Wet milling of buckwheat cultivars and some quality properties of the fractions

The hulled buckwheat cultivars (Aktaş cv. and Güneş cv.) were wet-milled, and then some chemical, yields, colour, functional properties, phenolic compound, antioxidant activity, and pasting, thermal and retrogradation properties of starches were investigated and compared with the wholegrain buckwheat flour (with hull) and buckwheat groat flour (without hull) of the same cultivars. Sodium dodecyl sulphate polyacrylamide gel electrophoresis patterns of flours and protein fractions were examined under reducing and non-reducing conditions. The hull, germ+dietary fibre, protein and starch fractions were collected. The total recovery for Aktaş cv. and Güneş cv. cultivars were 98.1% and 96.1%; total starch yields were 51.6% and 49.7%; pasting temperatures of the starches were found as 83.7 and 85.7°C; and final viscosities of starches were determined as 3.5 and 3.4 Pa·s, respectively. The resistant starch contents of starch fractions of Aktaş cv. ve Güneş cv. were found as 3.28% and 3.62%, respectively. The highest total phenolic compound contents were detected with dimethyl sulphoxide extraction in the germ+dietary fibre fractions. The highest 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity and trolox equivalent antioxidant capacity were found in the hull fraction (as 81.7%) and germ+dietary fibre fraction (as 11.8 mmol/kg) of Aktaş cv. cultivar.
This work was financially supported by grants QuiSalhis-Food (AGL2016-75687-C2-1-R) from the Ministry of Science, Innovation and Universities (MICIU), CYTED la ValSe-Food (119RT0S67) and LINCE (PROMETEO/2017/189) by the Generalitat Valenciana (Spain).