Towards suitable tests for the migration of metals from ceramic and crystal tableware: Work in support of the revision of the Ceramic Directive 84/500/EEC

This JRC report summarises and distils a series of investigations on the technical feasibility to testing compliance of tableware to potential lower limits for the release of metals. It investigated different protocols for articles ranging from tableware ,bakeware to crystalware, and for testing the rim of decorated wares. It also evaluated the performance of analytical methods for the quantification of a range of metals. The work provides scientific evidence needed in support of future risk management initiatives to ensure the safety of ceramics and crystal in the EU while fostering the EU single market.JRC.F.7-Knowledge for Health and Consumer Safet

Development of novel nano-biocomposite antioxidant films based on poly (lactic acid) and thymol for active packaging

Novel nano-biocomposite films based on poly (lactic acid) (PLA) were prepared by incorporating thymol, as the active additive, and modified montmorillonite (D43B) at two different concentrations. A complete thermal, structural, mechanical and functional characterization of all nano-biocomposites was carried out. Thermal stability was not significantly affected by the addition of thymol, but the incorporation of D43B improved mechanical properties and reduced the oxygen transmission rate by the formation of intercalated structures, as suggested by wide angle X-ray scattering patterns and transmission electron microscopy images. The addition of thymol decreased the PLA glass transition temperature, as the result of the polymer plasticization, and led to modification of the elastic modulus and elongation at break. Finally, the amount of thymol remaining in these formulations was determined by liquid chromatography (HPLC-UV) and the antioxidant activity by the DPPH spectroscopic method, suggesting that the formulated nano-biocomposites could be considered a promising antioxidant active packaging material.Spanish Ministry of Economy and Competitiveness (MAT2011-28468-C02-01). Marina Ramos would like to thank University of Alicante (Spain) for UAFPU2011-48539721S pre-doctoral research grant

Water kefir grains as an innovative source of materials: Study of plasticiser content on film properties

Microorganisms’ biomass is a sustainable and innovative source of biopolymers, such as proteins and polysaccharides, which are suitable for development of biodegradable films. In this work, an alternative material based on the entire biomass of water kefir grains was developed. The whole biomass was submitted to physical treatments of ultrasonic homogenization separated by a thermal treatment at 90 °C. The effect of glycerol on film properties was evaluated. The films obtained exhibited high transparency and homogeneity without cracks. Infrared spectroscopy revealed that the material is constituted basically by the polysaccharide dextran. The increasing plasticiser content decreased glass transition temperature. Indeed, the presence of plasticiser increased the amount of hydration water and the water vapour permeability. Moreover, the addition of 30 wt% of glycerol improved significantly the elasticity of films to 275 ± 15%. Results revealed that water kefir grains biomass is a viable and innovative source of biodegradable materials.Fil: Coma, Maria Eugenia. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; ArgentinaFil: Peltzer, Mercedes Ana. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; ArgentinaFil: Delgado, Juan Francisco. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; ArgentinaFil: Salvay, Andrés Gerardo. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; Argentin

Release and antioxidant activity of carvacrol and thymol from polypropylene active packaging films

The migration of antioxidant (AO) agents, carvacrol and thymol, from polypropylene (PP) packaging films containing the studied compounds at 80 g/kg separately and an equimolar mixture of them into food simulants was investigated. Fast and reliable analytical procedures were developed and validated for the analysis of the studied AOs in food simulants. For aqueous food simulants, solid phase extraction followed by GC–MS analysis was performed. Fatty food simulants were directly analysed by GC–MS and HPLC-UV for isooctane and ethanol 950 mL/L, respectively. The release of AOs from the films was dependent on the type of food stimulant and AO incorporated. In particular, high levels of migration were obtained for both AOs into isooctane, showing thymol higher migration. The release kinetics of AOs from PP films showed a Fichian behaviour with diffusion coefficients ranging from 1 to 2 × 10−14 m2/s; except for the diffusion into isooctane where 4-6 higher values were obtained. The antioxidant activity of migration extracts was confirmed by the DPPH method, showing thymol a higher antioxidant capacity especially into isooctane with a 42.2% of inhibition. The obtained results suggest that carvacrol and thymol show a potential use as AOs for active packaging for extending the shelf-life of food products.Spanish Ministry of Economy and Competitiveness (MAT-2011-28640-C02-01). Marina Ramos would like to thank University of Alicante (Spain) for UAFPU2011-48539721S predoctoral research grant

Kombucha fermentation in yerba mate: Cellulose production, films formulation and its characterisation

