Evaluation of the airflow characteristics, cooling kinetics and quality keeping performances of various internal plastic liners in pomegranate fruit packaging

There is a trade-off to be optimised carefully as plastic liners deal with postharvest cooling processes as well as the produce quality and sustainability requirements. Understanding the implementation of plastic liners in the fresh fruit cold chain is required to reconcile the opposing roles. In this paper, the performances of four types of internal packaging plastic liners were studied. The airflow characteristics, cooling rate, cooling uniformity and quality keeping performances were measured. Cases: no liner, non-perforated liner, micro-perforated liner, macro perforated liner with 2 mm diameter holes, macro perforated liner 4 mm diameter holes were investigated. Generally, the liners delayed the cooling rate significantly. Non-perforated and micro-perforated liners are similar in terms of airflow resistance and cooling rate, both delayed the optimum cooling time by 5 h compared to the plastic-free case. On the other hand, macro-perforated liners cause a delay of only 3 h.