The retrogradation characteristics of pullulanase debranched field pea starch: Effects of storage time and temperature

The structural changes and retrogradation behavior of the processed pea starch stored at 4 degrees C and 25 degrees C for different length of time (6, 12,24, 48, and 72 h) was investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), solid-state C-13 nuclear magnetic resonance spectroscopy ((CNMR)-C-13), Fourier transform infrared spectroscopy (FT-IR), and small angle X-ray scattering (SAXS), their corresponded physicochemical properties were studied by rapid visco-analyzer (RVA). A mixture of B- and V -type crystalline polymorph was observed by XRD for all processed and retrograded pea starch. A continuous increase in the following parameters was observed during the initial retrogradation of pea starch for 6-48 hat 4 degrees C and for 6-24 h at 25 degrees C, followed by a decreased trend during the subsequent storage time from 48 h to 72 h at 4 degrees C, and from 24 h to 72 h at 25 degrees C, including the values of relative crystallinity, degree of order, and degree of double helix measured by XRD, (CNMR)-C-13, and FT-IR, respectively. The results of this study would provide useful information for better designing of starch -based food ingredients with improved functional and health benefits. (C) 2019 Elsevier B.V. All rights reserved.