Strategy Towards Active Food Packaging Material From Cellulose Nanoparticles and its Characterization

The utilization of agro-industrial wastes such as sugarcane bagasse (SCB) as a source of cellulose has influenced a wide range of interest in various applications such as food packaging, drug delivery, paper production, etc. Owing to the rich source of cellulose in SCB, the nanoparticle was prepared efficiently. The pure form of cellulose was isolated from SCB by eliminating the remaining components such as hemicellulose and lignin by treating SCB with a soluble base and a bleaching agent. Cellulose nanoparticles were synthesized from the purified cellulose by acid hydrolysis using H2SO4 followed by dialysis to remove sulfate ions and attain neutrality. The obtained nanoparticles were characterized using FTIR spectroscopy that helped to confirm the exclusion of lignin and hemicellulose. The crystalline nature of the cellulose nanoparticles (CNPs) was confirmed using X-Ray Diffraction (XRD). The morphology of CNPs was studied by scanning electron microscopy (SEM), and the particle size of CNPs was found to be 189 nm by particle size analysis (PSA). Further, this study proved the nanomaterial preparation from agro-wastes can be utilized to develop food packaging film in food industries.

Cellulose Nanoparticles Prepared by Ionic Liquid-Assisted Method Improve the Properties of Bionanocomposite Films

Bionanocomposites have garnered wide interest from the packaging industry as a biocompatible alternative to non-biodegradable petroleum-based synthetic materials. This study presents a simple and eco-friendly alternative to produce cellulose nanoparticles using a protic ionic liquid, and the effects of their incorporation in cassava starch and chitosan films are evaluated. Bionanocomposite films are prepared using the solvent casting method and are characterized using X-ray diffraction, Fourier transform infrared spectroscopy, zeta potential, thermogravimetry analysis, and transmission electron microscopy. The achieved yield of cellulose nanoparticles is 27.82%, and the crystalline index is 67.66%. The nanoparticles’ incorporation (concentration from 0.2 to 0.3%) results in a progressive reduction of water vapor permeability up to 49.50% and 26.97% for starch and chitosan bionanocomposite films, respectively. The starch films with 0.1% cellulose nanoparticles exhibit significantly increased flexibility compared to those without any addition. The nanoparticles’ incorporation in chitosan films increases the thermal stability without affecting the mechanical properties. The study demonstrates that the use of cellulose nanoparticles obtained using protic ionic liquid can be a simple, sustainable, and viable method to produce bionanocomposites with tailored properties useful for applications in the packaging industry.

Preparation of Cellulose Nanoparticles from Foliage by Bio-Enzyme Methods

There are vast reserves of foliage in nature, which is an inexhaustible precious resource. In this study, the chemical components of five foliage types (pine needles, black locust tree leaves, bamboo leaves, elm leaves and poplar leaves) were analyzed, including cellulose content, hemicellulose content, and lignin content. The bio-enzymatic method was then used to prepare cellulose nanoparticles (CNPs) from these five kinds of leaves, and the prepared CNPs were analyzed using TEM, FTIR, FESEM, and XRD. The results showed that the content of hemicellulose in bamboo leaves was the highest, and the lignin content in the other four leaves was the highest. The cellulose content in the five kinds of foliage was arranged from large to small as pine needles (20.5%), bamboo leaves (19.5%), black locust leaves (18.0%), elm leaves (17.6%), and poplar leaves (15.5%). TEM images showed that the CNPs prepared by the five kinds of foliage reached the nanometer level in width and the micrometer level in length; therefore, the CNPs prepared in this study belonged to cellulose nanofibers (CNFs). The results of FTIR and XRD showed that CNFs prepared by the enzyme treatment exhibited a typical crystalline structure of cellulose II. The degree of crystallinity (DOC) of CNFs prepared from pine needle, poplar leaves, and bamboo leaves are 78.46%, 77.39%, and 81.51%, respectively. FESEM results showed that the CNFs prepared from pine needles, poplar leaves and bamboo leaves by enzymatic method presents a three-dimensional (3D) network structure, and their widths are 31 nm, 36 nm, and 37 nm, respectively. This study provides a meaningful reference for broadening the use of foliage types and improving their added value.

Cellulose as a Natural Emulsifier: From Nanocelluloses to Macromolecules

During the last decade, cellulose structural features have been revisited, with particular focus on its structural anisotropy (amphiphilicity) and interactions determining its recalcitrance to dissolution. Evidences for cellulose amphiphilicity are patent, for instance, in its capacity to adsorb at oil–water interfaces, thus being capable of stabilizing emulsions. This behavior is observable in all its forms, from cellulose nanoparticles to macromolecules. This chapter is divided into two main parts; first, the fundamentals of emulsion formation and stabilization will be introduced, particularly focusing on the role of natural emulsifiers. Secondly, the emerging role of cellulose as a natural emulsifier, where the ability of cellulose to form and stabilize emulsions is revisited, from cellulose nanoparticles (Pickering-like effect) to macromolecules (i.e., cellulose derivatives and native molecular cellulose).