Effects of different heat-induced setting methods on the structural stability and properties of 3D-printed surimi gels

Surimi has gained popularity as a food-grade ink for the creation of novel 3D-printed foods. However, existing research predominantly focus on the printability of surimi and the resulting printed models, with limited attention given to the post-processing of these 3D-printed structures. Towards this knowledge gap, our study systematically investigated the impact of five common heat-induced setting methods, including one-step water bath (W1), two-stage water bath (W2), steam (S), oven (O) and microwave (M), on various 3D-printed models. Results showed that water bath-based methods (W1 and W2) induced the swelling of the 3D-printed models along the vertical axis, while O and M led to structural shrinkage. Due to the compensatory effect of water, W1 and W2 exhibited minimal cooking loss but higher levels of free water. S significantly reduced the water holding capacity due to a decrease in hydrogen bonds among the proteins. O resulted in substantial moisture loss, surface condensation and insufficient gelation. M with superior heat transfer efficiency favored extensive protein aggregation driven by the increased chemical forces, leading to a coarser gel network with highest gel strength. We expect that this study could provide new insights into the role of heat-induced setting methods in manufacturing 3D-printed surimi foods.