Abstract

Isolation, Modification and Characterization of Sweet Potato (Ipomoea batatas L (Lam)) Starch

Marcquin Chibuzo Iheagwara

Sweet potato (Ipomoea batatas L (Lam)) starch was isolated and subjected to physical, chemical and enzymaticb modifications to generate hydrothermally modified (HMSPS), acid modified (AMSPS) and enzymatically modified (EMSPS) sweet potato starches. The proximate, physicochemical, pasting characteristics, light transmittance, freezethaw stability of the native and modified starches were characterized. Results obtained revealed that moisture, ash and protein contents were reduced following modifications. Hydrothermal modification (HMSPS) caused an increase in swelling power, solubility and water binding capacity while acid and enzymatic modifications reduced them. Also, there was significant reduction (P≤0.05) in sediment volume of all the modified starches with EMSPS (1.41 ml) having the least value. Breakdown (BD) and peak viscosity (PV) values declined for all modification with EMSPS having the least values of 519cP and 2027cP respectively for BD and PV. However, EMSPS and AMSPS exhibited improved pasting characteristics, freeze-thaw stability and paste clarity.