Obtaining a Functional Food from Andean Grains through Lactic Acid Fermentation

Abstract

Quinoa and amaranth have excellent nutritional compositions. Lactic fermentation iscapable of transforming the functional, structural, organoleptic and nutritional properties of rawmaterials. The objective of this study was to develop a product analogous to yogurt, which would besuitable for special diets. The product was formulated with quinoa and amaranth flours, water, sugarand strawberries, and it was fermented with an exopolysaccharide-producing strain of LactobacillusPlantarum. Chemical parameters and BAL growth were monitored. Sensory analysis determinedthe best formulation and fermentation time. In the final product, the proximal composition, microbial count, pH, antioxidant activity, color, viscosity and content of exopolysaccharides (EPS) weredetermined. The formulation of the selected product was 15 g quinoa/amaranth (50:50) flour, 12 gsugar, 25 g strawberry pulp and 85 g water, fermented for 8 h. The composition of the functionalproduct was 19.60 g carbohydrates and 1.74 g protein/100 g of the puree. The viable cell count was7.60 × 108 CFU/g; the pH was 3.86; and IC50 = 10.3 mg/mL. The color parameters L*, a* and b* were43.85, 15.24 and 11.72, respectively, with a reddish-brown color. During fermentation, the viscosityincreased to 5029 mPa*s at 10 rpm due to the production of EPS (6.78 g EPS/L fermented pure).However, EPS production was not enough to significantly modify the viscosity, probably due to theamylolytic capacity of BAL. Fermented pure was described as having a rich, fruity and acidic flavor,with a mild and pleasant smell and a viscous texture. The food obtained was analogous to yogurt withacceptable sensory characteristics and was suitable for vegetarians, coeliacs and lactose intolerants.