Investigation of the effect of orange peel powder on biskuit dough and biscuit quality

In this study, orange peel known as rich in dietary fiber was lyophilized and biscuits were obtained by incorporation of grinded orange powder to biscuit formulations at the rates of 1%, 3%, 5% and 7%. It was aimed to investigate of the effect of orange peel addition to some rheological properties of biscuit dough and some quality charactersitics of baked biscuits. It was also aimed to gain various functions to biscuits with dietary fiber and other components in orange peel. According to the farinograph analysis, increase in development time, water absorption and degree of softening of doughs and decrease in stability after increasing to 3% orange peel was determined. According to the extensograf results, it was determined that increase in energy and extensibility generally and no significant difference in resistance. Increase in antioxidant, total carotenoid, total phenolic compounds and dietary fiber amount of biscuit samples has been observed by increasing fiber rate. This result shows that addition of orange peel fiber provided expected contribution to nutritional value of biscuits. pH values, ash, fat, protein and moisture amounts of samples were also determined. Also, It is expected that additional fiber will retard rancidity of biscuit by reducing moisture and the amount of free water. At pH measurements, it has been determined that the medium becomes more acidic by the addition of orange peel powder, and 1% and % 3 is on the verge of the neutral taste. It was determined that diameter, thickness, flexibility and brightness reduced and biscuits progressively darkened and hardened by increasing orange peel powder rate. As a result of the sensory evaluation, it was observed that acceptable scores given to %1 ve %3 rated biscuits, and scores gradually decreased at 5% and 7% rates. After physical, chemical, rheological and sensory analysis, it can be said to be possible that incorporation of lyophilized orange peel fiber at rate of 3% or even % 5 to bicuits by making some changes in raw materials and production conditions.