Moisture migration model of packed fresh-filled pasta during storage under different humidity conditions

Abstract

Water migration in multi-component foods is one of the most significant factors limiting their shelf life. Therefore, a two-component model (pasta and filling) was proposed simulating storage in permeable packaging under two different humidity conditions (70 % and 100 % relative humidity (RH)) to model the moisture changes over time in fresh-filled pasta. Several sensors monitored moisture changes inside the packaging and the environment during storage. The moisture sorption isotherms (MSI) were determined on pasta and filling at 6 °C and 11 %–98 % relative humidity (RH) and fitted using the GAB equation. Depending on the RH condition, the water content of pasta and its filling changed during storage. Pasta in direct contact with the filling adsorbed water, and this did not depend on water permeating through the package but on the water that the filling released. Thus, the higher water affinity of pasta and the high free water content in the filling determine the initial water movement from the filling to pasta independent of their activity water values. The MSI, water transmission rate of the packaging, and multi-component food characteristics predicted the moisture gain or loss by the pasta-filling system during storage. A correction factor was introduced in the model because the data obtained from the humidity sensors suggested the formation of a humidity gradient inside the package and environment. The experimental data closely matched the model predictions.