Optimization of bread baking in a halogen lamp-microwave combination oven by response surface methodology

The main objective of this study was to optimize the baking conditions of bread in a halogen lamp-microwave combination oven. Independent variables were the baking time (4, 4.5, 5, 5.5, and 6 min), the power of the microwaves (20, 30, 40, 50, and 60%), and the power of the upper and lower halogen lamps (40, 50, 60, 70, and 80%). The quality parameters measured were the weight loss, the color, the specific volume, the porosity, and the texture profile of the breads. For the optimization, the response surface methodology was used. Baking time, upper halogen lamp power, and microwave power were found to be significant in affecting most of the quality parameters. On the other hand, the lower halogen lamp power was found to be an insignificant factor. The optimum baking conditions in the halogen lamp-microwave combination oven were determined as 5 min of baking time at 70% upper halogen lamp power, 50% lower halogen lamp power, and 20% microwave power. Breads baked at the optimum condition had comparable quality with conventionally baked ones. When the halogen lamp-microwave combination oven was used, the conventional baking time of breads was reduced by 60%.