Removing antinutritional compounds of buckwheat by different methods and its utilization in gluten-free bread production

The purpose of this study was to mill native eight buckwheat (Güneş cv.) grown in different locations and buckwheat cultivar of Aktaş cv. into break flour (BF) and reduction flour (RF) using roller mill and wholegrain buckwheat flour (WBF) using ultra-centrifugal mill, then investigate the contents of antinutritional compounds (AC), and then remove the AC by malting and ultra-violet light (UV-C) treatments and utilize the treated buckwheat flours in gluten-free bread (GB) production, and determine the quality properties. In all flour samples, phytic acid (PHA) contents were found as RF>WBF>BF; condensed tannin (CT) and total saponin (TS) contents changed as WBF>RF>BF; trypsin inhibitor activity (TIA) was similar in WBF and RF flours and was the lowest in BF samples; chymotrypsin inhibitor activity (CIA) changed like BF>WBF>RF on dry weight basis. Buckwheat (Güneş cv.) grown in Konya location was processed for malting at two different conditions for removing the AC. The contents of CT and TS was reduced at the highest rate in the malt flour 1 (M1) produced at first condition. The contents of PHA, TIA and CIA were reduced at the highest rate in malt flour 2 (M2) produced at second condition. M1 and M2 were incorporated into GB formulations at levels of 10% (M110, M210), 25% (M125, M225) and 50% (M150, M250). The lowest moisture and cooking loss was found in GB of M150 and the highest volume was determined GB of M210. Hardness generally increased and springiness, cohesiveness and resilience decreased while increasing of malt flour. While increasing of malt flour incorporation, total flavonoid compounds of GBs increased, however starch digestibility decreased. Buckwheat (Güneş cv.) was treated with UV-C light at four different power levels (15, 30, 45, 60 W) for removing the AC. The highest reduction was provided at 45 W energy levels. Buckwheat flours treated at 15 W (U1) and 45 W (U2) energy levels were incorporated into GB formulations at 10% (U110, U210), 25% (U125, U225) and 50% (U150, U250) levels. The lowest volume and specific volume were found in GB of U250 and the lowest baking loss was determined in GB of U150. The antioxidant activity of GBs increased while increasing the incorporation level of UV-C treated buckwheat flour. Protein profiles of WBF, RF, BF flours and GBs were also investigated on gel electrophoresis.