Parametric analysis of the spray drying process for the production of starch molecular inclusion complexes with fatty acids

Series of experimental runs were carried out using a pilot scale spray drying unit to produce starch molecular inclusion complexes with fatty acids. Native normal maize and tapioca starch suspensions with added myristic or palmitic acid were employed at various concentrations and feed rates whereas the spray drier was operated at various drying air inlet temperatures. The products were examined using X-ray diffraction analysis, scanning electron microscopy, Confocal laser scanning microscopy, differential scanning calorimetry, Laser diffraction particle size analysis. Experimental data analysis of process parameters was carried out to determine the main variables which affect the performance of the spray drying process. The critical factors were found to be the material feed flow rate in relation to the temperature difference existing in the spray drying chamber between the inlet temperature and the outlet temperature of the drying air. The results revealed that all spray dried products had the same morphological characteristics regardless the type of starch or fatty acid employed and desirable functional properties e.g., low tapped density, uniformity in size, low crystallinity and hollow porous structure. It is concluded that, spray drying is an appropriate technique for the industrial production of starch molecular inclusion complexes in powder form.