Formulation of Personalized, Fortified Beverage Nanoemulsions for Space Exploration with Omega-3 Polyunsaturated Fatty Acids

Current food trends (i.e., personalization and fortification with bioactives) can reduce food monotony and health risks experienced by astronauts during space missions. Using beverage nanoemulsions (beverage emulsions: oil content ≤1 g/kg; nanoemulsions: diameter ≤200 nm for high bioavailability) as a formulation approach for fortified beverages, this study investigates (1) how product formulation influences the emulsification process (self-assembly of droplets via low-energy emulsification, i.e., spontaneous emulsification) compared to a model system, (2) how to establish beverage personalization, and (3) how to achieve future beverage production. An emulsion model system (oil phase: medium-chain triglyceride and polysorbate 80 at a surfactant-to-oil mass ratio of 1.0; aqueous phase: 5 mM phosphate buffer at pH = 7.4; 1 g/kg oil) with an average droplet size of 184 ± 12 nm (batch process) was successively extended with common beverage ingredients (acids, sugars, aroma) and fish oil rich in omega-3 fatty acids. While aroma compounds and acids have a subsidiary influence on emulsion characteristics, an increase in sucrose concentration increased droplet size and the incorporation of fish oil decreased droplet size. Six different beverage recipes (varying in aroma compound and sweetness level) with a dosage of 90 mg bioactive per 330 mL serving were developed for a recipe library for future beverage personalization. Translating the emulsification to a continuous microfluidic (channel diameter ≤1 mm) process led to a further decrease in droplet diameter (final emulsions: 80–120 nm). Thus, emulsification efficiency (droplet size in relation to surfactant use) can be increased both via appropriate ingredient selection and process mode.