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 total 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 observed on the phenolic content of produced particles. For this reason, a kinetic law, which allows predicting 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 preservation of their bioactive compounds, offering the possibility to decrease food waste issues while improving industry economic benefits.