Volume 34, número 4, 2009
Thermal stability and thermal decomposition of sucralose.
Gilbert Bannach1, Rafael R. Almeida2, Luis. G. Lacerda3, Egon Schnitzler2, Massao Ionashiro4*.
1Faculdade de Ciências, UNESP, CEP 17033-360, Bauru, SP, Brazil
2Universidade Estadual de Ponta Grossa, UEPG, CEP 84030-900, Ponta Grossa, PR, Brazil.
3Universidade Federal do Paraná, UFPR, CEP 80060-000, Curitiba, PR, Brazil
4Instituto de Química, UNESP, C.P. 355, CEP 14801-970, Araraquara, SP, Brazil
Abstract: Several papers have been described on the thermal stability of the sweetener,
C12H19Cl3O8 (Sucralose). Nevertheless no study using thermoanalytical techniques was found
in the literature. Simultaneous thermogravimetry and differential thermal analysis (TG-DTA),
differential scanning calorimetry (DSC) and infrared spectroscopy, have been used to study the
thermal stability and thermal decomposition of sweetener.
Keywords: Sucralose, thermal behavior, TG, DTA, DSC
Nowadays, human beings are permanently
in contact with different compounds biologically
active. These are: medicaments, plant growth re-
gulators, active components of food additives as
antioxidants, sweeteners and many other com-
Escalating prevalence of worldwide obe-
sity and its correlation to other chronic diseases
has led to low calorie and sugar free products to
move into the main stream of food market. The
use of high potency sweeteners has emerged as a
major way of reducing calorie intake via complete
or partial replacement of calorie laden sucrose in
numerous food products .
The dietary options that such products pro-
vide may be especially helpful in the management
of obesity or diabetes mellitus . Consumers
also often select such foods and beverages becau-
se they want the sweet taste without addition of
calories or because they want to reduce the risk of
One group of sweeteners consists of non
caloric substances with a very intense sweet taste
that are used in small amounts to replace the swe-
etness of a much larger amount of sugar. The swe-
eteners of this type that are currently approved for
use in worldwide are acesulfame-K, aspartame,
neotame, saccharin, alitame, cyclamate, stevia/
steviol glycosides and sucralose .
A 2nd group of sweeteners consists of calo-
ric ingredients that can substitute both the physi-
cal bulk and sweetness of sugar. Products of this
type, sometimes called “sugar replacers” or “bulk
sweeteners,” include the sugar alcohols (also cal-
led “polyols”) sorbitol, mannitol, xylitol, isomalt,
erythritol, lactitol, maltitol, hydrogenated starch
hydrolysates, and hydrogenated glucose syrups
Two new sweeteners, trehalose and tagato-
se, has similar functions to the polyols although
they are actually sugars rather than sugar alco-
hols. Polyols and other bulk sweeteners are used
in food products where the volume and texture of
sugar, as well as its sweetness, are important, such
Ecl. Quím., São Paulo, 34(4): 21 - 26, 2009
Ecl. Quím., São Paulo, 34(4): 21 - 26, 200922
Ecl. Quím., São Paulo, 34(3): 27 -31, 2009
as sugar-free candies, cookies, and chewing gum.
Many of these products are marketed as “diabetic
galactopyranoside), is a chlorinated sucrose deri-
vative with enhanced sweetness [3-5].
Sucralose was discovered by British rese-
archers in 1976 . It is obtained from sucrose by
a process that replaces three hydroxyl groups by
three chlorine atoms the sucrose molecule (Fig.
Fig. 1: Structure of sucralose
Although sucralose is made from sugar, the
human body does not recognize it as a sugar and
does not metabolize it; therefore, it provides swe-
etness with no calories. Sucralose was approved
as a food additive in USA (1988), Canada (1991),
UK (2002), European countries (2005), followed
by others [2, 6]. It is potentially 600 times sweeter
than sucrose .
