Modeling of a spray-drying process for the encapsulation of high-added value extracts from food by-products

The main goal of this research was to develop a mathematical model for a co-current spray drying- assisted encapsulation of natural extracts from grape pomace and citrus fruit peels, aiming to predict both structural features and the retention of their bioactive constituents. Model validation was performed using a laboratory scale spray dryer, analyzing the product in terms of moisture content, solids and to- tal phenolic compounds recovery yields. The comparison between experimental and simulated results revealed that the model properly described the system. A slight effect of air inlet temperature was ob- served on the phenolic content of produced particles. For this reason, a kinetic law, which allows pre- dicting the degradation of phenols was proposed and validated. These results highlighted the potential of spray-drying technology to efficiently encapsulate high-added value compounds with good preserva- tion of their bioactive compounds, offering the possibility to decrease food waste issues while improving industry economic benefits.