Chain conformation of biopolymeric microgels modulates ice recrystallization and physicochemical stability of unfermented frozen dough.

Physical disruption of unfermented frozen dough induced by thermodynamic fluctuations necessitates targeted interventions. This study reveals that the chain conformation of biopolymeric microgels modulates ice recrystallization, an effect governed by microscale spatial confinement, establishing a structural basis for macroscopic cryoprotection. Microgels were fabricated via shear-induced mechanical activation from three structurally distinct polymers, including semi-rigid helical κ-carrageenan, rigid rod-like xanthan gum, and flexible random-coil guar gum. Morphological and rheological characterizations revealed that κ-carrageenan microgels assembled into an ordered lamellar network. This spatial architecture facilitated localized water sequestration, yielding a minimum melting enthalpy of 281.36 J·g-1 for freezable water, which effectively restricted macroscopic ice crystal propagation. Consequently, the κ-carrageenan matrix restricted the average equivalent ice crystal diameter to 66.53 μm with a narrow distribution span of 48.94%. Following incorporation into the dough matrix subjected to five freeze-thaw cycles, the κ-carrageenan microgel restricted water mobility, limiting the loss of the tightly associated water fraction to only 6.18%. Doughs formulated with κ-carrageenan exhibited maximum quantitative retention of dynamic viscoelastic properties (G' and G″) and microstructural integrity. Crucially, macroscopic evaluations using noodles prepared from the freeze-thaw stressed dough validated that such structural preservation minimized dry matter leaching and maintained mechanical robustness. The results demonstrate a performance hierarchy correlated with chain rigidity, where κ-carrageenan provided greater structural stability compared to xanthan and guar gums. The translation of microscale network architectures into macroscopic physicochemical stability provides a conformation-based framework for formulating structurally-tailored cryoprotectants in frozen food systems.