Structural and physicochemical properties of lotus seed starch treated with ultra-high pressure

Aqueous lotus seed starch suspensions (15%, w/w) were subjected to ultra-high pressure treatment (UHF, 100-600 MPa) for 30 min. The effects of UHF treatment on the structural and physicochemical properties of starch were investigated. The SEM and laser diffraction particle size analysis revealed that UHP treatment affected the shape and size distribution of starch granules. The morphological structure of starch was completely destroyed at 600 MPa, indicating complete gelatinization. Analysis of HPSEC-MALLS-RI suggested that the dispersity index of UHF-treated starch were decreased from 1.28 to 1.11. According to XRD analyses, UHF treatment converted native starch (C-type) into a B-type pattern. The swelling power and solubility presented a significant decrease at 85 and 95 degrees C, but opposite trends were found at 55-75 degrees C. The DSC results indicated a reduction in gelatinization temperatures and enthalpy with increasing pressure treatment. The RVA viscograms revealed that UHF-treated starch showed a decreased breakdown and setback viscosity, reflecting lower retrogradation tendency compared to native starch. (C) 2015 Elsevier Ltd. All rights reserved.