Rice protein stabilized high-internal-phase emulsions for delivery of α-tocopherol in 3D-printed dysphagia-friendly foods: Influence of extraction methods

Abstract

This study investigated how enzymatic and alkaline extraction methods affect the ability of rice protein (RP) to stabilize HIPE for α-tocopherol delivery in 3D-printed dysphagia-friendly foods. Extractions promoted protein liberation, yielding RP with protein contents of 29.47%–91.75%. The enzymatically extracted RP exhibited a higher α-helix content; conversely, alkaline extraction disrupted hydrogen bonds, resulting in reduced α-helix and elevated β-turn contents. This conformational reorganization reduced the particle size. These RP stabilized an 83% oil-phase HIPE, yielding an elastic structure. HIPE stabilized by thrice-enzyme- and alkaline-extracted RP exhibited smaller droplet sizes, enhanced elasticity, and superior stability. Both HIPE displayed rheological properties suitable for 3D printing, yielding products that align with IDDSI Level 4 criteria. The HIPE achieved an encapsulation efficiency of 97%, leading to a 41% increase in photostability and a bioaccessibility exceeding 66.3%. These findings pave the way for the development of personalized, dysphagia-friendly foods fortified with lipophilic functional ingredients.