Characterisation of internal oxygen concentration of strawberry (

Abstract

For full list of author affiliations and declarations see end of paper Gas exchange mechanisms play crucial roles in maintaining fruit post-harvest quality in perishable fruit such as strawberry (Fragaria × ananassa Duch.) and blueberry (Vaccinium corymbosum L.). The internal oxygen concentration ([O 2 ]) of strawberry and blueberry were measured using Clark-type oxygen sensing electrodes. The volume of intercellular voids in strawberry was obtained by microcomputed tomography (micro-CT). In both berries, internal [O 2 ] was consistent and relatively high across measured tissues. The overall [O 2 ] was well above the Michaelis constant (K m ) for cytochrome c oxidase in both fruit and different from previously examined grape (Vitis vinifera L.) berry mesocarp with near zero minimum [O 2 ]. In strawberry and blueberry, cell vitality was also maintained at full maturity in the mesocarp. Higher storage temperature (i.e. 20 vs 4°C) reduced internal [O 2 ] of strawberry. Pedicel detachment in blueberry was associated with greater fruit dehydration and lower internal [O 2 ] after short-term storage of 12 h. The results suggest that the intercellular voids of the fruit's mesocarp provide an efficient gas exchange route for maintaining high fruit internal [O 2 ] post-harvest.