Optimization of spray-drying conditions for green acerola concentrate juice: effect of temperature and maltodextrin

Acerola (Malpighia glabra and M. emarginata) is a tropical fruit predominantly cultivated in northeastern Brazil, notable for its abundance of health-beneficial bioactive compounds, including ascorbic acid, phenolic compounds, flavonoids, and anthocyanins. However, due to its high perishability, preservation processes such as spray drying have become essential. Given its low acidity, high sugar content, and the presence of low-molecular-weight substances, acerola poses several challenges during drying, which require careful evaluation of process parameters. This study aimed to evaluate and optimize the spray-drying process parameters, temperature and maltodextrin concentration, for the production of green acerola powder from concentrated juice.

A central composite rotatable design was conducted, varying temperature (110-180 °C) and maltodextrin concentration (3-30%, w/w, based on total solids content of the concentrated juice). Water activity, yield, color parameters, ascorbic acid, antioxidant activity by DPPH (2,2-diphenyl-1-picrylhydrazyl) and ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), total phenolic compounds, and hygroscopicity were analyzed as response variables. The best conditions for achieving higher yield, ascorbic acid retention, and antioxidant activity were a temperature of 145 °C and 16.5% maltodextrin. Increasing the maltodextrin concentration contributed to the reduction of water activity. Color was influenced by both the carrier concentration and temperature, and obtaining less hygroscopic powders was favored by increasing maltodextrin concentration and decreasing temperature. Overall, the results indicate that moderate drying temperatures combined with intermediate maltodextrin concentrations favor the preservation of ascorbic acid and antioxidant compounds, minimizing thermal degradation and oxidative losses during the drying process.

Spray drying of green acerola juice concentrate under optimized conditions enables the production of powders with improved yield, higher retention of bioactive compounds, and reduced hygroscopicity, highlighting its potential as a viable method for preserving acerola's nutritional and functional qualities. © 2025 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.