Stevia versus Phyla Dulcis.

Stevia Rebaudiana "Sweet-leaf" and Phyla Dulcis "Aztec Sweet Herb" 

Both grown as sweeteners and sugar substitutes, but which one is better?

Stevia "sweet-leaf" for decades used in Japan is now getting new life in Europe and USA. For centuries, more than 1500 years stevia have been used by Guarani peoples from Paraguay. Called by them ka'a he'ê ("sweet herb") and used in medicine and as a sweetener. Currently Japan consumes more than any other country, with stevia taking 40% of the whole sweetener market.

Sweet taste of stevia is given by steviol glycosides built by stevioside and rebaudioside which are 40-300 times as sweet as sucrose. These compounds are heat-stable, pH-stable, and do not ferment which make them perfect for cooking. Also stevia can by used by diabetics and any other people on carbohydrate-controlled diets, because has negligible effect on blood glucose.

Weight Fraction of the four major steviol glycosides found in stevia plant:

• 5–10% stevioside (250–300X of sugar)
• 2–4% rebaudioside A — most sweet (350–450X of sugar) and least bitter
• 1–2% rebaudioside C
• ½–1% dulcoside A.

Phyla Dulcis (sometimes called Lippia Dulcis or Sweet Aztec Herb) has been used by the Aztecs as a natural sweetener and medicinal herb. Sweet taste of herb is caused by hernandulcin 1000 times sweeter than suger and with minty aftertaste, and has no tooth decay effect. Plant is fast growing, low perennial creeper (up to 30cm). Medicinal used for coughs, colds, bronchitis, asthma and colic.

Hernandulcin from the aerial parts of the plant is presented in the amount of 0,04-0,15% w/w dry weight. Despite being about 1000 times sweeter than sucrose, naturally occurring hernandulcin is somewhat thermolabile and has some inherent bitterness (due to presence of camphor), which restricts its potential sweetening applications.