Isolation of novel wheat bran antifreeze polysaccharides and the cryoprotective effect on frozen dough quality

Different wheat bran antifreeze polysaccharides (WBAP) were first isolated by ice shell separation method. The composition and antifreeze activity of varied WBAP were characterized and their cryoprotective effects on frozen dough were comprehensively studied with the emphasis on ice crystals, yeast and gluten proteins. WBAP with enriched arabinoxylan (AX) of high arabinofuranose/xylopyranose ratio (A/X) showed superior effect on inhibiting ice recrystallization compared with WBAP with low A/X. WBAP could significantly improve the quality of frozen dough steamed bread, and the effect coincided with antifreeze activity. WBAP effectively inhibited the ice recrystallization and altered the shape of ice crystal from cubic to lamellate in frozen dough, consequently better preserving the yeast viability and dough structure. WBAP alleviated the depolymerization of glutenin macropolymers, and was conductive in developing more homogeneous and less distorted gluten network structures in frozen dough. The current study can provide a theoretical basis for the exploitation of WBAP as a technofunctional improver for frozen dough.