Obtención del complejo ciclodextrina-curcumina y su uso como reemplazante de tartrazina
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Date
2012
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Journal ISSN
Volume Title
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Corporación Universitaria Lasallista
Abstract
Introduction. Curcumin is the main colorant that can
be found in the Curcuma longa´s rhizome, in which
there are also small quantities of other compounds
insoluble in water, so its use in a pure state is not
ideal. Curcumin is used, principally, dissolved with a
mixture of alimentary degree solvents that allow its
emulsification. This way, the product has a 4 – 10%
of curcumin content, miscible in water. Other forms
of commercialization are also known, including the
suspension in vegetable oil and dispersion of this
colorant in starch. It has also been demonstrated
that cyclodextrin (CD) can be used as a solubilizing
agent for hydrophobic volatile oils. It is formed by
a hydrophilic external surface and an internal hydrophobic
cavity, which provides a capacity to form
inclusion complexes with a variety of guests. These
characteristics suggest that CD can be used to
increase the solubility of hydrophobic and insoluble
curcumin in water. Additionally, microencapsulation
protects curcumin against destructive changes and
allows it to flow freely when presented as powder. In
this study, βCD and CD were evaluated as encapsulation
agents for curcumin. Objective. Obtaining
the cyclodextrin-curcumine complex as a substitute
of tartrazine. Materials and methods. To develop
this research work, 3 experiments were performed:
In experiment 1 the effect of the concentration and
of the type of solvent on the curcumin´s absorption
was studied for different solvents; water, ethanol,
acetone, hexane, propylene glycol, ethyl lactate
and ethylene glycol. Aqueous solutions were prepared
in %v/v at 20%, 50%, 80%, 90% for each of
the aforementioned solvents. The final concentration
of the curcumin colorant was taken to 0.005%.
In experiment 2 the association and the stoichiometric
ratio between curcumin and two cyclodextrins,
β-ciclodextrina (β-CD) and γ-ciclodextrina (γ-
CD), were determined. Two cyclodextrin solutions in
the rank 0 – 0.02M,were used for that, plus a constant
curcumin concentration of 0.001M, by means of
agitation and heating at 50°C during 48 hours. In experiment
3, independent solutions of both cyclodextrins
were prepared in the presence of curcumin and
the physical mixture and the coprecipitation methods
were used to obtain the curcumin-cyclodextrin complex.
A subsequent Differential Scanning Calorimetry
analysis (DSC) was performed to corroborate
the formation of the complex. Results. The results
demonstrate that the maximum absorbance of the
curcumine takes place at a 425nm wavelength in the
presence of a solution of ethanol:water at 20% (v/v).
On the other hand, β-cyclodextrin (β-CD) reacts
with curcumin to form a host-guest complex 1:1 with
an apparent formation constant of 5,00x102 mol/L.
The γ-cyclodextrin (γ-CD) reacts with curcumin to
form a host-guest complex 1:1 with an apparent formation
constant of 7,51x103 mol/L. The complex is
obtained at a laboratory level with best results by the
use of the coprecipitation method, with 85% of performance
for γ-CD, and 69% for β-CD, so the most
adequate cyclodextrin is γCD. Conclusions. Curcumin
forms inclusion complexes with βCD and γCD
in solution. The solubility of curcumin in the presence
of βCD and γCD has demonstrated a higher
effectiveness in the second one. The association of
both cyclodextrins is 1:1, a fact that indicates that
it is stronger with γCD due to its structure (8 units
of glucose). The DSC analysis demonstrates that
the inclusion complexes by physical mixture and by
coprecipitation were formed. Nonetheless, for solubility
effects, coprecipitation is more recommended
because there is a prehydration.
Description
Keywords
Corporación Universitaria Lasallista, Curcumina, Tartrazina, Colorantes en los alimentos, Industria alimenticia, Ciclodextrina, Alimentos