Drying of jambolão (Syzygium cumini) pulp in spouted bed dryer: effect of egg white as drying carrier agent on product quality

Abstract

This work evaluates the drying and properties of jambolão pulp powder produced with egg white-maltodextrin 10DE mixture as drying carrier agents, at variable proportions (corresponding to 19.5% of the formulation mass). The product was dried in a spouted bed dryer (air temperature of 70 °C, air flow of 2.9 kg/min and feed flow rate of 11 g/min) using low density polyethylene as inert particles. We assessed the influence of the egg white-maltodextrin mixture composition in the drying recovery and in the powder properties, such as moisture, water activity, particle size, bulk density, wettability, solubility, hygroscopicity, color and anthocyanins retention. Powders produced with higher egg white concentration showed higher anthocyanins retention (79%) and lower wetting time (6 min) than the ones with higher maltodextrin concentration. Conversely, the former presented reduction of 31% on mean diameter and increase of 35% in hygroscopicity of powders and lower dried product recovery (27%). Bulk densities increased 14% to 19% after storage during 40 days. The use of binary egg white-maltodextrin mixture as carrier agent in drying of jambolão pulp is feasible and showed good results for retention of anthocyanins and protein enrichment in the product.

Keywords:
Anthocyanins; Jambolan; Maltodextrin; Physical property; Dehydration