Hygroscopic behavior of spray dried acerola and seriguela mixed juice powder stored

Spray drying is an alternative to extend the shelf life of fruits. However, fruit juice powders present problems during their storage because they are hygroscopic. The objectives of this study were to determine adsorption isotherms of mixed juice powder of acerola and seriguela at different temperatures, to identify the best-fit isotherms models and to assess their physicochemical properties. Following physics properties were assessed: apparent and absolute density, solubility, porosity, flowability, cohesiveness, morphology, mean particle size, surface analysis and pore distribution, thermal properties and antioxidant activity. Static-indirect method was used to determine the adsorption isotherms. Experimental data of the water activity and equilibrium moisture were fitted to five mathematical models. The models best fitted to the adsorption curves were the Guggenheim-Anderson-de Boer (GAB), Linearized Brunauer–Emmett–Teller (BET) and Oswin models, P < 10%. The value of the solubility was 79.45%, the absolute density was 1.03 g cm-3, the porosity was 84.47%, and the apparent density was 0.16 g cm-3. The mixed juice powder showed an irregular surface morphology and shape. The results indicated that the mixed juice powder has high thermal stability and can be used as a source of antioxidant with market potential by the food industry