The Modifications in Physicochemical and Functional Properties of Proso Millet Starch after Ultra‐High Pressure (UHP) Process

Abstract

Proso millet starch suspensions (30%, W/V) are subjected to UHP treatment at 150, 300, 450, and 600 MPa for 15 min in order to produce a modified starch for food applications. Besides, the UHP‐gelatinized starch gels are stored at room temperature for 192 h and the recrystallization characteristics are investigated during the storage time. The gelatinization extent of starch is increased with the increase in pressure level and the starch is fully gelatinized at 600 MPa. The XRD patterns show that the UHP at 600 MPa converted the A‐type crystals to the B‐type. The DSC data reveal an increase in gelatinization temperatures and a decrease in gelatinization enthalpy after treatment at 150–450 MPa. Pasting property analysis shows that trough and final viscosity, pasting temperature and peak time are increased; however, peak and breakdown viscosity are decreased with the increase in pressure level up to 600 MPa. UHP treatment resulted in a higher swelling capacity and solubility at a relatively low temperature. XRD and DSC are also used to monitor retrogradation through the growth of diffraction peaks of the recrystallized starch and the increase in the melting enthalpy. The extent of retrogradation is plotted as a function of the storage time.

Effect of germination and high pressure treatments on brown rice flour rheological, pasting, textural, and structural properties

“…SB reveals the gelling ability and retrogradation tendency of starch paste and is influenced by the structure of amylose and amylopectin. The decrease in SB of BR‐HP might be due to the fact that the spatial network was weakened by the formation of amylose‐lipid complexes during HP treatment (Li et al, 2018). After germination, more lipid was degraded, so less amylose‐lipid complexes formed than that in BR during HP treatment.…”

Recent advances in gelatinisation and retrogradation of starch by high hydrostatic pressure

“…At low HHP treatment (100–300 MPa), starch granules remained the native starch shape (Fig. 2b–d) (Li et al ., 2018; Zeng et al ., 2018). During partial gelatinisation, starch granules started to lose their native structure.…”

Capitalizing on a double crop: Recent advances in proso millet's transition to a food crop

“…Ultrahigh pressure (UHP) processing conveys unique properties to starch: only inner regions in the granules gelatinize, whereas outer regions remain relatively unaffected (Blaszczak et al., 2007). In a comparison among treatments, the highest applied pressure, 600 MPa, resulted in starch with significantly increased swelling power and solubility at 50 and 60° C than native starch (Li et al., 2018). These changes corresponded to loss of molecular order and to profound changes in gelatinization and pasting profiles, that is, the endotherm essentially disappeared, and the viscosity significantly decreased over the entire pasting program.…”

“…These changes corresponded to loss of molecular order and to profound changes in gelatinization and pasting profiles, that is, the endotherm essentially disappeared, and the viscosity significantly decreased over the entire pasting program. However, at intermediate pressure ranges, from 150 to 450 MPa, an annealing effect could be observed (Li et al., 2018). Overall, up to 450 MPa, a structural reorganization with a weakening effect occurred in the granules, whereas at 600 MPa, the gelatinization process was essentially complete.…”