Abstract:Chemical composition, particle morphology, crystal structure, thermodynamic properties, solubility, degree of expansion, paste clarity, and freeze-thaw stability of maca root starch were compared with those of potato and Chinese yam starches. Maca starch granules were oval or irregular. The long axis of these granules ranged between 7.2 and 15.6 μm and short axis ranged between 5.1 and 9.8 μm. A square cross was observed for the polarization cross of maca starch. X-Ray powder diffraction showed that maca starch had C-type crystalline patterns, and the characteristic peak of amylase-lipid complexes occurred at approximately 2θ (i.e., approximately 20o). Morphology and crystalline pattern of maca starch were similar to those of Chinese yam starch. Gelatinization temperature of maca starch was lower than that of potato and Chinese yam starches. Onset (To), peak (Tp), and conclusion temperatures (Tc) of maca starch were 46.88 ℃, 50.42 ℃, and 54.82 ℃, respectively. Gelatinization enthalpy of maca starch was 7.37 J/g. Solubility and paste clarity of maca starch were higher than those of Chinese yam starch and lower than those potato starch. Peak viscosity of maca starch was similar to that of Chinese yam starch but was lower than that of potato starch. Swelling power and freeze-thaw stability of maca starch were higher than those of Chinese yam and potato starches. As a new starch source, the maca starch has certain values and broad prospects for development.
