Microstructure of SMP granules: (a) conventional spray-dried SMP (4% db); (b) spray-dried skim milk rewetted at 18% db; (c) HAP-DIC expanded granule spray-dried SMP textured at P (air pressure) = 0.57 MPa; W = 8% db; t (treatment time) = 44 s; and (d) STEAM-DIC expanded granule spray-dried SMP textured at P (steam pressure) = 0.07 MPa; W = 18% db; t (thermal treatment time) = 9 s.