Carbohydrates in food occur as natural constituents or are added as ingredients or additives. The most important endogenous carbohydrates in food are starch, depolymerized starch, sucrose, lactose, glucose, fructose and sorbitol (digestible) and carbohydrates such as raffinose, stachyose, resistant starch, pectin, cellulose, hemicelluloses including pentosans, fructans, chitin, and seaweed polysaccharides (indigestible). Carbohydrates added to food are often derived from raw materials, e.g. sucrose, polyols, lactose, oligosaccharides, starch and pectins or they appear in plants not usually consumed as food like exudate gums, seed gums or algal polysaccharides. Many are conversion products: chemical like carboxymethylcellulose, polydextrose, lactulose, enzymatic like modified starches and starch syrups or microbial like xanthan and gellan gum.