Encapsulated curcumin shows potential to rival tartrazine as yellow food color

By Stephen Daniells

- Last updated on GMT

© Getty Images / alexander ruiz
© Getty Images / alexander ruiz
With demand for natural food colors continuing to increase, supercritical antisolvent (SAS) technology may allow for encapsulated curcumin to replace artificial tartrazine, according to a new study from scientists in Colombia and Spain.

The global food colors market is predicted to reach $3.75 billion in 2022, according to Markets and Markets, with a compound annual growth rate (CAGR) of over 8% between 2016 and 2022. Natural colors occupying the largest slice of the market, it added.

Tartrazine is a synthetic yellow dye used in a variety of food and beverage products, but demand for natural alternatives has led to curcumin, the yellow pigment in turmeric (Curcuma longa​ L.).

Curcumin is challenging to work with, however: It is soluble in a variety of organic solvents, like ethanol, but it is not soluble in water, and companies have explored various methods of encapsulating the yellow pigment.

SAS technology allows production in one precipitation-and-microencapsulation step using supercritical CO2, explained the authors of the new study, which is published in Food Chemistry​.

“SAS technology has been studied and applied in the processing of curcumin both for micronization of particles and for nanoencapsulation or microencapsulation in similar applications, mainly pharmaceutical, to improve stability, bioavailability, and water solubility,”​ they wrote.

“To date, however, the use of other polymers has not been studied, nor has a systematic study been performed to evaluate compound stability in response to the destabilizing effects of light, temperature, and pH.”

Study details

The scientists, affiliated with the Corporación Universitaria Lasallista in Colombia and the University of Valladolid in Spain, explored how to improve the aqueous stability and solubility of curcumin using SAS technology and different encapsulating polymers. The polymers tested were a mixture of Eudragit L100 and Pluronic 127 using tween 20 as a surfactant.

Results showed that the best results were achieved with a mass ratio between the extract and Eudragit and Pluronic and tween of 1:1:0.2:0.1.

The researchers also assessed the impacts of temperature and pH and found that the curcumin was most stable at pH4, but some degradation did occur at pH8 when the temperature was increased.

“From color analysis can be concluded that a 200 [micrograms per mL] solution of dye formulation based on curcuminoids is equivalent to an approximated 30  [micrograms per mL] tartrazine solution,” ​they concluded.

Source: Food Chemistry
Volume 258, Pages 156-163, doi: 10.1016/j.foodchem.2018.02.088
“Encapsulation of curcumin using supercritical antisolvent (SAS) technology to improve its stability and solubility in water”
Authors: A. Arango-Ruiz et al.

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