The production of Kombucha fermented beverage generates a side-stream composed of bacterial cellulose, a source of biopolymer to develop food contact materials. This work aims to study Kombucha fermentation in yerba mate infusion to maximise cellulose production and its processing for film formulation. Yerba mate infusion with sucrose resulted in an extraordinary substrate for Kombucha fermentation with an optimised cellulose production of 19.4 g/l and 0.29 g/g of yield. Filmogenic dispersions were analysed in terms of rheology and particle size distribution. Microscopic characterisation of films exhibited homogeneous surfaces. The addition of glycerol, as well as the solids from the fermented broth, resulted in a significant increase in hydration and a reduction in elastic modulus, ultimate tensile strength and glass transition temperature of the films. The results revealed that the formulation containing the Kombucha fermented media showed similar properties to the glycerol plasticised material. This could be considered a novel result as it may replace the use of traditional plasticisers. Bioactive compounds from yerba mate provided an antioxidant activity greater than 95% of ABTS radical inhibition to cellulosic material, demonstrating that natural bioactive cellulose-based films are materials that potentially protect food products against oxidation.Fil: Ramírez Tapias, Yuly Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; ArgentinaFil: Di Monte, Maria Victoria. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; ArgentinaFil: Peltzer, Mercedes Ana. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Salvay, Andrés Gerardo. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; Argentin

Characterization of thermal, mechanical and hydration properties of novel films based on Saccharomyces cerevisiae biomass

Characterization of films made of Saccharomyces cerevisiae biomass was performed so as to better understand their properties. The treated yeast biomass, named HTH, was prepared by subsequent steps including a first homogenization, heat treatment and final homogenization. Glycerol was added as plasticizer and films were evaluated using different techniques to measure mechanical behaviour, thermal properties and water sorption. Temperature of maximum decomposition rate was found near 300 °C, while the gradually disappearance of amide II band (1543 cm−1) occurred from 225 °C, identified by FTIR spectra of residues of thermally treated films by TGA. A glass transition at 64.5 ± 3.0 °C and two low energy endotherms at 61.2 ± 2.3 and 106.1 ± 0.7 °C were determined in completely dehydrated films without glycerol. When glycerol content was increased the glass transition temperature was shifted to lower values, a maximum elongation of 12% was reached, Young's modulus decreased from 88 to 9 MPa and the water uptake of films raised from 0.49 to 0.79 g H2O/g of dry matter. The characterization of yeast biodegradable films provided evidence of their properties for a potential future use in packaging industry. Industrial relevance: The development of biodegradable films based on yeast biomass carries many advantages to the food industry, such as, the possibility of using commercial pressed baker's yeast or an industrial residue from brewing industry, the use of a low-cost sources and the application of environmentally friendly procedures. The methodologies applied for the development of the film forming dispersion, high pressure homogenization and thermal treatment, are able to be scaled-up to an industrial level.Fil: Delgado, Juan Francisco. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Área Ingeniería en Alimentos; ArgentinaFil: Peltzer, Mercedes Ana. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Área Ingeniería en Alimentos; ArgentinaFil: Salvay, Andrés Gerardo. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Área Ingeniería en Alimentos; ArgentinaFil: de la Osa, Orlando. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Área Ingeniería en Alimentos; ArgentinaFil: Wagner, Jorge Ricardo. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Área Ingeniería en Alimentos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Biobased materials from microbial biomass and its derivatives

There is a strong public concern about plastic waste, which promotes the development of new biobased materials. The benefit of using microbial biomass for new developments is that it is a completely renewable source of polymers, which is not limited to climate conditions or may cause deforestation, as biopolymers come from vegetal biomass. The present review is focused on the use of microbial biomass and its derivatives as sources of biopolymers to form new materials. Yeast and fungal biomass are low-cost and abundant sources of biopolymers with high promising properties for the development of biodegradable materials, while milk and water kefir grains, composed by kefiran and dextran, respectively, produce films with very good optical and mechanical properties. The reasons for considering microbial cellulose as an attractive biobased material are the conformational structure and enhanced properties compared to plant cellulose. Kombucha tea, a probiotic fermented sparkling beverage, produces a floating membrane that has been identified as bacterial cellulose as a side stream during this fermentation. The results shown in this review demonstrated the good performance of microbial biomass to form new materials, with enhanced functional properties for different applications.Fil: Cottet, Agustina Celeste. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; ArgentinaFil: Ramírez Tapias, Yuly Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; ArgentinaFil: Delgado, Juan Francisco. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; ArgentinaFil: de la Osa, Orlando. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; ArgentinaFil: Salvay, Andrés Gerardo. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; ArgentinaFil: Peltzer, Mercedes Ana. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; Argentin

Nano-biocomposite films with modified cellulose nanocrystals and synthesized silver nanoparticles

