Oral carbohydrate sensing: Beyond sweet taste

Carbohydrates encompass a wide range of molecules, which can be classified into three groups: mono−/disaccharides (sugars), oligosaccharides, and polysaccharides. Despite all three classes of saccharides being naturally present in foods, research on the human gustatory responses to carbohydrates has focused almost exclusively on sugars, which elicit sweet taste. This review is intended to share recent knowledge regarding possible additional gustatory pathways, other than the known T1R2/T1R3 sweet receptor, involved in carbohydrate sensing. The review begins by providing a brief overview of the chemistry and classification of carbohydrates, along with examples of carbohydrates in the diet, particularly those that can be digested by the human body (i.e., glycemic carbohydrates). Discussions on the oral digestion of glycemic carbohydrates and the enzymes relevant to the digestive process follow. Finally, we discuss sensory perception and possible transduction mechanisms underlying starch hydrolysis products.