A Taguchi approach optimization of date powder production by spray drying with the aid of whey protein-pectin complexes

In this research, date powder was produced by drying aids including Tween 80, pectin, and whey protein concentrate (WPC) at different pH values (5.0, 6.5, 8.0, and 9.5) and using a spray drier at different temperatures (160, 170, 180, and 190°C); then moisture content, solubility, hygroscopicity, bulk density, and total phenolic compounds (TPC) were determined and their correlation with structural characteristics of date powder was analyzed by Taguchi method. Interactions of pectin-surfactant, and pectin-WPC were more effective on moisture and bulk density of date powder, respectively. Although hygroscopicity of different treatments was in narrow range of 25–29%, temperature had the highest impact on TPC; beyond 170°C, TPC of date powder decreased. Treatment No. 7, with the highest WPC level and pH values of 5, maintained the highest TPC content (701mg 100g−1) in date powder. SEM images revealed that pH=9.5 and lower temperatures led to smaller particles. Scanning Electronic Microscopy (SEM) analysis of date powder microstructures. [Display omitted] •Date powders with low moisture content were produced successfully by spray drier.•Total phenolic compounds of date syrup was conserved after converting it into date powder.•pH value plays a determining role in particle size of date powder.•Temperature was the most important factor in determining different properties of date powders.