Coriandrum sativum L.) essential oil. Three types of packaging papers (bleached, unbleached, and recycled) are treated with an essential oil and then stored for 2 h, 24 h, and 5 days. The antibacterial activity of coriander oil is tested against Gram-positive bacteria (Staphylococcus aureus ATCC 6538 and Bacillus subtilis ATCC 6633); Gram-negative bacteria (Escherichia coli ATCC 8739, Pseudomonas aeruginosa ATCC 9027, and Salmonella abony NTCC 6017); an yeast (Candida albicans ATCC 10231), and a fungal strain (Aspergillus brasiliensis ATCC 16404). A high fungicidal potential is observed in case of all packaging materials. The antimicrobial action of the bleached paper coated with coriander oil against Gram-positive bacteria during the five-day storage period decreases slightly from 100 % - 94 % to 79 % - 81 %. [ABSTRACT FROM AUTHOR]

Sea buckthorn is a promising species that, under the conditions of Eastern Europe, has shown high productivity and is also a good and possible source of a wide range of bioactive compounds that have a positive effect on the human body, especially polyphenols and carotenoids. Due to the content of biologically active substances in sea buckthorn (Hippophae rhamnoides L.), the species is of growing interest to scientists, the food industry, the pharmaceutical industry, the cosmetics industry and consumers. The aim of this study is to investigate the productivity and the correlation between the chemical composition and the antibacterial effect of four cultivars of sea buckthorn (Clara, Dora, Cora, Mara), cultivated in the Republic of Moldova. Sea buckthorn fruits were harvested at the stage of full ripening. Berry samples were frozen at minus 25 °C, stored for 6 months and whole fruits of sea buckthorn were studied. All quantitative characteristics were calculated in terms of absolutely dry raw material (dry weight). The sea buckthorn cultivars tested were found to have a different carotenoid contents (1.79–48.92 mg/100 g), ascorbic acid contents (74.36–373.38 mg/100 g), organic acids (malic acid 5.8–13.4 mg/100 g, citric acid 0.08–0.321 mg/100 g, succinic acid 0.03–1.1 mg/100 g), total dry matter contents (16.71–24.54%), titratable acidities (2.15–8.76%) and pH values (2.73–3.00). The antimicrobial activity of sea buckthorn, evaluated by the diameter of the inhibition zone, constituted for Bacillus pumilus 3.70–15.91 mm/g−1 for whole sea buckthorn fruits and 13.33–26.67 mm/g−1 for sea buckthorn purees. [ABSTRACT FROM AUTHOR]

Aims: A paper by Araújo et al. (2018) claims that a variety of compounds present in pyroligneous acid (guaiacol, phenols and furfural) are responsible for the observed antimicrobial activity. We show, on the other hand, that the low pH due to acetic acid present in pyroligneous acid is the real cause of the activity. Methods and Results: Pyroligneous acid (PA) was synthesized according to a previous method (Medeiros et al. 2019) with its inhibition activity tested on Escherichia coli and Staphylococcus aureus via the agar diffusion method. The activity of acetic acid at different concentrations was also evaluated for comparison. As expected, crude PA (pH 3.0) and acetic acid produced inhibition halos whose diameters varied according to their employed concentration. However, any PA inhibitory activity completely vanished upon neutralization (pH 7.0), a behaviour also observed for neutralized acetic acid. Conclusions: The claim that guaiacol, phenols and furfural are responsible for any inhibitory activity is unsubstantiated. The authors should have neutralized the pyroligneous acid if any activity was to be discovered. Significance and Impact of Study: To increase awareness that interfering species may play a detrimental role on the interpretation of results. In this case, the action of acetic acid is vastly more important for the inhibitory activity than any other compound present in PA. [ABSTRACT FROM AUTHOR]

