Selected properties of snacks extruded at various screw speeds supplemented with Moldavian dragonhead seed addition

The main aim of the study was to determine selected characteristics of extruded snacks supplemented with Dracocephalum moldavica L. seeds added to the recipe in amounts ranging from 5 to 20% of the basic raw material composition. The effect of the screw speed on the selected corn-based snacks characteristics has also been been studied. A single-screw extruder was employed to obtain the snacks in the form of readyto- eat extrudates. Several properties were evaluated, among them: the expansion ratio, the water absorption and solubility indices as well as pasting properties, depending on the level of the additive and the screw speeds applied. Extruded snacks supplemented with Dracocephalum moldavica L. seeds exhibited an enhanced nutritional value compared with corn snacks due to the high content of fibre, protein and ash. The addition of the seeds decreased the expansion ratio significantly. The water absorption index of the snacks decreased as the level of seed addition in the processed blends was raised, while the water solubility index was significantly affected by the variable screw speed during the processing of the supplemented snacks. The recommended level of Dracocephalum moldavica seeds in corn-based snacks should not exceed 15% due to the high nutritional value as well as the high expansion and efficient treatment intensity of the components resulting in the ready-to-eat characteristic of the supplemented snacks.