Some engineering properties of corn-banana starch composite custard flour.

Abstract

Engineering properties of composite corn-banana custard flour (CF) products developed by incorporating native, heat-moisture treated or annealed banana starch (BS) as a percentage (15, 25 or 35%) of the composite were determined. Morphological study showed bigger oval BS granules occupying void spaces in the matrix resulting in more compact composite CF structure and in turn, higher bulk density with increasing level of BS inclusion. Experimental variables had marked effect on the pasting properties of the CF samples. Incorporation of BS led to significant (P<0.05) reduction of the swelling power of the CF samples from 1.85 to 1.16 g/g. Gelling and boiling points varied significantly (P<0.05) between 73.00–81.678C and 78.33–88.338C, respectively. Moisture adsorption isotherm showed a type II sigmoidal shaped curve. Experimental variables and granules orientation in the matrices are suggested to be the major influence on the trends observed in the studied engineering properties.