This document discusses several plant-based high-potency sweeteners, including stevia (Stevia rebaudiana) and thaumatin (Thaumatococcus daniellii). It provides details on the source plants, chemical structures, relative sweetness, stability properties, regulatory status, and applications for food and beverage use. The document also reviews the absorption, metabolism, and safety of steviol glycosides from stevia leaves.

1. Plant-Based Sweeteners
Ph. D. Student
Atheer Jasim Mohammed
Master of Dairy Science and Technology/Iraq
May, 2015

3. Facts
 Most of high-potency sweeteners of diverse chemical structures are
known to occur naturally.
 Consumer interest in natural high-potency sweeteners has grown
dramatically in last decade, fuelled by concerns about the use of
artificial additives in foods.
 The level of development activity is high, as is the activity involved in a
continuing search for other natural sweeteners through the use of
various screening techniques.
 Natural sweeteners show many similarities to their synthetic
counterparts in terms of their overall taste properties.

4. Examples of high-potency sweeteners of plant origin
Sweetener Structural class Plant source Country of origin
Brazzein Protein Pentadiplandra brazzeana West Africa
Curculin Protein Curculigo latifolia Malaysia
Mabinlin Protein Capparis masakai China
Monellin Protein Discoreophyllum cumminsii West Africa
Pentadin Protein Pentadiplandra brazzeana West Africa
Thaumatin Protein Thaumatococcus daniellii West Africa
Monatin Amino acid Schlerochiton ilicifolius South Africa
Abrusoside Glycoside Abrus precatorius Thailand
Albiziasaponins Glycoside Albizia myriophylla Thailand
Baiyunoside Glycoside Phlomis betonicoides China
Bryoside Glycoside Bryonia dioica Italy
Cussoracosides Glycoside Cussonia racemosa Madagascar
Cyclocarioside Glycoside Cyclocarya paliurus China
Glycyrrhizin Glycoside Glycyrrhiza glabra China
Lo han guo Glycoside Siratia grosvenorii China
Mukurozioside Glycoside Sapindus mukurossi China
Osladin Glycoside Polypodium vulgare USA, Eur.
Periandrin Glycoside Periandra dulcis Brazil
Phlomisoside Glycoside Phlomis younghusbandii China
Polypodoside Glycoside Polypodium glycyrrhiza USA
Pterocaryoside Glycoside Pterocarya paliurus China
Rubusoside Glycoside Rubus suavissimus China
Steviol Glycoside Stevia rebaudiana Paraguay
Telosmosides Glycoside Telosma procumbens Philippines
Selligueain A Proanthocyanidin Selliguea feei Indonesia
Hernandulcin Bisabolane sesquiterpene Lippia dulcis Mexico
Phlorizin Dihydrochalcone Lithocarpus litseifolius China
Trilobatin Dihydrochalcone Lithocarpus litseifolius China
Phyllodulcin Flavonoid Hydrangea macrophylla Japan
Adapted from (Helen Mitchell, 2006)

5.  It is origin of Paraguay and Brazil. Stevia is cultivated primarily in
USA, Canada, Korea, Japan, Taiwan, china, and United Kingdom.
 In September 1995 the USA FDA allowed Stevia and it is extracted to be
imported as a food supplement but not as a sweetener. Major food
companies like coca cola and beatrice foods used Stevia extracts to
sweeten the foods for sale in Japan, Brazil and other countries.
 The plant grows up to range 65-180 centimeters when cultivated or
growing naturally in fertile soil. It is a short day plant and flowering from
January to March in the southern hemisphere. The suitable natural climate
is semi humid subtropical with temperature extremes from 21 to 43°C.
 The steviol glycoside sweeteners share a common aglycone, steviol.
Linked to steviol are carbohydrate moieties and it is the number and
linkages of these that differentiate the steviol glycoside sweeteners
Stevioside (Stevia rebaudiana)

6.  leafs considered the most parts of plant which is rich with stevia
rebaudiana A, and can be used these techniques to preparation of
sweetener from the leaves typically involves some or all of the
following unit operations: aqueous extraction reached by selective
extraction into a polar organic solvent, decolourisation, removal of
impurities through flocculation and filtration, ion exchange and
finally crystallization.
Stevioside (Stevia rebaudiana)

7.  A research report suggests rebaudioside A is less sweet than stevioside
that may be a significant of the methodologies employed or due to the
actual materials evaluated being mixtures of steviol glycosides rather than
the pure glycoside.
Sweetness potencies of
steviol glycosides.
Sensory properties
Compound Relative sweetnessa
Stevioside 300
Rebaudioside A 250-450
Rebaudioside B 300-350
Rebaudioside C 50-120
Rebaudioside D 250-450
Rebaudioside E 150-300
Dulcoside A 50-120
Steviolbioside 100-125
aSweetness potency measured relative to 0.4% (w/v) sucrose.
* Adapted from (Kim and DuBois, 1991)

