Morphological and physicochemical changes in the cassava (Manihot esculenta) and sweet potato (Ipomoea batata) starch modified by pyrodextrinization

Abstract

In recent years, resistant starch (RS) and slowly digestible starch (SDS) have been linked to the prevention of chronic noncommunicable diseases, such as obesity and its complications. Southern Mexico has an important role in the tuber crop production of M. esculenta and I. batatas, which contain considerable amounts of starch. The aim of this study was to evaluate the morphological and physicochemical changes of M. esculenta and I. batatas after pyrodextrinization, including the production of RS and SDS. The factors used in this study were the starch/acid ratio (2.2 HCl) (80:1 and 160:1 p/v); temperature (90 °C and 110 °C) and reaction time (1 and 3 h). The highest production of RS in M. esculenta was obtained with the highest starch/acid ratio and temperature, and the lowest reaction time. For pyrodextrins, loss of crystallinity and an increase in swelling power and water absorption capacity were observed. The highest production of RS in I. batatas was obtained with the highest starch/ acid ratio and reaction time, and the lowest temperature. Crystallinity and enthalpy of gelatinization decreased in modified starches. The solubility, swelling power and water absorption capacity increased in both sources.