The effects of using freeze-dried extracts (FDEs) of spearmint ( Mentha spicata), fennel ( Foeniculum vulgare), and turmeric ( Curcuma longa) as well as adjusting the baking temperature and time on acrylamide formation in pita bread were investigated to obtain the most acceptable conditions that produced the lowest acrylamide concentrations. A Box-Behnken design was adopted for optimization of the pita bread formulations by adding FDEs (3 to 25 g/100 g of wheat flour) and adjusting the baking temperature (200 to 300°C) and baking time (3 to 11 min), and the effects of these changes on color parameters, phytochemical attributes, and acrylamide concentrations were evaluated. Increasing the concentration of FDE and decreasing the baking temperature and time considerably decreased the acrylamide concentration in bread for all experimental trials. No acrylamide was detected in pita bread formulated with 25 g of mint FDE/100 g of wheat flour and baked at 250°C for 3 min, formulated with 25 g of mint or fennel FDE/100 g and baked at 300°C for 7 min, formulated with 3 g of mint, fennel, or turmeric FDE/100 g and baked at 200°C for 7 min, formulated with 14 g of mint FDE/100 g and baked at 300°C for 3 min, and formulated with 25 g of mint or fennel FDE/100 g and baked at 200°C for 7 min. Pita breads formulated with fennel and turmeric FDE were given high sensory scores.
Keywords: Acrylamide; Curcuma longa; Foeniculum vulgare; Mentha spicata; Response surface methodology; Wheat flour.