Use of gelatin-maltodextrin composite as an encapsulation support for clarified juice from purple cactus pear (Opuntia stricta)

Juice rich in betalains (with 62.69mgL^-1) and with a high antioxidant activity (14.35 TEAC) from purple cactus pear was encapsulated by spray-drying using gelatin (G) and maltodextrin (M) as the wall material. This investigation was conducted using an experimental design of 2² mixes with two replicates at the center point. The microstructures generated in all of the experiments (yield=7.76-14.86g100g^-1) were characterized in terms of their moisture content (1.87-6.95g100g^-1 dry basis), a_w (<0.3), betalain content (11-35mg100g^-1), antioxidant activity (4-29 TEAC), colorimetry (L=17.26-40.9; a*=17.16-37.20; b*=6.26-15.46), h° (15.06-29.66), C (18.75-43.29), hygroscopicity (19.39-28.13g100g^-1). Samples with G:M ratio (2.5:7.5) and high antioxidant capacity were analyzed by SEM which showed that the powders presented a spherical shape (particle size of 6.14μm±4.96) with melting points ranging from 205 to 235°C.