View All Molecular Gastronomy Glossary

Amphoteric

What is Amphoteric?

Chemically speaking, amphoteric refers to matter which may react as both an acid and a base. This term is derived from amphoteroi, a Greek word which means both. Acids are known as donors for protons, while bases are acceptors. In the case of amphoteric molecules, it has the capacity to both donate and accept protons since it carries both a positive and negative charge. Thus, it acts as either an acid or a base. Being neither definitely an acid nor a base it is neutral.

Water is perhaps the most common example of a self ionizing amphoteric molecule. Amino acids and proteins are likewise examples of amphoteric molecules. Due to this, many cooking ingredients are amphoteric, one of the most common example of which is starch. Potato, cassava, rice, corn starch and the like are all commonly used as thickeners.

Amphoteric surfactants can also be found in the food industry. Lecithin is a good example of this. Derived from soy protein, this is used in emulsification as well as in the creation of foams. Cooking ingredients with amphoteric characteristics are versatile and allow for many different uses.