Potencial fisiológico de sementes e qualidade nutricional de grãos de genótipos de chia (Salvia hispanica L.) e quinoa (Chenopodium quinoa Willd.)

Abstract

Quinoa and chia are two very nutritious species, with a high amount of protein, in addition to being gluten-free. Even with all the importance of these species, there are still not many cultivars in Brazil, as well as little information about the physiological and nutritional quality of the seeds produced here. Therefore, the objective was to establish methodologies for conducting seed viability and vigor tests, in addition to determining the nutritional composition of quinoa and chia genotypes. The characterization of the lots and evaluation of the physiological quality of the seeds was carried out by: mass of one thousand seeds, water content, germination, seedling emergence speed index, accelerated aging and electrical conductivity, with 20 genotypes and a completely randomized design with four replications. Data on water content and mass of a thousand seeds were subjected to comparison of means using the Tukey test, and data from the emergence speed index were subjected to the ScottKnott cluster test, dividing the genotypes into four vigor groups, these subjected to standardized accelerated aging and electrical conductivity testing, for both species. However, for quinoa, data on germination, accelerated aging and electrical conductivity were subjected to regression analysis. And for chia, the accelerated aging and electrical conductivity data were subjected to regression analysis, and the germination data to response surface analysis. For nutritional characterization, the grains were evaluated for grain dry matter, ash percentage, crude protein, lipid content, carbohydrates, total phenolic compounds, and antioxidant activity. In this experiment, the design used was completely randomized with 20 genotypes and three replications, and the data were compared using the Tukey test, for both species. The average grain dry matter and water content varied from 2.08 to 2.83 g and 12.64 to 13.91%, respectively for quinoa and chia, the average dry matter and water content varied from 0.25 to 1.40 g and 10.12 to 12.97%, respectively. The averages of the variables studied in this work were 90.69 and 96.23% of dry matter, 3.71 and 6.55% of ash, 15.15 and 24.27% of proteins, 6.24 and 28.41 % lipids, 3.57 and 29.49% fibers, 62.02 and 7.26% carbohydrates, 0.97 and 0.98 mg EqTrolox/g dry sample and 1.01 and 1.03 mg EqAG/ g dry sample of Phenolic compounds for quinoa and chia, respectively. It was concluded that the quinoa and chia germination test should be carried out at 20°C. 48 hours must be used for the accelerated aging test. The electrical conductivity reading can be taken after 6 hours and 40 minutes of soaking for quinoa and 15 hours and 30 minutes of soaking for chia, both with 75 mL of water and 100 seeds. The quinoa and chia genotypes studied are as nutritious as those studied around the world.