Innovative Parallel Airflow System for forced-air cooling of strawberries

Abstract

Strawberry is a high value crop and mostly is consumed as a fresh fruit over the world. Precooling of strawberry is one of the postharvest processes that reduces the fruit decay. However, in the traditional cooling system of strawberry considerable differences are observed between the fruit temperature located in the individual packages as well as in the various packages inside the tray. As a result, the self-life of fruit decreases. The aim of this research was introducing the new package and cooling system for precooling of strawberry in which some improvements were made in the uniformity of cooling of strawberry and reduced the fruit decay. The cooling process of strawberry was simulated based on simultaneous airflow and heat transfer process inside the new system and the developed model was validated experimentally, and a good agreement observed between the simulated and measured temperature of fruit. The results of simulator and experimental data showed that the new system had the higher uniformity in the cooling of fruit as compare with the traditional system so that the packages located along the cold air direction received the equal airflow rate. As a result, a difference of 0.84°C was measured in the average fruit temperature of the packages after 3h of cooling meaning that the differences in the 7/8th cooling time of fruit between the packages is negligible. Therefore, with the same airflow rate of traditional system, the cooling time of strawberries could be reducing by the proposed system significantly.