Prosopis alba exudate gum as new carrier agent for obtaining powdered Hibiscus sabdariffa aqueous extracts by spray drying

The objective of this work was to study the functional behavior of Prosopis alba exudate gum (G) as component of powders rich in antioxidant pigments. For this purpose, the morphological, structural and chromatic characteristics as well as physical, biological and stability properties of spray dried aqueous extracts of Hibiscus sabdariffa were evaluated for different ratios of maltodextrin and G, and opportunely compared with gum arabic (GA). Powders containing G showed low moisture (4.9% ds.), low water activity (a_w < 0.3), high solubility (>95%) and small (∼25 μm) spherical-shaped particles, with a glass transition temperature (T_g = 52 °C), similar to those containing GA. Phenolic compounds, naturally present in G, improved the storage stability of Hibiscus extract pigments contributing to the preservation of the antioxidant properties. Results encourage to consider Prosopis alba exudate gum as a promising alternative to gum arabic, with the subsequent benefits stemmed from adding value to an underutilized resource.