Encapsulation of betalains from beetroot stem by spray drying using Aloe vera gel as carrier

The effect of Aloe vera (A. vera) as a carrier on the encapsulation of beetroot stem juice by spray drying was studied. Mixtures in % A = A. vera and % B = beetroot stem juice were dried by spray: a) 25A:75B, 150 ºC, b) 25A:75B, 180 ºC, c) 75A:25B, 150 ºC, d) 75A:25B, 180 ºC. The obtained powders were evaluated for water activity (aw), moisture (M), pH, glass transition temperature (Tg), bulk density (BD), water solubility index (WSI), color parameters, betacyanin (BC) and betaxanthin (BX) contents, antioxidant activity (AA) and morphology. The results show that with increasing A. vera H, pH, BD, Tg, WSI, BC, BX and the tendency to red decreased, while brightness and tendency to yellow increased and more compressed capsules were observed in the powders. Temperature affected WSI, color parameters a* and b* and individual betacyanins. The beetroot stem powders presented characteristics that allow stability: low aw (<0.13), low moisture (<10 %), adequate pH for betalains (5.3-5.8) and Tg suitable for storage (around 50 ºC). The powder obtained with 25 % A. vera at 180 ºC presented a higher WSI and a tendency to red color, due to its higher BC and BX content, representing an alternative as a natural pigment in food formulation. DOI: https://doi.org/10.54167/tch.v18i4.1731