ABSTRACT
Nature utilizes sophisticated and ingenious biochemical pathways in developing plants and/or fruits to synthesize simple carbohydrates such as monomeric sugars and assemble them into simple to complex polysaccharide structures to perform various physiological functions. Many of the molecules that make up the living tissue in plants are polymers, which include cellulose, complex carbohydrates of starchy foods, protein molecules, lipid, and DNA. Additionally, polysaccharides are further complexed or linked with polymers such as protein, lipids, and lignin to construct complex supramacromolecular structures and to confer tailored properties. For example, in woody plants, lignin, a polyphenolic polymer, is complexed with waxes that confer a shiny and smooth surface coating on the exterior of the plant cell walls, providing protection from infections and restricting the flow of moisture across the cell wall. In the absence of such coating, carbohydrate polymers will be destined to rapid hydrolytic degradation and the plant will quickly dehydrate. In this chapter we will only focus on carbohydrates such as starch, cellulose, hemicellulose, and pectin, which play critical roles in providing the structural integrity and important functionalities to plants, particularly in fruits and vegetables, during their growth and maturity, as well as during their ripening, storage, and other postharvest processing.
