Effect of high speed jet on the physical properties of tapioca starch

Tapioca starch-water suspension was subjected to high speed jet (HSJ) treatment and the physical properties were investigated by Particle size analysis, Differential scanning calorimetry (DSC), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and Scanning electron microscope (SEM). Particle size analysis revealed a significant increase in volume mean diameter from 17.00 to 40.35 μm. SEM studies showed that treated tapioca starch (TS) was prone to aggregate with each other and markedly damaged at starch granule surface which eventually disintegrated into gel-like structures at high pressure level. XRD patterns showed that all samples exhibited A-type and there was an evident loss of crystallinity after treated over 160 MPa. The TS showed similarity on FTIR spectral pattern but had different intensity in some peaks at increasing pressure. DSC analysis confirmed that TS was partly gelatinized after HSJ treatment, and the degree of gelatinization increased to 34.34 ± 1.0% when the pressure was 240 MPa. These results provided the basic information on the physical properties of TS treated at different pressures and indicated the potential possibility of HSJ for starch modification.