Effect of different baking methods on the antioxidant activity of flour products which added naturalantioxidants

This study analyzed the effect of differentbaking methods on theantioxidant ability of flour products,the processing methods include fermentation+steamed,fermentation+baking and direct baking. Natural antioxidants(soybean isoflavones,tea polyphenol,anthocyanins,phytic acid,V_C/V_E)were added individually into wheat flour to make bread,biscuit and steamed bread,and to evaluate their free radical clearance rate(DPPH free radical,O₂^- free radical,OH^-free radical,ABTS free radical)of acetone extractbefore and after the process,respectively. And method of variation coefficient is used in comprehensive evaluation of flour products antioxidant capacity. It showed that processing methods and types of antioxidants both played important roles in improving the antioxidant capacity of wheat flour products. Soybean isoflavones can improve antioxidant capacity up to 3.85% under the direct baking condition. When tea polyphenols were added into dough,the loss rate of antioxidant capacity was -3.39% and it was lowest compared with other antioxidants under the direct baking condition. The anthocyanins can maintain their antioxidant capacity to the greatest extent possible under fermentation+baking condition activity,and the loss rate was -1.77%. The antioxidant capacities of phytic acid and V_C/V_Ecan retain higher antioxidant activity when they were used in the fermentation+steamed processing,the loss rate of antioxidant capacity was -4.66% and -5.14%. When these natural antioxidants compounds were added into dough,we should choose suitable processing methods to maintain the antioxidant capacities.