Starch digestion insights could yield healthier foods

Designing foods with controlled digestion, slowing the rate at which calories or nutrients are released, could help reduce risk of obesity and type-2 diabetes by better regulating blood glucose levels. Deeper understanding of how cooking and storage of starch products affects their mechanical properties and, in turn, their breakdown and digestion rates in the human body could help facilitate such engineering.

Liao et al. set out to elucidate how food texture and digestibility are influenced by food processing that impacts gelatinization and retrogradation of starch hydrogels.

“Cooking starch more thoroughly leads to a greater breakdown of its granule structure, resulting in a higher degree of gelatinization (DOG),” said author Zisheng Liao. “Meanwhile, storing starch products for longer periods at lower temperatures — like in a refrigerator — increases stiffness due to recrystallization, also known as degree of retrogradation (DOR).”

The authors developed a pseudoelastic-viscoelastic constitutive law to describe the mechanical behavior exhibited by starch-based gels across various DOG and DOR.

“The proposed model can be applied to various polymeric materials, as most polymers exhibit similar nonlinear, time-dependent, and deformation-history-dependent behavior due to their complex macromolecular structures,” said Liao. “Such models enable numerical simulations of real-world problems.”

Specifically, the findings could lend to the design of starch-based drug delivery vehicles with tailored release profiles, in addition to healthier foods.

Next, the investigators plan to develop a chemo-mechanical model that accounts for enzymatic reactions, providing a more comprehensive understanding that enables realistic simulations of in vivo gastric digestion.

Source: “On the pseudoelastic-viscoelastic behaviour of starch hydrogels at various degrees of gelatinisation and retrogradation,” by Zisheng Liao, Alexandros Makrypidis, Maria M. Papathanasiou, and Maria N. Charalambides, Physics of Fluids (2025). The article can be accessed at https://doi.org/10.1063/5.0251424 .