Evaluation and the Effect of Watermelon Seed Flour on the Functional Properties of Puffed Snack Regarding the Formulation and Process Conditions

The highconsumption of low nutritional value snacksand malnutrition of children and teenagers are one of the major problems in society. Usually, the small seeds that are in watermelon, although they are rich in nutrients including fatty acids, essential proteins, and many minerals are not used and have been thrown away.

This study was performed on the basis of a rotating central composite design. The effects of extrusion variables including screw speed (120-180 rpm), watermelon powder (10-20%) and feed moisture content (12-20%) on the physicochemical properties (expansion ratio, oil and water absorption index, porosity, and total acceptance) of expanded snack on the basis of corn-wheat flour grits were evaluated.

The results showedthat watermelon flour decreased the expansion coefficient and porosity, however, the interaction effect of screw speed and watermelon flour improved the physicochemical properties of the samples. The increasing screw speed led to a decrease in the viscosity and therefore the expansion coefficient and porosity increased.

The optimization of snack formulation was performed to find the optimum conditions of production. The watermelon flour of 11.31%, feed moisture content of 15.56% and a screw speed of 171.15 rpm were found to be to optimum conditions.