Combining heat treatment and conjugation between guarana extract and pea protein isolate to produce O/W emulsions loaded with vitamin D3

Abstract

Growing interest in plant-based materials for stabilizing food emulsions is driven by the clean-label trend. Conjugating plant proteins with phenolic compounds from plant extracts enhances their techno-functionality and allows their use as stabilizers of emulsion-based systems. This study aimed to (i) combine heat treatment (HT) and conjugation with guarana extract (GE) to improve the emulsifying ability of pea protein isolate (PPI); (ii) encapsulate vitamin D3 (VD) in PPI/GE-stabilized emulsions; (iii) evaluate the potential of these formulations in improving VD retention during storage and in vitro bioaccessibility. The particles showed a size distribution ranging from 0.5 to 10 µm, depending on the processing sequence. Furthermore, HT on PPI dispersions followed by conjugation with GE led to microgels that stabilized emulsions during 30 days of storage at 25 °C. Also, the conjugates significantly improved VD retention, ranging from 74 to 100 %, after 30 days of storage at 25 °C, even in the presence of UV light. VD-loaded emulsions produced by PPI-GE conjugates showed higher bioaccessibility values (>65 %) compared to emulsions produced by PPI alone (∼58 %) and VD-incorporated sunflower oil (37 %). Given the above, the technological modification of PPI through conjugation with GE phenolic compounds and HT efficiently produced O/W emulsions loaded with VD, improving its bioaccessibility and tailoring a system with potential application in plant-based beverage and dessert formulations.

Keywords: Bioaccessibility; Functional plant-based beverage; Guarana; Microgel; Plant protein.