Magnesium oxide nanoparticles (MgO NPs) have attracted considerable interest as antimicrobial agents in a wide variety of applications. We report a simple synthetic route towards MgO NPs (average diameter 10 nm) possessing potent antibacterial activity against both Gram-negative and Gram-positive bacteria. Detailed electron microscopy studies show how these particles induce oxidative stress, cell membrane leakage and cell death in bacteria at low NP concentrations, but remain non-toxic to eukaryotic cells. Applying a homogeneous dispersion of these nanoparticles on 18th century paper proved to be a highly effective means of preventing bacterial colonisation without altering the appearance of the paper samples, thus opening the doors to the use of these colourless, low-cost, and scalable nanoparticles for preventing biodeterioration in a range of paper-based objects and surfaces. • Nano-magnesium oxide particles (MgO NPs) of average size of around 10 nm have been synthesised using a simple one-pot synthesis. • The MgO NPs offer potent bactericidal activity but are non-toxic to mammalian cells at the same concentrations. • A combination of electron microscopy techniques shows how these nanoparticles produce oxidative stress, followed by cell membrane leakage and death. • The MgO NPs prevented bacterial colonisation of 18th century papers from the Archives of the Spanish Royal Botanic Garden. [ABSTRACT FROM AUTHOR]

Banana sap is currently designated as a waste subsequent to utilization of pseudo stem in pulp and paper industry as well as other applications which is contributing to the environmental pollution. In the present study, banana sap and its crude extracts were evaluated for antimicrobial, antioxidant and anticancer properties. The role of oxidized and un-oxidized banana sap for its antimicrobial potential against a microbial test panel comprising gram positive as well as gram negative bacteria and Candida albicans using in vitro micro broth dilution assay. The un-oxidized banana sap exhibited a significantly higher antibacterial potential as evident by a lower minimal inhibitory concentration (MIC) ranging between 15.625 to 62.5 mg/mL. In vitro radical scavenging activity of dichloromethane (DCM) extract of banana sap by DPPH method exhibited 54.62 ± 1.09 (µg/mL) IC50 value at the concentration of 1 mg/mL. Dichloromethane extract of banana sap showed maximum cytotoxic effect with human breast cancer (MCF-7) cell proliferation at the concentration of 100 µg/mL which was 78.37 ± 0.05% and the cytotoxic effect significantly increased with increasing concentration of banana sap extract. Furthermore, LCMS studies revealed the presence of bioactive compounds in dichloromethane extract of banana sap, such as rescinnamine derivative, dihydrorescinnamine and epimedin A. The present study suggested that banana sap is a promising source of bioactive compounds with relevant antimicrobial, antioxidant and anticancer properties. [ABSTRACT FROM AUTHOR]

Herein, we fabricated a starch-based flexible coating for food packaging papers with excellent hydrophobicity and antimicrobial properties. FTIR (Fourier transform infrared) and XRD (X-ray diffraction) spectra revealed the homogeneous dispersion of the ZnO nanoparticles (NPs) in the composite film within 5% ZnO NP dosage. SEM (scanning electron microscope) and AFM (atomic force microscope) micrographs confirmed the increased roughness on the composite film with the increased dosages of ZnO NPs. Hydrophobic characteristics showed that dramatic enhancement was obtained in the values and stabilities of DCAs (dynamic contact angles) in the resultant film and coated paper. TG (thermogravimetry) results demonstrated the increased thermal stabilities of the composite films. Significantly, a decreased water vapor transmission rate was observed in the coated paper. When 20% guanidine-based starch and 2% CMC (carboxy methyl cellulose) was added, a flexible coating with excellent antimicrobial activity towards Escherichia coli can be obtained. Furthermore, the migration of ZnO NPs into the food simulants was well below the overall migration legislative limit. The resultant starch-based flexible composite film and coated paper established an effective approach to develop a green-based material for food packaging applications. [ABSTRACT FROM AUTHOR]

In the present work, we report the synthesis of chitosan:starch‑silver nanoparticle (Cht:St-AgNPs) coated papers for antimicrobial packaging applications. The starch-assisted synthesized St-AgNPs are spherical in shape with an average particle size of 7 nm. Chitosan was mixed into the synthesized St-AgNPs solution with different ratios of 9:1, 8:2, 7:3, and 5:5 by weight. Further, the influence of different ratios of Cht:St-AgNPs on the various paper properties such as mechanical properties, water and oil resistance, and antimicrobial activities was investigated. It was observed that the properties of the coated papers were strongly dependent on the composition of Cht:St-AgNPs. The Cht:St-AgNPs-coated paper prepared with the ratio of 9:1 showed excellent mechanical properties and good resistance properties against water and oil. The Cht:St-AgNPs coated papers showed a remarkable enhancement in mechanical strength, oil and water resistance, and antibacterial and antifungal activity, which can make them a potential candidate for functional antimicrobial packaging applications. [ABSTRACT FROM AUTHOR]

