Ice recrystallization inhibition by amylose-oleic acid complex: Enhancing the freezing tolerance and shape fidelity of starch-based 3D printing ink in long-term frozen storage.

Developing starch-based 3D printing inks with stable texture and high shape fidelity is essential for producing higher value-added food products. However, inhibiting ice recrystallization and maintaining structural stability during cold-chain transport and frozen storage remain significant challenges. To address these questions, this study validates the hypothesis that starch-lipid complex intervenes the ice crystal growth in starch-based 3D printing ink, and investigates the effects of molecular conformation on the ice surface behavior of starch-lipid complexes. The amylose-oleic acid (OA) complex greatly suppresses ice recrystallization by stably adsorbing on the freezing interface, which induces a disordered arrangement of ice crystals. MD simulation supported a proposed mechanism for ice recrystallization inhibition that is consistent with the Gibbs-Thomson effect. The resulting edible ink of starch-OA complex exhibited a lower growth rate of ice crystal size (from 33.33 ± 2.44 μm2 to 96.51 ± 22.68 μm2 after 80 d at -24 °C) when compared with a control group (from 65.88 ± 5.43 μm2 to 187.78 ± 21.98 μm2). Moreover, the starch-OA complex still retains the ability to resist ice crystal growth after high-temperature treatment (e.g., 95 °C), enabling adapting to a variety of food processing conditions. This work offers potential applications for the starch-lipid complex in cold storage-enabling material and food preservation.