Sucralose is marketed for home use under
the brand name SPLENDA® Low Calorie Swee-
tener that also includes other concomitants and
is available under this name as table top granular
and tablet formats. The SPLENDA® brand will
also be seen to highlight the use of sucralose as an
ingredient in a growing range of low-energy foods
and beverages .
The use of heat-stable, high-intensity swe-
etener, such as sucralose, can result in signicant
improvements in the preparation of reduced-ca-
lorie sweet baked goods. In addition, sucralose
offers the aqueous and thermal stabilities required
for the preparation of consumer-acceptable, redu-
ced-calorie baked goods .
The present work deals mainly with the
thermal behavior and thermal decomposition of
sucralose, since no study using thermoanalytical
techniques was found in the literature.
Sucralose with assay > 98.0% (HPLC - gra-
de), was obtained from Sigma and commercial su-
cralose (Viafarma, lot no 1080001) was acquired
in local drugstore (Araraquara – SP – Brazil), and
studied by thermoanalytical techniques.
Simultaneous thermogravimetry and diffe-
rential thermal analysis (TG-DTA) curves were
recorded on a model SDT 2960 thermal analysis
system from TA Instruments. The purge gas was
an air ow of 100 mL min-1 and a heating rate of
10°C min-1 was adopted, with samples weighing
about 5mg. Alumina crucibles were used for re-
cording the TG-DTA curves.
DSC curves were recorded using a DSC 60
(Shimadzu) under an air ow of 100 mL min-1,
heating rate of 10°C min-1 and aluminum crucibles
with perforated cover.
The attenuate total reectance infrared
spectra were recorded on a Nicolet iS10 FT-IR
(Thermo Scientic) an ATR accessory with Ge
3. Results and Discussion
The simultaneous TG-DTA curves of the
sucralose from sigma (HPLC – grade) and Via-
farma (commercial product) are shown in Fig. 2
and 3, respectively. A close similarity is obser-
ved in the TG proles of these samples, however
signicative differences are observed in the DTA
curves, above 250°C. These curves also show that
the both samples are stable up to 119°C and above
this temperature the thermal decomposition oc-
curs in three steps up to 550°C.
The rst step that occurs between 119 and
137°C, corresponding to a sharp endothermic
Ecl. Quím., São Paulo, 34(4): 21 - 26, 2009 23
peak at 132°C in both samples is attributed to the
thermal decomposition of the compound with los-
ses of 2 H2O (water of constitution) together with
1 HCl (Calcd = 18.10%; TG= 18.0%). The last
two steps observed between 160-370°C and 370-
550°C, that occur through overlapping ones with
total mass loss, corresponding to the exotherm
with two peaks at 360°C and 500°C (Sigma) or a
single exothermic peak at 360°C (Viafarma), are
attributed to the oxidation of the organic matter.
The loss of constitution water and hydrogen
chloride in the rst step were conrmed through
an experiment with samples of sucralose heated in
a tube glass up to 140°C as indicated by the TG-
In this experiment, the condensation of wa-
ter in the tube glass wall was observed, and test
with pH indicator (Merck) showed pH=1. The
presence of chloride ions in the condensed water
was conrmed through a test with AgNO3/HNO3
During the heating of the sucralose in a hot
plate up to 140°C, the darkening of the sample
was observed showing that the thermal decompo-
sition occurs without melting. This observation is
in agreement with TG-DTA data and in disagree-
ment with the melting point (130°C) reported in
the literature [1, 3, 4].
This mistake was attributed to the fact that
the authors of these references did not based their
data on thermal analytical results. The TG-DTA
curves clearly revels that the sharp endothermic
peak is associated with mass loss, and can’t be as-
sociated with melting of the material.
Therefore the use of sucralose in backed
goods as in the case of cookies that are baked at
a temperature of 210oC or graham crackers usu-
ally baked at a temperature of 230oC as described
in reference , seem to be unsuitable since the
thermal decomposition occurs at 119oC with libe-
ration of constitution water and HCl.
