Experimental and numerical study of an alternative technique for fruit processing: Rotary drum with inert bed for acerola pulp dehydration

Abstract

Acerola is renowned as a potent natural source of vitamin C. However, its high perishability presents challenges for harnessing its health benefits. In this study, we explored an alternative method, the Rotary Dryer with Inert Bed (RDIB), to transform acerola pulp into a powdered form. Through both experimental and numerical investigations, we quantified how various operational variables affect RDIB's performance in acerola pulp dehydration. In numerical simulations using the Discrete Element Method (DEM), we analyzed the number and forces of particle collisions. We combined DEM results into a single response using a desirability function, pinpointing the optimal configuration: a drum with three continuous flights, each 25 mm long. Subsequently, experimental tests with this optimal setup considered temperature (T), inert fraction (FI), and maltodextrin concentration (M) effects on drying yield and bioactive compound levels. Multi-response optimization aimed to maximize both yield and bioactive compounds, yielding the optimal conditions: M = 6.25%, FI = 46.19%, and T = 77.2 °C. Thus, the results of this study show that RDIB efficiently dehydrates acerola pulp and has promising potential for industrial applications, facilitating the production of high-quality fruit powder.