Title: Alternative Sweeteners

Stevioside 173
the acid pH levels characteristic of many soft drinks (1, 2). At present, three
categories of products are produced from S. rebaudiana on the Japanese market,
namely, ‘‘stevia extracts,’’ ‘‘rebaudioside A-enriched stevia extracts,’’ and
‘‘sugar-transferred stevia extracts,’’ (16). ‘‘Stevia extracts’’ contain at least 80%
of total steviol glycosides, inclusive of stevioside, rebaudioside A, rebaudioside
C, and dulcoside A, and are specified to contain not more than 20 ppm of heavy
metals (determined as Pb) and not more than 2 ppm of arsenic (determined as
As 2O 3). ‘‘Rebaudioside A-enriched stevia extracts’’ contain larger amounts of
rebaudioside A than ‘‘stevia extracts,’’ whereas the ‘‘sugar-transferred stevia extracts’’
are treated with CGTase and β-amylase, as mentioned in an earlier section,
and contain more than 85% of total steviol glycosides (16). Table 1 provides
estimates of the major categories of Japanese foods in which S. rebaudiana products
were used in 1995.
Stevioside was initially approved as a food additive in South Korea in 1984,
and it must be of at least 98% purity for use after being dried for 2 hr at 100°C
(17). Stevioside is permitted for use in distilled liquors, unrefined rice wines,
confectionery, soy sauce, and pickles, although not so far in bread, baby foods,
dairy products, and as a tabletop sweetener (7, 17). Its use in liquor (particularly
soju) in Korea has been permitted since 1991 for domestic use only (7, 17).
Recently, there has been a considerable degree of scrutiny by governmental authorities
in Korea concerning the safety of stevioside, particularly in terms of
whether this compound is hydrolyzed to steviol in the approximately 45 types
of soju on the market (18).
Products manufactured from S. rebaudiana leaves also have some uses in
the People’s Republic of China. Teas are prepared from the plant using either
hot or cold water and are recommended for increasing the appetite, as a digestant,
for losing weight, for keeping young, and as a sweet-tasting low-calorie tea (2).
There is an active market for S. rebaudiana products in the United States,
which was estimated as being worth about $10 million in 1998. These products
are sold under the category of ‘‘dietary supplements,’’ either in the form of the
powdered leaf, as liquid extracts, or in sachets. Stevioside has not received approval
as a sucrose substitute by the U.S. Food and Drug Administration, and S.
rebaudiana products have not been accorded ‘‘Generally Recognized as Safe’’
status either. Although several U.S. herbal manufacturers began to use S. rebaudiana
in their products in the 1980s, an import ban on the plant was effected in
1991 but was rescinded in 1994 (19). Herbal products containing S. rebaudiana
are manufactured in Italy and are exported for retail sale to other European countries,
although, to date, stevioside has not been approved as a food additive by
any country in the European Union (20).
S. rebaudiana extracts containing high proportions of stevioside are available
in Japan in combination with glycyrrhizin, with which it is synergistic, re-