The impact of ultrasound treatment on the microencapsulation of bixin using high amylose corn starch was evaluated. The samples were subjected to three different power levels, 150 (BC1), 210 (BC2) and 300 W (BC3) at 78 °C, 20 kHz for 45 min using an ultrasonic homogenizer equipped with a standard probe 1.9 mm in diameter. After that, the gels formed were frozen at -18 °C for 12 h and lyophilized. The physicochemical interactions were analyzed by X-ray diffractometry, FT-IR spectrometry, scanning electron microscopy, encapsulation efficiency (%) and release profile under simulated gastrointestinal conditions. The morphology of the sonicated samples showed a surface eroded and irregular with protrusions occasioned by aggregation of amylose molecules. Encapsulation efficiencies were of 0.02, 39.2, 41.6 and 92.6 % to control, BC3 (300 W), BC2 (210 W), and BC1 (150 W), respectively. After 150 min, the release profile of samples BC1 and BC2 were 3.0 and 3.8 %, respectively, being lower than the observed in samples BC3 and control, with values of 6.9 and 21.8 %, respectively. The diffraction patterns observed in sonicated samples are a mixture of B-type and V-type patterns. The band at 1744 cm-1 , which is typical of the –C=O group of bixin and the band at 1618 cm-1 disappeared, indicating that stretching vibration from -C=O, C=C groups in the bixin were restricted after sonication. These changes occurred because these groups were entrapped by the starch matrix, restricting their vibrations. Such matrix can be used successfully for the protection of bixin and in the design of controlled delivery systems.