8.  Both stevioside and rebaudioside A appear to be stable sweeteners.
 One study was observed in carbonated beverages buffered with either
phosphoric acid or citric acid. After 2 months storage at 37◦C, some
degradation was reported, but no significant changes were seen when
formulated beverage products were stored at room temperature and below
for 5 months. Some shakiness (20% loss) of rebaudioside A on exposure to UV
light was mentioned following 1 week of exposure to sunshine, but stevioside
be completely stable under the same conditions.
 The authors conclude that these sweeteners are viable as commercial products
in that they show adequate hydrolytic stability. The solubility of stevioside in
water has been measured and found to be just less than 1% (w/v).
Physical and chemical properties
Physiological properties
 rebaudiana A leaves contain ent-kaurene diterpene glycosides (stevioside and
the rebaudiosides) 300 times sweeter than sucrose with superior solubility in
water and a positive taste profile that are safely metabolized by the body
without any side effect.
 Rebaudioside A in the digestive tract is first metabolized by microbes in the
colon to stevioside which is further converted into glucose molecule and
steviol. The released glucose molecule is used by the bacteria in the colon and
is not absorbed into the blood stream.

9.  Steviol glycosides are not readily absorbed from the upper small intestine
of the rat or human following oral administration. As human digestive
enzymes do not hydrolyse β-glycosidic linkages, digestion in the small
intestine is limited. Microbial fermentation occurs in the large intestine of
both rat and human, releasing the aglycone steviol. Steviol is then absorbed,
conjugated with glucuronic acid and excreted as steviol glucuronide, the
primary route being in feces for the rat and urine for humans.
 The study also showed that the majority of steviol glycosides are absorbed and
glucuronidated in the liver. The newly bonded glucuronidate is released in the
blood and filtered by the kidneys into the urine. Small amounts of glucuronide
that remain in the colon are excreted through fecal matter.
Applications
 In Korea, stevioside is an accepted sweetener in baked products, table-top
sweeteners, beverages and seasonings.
 steviol glycoside sweeteners have acceptance across the range of food and
beverage applications normally associated with the use of high-potency
sweeteners.

10.  particularly in Japan where it is considered a 'food’ because of its natural
origin.
 It is now accepted that whenever safety studies have been carried out using
purified and fully characterised steviol glycosides, the reproductive safety
of these sweetener materials has been fully demonstrated.
 A number of sub-chronic (13-week) toxicity studies have been completed in
recent years, these studies have all reported no statistically significant effects
in the great majority of cases; although some impact on body-weight gains for
groups receiving the highest doses tested .
 Matsui(1996). examined the genetic toxicity of stevioside and steviol in a
range of mutagenicity tests with metabolic activation. Stevioside was not
found to be mutagenic in any of the assays examined. Steviol, however,
produced dose-related positive responses in some mutagenicity tests.
 Other workers reported no compound-related alterations of blood, clinical
chemistry or urinalysis parameters. Although stevioside is not mutagenic, its
aglycone, steviol (13-hydroxy-ent-kaurenoic acid) has been shown to be
mutagenic in some tests with S. typhimurium strains.
Safety

11.  In July 2008, JECFA found steviol glycosides safe for use in food and
beverages.
 Also, the US Food and Drug Administration (FDA) announced in December
2008 that it had no objection to the use of rebiana in food and beverages in
the United States.
 In 2009, the French government was the first in the EU to approve the use of
rebausioside A in food and beverages in France.
 In 2010, the European Food Safety Authority published a Scientific Opinion
confirming that steviol glycosides are safe for use in foods and beverages.
Approval throughout the EU is anticipated, although the precise timing is
currently uncertain.
Regulatory status

12.  Thaumatin is normally described as being approx. 2000 times the sweetness
of sucrose.
 The temporal taste profile of Thaumatin is characterised by a delay in
perceiving sweetness, a lengthy sweetness growth phase until maximum
sweetness is perceived, followed by a lingering sweet/liquorice after taste.
Thaumatin (Thaumatococcus daniellii)
Sensory properties
 Thaumatin is the common name for a mixture of potently sweet proteins
that can be extracted from the West African plant Thaumatococcus
daniellii (Bennett), known locally as the katemfe berry.
 The plant divided in two kinds, Thaumatins I and II being the major
constituents, each with almost identical molecular weight of 22,000 Daltons.
Thaumatins I and II have very similar amino acid sequences, differing only in
five residues.
 The protein is stabilized by eight disulphide bridges, thus conferring a greater
stability to heat and pH denaturation to the molecule than might be expected
for a protein.
 Thaumatin was used as a tool in early studies that sought to understand the
structure of the mammalian receptor for sweetness .

