Smart packaging with temperature-dependent gas permeability maintains the quality of cherry tomatoes

Abstract

Phase change materials (PCM), as a smart material, may be used to control the gas concentration inside packaging by changing temperature-dependent gas permeability. A polypropylene (PP) film and two composite films (PP/OD and PP/OD/ZL) with a temperature-dependent gas permeability feature were prepared by incorporating octadecane (OD) (PCM material) and zeolite (ZL) into PP, and these films were used as the packaging pouches for the cherry tomatoes. The temperature-dependent gas permeability of packages and changes in gas composition inside the packages were studied during storage (10 and 23 °C). Changes in the quality of cherry tomatoes, and the effects of the relative ratio between the total volume of the pouch and volume of cherry tomatoes were investigated. The gas permeability of the newly developed packages showed significantly higher temperature-dependence compared to PP package. The relatively low concentrations of O2 and CO2 in the headspace of the composite packages indicated a higher temperature-dependent gas permeability. The higher gas permeability maintained the quality of the cherry tomatoes in the composite film pouches with better total soluble solid content, firmness, and color. These materials as the promising packages can minimize the effects of temperature on the quality of agricultural products and extend their shelf life by controlling the accumulated gas inside the packaging.