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BACKGROUND Brazil is responsible for 60% of the global production of orange juice, accounting for over three‐quarters of global orange juice exports, resulting in large quantities of orange bagasse (OB). This is an underutilized byproduct of the orange juice industry and corresponds to 50% of the fruit weight. The objectives of this study were to produce cellulose from OB using a combination of ultrasound and peracetic acid (PA) treatment, and to characterize the obtained materials according to their microstructure, crystallinity, thermal stability and water sorption behavior, and their cellulose, hemicellulose and lignin contents. RESULTS Ultrasound pretreatment alone was not effective in altering the composition of OB. Samples subjected to both ultrasound and PA presented higher cellulose contents and lower hemicellulose and lignin contents in comparison to their respective samples undergoing PA treatment alone. The sample subjected to ultrasound for 10 min at a 30% amplitude combined with PA treatment for 24 h (USPA.24) resulted in the highest crystallinity index (54%), with 81.49% cellulose, 0.88% hemicellulose and 2.68% lignin. The increase in cellulose content of samples also resulted in lower water‐holding capacity, solubility and water adsorption capacity of samples. CONCLUSION Ultrasonication associated with PA treatment can be considered a promising approach and effective protocol for the extraction of cellulose from lignocellulosic residues, and it has the advantages of simplicity and environmental friendliness when compared to conventional methods, reducing the toxicity and amount of the resulting effluents. © 2020 Society of Chemical Industry (SCI)

Cellulose is a natural, unbranched, and fibrous homopolymer that is a major component in several agroindustrial residues. The aim of this study was to extract cellulose from oat hulls and then to modify it using a green route to obtain esterified cellulose through reaction with organic acids employing the reactive extrusion process, which is a process that presents some advantages, including low effluent generation, short reaction times, and it is scalable for large scale use. Citric (CA) and succinic (SA) acids were employed as esterifying agents in different concentrations (0, 5, 12.5, and 20%). Modified cellulose samples were characterized by their degree of substitution (DS), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (DRX), scanning electron microscopy (SEM), wettability, oil and water absorption capacities, and thermal stability. DS of modified samples ranged from 2.28 to 3.00, and FTIR results showed that the esterification occurred in all samples for both acids by observation of important bands at 1720 and 1737 cm−1 for samples modified with CA and SA, respectively. All modified samples presented increased hydrophobicity. The modification did not have an influence on the morphological structure or crystallinity pattern of all samples. This study proved to be possible to modify cellulose using a simple and ecofriendly process based on reactive extrusion with organic acids.

BACKGROUND Orange bagasse (OB) is an agroindustrial residue of great economic importance that has been little explored for the extraction of cellulose. The present study aimed to investigate different combinations of chemical (sodium hydroxide, peracetic acid and alkaline peroxide) and physical (autoclaving and ultrasonication) treatments performed in one‐step processes for cellulose extraction from OB and to characterize the materials obtained according to their composition, morphology, crystallinity and thermal stability. RESULTS The processing yields ranged from 140 to 820 g kg−1, with a recovery of 720–1000 g kg−1 of the original cellulose. Treatments promoted morphological changes in the fiber structure, resulting in materials with higher porosity, indicating partial removal of the noncellulosic fractions. The use of combined chemical treatments (NaOH and peracetic acid) with autoclaving was more efficient for obtaining samples with the highest cellulose contents. CONCLUSION Therefore, ACSH (processed by autoclaving with NaOH) was the most effective one‐step treatment, resulting in 71.1% cellulose, 0% hemicellulose and 19.0% lignin, with a crystallinity index of 42%. The one‐step treatments were able to obtain materials with higher cellulose contents and yields, reducing reaction times and the quantity of chemical reagents employed in the overall processes compared to multistep conventional processes. © 2020 Society of Chemical Industry

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Recentemente tem aumentado o interesse no desenvolvimento de novos produtos obtidos a partir de matérias-primas de fonte renovável em todos os setores industriais, incluindo a indústria farmacêutica. O presente trabalho teve como objetivo produzir filmes orodispersíveis (ODFs) à base de amido de mandioca, gelatina e goma xantana, pelo processo de casting, assim como caracterizá-los quanto à sua microestrutura, solubilidade, grau de intumescimento, permeabilidade ao vapor de água e propriedades mecânicas. Foi empregado delineamento experimental de misturas ternárias para se avaliar o efeito dos três biopolímeros sobre as propriedades dos filmes produzidos. Os filmes à base de gelatina pura e a mistura binária entre amido e gelatina se mostraram às alternativas mais promissoras para serem usadas como matrizes poliméricas para a liberação de princípios ativos na cavidade bucal, uma vez que estes apresentaram os melhores resultados de solubilidade e as melhores propriedades mecânicas.