Antioxidant activity of coatings containing eugenol for flexible aluminium foils to preserve food shelf-life

Active food packaging is an innovative system that avoids food deterioration ensuring quality, safety and shelf-life extension of food. Herein, two novel eugenol vinyl-based resins were used for coating flexible aluminium foils with potential packaging applications. Coatings were prepared with single eugenol or loaded eugenol in Santa Barbara Amorphous15 (SBA-15) mesoporous silica nanoparticles, and their antioxidant activity was investigated by DPPH, ABTS, ORAC, TBARS assays and by the hydroxyl free radicals’ generator method with HPLC analysis. Antioxidant activity was also evaluated exposing the coatings to various food simulants. Both coatings revealed adequate antioxidant capacity when exposed to fatty food simulants and to vapour phase hydroxyl free radicals (scavenging > 50%). The incorporation of eugenol in SBA-15 reduced its release to 65%, promoting eugenol beneficial antioxidant effects over time. The release of eugenol from the coatings into food simulants is not required for the activity of free radical scavenging

Correction: High piezo-resistive performances of anisotropic composites realized by embedding rGO-based chitosan aerogels into open cell polyurethane foams

Correction for 'High piezo-resistive performances of anisotropic composites realized by embedding rGO-based chitosan aerogels into open cell polyurethane foams' by Tianliang Zhai et al., Nanoscale, 2019, 11, 8835–8844

Preparation, Characterization and Effectiveness to Delay Lipid Oxidation in Almonds and Beef Meat

Funding Information: This study was carried out under the VIPACFood project, funded by ARIMNet2 (Coordination of Agricultural Research in the Mediterranean; 2014–2017), an ERA-NET Action financed by the European Union under the Seventh Framework Programme, and by the Programa de Cooperación Interreg V-A España–Portugal (POCTEP) 2014–2020 (project 0377_IBERPHENOL_6_E). Cássia H. Barbosa is grateful for her research grant in the frame of the VIPACFood project (ARIMNET2/0003/2016) and the Foundation for Science and Technology (FCT), Portugal, for the Ph.D. grant 2021.08154.BD. This research was also funded by PT national funds (FCT/MCTES, Fundação para a Ciência e Tecnologia and Ministério da Ciência, Tecnologia e Ensino Superior) through grants UIDB/50006/2020 and UIDB/00211/2020. L. Barbosa-Pereira is grateful to the Spanish Ministry of Science, Innovation and Universities for her “Juan de la Cierva-Incorporación” grant (Agreement No. IJCI-2017-31665). Publisher Copyright: © 2023 by the authors.Low-density polyethylene-based packaging with 4% lemon extract (LDPE/4LE) and two polylactic-based (PLA) packaging materials with 4% and 6% lemon extract (PLA/PEG/4LE and PLA/6LE) were produced. O2 and water permeability tests were performed, the total and individual phenolic compounds content were measured, and the films’ antioxidant activities were determined. The films’ ability to delay lipid oxidation was tested in two model foods: almonds, packaged with LDPE/4LE, PLA/4LE and PLA/6LE for a maximum period of 60 days at 40 °C (accelerated assay); and beef meat, packaged with the PLA/6LE for a maximum period of 11 days at 4 °C. The LE improved the WVP in all of the active films by 33%, 20% and 60% for the LDPE/4LE, PLA/4LE and PLA/6LE films, respectively. At the end of 10 days, the migration of phenolic compounds through the PLA films was measured to be 142.27 and 114.9 μg/dm2 for the PLA/4LE and PLA/6LE films, respectively, and was significantly higher than phenolic compounds migration measured for the LDPE/4LE (15.97 μg/dm2). Naringenin, apigenin, ferulic acid, eriocitrin, hesperidin and 4-hydroxybenzoic acid were the main identified compounds in the PLA, but only 4-hydroxybenzoic acid, naringenin and p-coumaric acid were identified in the LDPE films. Regarding the films’ ability to delay lipid oxidation, LDPE/4LE presented the best results, showing a capacity to delay lipid oxidation in almonds for 30 days. When applied to raw beef meat, the PLA/6LE packaging was able to significantly inhibit lipid oxidation for 6 days, and successfully inhibited total microorganisms’ growth until the 8th day of storage.publishersversionpublishe

Zein-Based Nanoparticles as Active Platforms for Sustainable Applications: Recent Advances and Perspectives

Nanomaterials, due to their unique structural and functional features, are widely investigated for potential applications in a wide range of industrial sectors. In this context, protein-based nanoparticles, given proteins’ abundance, non-toxicity, and stability, offer a promising and sustainable methodology for encapsulation and protection, and can be used in engineered nanocarriers that are capable of releasing active compounds on demand. Zein is a plant-based protein extracted from corn, and it is biocompatible, biodegradable, and amphiphilic. Several approaches and technologies are currently involved in zein-based nanoparticle preparation, such as antisolvent precipitation, spray drying, supercritical processes, coacervation, and emulsion procedures. Thanks to their peculiar characteristics, zein-based nanoparticles are widely used as nanocarriers of active compounds in targeted application fields such as drug delivery, bioimaging, or soft tissue engineering, as reported by others. The main goal of this review is to investigate the use of zein-based nanocarriers for different advanced applications including food/food packaging, cosmetics, and agriculture, which are attracting researchers’ efforts, and to exploit the future potential development of zein NPs in the field of cultural heritage, which is still relatively unexplored. Moreover, the presented overview focuses on several preparation methods (i.e., antisolvent processes, spry drying), correlating the different analyzed methodologies to NPs’ structural and functional properties and their capability to act as carriers of bioactive compounds, both to preserve their activity and to tune their release in specific working conditions

