Water vapour condensation periods on fruit surfaces during CA storage of apples

Temperature and humidity fluctuations occur in apple storage rooms with every cooling cycle due to the operation of the refrigeration system.
As a result, the temperature on fruit surfaces can temporarily fall below the dew point, causing condensation.
The aim of this study was to examine the recurrent condensation that forms on apple surfaces and the duration of condensation in relation to the operation of the refrigeration system.
In an apple controlled atmosphere (CA) storage room, condensation periods during cooling and re-warming phases without disruption were compared with cooling cycles superimposed by defrost processes.
For this purpose, the duration of the active condensation and subsequent evaporation phase was qualitatively determined on the surface of the fruit bulk in a big bin in the supply air area of the room.
Active condensation occurred only during re-warming of the fruit surface, while during the cooling phase, the fruits still were wet due to the subsequent evaporation phase.
During short cooling cycles with defrosting in the cooling phase (<1 h), the fruit surfaces were covered with condensate all the time.
During longer cycles without disruption by the defrost process (>2 h), moisture on fruit surfaces occurred about 30% of the time.
Thus, the fruits had wet surfaces in the supply area of the room for more than one third of the storage time.

XXXI International Horticultural Congress (IHC2022): International Symposium on Postharvest Technologies to Reduce Food Losses

U. Praeger, M. Linke, D.A. Neuwald, M. Geyer

wetness sensor, dew point undershoot, condensation retention time atmospheric evaporation, fan operation

https://doi.org/10.17660/ActaHortic.2023.1364.8