Fig. 3

FESEM images of wheat surfaces treated with cold reactive air plasma. (a) Control (untreated). (b–d) Surfaces after 5, 10, and 30 min plasma treatment; cracks in the seed coat (green dashed lines) are visible at 30 min. (e–g) Surfaces after heat exposure (plasma without reactive species) for 5, 10, and 30 min.