Characterization, biological, and antimicrobial properties of nanocellulose isolated from peanut shells (Arachis hypogaea L.)

Due to its promising features, cellulose, the most plentiful renewable material in nature, is used in a variety of industrial processes. In this work, we used peanut shells (Arachis hypogaea L.) for the purpose of producing microcrystalline cellulose (MCCs) and nanocrystalline cellulose (CNCs), respectively. The following process was used to separate cellulose from peanut shells: dewaxing, delignification/bleaching, and acid hydrolysis. The structural features of the isolated microcrystalline cellulose (MCCs) and cellulose nanocrystalline (CNCs) samples were tested by Fourier transform infrared spectroscopy (FTIR). Scanning electron microscopy (SEM) was used to morphologically analyze of the samples (peanut shells, microcrystalline cellulose, and nanocrystalline cellulose). The prepared CNCs' elemental composition was revealed by energy dispersive X-rays (EDX), and their crystallinity was shown by X-ray diffraction (XRD). The yield of peanut shells cellulose was (31.81%). FTIR analysis for the bleached peanut shells cellulose revealed the efficacious removal of the non-cellulosic materials and amorphous components from the polymer matrix. The obtained peanut shells' XRD results showed native cellulose's typical peaks (type I), along with a crystallinity index (CrI = 72.53%). Also, acid hydrolysis phase was used to adapt microcrystalline cellulose (MCCs) into cellulose nanocrystalline (CNCs) with higher crystallinity (CrI = 77.96%). According to each of these assays, the chemical treatment was successful in eliminating the non-cellulosic substances and obtaining a cellulose nanofiber.The antibacterial activity carried out against three bacterial strains (Staphylococcus aureus, Escherichia Coli, and Salmonella typhimurium) that cellulose nanofibers showed moderate antibacterial activity against a strain Staphylococcus aureus and Salmonella typhimurium.The current study demonstrates the viability of employing peanut shells as a cost-effective source for acquiring CNCs that are intended for use in the food and pharmaceutical industries.