Recovery and evaluation of cellulose from agroindustrial residues of corn, grape, pomegranate, strawberry-tree fruit and fava

Mariana Vallejo,Marta Henriques,Cândida Maria Malça,Rachel Cordeiro,Pedro Morouço,Paulo A N Dias,Carla Moura,Inês J Seabra

doi:10.1186/s40643-021-00377-3

Abstract

Considering the expected increasing demand for cellulose fibers in the near future and that its major source is wood pulp, alternative sources such as vegetable wastes from agricultural activities and agro-food industries are currently being sought to prevent deforestation. In the present study, cellulose was successfully isolated from six agroindustrial residues: corncob, corn husk, grape stalk, pomegranate peel, marc of strawberry-tree fruit and fava pod. Cellulose fibers were characterized by Fourier-transform infrared spectroscopy, thermogravimetric analysis, stereomicroscopy and scanning electron microscopy (SEM). Despite the evident morphological differences among the extracted celluloses, results revealed similar compositional and thermal properties with the wood-derived commercial microcrystalline cellulose used as a control. Trace amounts of lignin or hemicellulose were detected in all cellulose samples, with the exception of corncob cellulose, that exhibited the greatest extraction yield (26%) and morphological similarities to wood-derived microcrystalline cellulose, visible through SEM. Furthermore, corncob cellulose was found to have thermal properties (TOnset of 307.17 °C, TD of 330.31 °C, and ΔH of 306.04 kJ/kg) suitable for biomedical applications.

Highlights

In the upcoming years, the demand for cellulose fibers is expected to exceed the available supply, considering the continual research that has led to the development of novel cellulose-based products, in the food and biomedical fields (Hindi 2017; Abdul Khalil et al 2020)
In an effort to seek alternative sources for wood-derived cellulose, cellulose derived from bacteria and chemical synthesis has recently been the focus of attention of the high-tech industry
In this study, agroindustrial residues of corn, grape, pomegranate, strawberry-tree fruit and fava were subjected to a multi-step extraction procedure in order to isolate cellulose with potential to be used in fiber-reinforced composite scaffolds for biomedical applications

Summary

Introduction

The demand for cellulose fibers is expected to exceed the available supply, considering the continual research that has led to the development of novel cellulose-based products, in the food and biomedical fields (Hindi 2017; Abdul Khalil et al 2020). Wood pulp remains the most popular source of cellulose due to its abundancy and cost-effective extraction which enable a large-scale production. The processes involved entail several environmental impacts, namely forest devastation and consequent contribution to global warming, which have driven researchers to seek environmentally friendly and biocompatible materials as Currently, tissue engineering is one of the research fields that is exploring cellulose as a raw material to be applied in the formulation of biomaterials to replace or contribute to the regeneration of biological tissues such as skin, bone and cartilage (Hickey and Pelling 2019). Cellulose has several features that provide significant improvements for biocomposites, such as nontoxicity, biocompatibility, biodegradability, low cost and high mechanical modulus (Carlström et al 2020; Naseri et al 2016; Sultan and Mathew 2019). In an effort to seek alternative sources for wood-derived cellulose, cellulose derived from bacteria and chemical synthesis has recently been the focus of attention of the high-tech industry.

Methods

Results

Conclusion