Effects of particle size on the physical, chemical, and technological properties of pre-gelatinized whole pinhão (Araucaria angustifolia) flour

This study investigates the influence of particle size on the chemical, technological, rheological, thermal, and structural properties of whole pinhão flour, employing pre-gelatinized seeds, in response to the growing demand for diverse and healthier food choices. The fractionation conducted using RO-TAP® at different particle sizes (210 μm - P1, 149 μm - P2, 105 μm - P3, and < 105 μm - P4) led to significant changes in chemical composition, mineral content, viscosity, and thermal characteristics. The P3 fraction emerged as particularly promising, with elevated levels of total carbohydrates (60.27 g/100 g), total starch (46.14 g/100 g), and viscosity (1,545.50 cP), making it ideal for baking. Remarkably, P1 and P4 fractions exhibited elevated levels of fiber (46.96 and 38.57 g/100 g), phenolic compounds (13.35 and 13.51 mg EAG/g), and in vitro antioxidant activity. Lipid content increased inversely with particle size, accompanied by a decrease in resistant starch. All the pinhão fractions exhibited substantial mineral content, ranging from 2 to 2.24 g/100 g. Infrared spectroscopy analyses highlighted compositional similarities in samples, which uniformly exhibited type C crystallinity and high crystallinity indices (38.89%, 44.28%, 47.11%, and 46.46%, respectively). Fibers negatively affected viscosity, thermal properties, and starch gelatinization. Notably, the fraction with the smallest particle size demonstrated improved suitability for developing gluten-free bread products. This study highlights the importance of processing and fractionating pinhão flour to enhance resource utilization efficiency. Furthermore, the findings provide tangible insights to enhance pinhão production and processing chains, fortifying the food industry and addressing consumer preferences for healthier and more diverse products.