RESUMEN
The objective of this study was to determine the best combination of extrusion process variables for the production of whole quality protein maize (EQPMF) and common bean (ECBF) flours to prepare a high antioxidant activity mixture (EQPMF + ECBF) suitable to produce a nutraceutical beverage with high acceptability elaborated with a traditional Mexican formulation. Processing conditions were obtained from a factorial combination of barrel temperature (BT = 120-170 °C) and screw speed (SS = 120-200 rpm). Response surface methodology was applied to obtain maximum values for antioxidant activity (A ( ox ) A) of the flour mixture (EQPMF + ECBF) and acceptability (A) of the nutraceutical beverage. The best combinations of extrusion process variables for EQPMF and ECBF to prepare an optimized mixture (60%EQPMF + 40%ECBF) were BT = 98 °C/SS = 218 rpm and BT = 105 °C/SS = 83 rpm, respectively. The optimized mixture had A ( ox ) A = 14,320 µmol Trolox equivalent (TE)/100 g sample dry weight (dw) and a calculated protein efficiency ratio (C-PER) of 2.17. A 200 ml portion of a beverage prepared with 25 g of the optimized flour mixture had A ( ox ) A = 3,222 µmol TE, and A = 89 (level of satisfaction "I like it extremely"). This nutraceutical beverage could be used as an alternative to beverages with low nutritional/nutraceutical value, such as those prepared with water, simple sugars, artificial flavoring and colorants, which are widely offered in the market.