Probing inside fruit slices during convective drying by quantitative neutron imaging

•Moisture distribution inside fruits is monitored dynamically during convective drying.•The impacts of process condition and peel are identified.•Neutron imaging provides unique graphical and quantitative insights.

Quantitative neutron imaging was applied for the dynamic monitoring of the internal moisture distribution of fruit slices during convective drying in a drying tunnel. The impact of several process conditions was evaluated, including airflow temperature, air speed and incident radiation. This technique also unveiled that anisotropic shrinkage was caused, in part, by spatially heterogeneous dehydration, as induced by the presence of the peel. Neutron imaging provided unique graphical and quantitative insights on how the internal water distribution evolved. Thereby, this imaging technique has large potential to complement conventional techniques for monitoring, controlling and optimising drying processes of complex biomaterials, or to generate high-resolution validation data for numerical simulations.