Water condensation on fruit surfaces during apple storage

Water condensation on fruit surfaces after harvest is undesirable because it provides favorable conditions for microbial growth.
In cold stores, condensation can occur due to unstable environmental conditions and repeated decrease of temperatures below the dew point at fruit surfaces.
The influence of condensation on fruit quality maintenance during long-time storage is unknown.
To investigate periods of condensation on apple surfaces a sensor prototype was developed based on resistive sensing.
In a 50 t apple CA store condensation periods on apple surfaces were measured with this sensor prototype at two different positions in the bin stacks.
The climatic conditions were verified by simultaneous measurement of temperature at the fruit surface and relative humidity next to the fruit.
Temperature fluctuations at the apple surface were 0.5 and 0.3°C at a high and a low bin position, respectively.
Periodic temperature decrease below the dew point was measured in every cooling cycle resulting in condensation.
Low air speed (20 mm s^‑1) between fruit in these bins was determined and mass loss of apples (2%) was similar over 19 weeks storage.

IV International Symposium on Horticulture in Europe – SHE2021

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

apple cold store, wetness sensor, air velocity, dew point temperature

https://doi.org/10.17660/ActaHortic.2021.1327.78