Physical–chemical and functional properties of maca root starch (Lepidium meyenii Walpers)

The starch of maca (Lepidium meyenii Walpers) presented oval and irregular morphology, with granule size between 7.4 and 14.9 μm in length and 5.8 and 9.3 μm in diameter. The isolated starch showed the following features: purity of 87.8%, with 0.28% lipids, 0.2% fibre and 0.12% fixed mineral residue, and no protein detected; the ratio between the amylose and amylopectin contents were 20:80; the solubility at 90 °C was 61.4%, the swelling power was 119.0 g water/g starch and the water absorption capacity was 45.9 g water/g starch; the gel turbidity rose 44% during the storing time; the gelatinization temperature was 47.7 °C and the transition enthalpy 6.22 J/g; the maximum viscosity reached 1260 UB at 46.4 °C, with breakdown, setback and consistence of 850, 440 and −410 UB, respectively. The low gelling temperature and the stability during gel refrigeration could be adequate for foods requiring moderate temperature process, but not for frozen food.