A Preliminary Study on Vitamin-Enhanced Extra-Virgin Olive Oil: Functional Food Design via Advanced Emulsion Systems

Micronutrient deficiencies, particularly of vitamins A, D₃, and B₉, remain a significant global health challenge despite established dietary recommendations. This study proposes a novel fortification strategy using advanced emulsion technology to enrich extra-virgin olive oil (EVOO) with these essential micronutrients. Water-in-oil (W/O) and double oil-in-water-in-oil (O/W/O) emulsions were designed to enable the simultaneous encapsulation of lipophilic (A and D₃) and hydrophilic (B₉) vitamins within a single functional food matrix. Vitamin concentrations were quantified using high-performance liquid chromatography (HPLC) coupled with a photodiode detector (PDA) to evaluate retention during processing. Bioaccessibility was assessed by subjecting vitamin-enriched emulsions to a standardized in vitro digestion model simulating gastrointestinal conditions. Results showed significantly higher incorporation efficiency in the O/W/O system compared to conventional W/O emulsions, regardless of the physicochemical properties of the vitamins. Both lipophilic (A and D₃) and hydrophilic (B₉) compounds exhibited satisfactory retention, highlighting the versatility of the double-emulsion approach. This study represents the first report of simple and multiple oil-continuous emulsions that simultaneously incorporate vitamins A, D₃, and B₉, providing preliminary evidence of their stability and gastrointestinal release under simulated digestion conditions.