Development and Evaluation of Color Parameteres of Curcumin Nanocomplex

Color is the fundamental qualitative characteristic of food products. Curcumin is a natural polyphenol found in the rizome of the turmeric. Curcumin, possesses multiple biological activities. However, its application is limited due to its poor water solubility and instability under adverse conditions. Encapsulation is a way to overcome these challenges. The aim of this study was to develop curcumin-loaded nanocapsules and evaluate the particle size and color parameters of the prepared product.
Initially, the organic phase (curcumin in ethanol) was introduced to aqueous phase (sodium caseinate, gum arabic and Tween 20). By reduction of the pH from 7 to 4.8, 5 and 5.2 nanoparticles were formed. Measurement of the particle size was carried outbyusing particle size analyzer. Color indices were determined using a Hunter lab. Box-Behnken design was used to explore the effects of 4 independent variables consisting of sodium caseinate (0.1-0.3 %w/w), gum arabic (0.5-1% w/w), Tween 20 (0.1, 0.2 %w/w) and pH (4.8, 5, 5.2) on the responses.
Theresults of the analysis showed that the effects of linear, quadratic and interaction of parameters on responses were significant. By increasing the biopolymers concentration, the particles size was increased from 120 nm to 984 nm. By increasing the concentration of sodium caseinate the brightness of samples was reduced.Samples containing Tween 20 had brightness and higher L*. In general, by reducing the particle size the color intensity of the samples was increased.
The best sample regarding the smallest particle size and curcumin color index was obtained at the concentration of 0.2 % sodium caseinate, 0.75 % gum arabic, 0.1 %Tween 20 and pH of 5. These nanodispersions might be useful as a hydrophobic nutrient delivery system as well as color factor for utilisation in functional food and beverage products.