Sprouting as a bio-technological process to enhance the use of quinoa (Chenopodium Quinoa Willd.) in cereal-based products

Awareness o f the several agronomic, environmental, and health benefits of quinoa has led to a constant increase in its consumption. However, producing quinoa-enriched products alters some quality characteristics, including dough development and sensory acceptance, due to the lack of gluten and the presence of saponins, bitter compounds mainly located in the pericarp. Developing processes to decrease or modify the bitterness of quinoa can enhance its palatability and consumption. The aim of the study was to investigate the effect of sprouting on the molecular, functional and sensory properties of quinoa, in order to enhance the use of sprouted seeds as a new ingredient in food formulation. Whole quinoa was sprouted for 12, 24, 48 and 72 h at 22 °C and 90% of relative humidity and dried at 55 °C for 6 h. The development of amylases and proteases promoted changes in both starch and protein features, reaching the maximum extent after 48 h of sprouting. The molecular changes affected flour functionality, by: (1) decreasing the ability of absorbing and retaining water; (2) lowering syneresis during freeze-thawing; (3) decreasing foaming capacity and improving the stability of the foam. The 20% enrichment level was able to assure a good gluten aggregation suitable for the formation of dough able to maintain its structure during leavening and retain a high percentage of gas. The behavior of sprouted quinoa enriched-bread was compared with that of pearled quinoa-enriched bread at the same percentage (20%). Sprouted quinoa-enriched bread showed the best results in terms of volume and crumb softness up to three days of storage, suggesting that sprouting can be preferred to pearling, which is the most common pre-treatment for allowing the use of quinoa in bread-making. The increase in total titratable acidity and the decrease in pH upon sprouting time affect quinoa sourness. On the other hand, the decrease in foaming capacity observed in quinoa after 48-72 h sprouting could be associated with a decrease in saponin content, as measured by the afrosimetric method. In conclusion, sprouting can be proposed as an alternative method to washing or pearling to decrease the amount of saponins starting from 24-48h of process. Thus, sprouted quinoa can be used as a new ingredient in cereal-based products thanks to its capacity of enhancing bread performance, without using additives. Diego Suárez-Estrella is supported by a Doctoral Fellowship from the Secretaría de Educación Superior, Ciencia, Tecnología e Innovación, Ecuador.