Influence of Extrusion Cooking on In Vitro Digestibility, Physical and Sensory Properties of Brazilian Pine Seeds Flour (Araucaria Angustifolia)

Brazilian pine seeds (pinhao) are gluten-free products derived from Araucaria angustifolia. The commercialization of these seeds is essentially associated with a low level of industrialization. In this context, extrusion cooking is a potential alternative for preparing extrudates of pinhao as a food product, which can be easily digested and is ready for human consumption. Brazilian pine seeds flour was processed in a single-screw extruder following a central composite rotatable design. Three factors (independent parameters) were considered: moisture content (14 to 22 g/100 g), screw speed (100 to 250 rpm), and temperature in the 3rd heating zone (120 to 200 °C). The structural characteristics, in vitro digestibility and sensory acceptance were also evaluated. The resistant starch contents is almost reduced to zero after extrusion cooking while the slowly digestible starch content is increased. An increase in moisture positively affected the hardness and the luminosity (L*), although it negatively affected the volumetric expansion index, crispness, and color parameters (a*, b*, and ΔE). The experimental conditions of this study allowed the production of expanded extrudates from Brazilian pine seeds with good expansion, texture properties, and acceptance qualities. Thus, extrusion cooking was found to be a potential method for the industrialization of Brazilian pine seeds as a food product.