Effect of preparation factors and storage temperature on fish oil-loaded crosslinked gelatin nanoparticle pickering emulsions in liquid forms

Abstract Fish oils are rich in omega-3 unsaturated fatty acids and have many important physiological functions and potential disease prevention abilities. It is necessary to develop novel dosage form and formulation such as food emulsions to encapsulate fish oils for protection, increase water solubility, and isolate the fishy taste. In this work, we mainly explore the effects of preparation factors and storage temperature on fish oil-loaded crosslinked nanoparticle Pickering emulsions in liquid form. Firstly, we prepared the crosslinked gelatin nanoparticles by a two-step desolvation method. Then we prepared fish oil-loaded gelatin nanoparticle Pickering emulsions by a homogenization processes. Subsequently, we explored the effects of preparation and storage factors (gelatin nanoparticle solution pH, homogenizing time, homogenizing speed, and storage temperature). Our results confirmed the successful preparation of crosslinked gelatin nanoparticles and fish oils-loaded gelatin nanoparticle Pickering emulsions. The Pickering emulsions mainly consist of three types of droplets with different sizes. The droplet sizes linearly decreased with the increase of gelatin nanoparticle solution pH and homogenizing time, whereas exponentially decreased with the increase of homogenizing speed. Storage temperatures had obviously different effects on the storage of the fish oil-loaded crosslinked gelatin nanoparticle Pickering emulsions. This work provides a way to encapsulate fish oils in emulsions and provides potential promising application prospectives in food beverages. It would be also beneficial to basic understanding of the formation of gelatin nanoparticle-based Pickering emulsions.