Nondestructive characterization of structural changes during in vitro gastric digestion of apples using 3D time-series micro-computed tomography

An in-depth understanding of food structural breakdown during gastric digestion is paramount for development of health-promoting foods. This study presents a novel application of nondestructive time-series micro-computed tomography (micro-CT) to study structural breakdown during in vitro gastric digestion of apples (var. Granny Smith). Data collected from micro-CT images were compared with results from destructive analyses of apple tissue hardness (texture analysis) and moisture uptake during soaking in gastric juice or deionized water. Apples in gastric juice showed similar trends in intensity change (from micro-CT images) and hardness decrease (from texture analysis) over time compared with apples in water (p < 0.001). Apples in gastric juice or water exhibited similar changes in porosity and showed similar moisture uptake (p > 0.05). Overall, micro-CT imaging allows for assessment of changes along with detailed structural characterization of solid foods during in vitro gastric digestion.