In vitro digestibility, physicochemical, thermal and rheological properties of banana starches

•Amylose content was the main factor influencing the banana starch properties.•All the starches exhibited Type III behaviour (G″ overshoot).•Lixiviated amylose formed a complex gel reinforced by swollen starch granules. Banana starches (BS) were isolated from Enano, Morado, Valery and Macho cultivars. The BS possessed B-type crystallinity and an amylose content varying from 19.32 to 26.35%. Granules had an oval morphology with different major-to-minor axis ratios, exhibiting both mono- and bi-modal distributions and mean particle sizes varying from 32.5 to 45μm. BS displayed zeta-potential values ranging between −32.25 and −17.32mV, and formed gels of incipient to moderate stability. The enthalpy of gelatinization of BS affected the crystalline order stability within the granules. In-vitro digestibility tests showed fractions as high as 68% of resistant starch. Rheological oscillatory tests at 1Hz showed that BS dispersions (7.0%, w/w) exhibited Type III behaviour, attributed to the formation of a continuous phase complex three-dimensional amylose gel reinforced by swollen starch granules acting as fillers. Amylose content and granules morphology were the main factors influencing the BS properties.