A close similarity is also observed in the
DSC curves of the samples from Sigma and Via-
farma, therefore only the DSC curve of the sucra-
lose from Sigma is shown in Fig. 4, which was
obtained up to 250°C due to the elimination of
hydrogen chloride during the thermal decomposi-
tion as already conrmed by the tests previously
described. This curve shows a sharp endothermic
peak at 128°C, corresponding to the rst mass
loss observed in the TG curve. The disagreement
between the peaks temperatures observed in the
DSC or DTA curves, undoubtedly is because the
TG-DTA and DSC curves were obtained in enou-
gh different conditions.
Due to similarity between the reectance
infrared spectra of both sucralose samples, only
the reectance infrared spectra of sucralose from
Sigma as received and heated up to 130oC are sho-
wn in Fig. 5.
The infrared spectra showed signicant
structural changes between the sample before
and after heating, as can be seen in Fig. 5, where
the appearance or disappearance of several peaks
are observed. As an example the peak observed
at 1711 cm-1 attributed to the carbonyl stretching
frequency appeared after heated the sample is up
These results are in agreement with the
TG-DTA and DSC curves, indicating that the en-
dothermic peak at 131oC (DTA) or 128oC (DSC) is
not due to the melting, but is related to the thermal
decomposition of the sucralose, with releasing of
constitution water and hydrogen chloride.
Ecl. Quím., São Paulo, 34(4): 21 - 26, 200924
0100 200 300 400 500 600
Mass loss / %
Temperature / °C
DTA / °C mg
Fig. 2: TG and DTA curves of HPLC grade sucralose. (mi = 7.195 mg).
0100 200 300 400 500 600
Mass loss / %
Temperature / ºC
DTA / µV mg
Fig. 3: TG and DTA curves of technical grade sucralose. (mi = 5.174 mg).
Ecl. Quím., São Paulo, 34(4): 21 - 26, 2009 25
050 100 150 200 250
Heat flow / µV
Temperature / ºC
Fig. 4: DSC curve of HPLC grade sucralose (mi = 3.004 mg).
4000 3500 3000 2500 2000 1500 1000
Transmitance / %
Wave number / cm
Fig. 5: Infrared spectra of: (a) Sucralose (HPLC grade) at room temperature; (b) Sucralose (HPLC grade)
heated up to 130oC.
Ecl. Quím., São Paulo, 34(4): 21 - 26, 200926
The TG-DTA and DSC data allowed us to
verify that the sucralose is thermally stable up to
119oC and above this temperature the thermal de-
composition takes place in three steps up to 550oC
and without melting. The endothermic peak at
131°C (DTA) and 128°C (DSC) is due to the ther-
mal decomposition with release of constitution
water and hydrogen chloride.
The infrared spectra also conrm that the
thermal decomposition occurs above 119oC in di-
sagreement with the literature data.
The authors acknowledge FAPESP for the
nancial support and Prof. Dr. Marco Aurélio da
Silva Carvalho Filho, for permitting the use of his
DSC equipment from Shimadzu.
 G. E. Morlock, S. Prabha. J. Agric. Food Chem. 55 (2007)
 M. Kroger, K. Meister, R. Kava. Compr. Rev. Food Sci.
Food Saf. 5 (2006) 35-47.
 M. J. O`Neil, (Ed.) et al. The Merck Index. 13rd ed. Whi-
thouse Station, 2001, pp. 8965.
 The United States Pharmacopeial Convention. Material
Safety Data Sheet: Sucralose. Rockville. Catalog number:
 N. M. Binns. Br. Nutr. Found. Nutr. Bull. 28 (2003) 53-
 H. C. Grice, L. A. Goldsmith, Food Chem. Toxicol. 38
 R. L. Barndt, G. Jackson, Food Technol. 44 (1990) 62-66.