Impact of drying processes on the functional and nutritional properties of instant riceberry powder

The drying method determines reconstitution and antioxidant properties of instant riceberry powder (IRP) with studies comparing techniques. This work prepared IRP using six methods as freeze drying (FD), vacuum drying (VD), drum drying of uncooked (DUC) and cooked (DC) pastes, fluidized‑bed drying combined with microwave heating (FDB‑MW), and tray drying (TD) with a targeted moisture lower that 10% wet basis. Reconstitution (wettability, solubility), flow (bulk/tapped/particle densities, porosity, Carr index, Hausner ratio), color (ΔE), antioxidant contents/activities (TAC, TPC, TFC, DPPH, FRAP), and predicted glycemic index (pGI) were then evaluated. A weighted synthetic evaluation index (SI) integrated nine attributes to compare performance. FD best preserved antioxidants (TAC 31.65 mg⋅(100 g DM)−1; FRAP 6.886 mg TE⋅(g DM)−1) and achieved the highest SI. DC produced the most favorable reconstitution (wettability 68.10 s; solubility 82.79%). VD and TD offered balanced, scalable outcomes, while FDB‑MW showed higher color change and greater cohesiveness. All thermal methods increased pGI relative to raw riceberry. These head‑to‑head data provide IRP producers with a practical map. FD should be chosen when antioxidant preservation is paramount, with DC optimal for fast and uniform dispersion, while VD/TD maximizes cost saving and throughput. Microwave power density and residence time can be tuned to mitigate quality losses.