MICROENCAPSULATION BY SPRAY DRYING OF A PHENOLIC-RICH EXTRACT OBTAINED FROM AVOCADO POMACE

Spray drying is an encapsulation technique that produces small particles with enhanced stability and bioavailability of bioactive compounds and is widely used in the food industry. This study aimed to produce microparticles with antioxidant potential from a phenolic-rich extract obtained from avocado oil production waste. For this purpose, a full 2² central composite rotatable design was applied in order to verify the effects of drying air temperature (148–198 °C) and solids from extract to maltodextrin ratio (1:1 to 1:3) on the powders’ phenolic content and antioxidant capacity. The hydroethanolic avocado extract (50%), prepared at a solid-to-liquid ratio of 1:10, was concentrated in a rotavapor, mixed with the carrier agent, homogenized using a high-shear homogenizer (IKA T25, FORLAB, Brazil), and dried in a mini spray dryer (S-300, Büchi, Switzerland) equipped with a 1.5 mm nozzle, air flow rate of 35 m³/h, and feed rate of 4.0 mL/min. Total phenolic content, antioxidant capacity (ABTS⁺ and DPPH methods), and bioactive compound retention were evaluated as responses. The results confirmed the effectiveness of spray drying for microencapsulation of antioxidant compounds extracted from avocado pomace. The obtained microparticles showed good retention of phenolic compounds (> 90%), preserving their functional properties after processing. Total phenolic content varied from 648.00 to 3263.63 mg/100 g, antioxidant activity varied from 75.03 to 256.12 μmol Trolox/g and from 32.45 to 124.84 μmol Trolox/g for the ABTS⁺ and DPPH methods, respectively. Maltodextrin concentration was the variable that most affect the final phenolic content and antioxidant activity in powders. Encapsulation efficiency was also mainly influenced by maltodextrin concentration, being higher with higher concentrations of wall material. Overall, spray drying proved to be an efficient technique for producing microparticles with antioxidant potential, highlighting their potential application in functional food formulations and contributing to the valorization of agro-industrial residues.