High hydrostatic pressure processing of whole buckwheat grains to obtain functional gluten-free ingredients: Effect of pressure and holding time

High Hydrostatic pressure (HHP) represents an environmental-friendly and efficient non-thermal technology capable of inducing changes that can lead to functional improvements on starchy materials preserving the nutritional value of the original flours. The development of gluten-free (GF) flours and ingredients remain a challenge due to the need to improve the nutritional and techno-functional aspects of these commodities. Pre-soaked whole buckwheat (BW) grains were subjected to HHP treatment under different processing conditions: two pressure levels (300–600 MPa) and three holding times (0-5-15 min) to evaluate the techno-functional and nutritional response of the resulting flours. Significant (p < 0.05) increases in water absorption capacity and swelling capacity were observed in the flours resulting from longer treatment times (5–15 min) and the highest-pressure level (600 MPa). Higher thermal stability was also observed in the pasting profiles obtained for these flours. Flours resulting from HHP treatments at 600 MPa for 15 min also showed higher antioxidant capacity (DPPH and ORAC). The resulting flour from these processing conditions was used at different concentrations (15, 30, 50, and 70 %) in a GF bread formulation. An increase in the elastic modulus values of the doughs, the specific volume of the resulting bread and a reduction in the crumb firmness were observed in the formulations containing the BW-modified flour compared to the counterparts made with a native flour. Therefore, it can be concluded that the HHP treatment of whole buckwheat grains represents an interesting alternative for the development of ingredients with suitable technological and nutritional properties for gluten-free bakery formulations.