Protein high-potency sweeteners (HPS) are receiving increased attention. Over the years eight, structurally unrelated natural proteins have been proposed as potential HPS: thaumatin, brazzein, monellin, pentadin, mabinlin, miraculin, neoculin and lysozyme. To these can be added non-nature-identical “designer” protein sweeteners now under development. Currently, only thaumatin is a successful, if niche, commercial ingredient. This talk will examine critically the extent to which any of these compounds meets all the requirements of a practical sweetening agent, including safety, taste performance and processability. Possible winners will be identified.
John C. Fry, Ph.D., CChem, FRSC, FIFST, Director, Connect Consulting, The Potential of Protein Sweeteners
Excerpt from Summary of this Presentation titled: Beyond Stevia: Are Protein Sweeteners the Next Big Thing?
There is a surprisingly short list of sweetener candidate proteins. Most are from plant sources; one (lysozyme) is animal, but there is growing interest in customized synthetic proteins. Many protein sweeteners of natural origin have defects that make them unsuitable for commercialization. After eliminating the candidates with significant flaws, four remain and have received some attention: thaumatin, miraculin, brazzein and designer proteins.
Thaumatin is derived from the katemfe fruit that grows wild in Western Africa. There are five isoforms, but the sweetener is mainly in forms I and II. There are widely differing potency estimates, but most agree that it is several thousand. Thaumatin has a prolonged onset and a long linger. At 5% sucrose equivalent, some individuals can still taste thaumatin 30 minutes later. However, thaumatin is commercially successful and widely used as a flavor modifier rather than a sweetener.
There has been much recent attention paid to miraculin. This protein is present in the miracle fruit that grows wild in Western Africa but can be grown commercially in many parts of the world. Miraculin is only sweet when exposed to acids. In neutral saliva, miraculin is tasteless and blocks the sweetness of other sweeteners. When exposed to acid, miraculin’s structure changes and triggers a very sweet taste. Miraculin remains bound to the sweetness receptor for 20 minutes to an hour. The EU has approved miraculin as a novel food, but a recent USA GRAS notification has been withdrawn because of insufficient safety data. Owing to the need for acid; the unpredictability of the sweet response; and the long-lasting effects, the practicality of miraculin as a sweetener is dubious.