Vitamin E-loaded hydroxyapatite Pickering emulsions as new product design for fortified food applications

Abstract

Lipophilic vitamin E is a vital component of human health; however, it degrades quickly and loses bioactivity due to oxidative instability. In this study, vitamin E-loaded Pickering emulsions stabilised by nano-hydroxyapatite (n-HAp) were produced using a static mixer (NETmix), a technique enabling continuous production and droplet size tailoring. Thus, oil-in-water (O/W) emulsions containing vitamin E at a content of 1mg/mL were produced with different droplet sizes using an O/W ratio of 20/80 (v/v). Their stability during in vitro gastrointestinal digestion and vitamin E bioaccessibility was studied. It was observed that n-HAp particles break in the stomach and subsequently aggregate as random calcium phosphates in the small intestine, leading to low vitamin E bioaccessibility due to oil entrapment. The emulsion showing the highest vitamin E bioaccessibility (3.29±0.57%, sample with the larger average droplet size) was used to produce fortified gelatine and milk, resulting in an increased bioaccessibility (10.87±1.04% and 18.07±2.90%, respectively), associated to the presence of macronutrients. Overall, n-HAp Pickering emulsions offer advantages for vitamin E encapsulation directed to fortified foods development, a process that can be extended to other lipophilic vitamins.