Gelatinization and retrogradation of native starch from cherimoya fruit during ripening, using differential scanning calorimetry

The aim of this work was to determine the physicochemical characteristics of non-conventional starch from cherimoya fruit in order to suggest possible applications of these polymers in various food systems. The influence of the stage of ripening on thermal behaviour of cherimoya fruit starch was also analysed. Starch was visualized by cryo-SEM, and gelatinization and retrogradation properties were studied by differential scanning calorimetry (DSC). DSC was also used for accurate determination of the starch content of cherimoya dry matter. The calorimetric profile for cherimoya fruit starch showed a peak temperature (gelatinization) over a range from 63.7 to 65.2 °C and enthalpy values between 14.8 and 15.9 J g⁻¹ during ripening. Neither temperatures nor melting enthalpy of recrystallized amylopectin differed over the ripening period. The recrystallization rate, as measured by changes in melting enthalpy with time according to the Avrami model, showed a very slight retrograde tendency. It is suggested that these characteristics could be useful in products where good quality and long shelf-life are required.