Efficient temperature control in okra transportation using phase change materials inside packaging box

Abstract

Okra, a high respiration rate crop, is vulnerable to significant damage during transportation and storage without proper temperature control. This study aimed to evaluate the effectiveness of different thermal insulation boxes combined with phase change materials (PCMs) in maintaining the temperature and quality of okra during simulated transportation and storage. Two prototype thermal boxes (A and B) and a control (foam box) were tested, with and without the addition of either commercial gel packs or ice water bottles. The experiment involved cooling okra samples at 0 °C for 2 hours before packing, followed by 48 hours of simulated transportation at 25 °C. Air and okra temperatures were continuously monitored, and thermal imaging was used to analyze temperature profiles and okra color. The results indicate that the addition of PCMs effectively maintained lower temperatures, with reductions of 3.2 °C for IB and 3.6 °C for GP, compared to a minimal reduction of 0.35 °C in boxes without PCMs. Foam box treatments, with or without PCMs, led to CO₂ accumulation levels of up to 15 %. The ice water bottle, wrapped in kraft paper to prevent wetting the okra, resulted in lower relative humidity compared to the commercial gel pack. There were no significant differences in okra mass loss, which was below 5 % among the nine treatments. This study demonstrated that the developed thermal insulation boxes combined with ice water bottles effectively maintained cool temperatures under ambient conditions and have potential as eco-friendly distribution packaging for okra.