Physical and chemical properties of powder produced from spray drying of inulin component extracted from Jerusalem artichoke tuber powder

In this study, inulin was extracted from Jerusalem artichoke tuber (JAT) powder and then concentrated before spray drying. The aims of this study were to (1) determine the drying condition that provided high powder yield together with superior qualities of JAT inulin powder and (2) investigate the chemical and physical properties of inulin powder. The inulin extracts at different concentrations of 10, 20, and 30 degrees Brix were spray-dried and then compared. The spray drying experiments were conducted at the inlet/outlet air temperatures of 150/90, 170/90, and 190/90 degrees C for the chosen concentration of inulin extract. It appeared that spray drying of the 30 degrees Brix extract at the inlet/outlet drying air temperatures of 190/90 degrees C resulted in the highest value of powder recovery, bulk density, water solubility and the lowest moisture content and hygroscopicity in comparison with its counterparts. SEM micrographs showed that the powder produced by this condition was more stable and less sticky than others. The sugars, total fructo-oligosaccharides (1-kestose, nystose, and 1(F)-beta-fructofuranosyl nystose) and inulin-type fructans contents of powder were 12.88, 11.12, and 64.36 g/100 g of powder, respectively. The moisture sorption data and models developed in this work could be used for determining the suitable condition of surrounding air for inulin powder storage.