Development of a ready-to-eat food from freeze-dried quinoa seeds

TORREZ IRIGOYEN, MARTÍN R.; GINER, SERGIO A.

Simposio; IV Conferencia Internacional del Grupo IA Valse Food CYTED y VII Simposio Chia link; 2022

Quinoa is a valuable seed mainly for its essential amino acid and mineral content. Theobjective of this work was to characterize the freeze-drying process of quinoa to produce aready-to-eat food. Quinoa (var. CICA) were washed with water to eliminate the saponinsand treated with steam to favour the starch digestibility. Following, the samples werearranged in stainless steel trays and frozen at -20°C. A freeze-dryer Mod. L-A-B4-C (Rificor,Argentina) was used for the drying. Experiments were carried out at different tray temperatures(Tb): 30, 40 and 50ºC. In each case, moisture content (W) vs process time curveswere determined. To ensure storage stability, it was proposed to reach a water activity(aw) ≤ 0.45 in the final product. The results showed that an increase in Tb reduced the processingtime, finding that at 50ºC a time of 1.5 h was sufficient to achieve a W of 0.02 kg water/kg dry matter and aw=0.123. Regarding nutritional properties, the main minerals werequantified: Calcium (Ca), Iron (Fe), Potassium (K) and Phosphorus (P) using the inductivelycoupled plasma technique (ICP-OES). The results (mg/ kg dry matter) were Ca: 601.9; Fe:22.6; K: 4342.2; P: 3975.2. The total antioxidant capacity was determined by ABTS (μg Trolox/g d.m.), FRAP (μmol Fe/ g dm) and total phenols (μg Gallic Acid Eq./ g dm). The values were:574.6 in ABTS; 3.04 in FRAP and 569.6 in total phenols. Freeze-drying can be a suitable processto produce a dehydrated product with good nutritional profile.