Ternary nano-biocomposite films based on poly(lactic acid) (PLA) with modified cellulose nanocrystals (s-CNC) and synthesized silver nanoparticles (Ag) have been prepared and characterized. The functionalization of the CNC surface with an acid phosphate ester of ethoxylated nonylphenol favoured its dispersion in the PLA matrix. The positive effects of the addition of cellulose and silver on the PLA barrier properties were confirmed by reductions in the water permeability (WVP) and oxygen transmission rate (OTR) of the films tested. The migration level of all nano-biocomposites in contact with food simulants were below the permitted limits in both non-polar and polar simulants. PLA nano-biocomposites showed a significant antibacterial activity influenced by the Ag content, while composting tests showed that the materials were visibly disintegrated after 15 days with the ternary systems showing the highest rate of disintegration under composting conditions.L.V. would like to acknowledge the financial support from MIUR, PRIN 2010–11 project entitled “Nanomed” (prot.2010FPTBSH 009). M.P. and A.J. acknowledge the financial support from the Spanish Ministry of Economy and Competitiveness (MAT2011-28648-C02-1)

Controlled Release of Thymol from Poly(Lactic Acid)-Based Silver Nanocomposite Films with Antibacterial and Antioxidant Activity

Thymol and silver nanoparticles (Ag-NPs) were used to develop poly(lactic acid) (PLA)-based films with antioxidant and antibacterial performance. Different amounts of thymol (6 and 8 wt%) and 1 wt% Ag-NPs were added to PLA to produce the active films. Ag-NPs and thymol were successfully identified in the nanocomposite structures using spectroscopic techniques. A kinetic study was performed to evaluate the release of thymol and Ag-NPs from the nanocomposites to an aqueous food simulant (ethanol 10%, v/v) at 40 °C. The diffusion of thymol from the polymer matrix was affected by the presence of non-migrating Ag-NPs, which showed non-Fickian release behavior. The ternary system including 1 wt% Ag-NPs and 8 wt% thymol showed clear antibacterial performance by reducing the cell viability of Escherichia coli and Staphylococcus aureus by around 40% after 3 and 24 h of storage at 4, 25, and 37 °C compared to neat PLA. Significant antioxidant behavior of all active films was also confirmed using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method. The obtained nanocomposite films based on PLA and the addition of Ag-NPs and thymol were proven to have combined antioxidant and antibacterial performance, with controlled release of thymol. These formulations have potential applications in the development of innovative and customized active packaging systems to increase the shelf-life of food products.Authors would like to thank Spanish Ministry of Economy and Competitiveness (MAT-2015-59242-C2-2-R) and Generalitat Valenciana (IDIFEDER/2018/007) for their support of this research. Marina Ramos would like to thank University of Alicante (Spain) for the UAFPU2011-48539721S predoctoral research grant

Controlled Release, Disintegration, Antioxidant, and Antimicrobial Properties of Poly (Lactic Acid)/Thymol/Nanoclay Composites

Nano-biocomposite films based on poly (lactic acid) (PLA) were prepared by adding thymol (8 wt.%) and a commercial montmorillonite (D43B) at different concentrations (2.5 and 5 wt.%). The antioxidant, antimicrobial, and disintegration properties of all films were determined. A kinetic study was carried out to evaluate the thymol release from the polymer matrix into ethanol 10% (v/v) as food simulant. The nanostructured networks formed in binary and ternary systems were of interest in controlling the release of thymol into the food simulant. The results indicated that the diffusion of thymol through the PLA matrix was influenced by the presence of the nanoclay. Disintegration tests demonstrated that the incorporation of both additives promoted the breakdown of the polymer matrix due to the presence of the reactive hydroxyl group in the thymol structure and ammonium groups in D43B. Active films containing thymol and D43B efficiently enhanced the antioxidant activity (inhibition values higher than 77%) of the nano-biocomposites. Finally, the addition of 8 wt.% thymol and 2.5 wt.% D43B significantly increased the antibacterial activity against Escherichia coli and Staphylococcus aureus 8325-4, resulting in a clear advantage to improve the shelf-life of perishable packaged food.Authors would like to thank Spanish Ministry of Economy and Competitiveness (MAT2017-84909-C2-1-R) and Generalitat Valenciana (IDIFEDER/2018/007) for their support of this research. Marina Ramos would like to thank University of Alicante (Spain) for the UAFPU2011-48539721S predoctoral research grant. AJMV thanks ´Coimbra Chemistry Center and Fundação para a Ciência e Tecnologia (FCT) for the financial support through the programmes UID/QUI/UI0313/2020 and COMPETE