Design and Optimization of a Second-Generation Extruded Snack Using Carrot Waste, Blue Corn Flour, and Ellagic Acid as Functional Ingredients

Blue maize is rich in bioactive compounds which are at risk of extinction due to monoculture practices. Carrot bagasse, considered a byproduct of the food industry, contains compounds that have been shown to benefit human health while also enhancing sustainability. Ellagic acid can prevent and assist in the treatment of various pathologies. Extrusion is a process characterized by its use of low energy, which minimizes the degradation of nutrients and bioactive compounds compared to other technologies. The objective of this research was to develop a functional food with high value of sensorial acceptance, desirable physicochemical, and antioxidant properties, using an 85:13:2% mixture of nixtamalized blue maize flour, carrot bagasse flour, and ellagic acid, processed with optimal conditions of extrusion determined with a surface response model. Operational conditions using a central rotatable experimental design were die temperature (DT = 120-170 °C), and screw speed (SS = 50-240 rpm), while response variables were physicochemical properties (expansion index, bulk density, breaking force, water absorption index and water solubility index) and antioxidant activity (free phenols inhibition of ABTS and DPPH). Sensory analysis, bromatological characterization and ellagic acid content determination with HPLC-DAD in reversed phase were also made. The optimal operational conditions were found to be DT = 144 °C and SS = 207 rpm, resulting in a mixture with high sensorial acceptability on a five-point hedonic scale. The optimized functional food may be used to promote the utilization of endemic ingredients and reduce food waste in the treatment of pathologies and prevention of diseases due to its high antioxidant activity attributed to phenolic and terpene compounds.