Impacts of Protein from High-Protein Rice on Gelatinization and Retrogradation Properties in High- and Low-Amylose Reconstituted Rice Flour

Abstract

High-protein rice is nutritional, but its taste attributes are inferior to low-protein rice. Many documents correlate its taste attributes with its gelatinization and retrogradation properties. This study investigated the changes in gelatinization and retrogradation properties of low- and high-amylose reconstituted rice flour (RRF) added with different fractions of proteins extracted from high-protein rice. The addition of protein decreased the RVA (rapid viscosity analyzer) viscosity parameters of the RRF but increased the peak time. The high amylose fractions in the RRF mainly increased the parameters PV, FV, SB, and peak times, and scarcely affected the parameters BD and PaT. The interaction between amylose and protein determined the pasting temperature. Protein addition in RRF significantly decreased gelatinization enthalpies but increased the onset temperature (To) and peak temperature (Tp), while the amylose in RRF increased the gelatinization enthalpies, To and Tp. Protein additions decreased the gel hardness and the pore size, while the amylose increased the gel hardness but decreased pore size. Our findings may be potentially useful in breeding and cultivating high-protein rice.

Selected physicochemical properties of rice flour, modified tapioca starch, and their mixtures after a limewater soaking treatment

“…Regardless of the limewater soaking treatment, KDML105 had a lower amylose content (19.5% dry wt) than the commercial rice flour (31% dry wt), which can also be related to the weaker (lower firmness and consistency) gel (Table 4). Rice flour containing higher amylose produced firmer (harder) gel than that containing low amylose (Zhao et al ., 2022). On the other hand, the magnitude of cohesiveness and an index of viscosity of gel showed the opposite trend of the firmness and consistency (Table 4).…”

“…Zhao et al . (2022) revealed that the gelatinisation temperature of rice flour was influenced by the type, granule size, shape, and non‐starch components such as, protein and lipids, which affected the heat transfer hindrance for starch gelatinisation.…”

“…Rice flour and KDML105 flour exhibited higher T o and T p compared to MTS which were caused by various factors such as a botanical origin, an amylose-amylopectin ratio, non-starch component, and starch modification method. Zhao et al (2022) revealed that the gelatinisation temperature of rice flour was influenced by the type, granule size, shape, and non-starch components such as, protein and lipids, which affected the heat transfer hindrance for starch gelatinisation.…”

Increasing Protein Content of Rice Flour with Maintained Processability by Using Granular Starch Hydrolyzing Enzyme

“…In the early stages of GSHE hydrolysis, the increase in very short chains in amylopectin reduced the cross-linked interactions between starch components [49]. In addition, rice protein in the RF group inhibited starch swelling, playing a significant role in the viscosity drop [50]. With the continuation of hydrolysis, the relative content of DP > 6 components, especially the DP > 36 components (Table 4) which were regarded as the backbone of amylopectin, increased, promoting cross-linking interactions between starch molecules [51].…”

Effects of storage temperatures on the starch digestibility of whole rice with distinct starch fine molecular structure

“…It is hypothesized that starch-protein interactions are strengthened when stored at −18 °C, as it has been reported that the electrostatic and hydrogen bonding interactions between amylose and protein significantly decrease the ΔH but increase melting temperatures. [41][42][43] Also, removal of these endogenous proteins decreases in the starch thermal stability of adlay seed. 44…”