Ultrasound modification of white garland-lily starch: functional, thermal, and pasting properties

Abstract

Ultrasound has been investigated to improve the processes of physical and chemical modifications of starches through cavitation effects. Hedychium coronarium J. König, popularly known as white garland-lily, has medicinal properties and its rhizomes are a potential source for starch extraction. Since there are still no data available using ultrasound without cooling to obtain modified white garland-lily starch (WGLS), this study aims to verify how the starch solution concentration, intensity, and time of application of ultrasound affect the thermal, function, and pasting properties of WGLS. WGLS modified by ultrasound without cooling shows significant variations in its characteristics, for example, water absorption at 55 °C ranges from 2.98 to 7.39 g 100 g−1, peak viscosity from 394 to 2773 cP, pasting temperature from 65.9 to 75.13 °C, setback from 1295 to 2079 cP, and gelatinization enthalpy from zero to 17.62 J g−1. Cracks are visualized on the surface of some starch granules depending on the experimental conditions employed. The studied variables affect the functional, thermal, and pasting properties, it is found that ultrasound (20 kHz, 500 W) applied without cooling is efficient in the modification of WGLS, providing modified starches with differentiated characteristics that can expand their industrial applications.