Some Structural, Physicochemical and Functional Studies of Banana Starches Isolated from two Varieties Growing in Guerrero, México

Two varieties of green fruit banana growing in Guerrero State México, were used for starch isolation. Starch yields from the bananas varieties "macho" and "criollo" were 43.8% and 11.8%, respectively. Thermal transition temperatures assessed by differential scanning calorimetry (DSC) were higher for "criollo" than for "macho" starch but the enthalpy changes in both starches were not different. Both starches showed A-type diffraction pattern, until now not reported for banana starches. Light microscopy revealed some structural characteristics of banana starches as shape and size and eccentric birefringence was observed under polarized light. The iodine-stained differed in their blue color intensity. The viscosity profiles of both samples evaluated with the Rapid Visco Analyzer (RVA) were similar, and the gelatinization temperatures agree with those obtained by DSC. The pastes formed from banana starches in general were opaque and the storage temperature had a slight effect on clarity.