Agro-industrial waste is a by-product of agriculture-based industries which are often rich in lignocellulosic materials and bioactive compounds. The management of these wastes is poorly regulated by the industries where it is commonly discarded in uncontrolled practices. Such activities have created an adverse effect on ecosystem and the economy as a whole. Due to this matter, enormous researches have been conducted to recover usable compounds from these wastes. Cellulose from agro-industrial residue has become a type of renewable resource in various applications. This review article describes the chemistry, structure, and method used to obtain cellulose and nanocellulose from various sources of agro-industrial waste. This report also covers some of the recent innovative food applications of cellulose and nanocellulose. In the latter part of this review, the safety issues regarding the use of nanocellulose in food application are summarized.

The application of renewable nanomaterials, like nanocrystalline cellulose (NCC), has recently been widely studied by many researchers. NCC has many benefits such as high aspect ratio, biodegradability, and high number of hydroxyl groups which offer great opportunities for modification. In this study, the NCC derived from empty fruit bunches (EFB) was modified with aminosilane, 3-(2-aminoethylamino)propyl-dimethoxymethylsilane (AEAPDMS), and the characterization was performed to investigate the potential as carbon dioxide (CO₂) capture. Modification of NCC with AEAPDMS was carried out in water/ethanol solvent (80/20) (v/v) with a ratio of NCC to aminosilane of 1 : 1, 1 : 2, 1 : 3, and 1 : 4 w/w%. The effects of AEAPDMS on NCC were characterized using Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), X-ray diffraction (XRD) analysis, elemental analysis (CHNS), and transmission electron microscopy (TEM). The existence of AEAPDMS onto NCC was confirmed by ATR-FTIR spectroscopy as the new peaks of NH₂were bending and wagging, and Si-CH₃appeared. The thermal stability of NCC increased after modification due to the interaction with AEAPDMS. The elemental analysis result showed that the nitrogen content increased with an enhancement ratio of the modifiers. The XRD indicated that the crystallinity decreased while the rod-like geometry of NCC was maintained after amorphous AEAPDMS grafted on the NCC. Since AEAPDMS can be grafted on the NCC, the sample is applicable as CO₂capture.