Influence of Hydrocolloids on the Drying and Functional Properties of Facheiro (Pilosocereus pachycladus) Fruit Pulp Powders

Numerous native fruits with technological, nutritional, and economic potential remain largely unexplored in Brazil. Among these is the facheiro fruit (Pilosocereus pachycladus F. Ritter), a tree-like cactus native to the Brazilian semi-arid region. When ripe, this fruit yields a dark purple pulp characterized by a mildly sweet and slightly acidic flavor. This study aimed to produce and characterize powders derived from facheiro fruit pulp. The powders were prepared with different hydrocolloids—carboxymethylcellulose (CMC), guar gum, and xanthan gum—at varying concentrations and were labeled as follows: FI (pulp without additive), FC (pulp + 1% CMC), FG (pulp + 0.5% guar gum), and FX (pulp + 0.5% xanthan gum). These formulations were dried in a thin layer at 70°C in a forced-air oven until reaching hygroscopic equilibrium. The powders were subsequently analyzed for their physical, physicochemical, technological, and hygroscopic properties. The analyses included water adsorption isotherms at 20°C, 30°C, and 40°C, as well as thermodynamic, thermal, and morphological evaluations. The powders exhibited a predominance of sugars, low protein content, and low acidity (pH > 5.0). The addition of hydrocolloids enhanced water, oil, and milk absorption capacities without significantly affecting flowability or cohesiveness but led to a reduction in porosity. Notably, xanthan gum also reduced the angle of repose. Water adsorption isotherms exhibited a type II sigmoid shape and were effectively described by the Oswin, Peleg, and GAB models. Thermodynamic analysis indicated that the adsorption process was entropy-driven and spontaneous. FTIR and UV–vis analyses confirmed the presence of lipids, proteins, phenolics, flavonoids, alkaloids, polysaccharides, and glycosides in the powders.