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

Juice rich in betalains (with 62.69 mg L−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 = 7.76-14.86 g 100 g−1) were characterized in terms of their moisture content (1.87-6.95 g 100 g−1 dry basis), aw (<0.3), betalain content (11-35 mg 100 g−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 (19.39-28.13 g 100 g−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.