Soy protein fibrils–β-carotene interaction mechanisms: Toward high nutrient plant-based mayonnaise

This study systematically explored the interaction mechanisms of soy protein fibrils–β-carotene complex. Herein, we used plant-based ingredients (β-carotene and protein fibrils) to fabricate high nutrient plant-based mayonnaise by a facile method, also investigated sensory properties and β-carotene bioaccessibility. Thioflavin T fluorescence, zeta potential, X-ray diffraction, and transmission electron microscopy results revealed that the conformational transition of protein fibrils had occurred as the addition of β-carotene. Intrinsic fluorescence quenching, FTIR spectroscopy, and surface hydrophobicity suggested that the main interaction between protein fibrils and β-carotene was hydrophobic interaction, and the formation of the complex was attributed to entropy-driven. Compared with native proteins, protein fibrils had a higher binding ability to β-carotene. Additionally, the antioxidant activity was improved after the formation of β-carotene–protein fibrils complexes (F-0.3β, 61.50%). Upon such molecular encapsulation, the stability of β-carotene was greatly improved compared with that of β-carotene only. F-0.3β-based mayonnaise (F-0.3β-M) showed a solid-like property and lower droplet size than other plant-based mayonnaise, indicating good plasticity and smoothness. In vitro digestion revealed that F-0.3β-M exhibited higher transformation (63.95%) and bioaccessibility (87.63%). This work shed light on the understanding of β-carotene–protein fibrils binding, and develop egg-free mayonnaise to attract plant-based diet lovers.