Highlights: [•] Carboxymethyl cellulose (CMC) was oxidized to form dialdehyde CMC (DCMC). [•] Guanidine hydrochloride (GH) was grafted onto the DCMC to obtain DCMC-GH. [•] The coating of DCMC-GH onto paper resulted in the improvement of paper strength. [•] The DCMC-GH-coated paper exhibited excellent antimicrobial activities. [Copyright &y& Elsevier]

Paper items from historical archives and libraries are frequently colonized by biodeteriogens, the management of which is a major concern. Essential oil Volatile Organic Compounds (VOCs) of thymol, carvacrol and eugenol, with high levels of antimicrobial and insect repellent activity, were stabilized within crystalline networks of β-cyclodextrins and phenazine-based cocrystals, as a new tool for the control of paper-degrading agents. These formulations were obtained via solvent-free methodologies and resulted as easy handling powders, suitable for the treatment of paper items by indirect contact. Their antimicrobial activity was evaluated on the following species isolated from a book depository at Forte Belvedere (Florence, IT): Alternaria alternata , Aspergillus sp., Cladosporium sp., Trichoderma orientale , Metschnikowia sp., and Bacillus sp. Both formulates displayed a significant antimicrobial activity in vitro , with cocrystals showing higher efficacy than β-cyclodextrins. The formulates were also tested against the pest Lasioderma serricorne , towards which the cocrystals entrapping carvacrol and thymol exhibited repellent activity. Overall, the phenazine-carvacrol cocrystal was the best-performing formulate, also giving favourable outcomes in terms of antifungal activity in an on-paper in vitro experiment designed to reproduce on a small-scale the critical conditions of an infested archive. These promising results pave the way towards further experimentations of VOC-based solid formulates, to shed light on such products applicability for the preservation of paper items. [Display omitted] • Volatile organic compounds (VOCs) trapped into β-cyclodextrins and cocrystals. • Solid formulates of thymol, carvacrol and eugenol to combat paper biodeteriogens. • Powdery formulates releasing VOCs with high antimicrobial activity. • VOC-based formulates showing insect repellent activity. [ABSTRACT FROM AUTHOR]

Alternaria sp. causes discoloration and black spot disease in Pyrus pyrifolia (Japanese or Nashi pear). We investigated the antimicrobial properties of an emulsion oil of natural antimicrobial substances, such as allyl isothiocyanate (AITC) and lemongrass oil. The effect of oil-droplet size in the emulsified oil containing AITC and lemongrass oil with modified starch was assessed. Furthermore, the effect of different oil ratios on the antimicrobial properties was also investigated. When the emulsion oil weight ratio of AITC to lemongrass oil was 0.15, Alternaria sp. growth was not observed after 16 days. In paper bags coated with the emulsified oil, the amount of lemongrass oil retained on the paper increased with a decrease in the average oil-droplet size. [ABSTRACT FROM AUTHOR]

Copyright of Food Research & Development is the property of Food Research & Development Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The demand for increasing the shelf life of fresh food as well as the need for protecting the food against foodborne infections warrant the demand for increasing the shelf life of fresh food. The incorporation of nanoparticles into the packaging material can enhance the preservation of perishable foods. Silver nanoparticles (AgNPs), in particular, have antibacterial, anti-mold, anti-yeast, and anti-viral activities can be embedded into the biodegradable packaging materials for this purpose. This study focuses on antimicrobial packaging materials for food by mixing the extracts of different plants with silver nitrate and depositing this mixture as a layer on the blotting papers, which are thick sheets of paper made of cellulose. Because the blotting papers are highly absorbent and porous, silver nitrate solution along with the plant extracts can be easily applied and allowed for in situ synthesis of AgNPs. Subsequently, these papers were analyzed and characterized using scanning electron microscopy, transmission electron microscopy, atomic absorption spectroscopy, and energy dispersive X-ray analysis. The coated paper exhibited good antibacterial activity against Escherichia coli and Staphylococcus aureus. Furthermore, the coated paper when used as a packaging material for tomatoes and coriander leaf, the shelf life was extended to about 30 days and 15 days respectively. The prepared cost-effective silver packing material can be used in food packaging for various perishable foods.

