Physicochemical Characterization of Cassava (Manihot esculenta) and Potato (Ipomea batatas) Varieties from Southeast of Nigeria in Comparison with Agarose for use in the Separation of Deoxyribonucleic Acid

Starch is an essential biomaterial and food product globally used for different purposes. This study determined the physicochemical composition of starch extracted from selected cassava (M.ExOboma I and M.ExOboma II) and sweet potato (I.ExOboma I and I.ExOboma II) varieties in comparison with agarose for use in the separation of deoxyribonucleic acid. Starch extraction was carried out using standard procedure. Granule morphology and amylose-amylopectin contents were determined using Polarized Light Microscopy and Dual Wavelength Iodine-Binding methods respectively. Relationships between starch properties were determined using correlation analysis. The result of the starch granule morphology revealed that there was no significant difference (p > 0.05) in the pore sizes of M.ExOboma I (5.527 ± 1.9346 µm) and M.ExOboma II (5.650 ± 1.0472 µm). Similarly, I.ExOboma I (8.275 ± 1.5064 µm) and I.ExOboma II (6.075 ± 2.3838 µm) showed no significant difference (p > 0.05) in their pore sizes. Meanwhile, the pore size of agarose was reported to be within the range of 6 to 35μm. No significant difference (p > 0.05) was also observed in the ratios of amylose and amylopectin (Am:Ap) contents between the varieties of cassava (M.ExOboma I 25:75 and M.ExOboma II 24:77) and sweet potato (I.ExOboma I 26:72 and I.ExOboma II 27:75). No significant difference (P > 0.05) between the pH range values (7.7 to 7.8) of cassava and sweet potato with that of agarose (7.5). The study also revealed that there were significant differences (p ≤ 0.05) in the clarity as well as the purity level of the starch samples compared to agarose. The results of this study are of great significance in predicting starch functionality and will form a basis for the improvement of the physicochemical attributes of starch for use in gel electrophoresis for the separation of biomolecules.