Effect of miniemulsion cross-linking and ultrasonication on properties of banana starch

Miniemulsion technique has been widely used to prepare cross-linked starch microsphere for food application. The objective of this study was to examine the effect of miniemulsion and ultrasonic treatment on the morphological, physicochemical and thermal properties of banana starch. Results showed that the miniemulsion cross-linked banana starch (MCBS) exhibited lower swelling power (SP) and solubility (S) but higher gelatinisation enthalpy (H-gel) than native banana starch. Ultrasonic treatment conditions (amplitude and time) did not show any significant difference in SP and H-gel of MCBS. Ultrasonicated MCBS showed rough surfaces and slight fragmentations without any change in particle size. At gelatinisation temperature (80 degrees C), the SP and S of MCBS were higher than those at 29 degrees C. Moreover, MCBS with ultrasonic treatment showed a lower range in the gelatinisation temperature (T) than untreated. The FT-IR spectrums revealed that MCBS were fully cross-linked and had high extent of hydrogen bonding.