Title: Alternative Sweeteners

Less Common High-Potency Sweeteners 211
of the other periandrins (10). While it was at one time thought that glycyrrhizin
was the sweet principle of the leaves of Abrus precatorius L. (Fabaceae), five
novel cycloartane-type triterpene glycosides, abrusosides A-E, proved to be responsible
for this sweetness. Although these compounds are pleasantly sweet and
their water-soluble ammonium salts were rated as up to 100 times the sweetness
potency of sucrose, they produce a long-lasting sweet sensation and occur in the
leaves in less than 1% w/w combined yield (11, 12).
Partially purified Glycyrrhiza extracts, which contain at least 90% w/w
glycyrrhizin, are used widely in Japan for sweetening and flavoring foods, beverages,
oriental medicines, cosmetics, and tobacco (1, 2). In 1994, it was reported
that about 9000 tons of licorice are imported into Japan each year, mainly from
Afghanistan, Pakistan, the People’s Republic of China, and Russia (4). In the
United States, ammoniated glycyrrhizin is included in the generally recognized
as safe (GRAS) list of approved natural flavoring agents, not as an approved
sweetener (13). There are many applications for this compound as a flavorant,
flavor modifier, and foaming agent. Although it is useful for incorporation into
confectionery and dessert items, ammoniated glycyrrhizin is only used in carbonated
beverages that do not have too low a pH because this substance tends to
precipitate at pH levels less than 4.5 (1).
There is a very extensive literature on biological activities of glycyrrhizin
other than its sweetness as exemplified by its antiallergic, anti-inflammatory, antitussive,
and expectorant actions. Unfortunately, the widespread use of glycyrrhizin
and ammoniated glycyrrhizin by humans has been found to lead to pseudoaldosteronism,
which is manifested by hypertension, edema, sodium retention,
and mild potassium diuresis (1, 2, 14, 15). The 11-oxo-∆ 12,13 -functionality in ring
C of glycyrrhetinic acid has been attributed as the part of the molecule responsible
for this untoward activity (2). Glycyrrhetinic acid is known to inhibit the renal
enzyme 11β-hydroxysteroid dehydrogenase, which catalyzes the inactivation of
cortisol to cortisone (14). The Ministry of Health in Japan has issued a caution
stipulating that glycyrrhizin consumption should be limited to 200 mg/day when
used in medicines (2). Similarly, the Dutch Nutrition Information Board has advised
against daily glcyrrhizin intake in excess of 200 mg, corresponding to about
150 g of licorice confectionery (3). Glycyrrhizin, at a level of 0.5–1%, has been
shown to inhibit plaque formation mediated by Streptococcus mutans, a cariogenic
bacterial species (2). As a consequence, it has been suggested that glycyrrhizin
is suitable for wider use as a vehicle and sweetener for medications used
in the oral cavity (2).
B. Mogrosides
Mogrosides IV and V are the principal sweet cucurbitane-type triterpene glycoside
constituents of the dried fruits of the Chinese plant lo han kuo. This species,
a member of the family Cucurbitaceae, was accorded the binomial Momordica