Microencapsulação de extrato do resíduo de seriguela (Spondias purpúrea L.) usando maltodextrina, goma arábica e soro de leite : desenvolvimento e caracterização

Abstract

The agroindustrial residue of the seriguela (Spondias purpúrea L.) has a signifi- cant amount of phenolic compounds. Therefore, the objective of this study was to evaluate the feasibility of atomic encapsulation of the hydroethanolic extract of the seriguela residue (containing 3% total solids), using different temperatures (120; 140 and 180 ºC) and wall materials (MP) , [maltodextrin (MD), gum arabic (GA) and whey (SL)], isolated and in blends, [MD; GA; MD + GA; MD + SL; GA + SL and MD + GA + SL, in the proportion of 100: 0; 100: 0; 50:50; 90:10; 90:10; 45:45:10 (v / v), respectively], reaching a final concentration of 30%. In the atomi- zation process, the pressure of 6.5 Bar was kept constant; drying airflow (28 m3 / h); feeding the drying chamber with the mixture through a peristaltic pump with a flow rate of 12 mL / min. The microencapsules were subjected, in the first stage, to the determination of moisture content, water activity, phenolic compounds content, antioxidant action, encapsulation efficiency, and encapsulation yield. The microen- capsules selected in the first stage were subjected to determination of bulk densi- ty, hygroscopicity, colorimetric analysis, stability test, and morphology. Regardless of the process condition, the microencapsulados showed low moisture content (3.35 to 6.96%) and aw (0.11 to 0.16). However, the best results for encapsulation efficiency (90.79 to 96.07 %); yield (39.37 to 52.81%) and antioxidant capacity (28.95 to 43.76%) were obtained using temperatures of 140 ºC and GA; MD + GA and MD + SL. In general, these particles were spherical, slightly protruding, intact and without fissures and light yellow (L = 91.34 to 92.38; Hue = 85.18 to 88.77; Chroma = 7.43 to 11.15). Hygroscopicity was <20%, with emphasis on the micro- encapsulated with MD + GA, which showed the lowest value (9.87 g / 100 g); ap- parent density of 0.49 g / mL and stability of the phenolic content and antioxidant action until the 18th day of storage under refrigeration (4 ºC). The microencapsula- tion of the seriguela residue, using a temperature of 140 ºC and GA; MD + GA and MD + SL as an encapsulating material proved to be a promising technique for ob- taining the powdered extract, with potential application in foods, aiming at the ela- boration of products with functional properties.