Antioxidant Activities of Sourdoughs

Antioxidant activity of sourdough was assayed as scavenging activity on 1,1-diphenyl-2-picrylhydrazyl radical (DPPH^⋅) (Yu et al., 2003). The analyses were carried out using WSE and methanol-soluble extracts (MSE). For MSE preparation, 1 g of freeze-dried dough was resuspended in 9 ml of methanol acidified with HCl (0.1% v/v) and incubated at room temperature for 1 h under stirring condition (200 rpm). The supernatants were collected by centrifugation (11,000 × g for 20 min). The reaction mixture was prepared by diluting both WSE and MSE extracts in water and methanol, respectively. The reaction was monitored by reading the absorbance at 517 nm every 2 min for 30 min. A blank reagent was used to verify the stability of DPPH^⋅ over the test time. Butylated hydroxytoluene (BHT) was used as the antioxidant reference.