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This work is focused on the development of renewable and biodegradable films by the valorisation of wastes from food processing industries, with the aim of contributing to the development of more sustainable films. In this context, different contents of blueberry pomace (BP) were incorporated into cassava starch (CS) film forming solutions and the functional properties of the films prepared by solution casting were investigated, specifically, thermal, optical and physicochemical properties. BP-incorporated films showed good barrier properties against light, indicating their beneficial effect to prevent food deterioration caused by UV radiation when these films are used for food packaging applications. These results were related to the presence of aromatic compounds in BP, which can absorb light at wavelengths below 300nm. Furthermore, all films maintained their structural integrity after immersion in water (24h) and the maximum swelling displayed was lower than 300%. Additionally, the release of active compounds from BP into food simulants (after 10days) showed higher migration into the acetic acid medium in comparison with the ethanol medium. Therefore, the incorporation of BP into CS film forming solution resulted in the improvement of film performance, suggesting the potential application of these films as active packaging.

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Concern about environmental issues has motivated research into the development of biodegradable packaging from renewable sources. Natural polymers such as starch constitute a good alternative for diminishing the use of nonbiodegradable and nonrenewable components in the packaging industry. However, depending on the botanical source, films with different properties are formed. The aim of this study was to evaluate the film‐forming capacity of different starch sources (cassava, corn, potato, and wheat) by casting with starch contents from 2 to 6%. Principal component analysis methodology was used to evaluate the correlation between the formulations and their physicochemical and mechanical properties. It was not possible to produce continuous films based on potato starch, probably because of its very low amylose content (10%). The corn‐, cassava‐, and wheat‐starch‐based films were characterized by their thicknesses (0.06–0.22 mm), moisture contents (19–26%), water solubilities (13.7–26.5%), water‐vapor permeabilities (WVPs; 0.19–0.48 g mm h−1 m−2 kPa−1), wettabilities (35–106°), biodegradabilities in soil, and thermal and mechanical properties (tensile strength = 1.9–6.7 MPa, elongation = 41–166%, and Young's modulus = 8–127 MPa). The wheat starch films presented higher WVPs and lower mechanical properties. The cassava starch films presented lower wettabilities and good mechanical properties; this suggested that their use in packaging for products, such as fruits and vegetables, with higher water activities could be feasible. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46564.

Intelligent packaging is an emerging area of food technology that can provide better preservation and be of further convenience for consumers. It is recommended that biodegradable materials be used to develop low-impact designs for better packaging, which could benefit the environment by simply expanding their use to new areas. In this work, corn starch, glycerol and blueberry powder (with and without prior fruit bleaching) were used to produce films by casting. Blueberry powder, a co-product from juice processing, which is rich in anthocyanins, was added in the films to evaluate its potential as a colorimetric indicator, due to the ability of anthocyanin to change color when placed in an acidic or basic environment. After the films were immersed in different buffer solutions, visual color changes were observed, where the films became reddish at acidic pH and bluish at basic pH. The ΔE* values were greater than 3, suggesting a visually perceptible change to the human eye. The samples with fruit bleaching (CB) were visually darker (lower luminance values), while the samples without bleaching (SB) had a lighter color and higher brightness, represented by larger L* values. These results indicate the potential of blueberry powder as a pH indicator for intelligent food packaging or even for sensing food deterioration.

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Beta-carotene was microencapsulated by freeze-drying using native pinha˜o starch, hydrolysed pinha˜o starch 6 dextrose equivalent (DE), hydrolysed pinha˜o starch 12 DE and the mixture of these materials with gelatin as coating material. The purpose of this research was to produce and characterize these microcapsules. The capsules' efficiency, surface content, moisture, morphology, solubility, particle size and glass transition temperature were analysed. The hydrolysed pinha˜o starch 12 DE showed the highest total b-carotene content and the lowest surface b-carotene content, unlike the native starch. Using scanning electron microscopy, it was observed that all microcapsules presented undefined shapes. The samples with gelatin had wider particle size distribution, higher diameters, lower solubility and higher glass transition temperature when compared with other the samples. Results obtained suggest that the modified pinha˜o starch can be considered as potential wall material for encapsulation of b-carotene.