Fig. 5. Dynamic mechanical analysis (DMA) data of olive leaf cuticles with and without waxes.

a, b Representative DMA traces of a the storage modulus E′ and b the damping factor tan δ displaying the cuticular phase transitions. c Box chart displaying the storage modulus E′ of olive cuticles at 25 °C conditioned at 50% RH and wetted with water showing the plasticizing effect of water. In all boxes, the whiskers extend to min and max values, box edges show 25–75 percentiles, center line represents median, and hollow square represents mean. Reported values are the mean ± s.d. of paired measurements at ambient and wet conditions (n = 5 olive with waxes; n = 3 olive without waxes). Note that the data were analyzed using the overall average thickness that is “inflated” by the protruding trichomes; as a result, the reported storage modulus E′ values are systematically underestimated by a factor of ca. 2–3 (see also “DMA measurements” section).