| Pinhao is the seed of Brazilian Pine ( Araucaria angustifolia), a conifer that grows in the south of Brazil, Argentina, and Paraguay. Pinhao seeds are very good source of carbohydrates but there is no wide scale consumption of these seeds hence a large quantity is lost at the end of each harvest. Due to high humidity, seeds can easily be contaminated by fungi during stockpiling, thus hindering its commercialization. The seeds are traditionally used as source of flour for baking or cooked in hot water, peeled, and consumed. The objectives of my research were: (1) To study the migration of polyphenols from hull to seed during atmospheric and pressure cooking of Pinhao seeds and; (2) To test the extrudability of Pinhao flour fortified with soy flour to make snack food.;The hull of Pinhao has ample amount of phenolics but hull forms the non-edible part of the whole nut. It has been proved by previous researchers that phenolics diffuse from the hull to the seed during atmospheric cooking. In this study we investigated the migration of phenolics during atmospheric and pressure cooking as a function of time. More migration of phenolics from hull to seed occured in a shorter time period during pressure cooking as compared to atmospheric cooking which proved that pressure cooking is an efficient cooking process as regards to polyphenolic content in cooked seeds.;We also studied the single screw extrusion of Pinhao flour fortified with soy flour using Response Surface Methodology. Box-Behnken (BBD) design was used to obtain the extrusion conditions to make extrudates. The process parameters during the extrusion were moisture content of the blended flour (17-24% w.b.), barrel temperature (120- 180°C), and percentage of Pinhao flour (50-75%). The physical characteristics studied were sectional expansion index, bulk density, breaking strength, hue, chroma, water absorption index, and water solubility index. The total phenolic content of the blended flour and extrudates was also compared; it was found that there was substantial loss in polyphenols after extrusion cooking. For the expansion of the extrudates, maximum puffing of the samples was obtained at 17% moisture content of the blended flour, 150°C barrel temperature, and 75% of Pinhao flour. Sensory testing of the selected extrudate samples was also conducted and results showed that sample extruded at low moisture content and high percentage of Pinhao flour was perceived and liked by subjects the most. |
