Cryoprotective effect of wheat starch granular surface proteins on frozen HMW and LMW glutenins: Structure, property and functionality across length scales

Although frozen dough technology has demonstrated significant benefits, the mechanisms underlying dough deterioration during freezing remain unclear. To overcome this obstacle, the effect of freezing-induced deteriorations of wheat starch granular surface proteins (SGSPs)-high/low molecular weight (HMW/LMW) glutenins complexes were analyzed from the molecular to macroscopic scales. After 7 cycles of freezing/thawing treatment, SGSPs-LMW complex showed a higher antifreeze stability than SGSPs-HMW complex. The freezable water content of SGSPs-HMW increased from 32 % to 39 %, indicating a marked migration and recrystallization of ice. In this situation, the interactions of SGSPs-HMW complex were affected and destabilized, leading to partially denatured and depolymerized molecular structures. Furthermore, the bulk protein aggregation network was also dissociated under the ice tearing and splitting, which irreversibly collapsed to small molecular protein particles. In comparison, the resistance of SGSPs-LMW complex on continued network disruption appear to be the key to maintain the quality of frozen dough.