Controlled shape morphing of potatoes and carrots during drying using a novel stamping approach

This study investigates groove-based controlled shape morphing in potatoes and carrots during drying. Stamps were manufactured and used to create groove depths (2 mm and 4 mm) onto the surface of the samples, which were then dried at various temperatures (45 °C, Equation5(5) True density(ρs)=wsvs(5) 5 °C, and Equation6(6) Bulk density (ρapp)=wsvt(6) 5 °C). Bending transformation, drying profiles, shrinkage, porosity, and surface morphology were measured as indicators of shape morphing. Potatoes exhibited a positive correlation between morphing transformation with increasing temperatures, reaching maximum angles of Equation2(2) Drying rate=wt−wt+ΔtΔt(2) 44° (2 mm) and Equation2(2) Drying rate=wt−wt+ΔtΔt(2) 63° (4 mm). Similarly, carrots showed similar observations with maximum bending angles of 145.1° (2 mm) and 153° (4 mm). The morphing in these samples was observed within the moisture content range of 1–0.5 kg water per kg solids and was concomitant with a substantial shrinkage of 80–84% in both samples. Grooving significantly affects the morphing, creating high-stress points and increasing the moisture transfer rate during drying. This study lays foundational knowledge for the controlled shape morphing of foods using drying technology.