Solar and tray-drying methods and physicochemical properties of sweetpotato starch

Abstract

Two drying methods were investigated to determine if drying is possible without affecting the quality of starch. The drying methods were solar dryer (53-55 °C) and electrically powered tray dryer (60 °C). The physicochemical properties of starch from five sweetpotato were evaluated after dehydration using the two methods. The results showed that drying methods
had effect on some physicochemical properties of sweetpotato starch. The tray-dried starches had higher moisture, ash, viscosity, and L* values. The swelling power and solubility values for tray-dried starches were significantly different from solar-dried ones, except for the tray-dried “Sauti” starch. Although the water binding capacity and amylase content were higher in solar-dried starches relative to tray-dried starches, statistically there
was no significant difference(P<0.05) in amylose content. This study has shown that in the drying of starch, the drying method is very essential because it has effect on the final quality of starch. Therefore, in setting up a
starch factory, the need is to consider the type of drying method to be used.