Development of food grade colloidal system for delivery of vitamin A and D

Abstract

Nutritional deficiency of vitamin A and D is causing a lot of problems in the world. It is estimated that about one billion people worldwide are either vitamin D deficient or have insufficient vitamin D intake. In Pakistan about 85% of both pregnant and non-pregnant mothers have been found vitamin D deficient. Apart from this, 5.7 million children below 5 years of age and 42.5 % women were identified as vitamin A deficient in Pakistan. Being food fortification or supplementation a best approach, the food manufacturers are interested in fortifying their products with vitamin A and D. As both vitamins are restricted to fats and oils due to their non-solubility in water. Nanoemulsions are ideal solution to address this problem because this technique enhances the solubility, kinetic stability, bio efficacy and bioavailability of encapsulated material due to their smaller size. The purpose of present study was to fortify beverages with nanoemulsions of vitamin A and D. The nanoemulsions were prepared by using food grade surfactants (Tween 80 and soya lecithin), deionized water and vegetable oil (olive and canola oil). Preparation conditions for beta carotene and vitamin D nanoemulsions were optimized using response surface methodology. These nanoemulsions were further characterized against different physico-chemical parameters. In vivo study was carried out on animal model to investigate the safety of nanoemulsions. The nanoemulsions based delivery system was used to fortify the beverages with these vitamins. The results manifested that, ideal optimum preparation conditions for beta carotene nanoemulsions were 6.07% surfactant, 4.19 minutes homogenization time and 6.50% oil contents. For vitamin D nanoemulsions, optimum preparation conditions were 4.82 minutes xxii xxii homogenization time, 0.67 surfactant to oil ratio (S/O) and 7% disperse phase volume. During two months of storage studies, these nanoemulsions remained stable against phase separation and creaming. Moreover, droplet size of nanoemulsions stored at 4 °C slowly increased as compared to nanoemulsions stored at 25 °C. Additionally, p-Anisidine value of the vegetable oil (canola and olive oil) incorporated into nanoemulsions were significantly lower as compared to free vegetable oil. These nanoemulsions were stable against droplet aggregation and phase separation over a wide range of pH (2-8), salt concentration (50-400 mM) and temperature (30-80°C). During toxicity study, bi-nuclear assay, multinuclear assay and comet assay did not showed any toxic effect of nanoemulsions on animal models. During last part of study, vitamin beta carotene and vitamin D fortified model beverages was developed successfully. Hence, nanoemulsions based delivery system can be used for fortification of aqueous products with fat soluble vitamins and other nutraceutical compounds.