*2.1. Materials and Chemicals*

Pancreatin (4 × USP specification) and zein ( ≥95%) and were bought from Sigma-Aldrich (Missouri, USA). 7,8-dihydroxyflavone ( ≥98%) was purchased from TCI Co., Ltd. (Tokyo, Japan). Sophorolipid was purchased from the Boliante Chemical Company (Xian, China). Sodium alginate (>90%) was obtained from Macklin (Shanghai, China). Sodium carboxymethyl cellulose was purchased from Aladdin (Shanghai, China). Bile salts and pepsin (activity 3000~3500 U mg<sup>−</sup>1) were obtained from Sangon Biotech Co., Ltd. (Shanghai, China). Other utilized reagents and chemicals were of analytical grade.

#### *2.2. Zein/Sophorolipid/Polysaccharide Ternary Nanoparticles Preparation*

Zein/sophorolipid/polysaccharide ternary nanoparticles and zein/sophorolipid binary nanoparticles (S/Z) were fabricated based on our previous study [25]. In detail, zein and sophorolipid (mass ratio 1:1, *w*/*w*) were both dissolved in 80% ethanol/water solution to prepare the stock solution (1% sophorolipid +1% zein, *w*/*v*). For preparation of zein/sophorolipid/polysaccharide ternary nanoparticles, the stock solution was quickly added into the polysaccharide (ALG or CMC) aqueous solution (antisolvent) in a volume ratio of 1:3 (*v*/*v*) under continuous stirring at 800 rpm for 30 min. Subsequently, ethanol was removed by a rotary evaporator at appropriate temperature. The mass ratio ( *w*/*w*) of zein to polysaccharide was set to 30:1, 20:1, 10:1, 5:1, 3:1, 2:1, and 1:1, respectively. The prepared CMC-based ternary nanoparticles were expressed as CMC/S/Z 30:1, CMC/S/Z 20:1, CMC/S/Z 10:1, CMC/S/Z 5:1, CMC/S/Z 3:1, CMC/S/Z 2:1, and CMC/S/Z 1:1, respectively. And the ALG-based ternary nanoparticles were denominated as ALG/S/Z 30:1, ALG/S/Z 20:1, ALG/S/Z 10:1, ALG/S/Z 5:1, ALG/S/Z 3:1, ALG/S/Z 2:1, ALG/S/Z 1:1, respectively. In addition, the S/Z was also fabricated by ASP methods; the difference was that antisolvent was deionized water without ALG or CMC. The final concentration of zein in every nanoparticle was 2.5 mg/mL. Then, the pH value of each nanoparticle dispersion was adjusted to 4.0 for dispersions stability investigation. The CMC/S/Z 5:1 and ALG/S/Z 5:1 were used for the following structure characterization. The freshly prepared samples were stored at 4 ◦C, and a portion of each sample was freeze-dried into lyophilized powder for the following testing and analysis.

#### *2.3. Polydispersity Index (PDI), Particle Size, Zeta Potential and Turbidity*

PDI, particle size, and zeta potential of fresh dispersions were characterized using a dynamic light scattering (DLS) instrument (Nano-ZS90 analyzer, Malvern, UK) at 25 ◦C. PDI and particle size was detected via light intensity at a fixed scattering angle of 90◦, and the refractive index of water was set at 1.45. The zeta potential was calculated by Smoluchowski model. The turbidity of complex particles was tested at 600 nm using an ultraviolet-visible spectrophotometer at 25 ◦C.

#### *2.4. Physical Stability of Ternary Nanoparticles*
