Use of corn flour and polydextrose in fried extrudate making: Effects of polydextrose content in the blend and extrusion temperature on the product quality

High fiber snack food has attracted great attention due to many health benefits. In this study, the effects of polydextrose content and extrusion temperature on proximate composition, physical and sensory properties of the fried corn snack were investigated. Firstly, the polydextrose content in the blend was varied from 0 to 10% while the extrusion temperature was fixed. Then the blend formula was fixed while the die temperature was changed from 60 to 110°C. An increase in polydextrose content in the blend from 0 to 10% augmented the product density and decreased its radial and axial expansion ratio and crispness. Moreover, small air cells and thick cell walls were observed in the texture of the product with high polydextrose content. An increase in die temperature from 60 to 100°C reduced the product bulk density and enhanced the radial and axial expansion ratio, hardness, and crispness. High die temperature also resulted in large air cells and thin cell walls in the product texture as well as high water absorption and water solubility index of the snack. However, further, an increase in die temperature from 100 to 110°C reduced the expansion ratio, hardness, and crispness of the fried extrudate. It can be concluded that snack quality was greatly influenced by polydextrose content and extrusion temperature. The use of polydextrose is the potential for the development of high fiber snack food. PRACTICAL APPLICATION: Recently, many studies focus on the possibility of the application of various dietary fiber sources in the production of extruded snack food. Most of the investigated fiber materials are whole grain cereal flour, cereal bran or fruit, and vegetable fibers. Nowadays, commercial soluble dietary fiber preparations are well‐known in food industry. Their proximate composition and properties are stable and highly standardized. However, their use in extruded snack production has not been considered. In this study, corn flour and polydextrose were extruded to produce snack with high fiber content. The effects of polydextrose ratio in the blend and extrusion temperature on proximate composition, physical and sensory properties of the fried extrudate were investigated. The obtained results would be useful for food scientists and technologists who look for a potential dietary fiber source in the production of snack food with high fiber content.