The influence of indirect air-cooling combined with evaporative cooling on tomato fruit cooling time and temperature

Abstract

This study developed a low cost and affordable to small-scale farmers’ indirect air-cooling combined with evaporative cooling (IAC+EC) system for storage of fruit and vegetables under both arid and hot; and humid and hot climatic conditions. Field heat from freshly harvested produce should be immediately removed through cooling to the desired storage temperature. The aim of this study was to determine the effectiveness of IAC+EC system in terms of the cooling time requirement of the fresh tomato fruit. A fresh tomato cooling experiment to remove field heat during the summer month of September in Pietermaritzburg was conducted for 36 hours where the IAC+EC system was compared to storage under ambient conditions. The results showed that 16 hours was required to reduce the flesh temperature of tomatoes to 16.5°C while the flesh temperature for tomatoes under ambient conditions followed the ambient temperature profile with time of storage. The IAC+EC system reduced and maintained the microenvironment air temperature inside the coolers to 16.5°C-19°C. The ambient temperature varied between 21 and 32°C. The results in this study are evidence that IAC+ EC system can be a choice for farmers, for cooling the fresh by reducing the field temperature after harvest.