Quinoa and tarwi are characterized by their high nutritional value so their crops have spread to various countries. In recent years to increase consumption new food processing alternatives are sought, artisanal and biotechnological. In this study the digestibility of polysaccharides contained in quinoa flour (Chenopodium quinoa Willd), white variety (QB), black variety (QN) and oligosaccharides of tarwi flour (Lupinus mutabilis) (T) by enzymatic application of a-amylase was evaluated in vitro. The proximal analysis of the grains was performed, finding values similar to those of reference (AOAC methods). The content of free sugars in flour of the grains was 10,05 ± 0,3 for QB, 8,25 ± 0,3 for QN and 0,19 ± 0,01 for T. The starch content was determined, 51,08 ± 0,3% in white quinoa (QB) and 49,04 ± 0,4% in black quinoa (QN). The reducing sugars by the effect of Termamyl Sc in % of substrate was 25 ± 1,9 (QB), 27,5 ± 1,5 (QN) and 2,01 ± 0,3 (T). The kinetic parameters found: Km: 80,4 mg/mL, Vmax: 0,36 mg/mL min-1 (QB); Km: 98,8 mg/mL, Vmax: 1,72 mg/mL min-1 (QN); Km: 3,14 mg/L and Vmax 4,81 mg/L min-1 (T), were derived from the Lineweaver Burk plot.