**Abstract**

In recent years, the potential of agricultural wastes has received increasing attention from academia and industry. The aim has been to identify strategies for the conversion of low-value wastes into new materials and other value-added products. Cellulose is a naturally abundant polymer that is readily available in various agricultural wastes. It is a linear polymer consisting of β-D-glucopyranose units (disaccharides) joined by glycosidic β-1,4 bonds. Nanoparticles can be extracted from cellulose fibers using a top-down mechanically or chemically treatment. Cellulose nanomaterials have generated significant interest due to their intrinsic properties such as large surface-to-volume ratios, high tensile strength, stiffness, and flexibility in addition to good dynamic mechanical, electrical, and thermal properties. The use of nanocellulose for reinforcement in matrices improves thermo-mechanical properties, decreases the sensitivity of polymers to water, and preserves biodegradability. The mixing of nanocellulose with polysaccharides improves mechanical properties. Nano-sized cellulose fibers possess unique physical, chemical, and morphological characteristics. Hence, nano-sized cellulose fibers are considered versatile materials for addition to polymers, and application in high gas barriers and packaging materials. Other uses include electronic devices, foods, medicine, cosmetics, and health care. This chapter focuses on the cellulose nanofibers attained from banana, pineapple and corn-based agricultural wastes.

**Keywords:** fiber, post-harvest, nanocellulose, chemical hydrolysis, enzymatic hydrolysis, agricultural waste

### **1. Introduction**

#### **1.1 Agricultural industry**

Agricultural development is one of the most powerful tools used to boost shared prosperity and economic growth as well as to alleviate extreme poverty and feed an estimated population of 9.7 billion people by 2050. In 2018, agriculture accounted for 4% of global gross domestic product (GDP) and over 25% of the GDP of some developing countries. However, current food systems pose threats to human health and the planet since agriculture accounts for 70% of water use, while generating

alarming rates of pollution and wastes. According to the World Bank (2021), onethird of the food produced globally is either lost or wasted [1]. **Table 1** shows the GDP of Malaysia by sector from 2019 to 2021 (at constant 2015 prices).

## **1.2 Crop production**
