Elaboration of functional snack foods using raw materials rich in carotenoids and dietary fiber: effects of extrusion processing

This research studied the effect of extrusion temperature (ET, 93.45–140.55°C), moisture content (MC, 21.27–34.73%), and the winter squash flour content (WSF, 0.43–15.57%) on physicochemical characteristics and content of bioactive compounds of third-generation (3G) snack foods expanded by microwave heating. The ingredients used for their elaboration were corn starch, whole-grain yellow corn and winter squash flours. A single-screw extruder was employed, and the response surface methodology was applied. The lowest bulk density and the highest water solubility index (WSI) and water absorption index, occurred at high ET with low MC. The highest values of total carotenoids and dietary fiber (total and soluble) were obtained at high WSF and ET. Furthermore, when the WSF was increased, the color L* value diminished, whereas b* value and WSI increased. These results suggest that it is possible to elaborate 3G snack foods with acceptable physicochemical characteristics and excellent bioactive compounds content, improving their potential health benefits.