Effects of freeze-thaw cycles on the structural and thermal properties of wheat gluten with variations in the high molecular weight glutenin subunit at the Glu-B1 locus

Freeze-thaw cycles can degrade the structural and thermal properties of gluten. We used near-isogenic lines NIL1 (Bx6 + By8) and NIL2 (Bx14 + By15) to study the effects of freeze-thaw cycles on the structural and thermal properties of gluten for high molecular weight glutenin subunit (HMW-GS) variants at the Glu-B1 locus. After several freeze-thaw cycles, the increases in the frozen water content, surface hydrophobicity, beta-sheets, intermolecular beta-sheets, and peak temperature (T-P) were significantly lower for NIL2 than NIL1, and the reductions in the amount of disulfide bonds (-S-S-), alpha-helix, thermal enthalpy (Delta H), and degradation temperature (T-d) were also lower for NIL2 than NIL1. Furthermore, our results showed that the protein weight loss was independent of the composition of HMW-GS. Therefore, the effects of freeze-thaw cycles on the gluten structure and thermal properties of NIL2 with superior subunits were less than those for NIL1, and thus NIL2 is more suitable for making frozen dough than NIL1.