2.10.1. DPPH free radical scavenging activity determination

Lyophilized camellia seed meal and MRPs obtained from enzymatic hydrolysis of camellia seed meal were dissolved in distilled water and prepared into 0.5 mg/mL, 1.0/ 1.5/2.0/2.5/3.0 mg/mL, respectively. 2.5 mL of 100 μmol/L DPPH methanol solution and 2 mL of the corresponding MRPS solution were mixed, shaken, and they were placed in a 37℃ under dark conditions for 40 min. The absorbance A₁ was measured at 517 nm with double steamed water as the reference, and A₂ was measured with deionized water instead of DPPH under the same conditions, and the camellia seed meal solution with the same concentration was used as the control (Wu, Chen, & Shiau, 2003).