Abstract

The aim of this study was to prepare and characterize the curcumin-loaded biopolymeric nanodispersion containing sodium caseinate and gum Arabic. Box-Behnken design was used to explore the effects of sodium caseinate concentration (0.1-0.3 wt%), gum Arabic concentration (0.5-1 wt%), Tween 20 concentration (0-0.2 wt%) and pH (4.8-5.2) on the particle size, span and encapsulation efficiency. Applying graphical method, optimum preparation zone was found to be sodium caseinate concentration of 0.24-0.28 wt%, gum Arabic concentration of 0.59-0.87 wt%, Tween 20 concentration of 0.13-0.2 wt% and pH of 5.04-5.11. At this optimum zone, particle size and span were smaller than 80 nm and 0.6, respectively and encapsulation efficiency of nanodispersion was greater than 90%.

INTRODUCTION

Curcumin [(1E,6E)-1,7-bis(4-hydroxy-3-methoxyphenyl)-1,6-heptadiene-3,5-dione], is a natural, lipophilic polyphenol found in the rhizome of turmeric (Curcuma longa). There has been considerable interest in the use of curcumin as a functional ingredient in foods and pharmaceuticals because of the potential of its beneficial activities, such as anti-microbial, anti-oxidant, anti-carcinogenicand anti-inflammatory activities (1, 2). However, utilisation of curcumin as a nutraceutical ingredient is limited due to its low oral bioavailability, low water solubility and chemical instability. Various encapsulation technologies are available that may be able to overcome these challenges. The two most important types of surface-active materials that are preferably used to produce food-grade dispersions are proteins and polysaccharides (3). Sodium caseinate (SC) has attracted extensive interest among proteins that are used in food industry, as a suitable vehicle for nutraceutical delivery (4). The Gum Arabic (GA) is a hybrid polyelectrolyte containing both protein and polysaccharide subunits. GA has been chosen in this study, d ...