Pinhão Seeds and Coats: Drying Process and Flour Characterization for Application in Food Products

Non-timber forest products originating from native Brazilian trees, such as Araucaria angustifolia (Bertol.), stand out within the scope of the global concept of bioeconomy. The pine fruit from A. angustifolia, known in Portuguese as pinhão, is an edible seed covered with a coat that is considered as solid waste. The aim of this study was to investigate the drying kinetics of the pinhão coats and seeds to obtain and characterize two types of flour. The drying temperature (70°C) and air velocity (1.0 ms-1) were the parameters used to obtain the drying curves. These curves were fitted using five empirical and semiempirical mathematical models to establish predictive equations for the drying process. After drying, the coats and the seed were ground (30-mesh sieve) separately to obtain two types of flour samples, which were nutritionally characterized and their antioxidant activity was quantified. The equilibrium moisture values were 2.90% for the coats and 1.71% for the seeds. The Page and the Overhults models provided the best results for both coats and seeds (R2 = 0.9996; χ2 = 0.1926 and R2 = 0.9971; χ2 = 0.3702, respectively). The nutritional composition results for the coat flour indicated high values for dietary fiber (84.91%), phenolic compounds (39.53 mgEC g−1) and DPPH radical scavenging activity (93.23%), while the seed flour showed a high content of total carbohydrates (80.07%). Thus, the use of these products obtained from pinhão coats and seeds as a food ingredient is a promising strategy to promoting environmental sustainability and bioeconomy, while also enhancing human health.