Study on mechanism of starch phase transtion in wheat with different moisture content

Abstract

Using Bainong 365 wheat starch as raw material, starch samples were preheated in a RVA to simulate DSC heating profiles. The thermodynamic properties, long-range orderliness, short-range orderliness, and structure of wheat starch were determined by DSC, XRD, FTIR, LF-NMR and SEM to explore the phase transformation mechanism of Bainong 365 wheat starch at different water contents. The results show that at different moisture contents, when the endothermic transition temperature of starch samples determined by DSC was reached or exceeded, the enthalpy of starch was 0, all free water was converted into uneasy flowing water and bound water, and the surface structure of starch was severely damaged. At this time, starch was completely gelatinized, but the short-range and long-range ordered structures of starch determined by FTIR and XRD still existed and gradually decreased with increasing temperature. Therefore, it was concluded that the temperature range of the starch endothermic transition does not represent the temperature range of complete gelation of starch, and the structure destroyed by complete gelation of starch may not be simple short-range and long-range ordered molecular structures.

In Vitro Lipid Lowering Effect of Mixed Carboxymethyl Dietary Fiber from Rosa sterilis Pomace

“…CTDF 1/3 exhibited a significantly higher cholesterol adsorption capacity (p < 0.05) than RTDF 1/3 . Figure 1 shows that the result can be attributed to the loose internal network structure of CTDF 1/3 in our previous research, [23] which resulted in a large surface area that can adsorb cholesterol. [24] In addition, compared with RTDF 1/3 , CTDF 1/3 presented an increased surface carboxyl group content and could easily adsorb cholesterol groups.…”

“…Therefore, in the present study, the SDF and IDF of RSP were carboxymethylated to obtain carboxymethyl SDF (CSDF) and carboxymethyl insoluble IDF (CIDF). On the basis of the previous results of a study on mixed carboxymethyl DF, [23] CSDF, and CIDF were mixed at the optimal ratio of 1:3, producing the CTDF 1/3 (CSDF:CIDF = 1:3). Meanwhile, the SDF and IDF of RSP were mixed at the same ratio of 1:3 (RSDF:RIDF = 1:3, RTDF 1/3 ).…”

Preparation and characterization of an oridonin and γ-cyclodextrin complex

“…The XRD patterns of oridonin, γ-cyclodextrin, the oridonin/γcyclodextrin physical mixture, and the oridonin/γ-cyclodextrin complex, were analyzed using a Bruker D8 Advance X-ray diffractometer (Ettlingen, Germany) with Cu Kα radiation (λ = 1.54056 Å). The diffraction angle ranged from 10° to 80° (Abarca et al, 2016;Su et al, 2022).…”

Reveal the internal moisture changes of white gourd during hot air-drying process using low-field NMR

“…Low field nuclear magnetic (LF-NMR) utilized the hydrogen nucleus spin relaxation characteristics in the magnetic field (Su et al, 2022). It could be used for investigating the moisture distribution changing and the moisture transferring in the sample utilizing the changes of relaxation time (Hansen et al, 2010;Aursand et al, 2008).…”