Encapsulation strategies to enhance the stability and bioaccessibility of bioactive components from tomato by-product extracts for nutraceutical applications.

Tomato processing generates large volumes of by-products that remain underexploited despite their high content of bioactive compounds with potential health benefits. In this study, the extraction of tomato by-products to produce an extract with neuroprotective-related bioactivity is targeted. Moreover, three encapsulation approaches aimed at increasing the stability of their bioactive compounds were evaluated and compared, namely, spray-drying (SDE), non-modified lecithin liposomes (NLE), and inulin-modified lecithin liposomes (ILE). Encapsulation efficiency, stability under accelerated conditions (45 °C), thermal and pH tolerance, and bioaccessibility during in vitro gastrointestinal digestion and bioactivity were studied. SDE resulted in poor encapsulation efficiencies and substantial degradation of bioactive compounds, leading to significantly reduced bioactivity values. In contrast, liposomal encapsulation preserved phytochemicals more effectively, with NLE retaining up to 95.8% of the initial phenolic compounds amount, and 80.6% of initial carotenoids. Thermal and pH stability confirmed the robustness of NLE, while in vitro gastrointestinal digestion highlighted the higher bioaccessibility of encapsulated systems. Notably, incorporation of inulin did not improve the overall performance of the liposomal system. Overall, non-modified lecithin-based liposomes emerged as the most effective encapsulation strategy, offering a promising route for valorising tomato by-products into ingredients with potential bioactivities indirectly associated with a neuroprotective potential.