Generally, the study evaluated the in vitro antimicrobial activity of fecal bacteria isolated from Philippine native chicken against Staphylococcus aureus. Specifically, this study measured the antimicrobial activity of the crude extracts from fecal bacteria cultured at different time intervals, and compared with selected antimicrobials against S. aureus. A loopful of isolated fecal bacteria was cultured in nutrient broth at different time intervals (6, 12, 18, and 24 h). After each time interval, the broth culture was centrifuged at 6,000 rpm for 15 min and the cell-free supernatant (crude extract) was collected. Sterile filter paper discs were impregnated with a total of 30 μl crude extracts and placed on spread plate culture of S. aureus on Mueller-Hinton (MH) agar, including selected antimicrobials discs (2 μg clindamycin, 5 μg enrofloxacin, and 10 μg penicillin V), then incubated at 37 °C for 18 to 24 h. The zones of inhibition were measured using a Vernier caliper and compared. The crude extracts of fecal bacteria from different breeds of Philippine native chicken have antimicrobial activity against S. aureus as shown by various sizes of zone of inhibition. The Banaba breed had the greatest number of isolates with zone of inhibition. The crude extracts that produced zone of inhibition were significantly higher compared to selected antimicrobials - clindamycin and penicillin V, but significantly lower compared to enrofloxacin. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Central China Normal University is the property of Huazhong Normal University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The aim of this study was to examine the impact of microbiocides on the reduction of the microbial population on paper in order to protect it against biodeterioration. The cellulose products were modified with the cationic gemini surfactant hexamethylene-1,6-bis-(N,N-dimethyl-N-dodecylammonium bromide) C6 and its monomeric analog (didecyldimethylammonium chloride) DDAC. The microbiocides were introduced into the paper by coating and spraing. In the coating method the microbiocides were mixed with starch solution and applied to paper surface as a wet film with a thickness of 24 and 50 µm. In the spraying method the surfactants were applied at 3% concentration in water to get 0.005 ml/cm2 of paper. Experiments were performed with moulds of the genera Aspergillus, Penicilllium, Chaetomium and Trichoderma and bacteria represented by the genera Bacilllus and Pseudomonas. The antimicrobial properties of the paper modified with surfactants were determined by qualitative and quantitative methods. The zones of inhibition were measured using the parallel streak method. Macroscopic assessment of mould growth on the surface of the paper samples was performed over 21 days of incubation. In quantitative analysis, the survival rate of microorganisms on the modified paper samples was determined over 24 h. Aspergillus brasiliensis was the least sensitive mould, with no observable inhibition zones. No growth of this mould was observed either on or underneath the sample. Both of the surfactants applied as coatings or sprays protected the paper effectively against the growth of bacteria and mould. However, the spraying method is simpler to use. Over 24 h, the number of spores and bacteria in all the samples containing surfactants was reduced to below 1 log/10 cm2 (reduction factor up to 99.9%). The compounds may therefore be applied as antimicrobial agents for the protection of paper. [ABSTRACT FROM AUTHOR]

The study isolated and prepared crude extracts of fecal bacteria from four known strains of Philippine native chicken. It also evaluated the antimicrobial activity of the crude extracts against E. coli as indicator bacteria and compared to selected antimicrobials using modified disc diffusion method. Fecal suspensions were plated on nutrient agar and then incubated at 37 °C for 24 to 48 h. Colonies were purified and two distinct isolates were characterized morphologically through Gram-staining. A loopful of bacteria was inoculated in 10ml nutrient broth and incubated at 37 °C at different time intervals (6, 12, 18 and 24 h), then centrifuged and the cell-free supernatant (crude extract) was collected. Filter paper disc was impregnated with a total of 30 μl of crude extract and was used for antimicrobial activity testing along with three selected antimicrobial discs against E. coli. A total of 26 bacterial isolates was identified while two distinct colony morphologies were observed, and all isolates have rod shape appearance. The incubation period with the greatest number of isolates with zone of inhibition is 6 h, while the strain with the greatest number of isolates having zone of inhibition was Joloanon. All crude extracts showed significantly higher antimicrobial activity compared to these two antimicrobials except gentamicin. [ABSTRACT FROM AUTHOR]