Vegetable Tannin as a Sustainable UV Stabilizer for Polyurethane Foams

A vegetable tannin, a flavonoid-type natural polyphenolic compound, was used to promote the stabilization of polyurethane foams against UV radiation. Several polyurethane foams were synthesized by using an isocyanate, and a mixture of ethoxylated cocoalkyl amine and vegetable tannin. The content of vegetable tannin was varied from 0 to 40 wt %. The effects of tannin and water (used as a blowing agent) on the foaming kinetics and cellular morphology of foams were investigated. Samples were subjected to accelerated weathering under UV radiation for 3 to 24 h, and FTIR and DMA analyses were conducted to assess the performance change. The former analysis revealed a strong inhibiting effect of tannin on urethane linkage degradation during the UV treatment. The mechanical properties were significantly affected by the addition of tannin. The capability of the foams to withstand UV radiation was dependent on the amount of tannin. At tannin contents higher than 20%, the decrease in mechanical properties under UV irradiation was almost avoided

Novel eugenol‐based antimicrobial coatings on aluminium substrates for food packaging applications

Active packaging systems, interacting directly with the enclosed food, can delay or inhibit those phenomena responsible for food quality decay, contributing to the food shelf-life extension. In this work a vinyl resin-based coating containing free or loaded eugenol (EG) in Santa Barbara Amorphous (SBA)15 mesoporous silica nanoparticles is designed to coat flexible aluminium foils to obtain an antimicrobial material. Thermogravimetric analysis shows a good loading capacity of eugenol in SBA15 (48% wt/wt). SEM analysis shows a good dispersion of free EG in the hosting polymeric matrix, whereas some EG/SBA15 particles aggregations are observed in the material. Water contact angle highlights a higher hydrophobicity of the eugenol based-materials (>90°) compared to the pristine vinyl coating (85°). Electrochemical impedance spectroscopy highlights no corrosion phenomena of the VIN/5%(EG/SBA15EG) coating and corrosion phenomena of the VIN/5%EG coating after 7 days of exposure to lactic acid pH = 4. Finally, the two active coatings are studied to evaluate their antibacterial activity using the ISO 22196. Interestingly, results demonstrate that when eugenol is loaded in the SBA15 mesoporous silica nanoparticles the antimicrobial activity of the material significantly increases against both foodborne pathogens and food spoilage bacteria, achieving the highest microbial growth reduction on S. aureus (R = 3.62 log)

Enhanced in vitro antitumor activity of a titanocene complex encapsulated into polycaprolactone (PCL) electrospun fibers

The purpose of this work was to achieve detailed biomaterials characterization of a drug delivery system for local cancer treatment based on electrospun titanocene trichloride-​loaded resorbable polycaprolactone (PCL) fibers. METHODS: The PCL fibers were characterized for their structural, morphologic and physical properties. The drug release kinetics of the titanocene complex was investigated at different concentrations, to obtain a set of correlations between structure and tuneable release. After exposing cancer cells directly onto the surface of PCL fibers, the anti-​proliferative effects of titanocene-​loaded PCL were assessed by: (i) counting viable cells via live​/dead staining methods, and (ii) analyzing cell apoptosis. Titanocene concentration influenced fiber diameters reduced for PCL filled with titanocene. X-​ray analysis suggested that the titanocene, encapsulated into the PCL fibers, is not allowed to crystallize and exists as amorphous aggregates into the fibers. The titanocene release curves presented two stages unrelated to PCL degradation: an initial burst release followed by a release linear with time, extending for a very long time. All of the titanocene-​loaded fibers revealed sustained drug release properties suggesting their potential clinical applicability for the treatment of local cancer diseases

Development of active films utilizing antioxidant compounds obtained from tomato and lemon by-products for use in food packaging

This study focused on the recovery of antioxidant compounds from lemon and tomato by-products for use as natural additives in the development of active food packaging formulated using three different polymeric matrices that included low-density polyethylene (LDPE), polylactic acid (PLA), and G-polymer (GP). The films were characterized according to chemical-physical, thermal analyses, and their barrier and mechanical properties. Migration assays were performed to evaluate the release of active compounds from polymeric matrices, which were quantified in the food simulant by high-performance liquid chromatography with a diode array detector and then confirmed via liquid chromatography coupled to mass spectrometry. The antioxidant capacities of the films were determined to evaluate their applicability for use as antioxidant-active packaging. The incorporation of extracts into polymers resulted in different structural changes and enhanced properties according to the nature of the polymeric matrix based on the interactions of the –OH groups of polyphenols and the chemical groups of the polymers. The lemon (LE) and tomato (TE) extracts lead to a substantial improvement in water barrier properties of PLA and GP-based films. The active PLA and GP films released high amounts of polyphenolic compounds (up to 65% for GP containing LE); mainly hesperidin and eriocitrin for LE films, and chrologenic acid for TE films. PLA loaded with lemon extract at 4% was selected as the most suitable for use as antioxidant packaging to extend the shelf-life of foods with high fat contentL. Barbosa-Pereira is grateful to the Spanish Ministry of Science, Innovation and Universities for her “Juan de la Cierva-Incorporación” Grant (Agreement No. IJCI-2017-31665). C. H. Barbosa is grateful for her research grant in the frame of the VIPACFood project (ARIMNET2/0003/2016) and for the Ph.D. Grant 2021.08154.BD from the Fundação para a Ciência e Tecnologia (FCT), PortugalS