Abstract

MANRIQUE-QUEVEDO, Nancy et al. Characterization of pregelatinized blends of mango and banana starches with different extrusion conditions. Agrociencia [online]. 2007, vol.41, n.6, pp.637-645. ISSN 2521-9766.

Pregelatinized starches were obtained by blending banana and mango starches in a twin-screw extruder. The amount of both starches in the blend and the screw speed were independent variables. Molecular characteristics of pregelatinized starches were assessed by X-ray diffraction and Fourier transform infrared spectroscopy. Additionally, the gelatinization degree, water absorption index (WAI), water solubility index (WSI) and resistant starch (RS) content were tested. Native banana and mango starches showed a Cand Atype X-ray diffraction pattern, which was lost in the extrusion process. These results agree with the infrared spectroscopy study, since the absorbance ratio in the pregelatinized starches was <1, indicating that the crystallinity was lost. The WAI and WSI increased with the increase in screw speed and mango starch level. The extruded samples had an almost complete gelatinization. RS content increased when banana starch in the blend was higher. The obtained pregelatinized starches had functional properties and RS content that suggest some industrial food applications as a nutraceutical ingredient.

Keywords : Musa paradisiacal; Manguifera indica; modified starch; X-ray diffraction; infrared spectroscopy.

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