High pressure processing (HPP) of pea starch: Effect on the gelatinization properties

High pressure processing (HPP), an emerging technology, can be used to promote gelatinization of starch granules. This phenomenon is highly dependent on the source of starch, pressure level, time and temperature applied as well as the dispersion medium. This work evaluated the effect of HPP (up to 600MPa/15 min/25 degrees C) on particle size distribution, optical microscopy, differential scanning calorimetry and pasting properties of pea starch. Results showed no difference between control samples and processed ones up to 400 MPa (water dispersion) or all samples dispersed in ethanol, except for the thermal properties at 400 MPa that showed 31% of gelatinization in water dispersion. Samples processed at pressures higher than 500 MPa showed changes on particle size and distribution (increase at 500 MPa and a slight reduction at 600 MPa), and no detected gelatinization enthalpy at DSC. The optical microscopy observation indicated that HPP (>400 MPa) caused the loss of birefringence. Regarding the pasting properties, the initial viscosity increased from 8 cP at 0 MPa to 34 cP at 600 MPa. All results indicated that HPP can be used to promote "cold gelatinization" on pea starch water dispersion, achieving a specific technological profile and possibly leading to new ingredients. (C) 2016 Elsevier Ltd. All rights reserved.