| Rice brans with different extent rancidity were obtained from fresh rice bran which stored at room temperature for 0, 1, 3, 5 d and 10 d, and rice bran soluble dietary fiber was prepared after stabilization and defatting of rancid rice bran, and effects of rice bran storage time on the antioxidant activity of rice bran soluble dietary fiber were investigated. The results indicated that as storage time of fresh rice bran increased, reducing ability, metal chelating activity, and free radical scavenging abilities of rice bran soluble dietary fiber on ABTS+·, DPPH·, ·OH and O-2· firstly increased, and then decreased. Reducing ability, metal chelating activity, and free radical scavenging abilities of rice bran soluble dietary fiber on ABTS+·, DPPH·and·OH achieved the maximum value as fresh rice bran stored for 5 d, reaching 0.943(OD700), 35.16%, 32.28%, 73.51% and 13.83%, respectively. The maximum value of free radical scavenging ability of rice bran soluble dietary fiber on O-2· was 60.58% as fresh rice bran stored for 1 d. |
