Sucrose

The predominant disaccharide, sucrose is naturally present in large quantities in sugar cane and sugar beet, as well as in many vegetables, roots and fruits. Major dietary sources include, apart from table-top use and cooking, a variety of processed foods and beverages sweetened with sugar, e.g. soft drinks and juices^a, sports and energy drinks as well as confectionary products, sweet and savoury snacks, sweet spreads and jams, dairy products and ice-cream. In the body, sucrose is metabolised into glucose and fructose.

Lactose

Another major disaccharide, predominantly found naturally in milk and dairy products. In the body, lactose is hydrolysed into galactose and glucose.

Maltose / Trehalose

Maltose, (made up from 2 molecules of glucose) is the least common of the three major disaccharides, and is found in nature in small amounts (e.g. in barley, wheat, germinating grain). Major dietary sources include beer, cereals, cooked sweet potatoes, pasta and sweetened processed products. Trehalose is also made from two glucose molecules; the difference with maltose lies in the configuration of the chemical bond between the glucose molecules. It is found in yeast products, mushrooms and crustaceans.

Glucose

Fructose

Galactose

These monosaccharides occur naturally in small amounts in fruits, vegetables and plant juices. Apart from the consumption of the above, dietary sources include honey and syrups. Free galactose is rare in foods, except in fermented and lactase-hydrolysed milks.