Effects of carriers and addition modes on the physical and chemical properties of green pepper (Piper nigrum L.) powders treated by freeze-far infrared drying during storage.

Green pepper powder (GPP) via freeze-far infrared drying (FD-FIRD) features unique pungency, but easily suffers flavor loss and quality decline in storage. Thus, this study investigated the effects of three carriers-maltodextrin, trehalose, and inulin-and two application methods, mixed pulping (MP) and osmotic soaking (OS), on the 70-day storage stability of FD-FIRD GPPs. Trehalose best maintained color and bioactive components due to its high glass transition temperature and matrix-stabilizing effect, while maltodextrin mainly improved particle-size uniformity by narrowing the D10-D90 range by 30-60%. Among all treatments, OS-trehalose showed the highest initial lightness (L⁎ = 64.26), the lowest color change (ΔE = 5.87), and the most stable flowability. XRD and FTIR analyses further showed that the carriers and application methods mainly affected crystalline domain formation without altering the amorphous structure. Overall, OS-trehalose is a promising strategy for producing shelf-stable, high-quality GPPs.