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The ionic gelation technique using chitosan to encapsulate active compounds has received lots of attention in the literature due to its ease-of-use and known biodegradability, biocompatibility and antimicrobial properties of the polymer. In this review, main studies from the last five years involving encapsulation of active compounds (natural and commercial/synthetic) are brought together in order to understand the encapsulation mechanisms of components with chitosan as well as the physical, chemical and morphological properties of the resulting particles. The application of these nanostructures in polymeric films was then investigated, since additives for packaging are an attractive premise and have only recently started being studied in the literature. Herein, comparisons are made between free and encapsulated bioactive compounds in different film matrices, as well as the effect of this activation on structure. Finally, this work details the mechanisms involved in the production of chitosan nanoparticles with active compounds and encourages new studies to focus on their application in packaging., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

The objectives of this study were to extract bioactive compounds from carrot by-products and evaluate their chemical stability after encapsulation in liposomes (L) coated either with chitosan (Ch) or using sodium tripolyphosphate for chitosan complexation (TPP-Ch). The main compounds quantified in this study were carotenoids and total phenolic compounds, which reached encapsulation efficiencies higher than 75%. The TPP-Ch charged with carrot extract showed greater particle size (90.5 nm) and zeta potential (+22 mV) than vesicles without coating (68.0 nm and -2 mV, respectively), indicating that liposomes were successfully coated with chitosan. Regarding results of the carotenoid's encapsulated stability, TPP-Ch particles were more efficient preventing their degradation in all the experimental conditions studied (40 and 70 °C). It is significant that loaded TPP-Ch particles demonstrated similar results for the stability of carotenoid-rich extracts in ethanol, which would therefore be suitable for application in food industry or any aqueous matrices., (Copyright © 2022. Published by Elsevier Ltd.)

Aiming the simplification of the production of chitosan nanoparticles as an encapsulating material, the primary approach of this study was to investigate the extraction of active compounds from acerola-pulp by-products directly in chitosan solution by using tip sonication. The results have shown that chitosan solution can be used as a good solvent, mainly for total phenolic compounds (TPC) extraction (1792.7 mg/100 g of dry by-product). The extract was submitted to ionic gelation process using, as counter-ion, the sodium tripolyphosphate to form loaded nanoparticles with TPC. The suspension was applied as protective coatings on the guavas. The nanoengineered coatings provided an effective barrier that delayed the maturation and maintained the green pigmentation for longer periods along with good firmness. To the best of our knowledge, this was the first study that uses chitosan solution as extraction solvent of TPC from food byproducts in order to facilitate the encapsulation process., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

This work is a comparative study of the application of mercerized soybean straw (MSS) and nanocellulose produced by acid (CNCs) or enzymatic hydrolysis (CNFs) as reinforcing fillers in soy protein isolate (SPI) films. CNCs presented average dimensions of about 10 nm-thick and 300 nm-long with a crystallinity index of 57%, whereas CNFs have similar diameters, though with greater lengths (>1 μm), lower crystallinity index (50%) and greater thermal stability. Incorporation of 5% of CNCs and CNFs (g/100 g of SPI) improved the SPI film tensile strength by 38 and 48% respectively, and decreased the SPI film elongation at break when compared to control films. The SPI-CNC films showed the lowest values for solubility, probably due to their higher crystallinity (63%). On the other hand, the water vapor permeability was solely reduced with CNF addition, which can be attributed to their higher aspect ratio (length/diameter) and a better incorporation into the protein matrix., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

This work investigated changes in the chemical composition and structure of soybean straw (SS) treated with alkali (NaOH 5% and 17.5%) and bleached with hydrogen peroxide (H 2 O 2 ) or sodium hypochlorite (NaOCl). Removal of the amorphous constituents increased the degree of crystallinity and the content of cellulose fibers particularly after reaction with high concentrations of alkali. Treatment with NaOH 17.5% contributed to the allomorph transition from cellulose I to II regardless of the bleaching agent, but H 2 O 2 as bleaching agent promoted more effective delignification. This work also evaluated the potential use of treated and non-treated SS as reinforcement filler in soy protein isolate film (SPI). Films added with treated SS presented higher mechanical resistance, lower elongation at break, and lower solubility in water. Addition of non-treated SS did not affect the properties of the SPI film significantly. The low solubility and the reasonable water vapor permeability of the composite films make them suitable packaging materials for fresh fruit and vegetables., (Copyright © 2016 Elsevier Ltd. All rights reserved.)