Moisture barriers to control drying of fresh-cut fruit: Quantifying their impact by modeling

- The drying kinetics of composite fruit-barrier systems are investigated by modeling.
- The impact of barrier properties on the dehydration process is quantified.
- A barrier induced a lower evaporation rate and a higher tissue temperature.
- The coated fruit tissue leads to a more homogeneous water activity distribution inside the tissue.

Moisture barriers are applied as functional interfaces between food products and their environment to control or limit the moisture exchange, a typical example being edible films. Hygrothermal continuum modeling is used to obtain insight on the impact of moisture barriers on the fruit dehydration process. The effects of moisture permeability and thickness of the barrier on the drying process are quantified, by looking into the drying kinetics and the internal moisture transport. Barriers are found to induce a smaller drying rate and a higher product temperature, but lead to more spatially-uniform drying within the sample. The sensitivity of the total drying time to the barrier's permeability is also found to be dependent on the permeability of the fruit tissue itself. The presence of a barrier significantly reduced the sensitivity of the drying time to an increase in air speed, thus convective transfer coefficients. Such hygrothermal simulations are a promising way to tailor moisture barriers to a specific application, in terms of optimal barrier permeability and thickness, to obtain the required drying characteristics.