Dietary Fibers as a Functional Food and Nutraceutical

India is the major producer of fruits and vegetables after China. This agriculturally driven country has fast-growing food processing-based industries which produce ample quantities of food products, and along with it is a huge production of secondary products like bran, husk, seeds, etc. Keeping in view the heath concerns of the consumers, there is a need of functional and nutraceutical products. Dietary fiber and bioactive components can be extracted as by-products from the generated waste of various food industries. Humans typically cannot digest dietary fibers, though some varieties may be both soluble and insoluble in water. The indigestible portion of the food known as dietary fiber can be added to a variety of food formulations as an active functional food component and nutraceutical to the target sites. Principal contributors of soluble dietary fiber, also known as polysaccharides, include oat bran, barley, lentils, nuts, beans, and a few fruits and vegetables, which are typically high in pectin (beta-glucans and inulin). Vegetables, cereal grains, and wheat bran all contain insoluble dietary fiber, primarily in the form of cellulose and hemicellulose. This chapter mainly highlights the role of dietary fiber in controlling various diseases, processing of dietary fiber from various sources, their bioactive components, and its use in formation of various functional and nutraceuticals products.