13. Physical and chemical properties
 Thaumatin is stabilized by the eight disulphide bridges that result in a cross-
linked network of amino acid chains. This confers a measure of stability to
heat and extremes of pH.
 These disulphide bridges are also responsible for holding the protein chain in
the correct conformation to elicit sweetness, as has been confirmed by
demonstrating that cleavage of a single disulphide bridge results in loss of
sweetness.
Physiological properties
 Thaumatin is a natural plant protein of known structure containing normal amino
acids.
Applications
 The main commercial applications for Thaumatin its claimed flavor modifying
and enhancing functionalities.
 Thaumatin has found application in liquid medicines.
 The oral care products and in the nutraceutical/fortified foods industries.
 increasing concentrations of Thaumatin appear to have increasing effects on the
bitterness associated with vitamin B complex preparations, caffeine and soybean
peptides.

14.  Thaumatin was studied for its sub-acute toxicity in rats and dogs and its
ability to produce anaphylactic antibodies following oral administration to
rats and normal human subjects. It was found to be readily digested prior to
absorption in rats and no adverse effects resulted from its continuous
administration to rats and dogs at dietary concentrations of 0%, 0.3%, 1.0%
and 3.0% for 13 weeks.
 Also, it was shown to be non-teratogenic when administered orally to rats at
0, 200, 600 and 2000 mg/kg body weight/day from day 6 to 15 of gestation
and was without effect on the incidence of dominant lethal mutations when
administered on five consecutive days to male mice at 200 and 2000 mg/kg
per day.
 The results indicate that Thaumatin when used as a flavor modifier and
extender, and partial sweetener, is unlikely to be hazardous at the expected
level of consumption.
Safety

15.  Thaumatin was originally permitted as a natural food additive in Japan in
1979.
 It was approved as a sweetener in the United Kingdom and Australia.
 In the United States, Thaumatin was accorded GRAS status as a flavor
adjunct for chewing gum in 1984 and this has since been extended by FEMA
to general use across all food categories.
Regulatory status
Sweetener Product category Maximum usable dose
Thaumatin (E957) Confectionery
 Confectionery with no added sugar
 Cocoa or dried fruit based
 Confectionery; energy reduced or with no
added sugar
 Chewing gum with no added sugar
Food supplements
Edible ices, energy reduced or with no added
sugar
50 mg/kg
50 mg/kg
50 mg/kg
400 mg/kg
50 mg/kg
Table shows regulatory approval of Thaumatin in the EU

16.  The Chinese plant Siraitia grosvenorii family that grows mainly in Guangxi
Province, with most of the product from the mountains of Guilin. Siraitia
fruits are used both inside and outside the People’s Republic of China as a
food, beverage, and traditional medicine.
 The sweet constituents of the plant are triterpene glycosides, known as mogrosides.
 Common names for the plant include: lo han guo, lo han kuo, Arhat fruit, Monk
Fruit, Fructus momordicae and Momordicae grosvenori fructus.
 Subsequent isolation of two sweet components (named mogrosides IV and V) was
completed successfully and their sensory properties described. Mogroside V is the
most abundant component, occurring at around 1% in the dried fruits.
Lo Han Guo (morgroside)
Structure of morgroside V

17.  In study was described the sweetness of mogroside as being 150 times as
potent as sucrose. In other report estimated the potency of mogroside V
as approximately 250 times as sweet as sucrose at a 5% sucrose equivalent
concentration.
 the sweetener is known to deliver a taste profile that contains taste
elements commonly seen in natural potent sweeteners, such as a slight
delay to reaching maximum sweetness intensity and an aftertaste that
contains liquorice and cooling elements.
Sensory properties
Physical and chemical properties
 There are no study reports detailing the stability of mogroside.
 In addition, the indigenous use of the lo han guo fruit involves drying the
fruit and then preparing an aqueous decoction that also indicates that the
sweet principle is likely to be a relatively stable molecule.
 Aqueous solutions containing mogroside V are reported to be stable, even
under boiling conditions.
 the β-linkages of the carbohydrate moieties are intrinsically resistant to
hydrolysis.

18.  Extracts of lo han guo fruit have long been used indigenously to treat
colds, sore throats and minor stomach and intestinal complaints.
 Recent studies suggest that the mogrosides may exhibit anti-cancer
properties, possibly based on their researches anti-oxidant characteristics.
Physiological properties
Applications
 The traditional use of the lo han guo fruit has been to prepare an aqueous extract
that is then consumed as a tea or tonic drink.
 There have been some minor beverage products on the market in USA that have
contained (lo han fruit extract) as a part of the overall sweetening system.
 In addition, can be used as table-top sweeteners will be a target.

19.  In safety studies that have been completed, it has been shown to be non-
mutagenic in short-term predictive tests and to produce no mortalities
when administered to mice at doses up to 2 g/kg body weight.
Safety
Regulatory status
 Lo han guo fruits and extracts are considered to be foods in China.
 A GRAS petition has been reviewed by FDA which issued a ‘no
objection’ letter, thus confirming its GRAS status within the US market.

20. Thanks for your attention …