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This study aimed to investigate the effects of polydimethylsiloxane (PDMS) with a low surface energy on the structure and physicochemical properties of starch/poly (butylene adipate- co -terephthalate) (PBAT) blown films. The film's appearance was not significantly changed after the addition of PDMS. Compared with the films without PDMS, the films with PDMS displayed a smoother surface. A 2% w/w PDMS addition resulted in the maximum mechanical properties (8.10 MPa of strength, 211.00% of modulus) and surface hydrophobicity (87°) of the films. By contrast, the film with 3% w/w PDMS showed the lowest light transmittance, water vapor (2.73 × 10−11 g·cm·cm2·s−1·Pa−1) and oxygen permeability (9.73 × 10−13·cm3·cm·cm−2·s−1·Pa−1), owing to the improved tightness of the matrix, which increased the zigzag path for molecules to pass through. Films with higher PDMS contents effectively extended the shelf life of packaged bananas and shiitake mushrooms, benefiting from the outstanding and appropriate barrier properties, according to principal component analysis results. Findings supported that high-content starch/PBAT films containing PDMS had potential in the preservation of fresh agricultural products. [Display omitted] [ABSTRACT FROM AUTHOR]

Cassava starch was grafted with three different esters by the etherification reaction and its modification was characterized by 1 H NMR, FTIR, DSC, SEM, XDR, contact angle and SLS. The samples grafted with diethyl maleate, dipropyl maleate, and dibutyl maleate showed DS values of 2.3, 1.0 and 2.0, respectively, determined from 1 H NMR analysis and confirmed by FTIR analysis, with the appearance of bands at 1721, 1550 and 1126 cm −1 . The FTIR, XRD, SEM and DSC results indicated a change in the intra and intermolecular hydrogen interactions in the grafted starch when compared to native starch. Based on the contact angles, it was observed that the macromolecular starch chain acquired hydrophobic characteristics through the substitution of the hydrogens with di maleate esters. The characteristics acquired by grafted starch allow it to be used for the encapsulation of bioactive molecules for the production of bioactive packages and the production of biodegradable packages. [ABSTRACT FROM AUTHOR]

Abstract: Three different types of cellulose nanoparticles: (i) nano-fibrils cellulose (NFC), (ii) nano-fibrils cellulose oxidized using the tempo reaction (NFCt) and (iii) cellulose whiskers, were incorporated into HPMC edible films at different concentrations. The films were examined for mechanical and moisture barrier properties verifying how the addition of cellulose nano-particles affected the water affinities (water adsorption/desorption isotherms) and the diffusion coefficients. In general, addition of NFC or NFCt negatively affected the performance of the HPMC films. However the reinforcing effect of the cellulose particles was observed when whiskers were used as the filling material; an increase of 22% in tensile strength and 55% in Young''s modulus were achieved while the elongation at break of the films was preserved. Addition of whiskers also improved the water barrier properties of the composite films. This effect was attributed to the lower water affinity of the composite films, as compared with the HPMC films, since the water diffusivity values were not affected by the addition of whiskers. Furthermore, the whiskers only decreased 3–6% the transparency of the HPMC films showing 86–89% visible light transmission values, allowing application as edible barrier and transparent film. [Copyright &y& Elsevier]

Abstract: Bioactive composite coatings based on hydroxypropyl methylcellulose (HPMC), broad-spectrum food preservative nisin (Nisaplin®), and hydrophilic plasticizer glycerol were evaluated for mechanical, barrier (O2, H2O), transparency and microbiological effectiveness. Incorporation of Nisaplin® into cellulose derivative, i.e. HPMC-based films strongly increased the film thickness due to salt crystallization while glycerol had normalized it by homogenous dispersibility. The tensile strength of composite films decreased, however ultimate elongation was increased significantly. The dynamic vapour sorption experimental data fitted by different models had shown lesser values of respective energy constants for composite films. The transparency and water permeability of HPMC films were negatively affected by the additives as an effect individual but conversely as combined effect for film transparency. Film bioactivity demonstrated efficacy against Listeria > Enterococcus > Staphylococcus >Bacillus spp. These cellulose derivative based active films may thus be a key approach towards eradicating post-process contamination of healthy foods. [Copyright &y& Elsevier]