Carbohydrates: Chemistry and Classification

Carbohydrates are the most abundant constituents of cereals, fruits, vegetables, and legumes, and the most important energy source in human nutrition. According to their chemical structure and degree of polymerization, they are categorized into mono-, di-, oligo-, and polysaccharides. Nutritionally important carbohydrates are sugars and sugar alcohols, namely, mono- and disaccharides and their derivatives, starch polysaccharides, and dietary fiber. Depending on the attached functional groups and structural properties, carbohydrates exhibit differences in solubility and chemical reactions.