Computer aided analysis of gas exchange in pear fruit packages during long distance transport

To ensure profitable margins, European pear fruit producers are forced to explore more and more distant overseas markets. After controlled atmosphere storage, however, pear fruit is susceptible to relatively fast quality loss if conditions during packaged transport are sub-optimal. Both excessive water loss (causing weak necks and shrivelling) and accumulation of carbon dioxide from respiration (causing internal disorders) could cause severe losses at the point of delivery and lead to an unacceptable reduction of shelf life at the destination. To properly design and optimize the transport of pear fruit, therefore, analysis of temperature, humidity and respiratory gas conditions in the package is required. To this end, a modelling approach is proposed. A computational fluid dynamics (CFD) model is developed that solves flow, heat and mass transfer inside pear fruit packages. The mass transfer model includes both transport of water vapour from the fruit and transport of gasses due to fruit respiration. The fruit load inside the package is generated using discrete element simulations of fruit filling using a statistical shape model of pear fruit ('Conference'). The model is used to predict the distribution of temperature, humidity and respiratory gasses in typical fibreboard package. The effects of internal packaging materials (films) is considered. The methodology provides a more versatile tool compared to previous proposed models.