Effect of cell size on mechanics of strawberry fruit tissue

Strawberry fruit are high value products because of their unique flavor appreciated by consumers. However, the soft texture of strawberries makes them sus-ceptible to mechanical damage during post-harvest han-dling, which accelerates the fruit decay. Better insight in the varying mechanical properties of strawberry is needed. Strawberry fruit cells were suspended by 0.3 M mannitol solution and microwave heating. Cell size was measured with particle size analyser based on laser scat-tering technology. Average diameter of cells wasn't re-lated to ripeness stage with 263, 270, and 259 $\mu m$ at light, medium and dark red stages, respectively. The absorption coefficients measured in the anthocyanine and chloro-phyll absorption ranges were correlated with the colour appearance as expected. The average absorption coeffi-cient at 655 nm was 3.70, 3.23, and 2.14 cm−1 at dark, me-dium and light red ripening stages, respectively. The average of absorption coefficient at 405 nm was 0.39, 0.31, and 0.13 cm−1 at dark, medium and light red appearing fruit, respectively. The dark red fruit showed enhanced elastic modulus and failure stress, while failure strain was reduced. The cell size, grouped with means of 225, 250, and 275 $\mu m$, affected the failure stress in all size groups. Failure strain was different in fruit with small, 225 $\mu m$, cell size, whereas the elastic modulus appeared unaffected from cell size.