Enzymatic Hydrolysis of Broken Rice Protein: Antioxidant Activities by Chemical and Cellular Antioxidant Methods

Abstract

Excessive reactive oxygen species (ROS) is an important cause of aging, and supplementing antioxidants through diet is one of the important ways to delay aging. Some studies have confirmed that rice protease hydrolysate has antioxidant activity, but was rarely been investigated on cells. Thus, commercial enzymes, alkaline enzyme, neutral enzyme, pepsin, chymotrypsin, and trypsin were selected to hydrolyze broken rice protein (BRP) to obtain the corresponding hydrolysates, which were A-broken rice protein hydrolysate (BRPH), N-BRPH, P-BRPH, C-BRPH, and T-BRPH, respectively. Then the antioxidant properties of BRPHs were evaluated by different chemical and cellular antioxidation. Molecular weight, peptide length distribution, and amino acid sequence were detected to insight into the antioxidant properties. Among BRPHs, the A-BRPH displayed the strongest hydroxyl radical scavenging activity (IC50 = 1.159 mg/ml) and metal ion-chelating activities (IC50 = 0.391 mg/ml). Furthermore, cellular antioxidation confirmed that A-BRPH significantly increased cell viability and inhibited the intracellular ROS release in both aging cells and cell-aging processes. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) results revealed that peptides with molecular weight <14.5 KDa were produced by enzymatic hydrolysis. Additionally, A-BRPH rich in low molecular weight (<3 kDa) and short-length peptides with some specific amino acids, such as aromatic and hydrophobic amino acids, contributes to the antioxidant properties. This study provided theoretical to the utilization of broken rice and confirmed that A-BRPH could be used in new anti-aging food and health products for human consumption.

Improving functional properties of rice protein isolates by hydrolysis using alcalase enzyme and assessing bioactivities of hydrolysates

“…Our data are comparable to those of a previous study that showed an excellent hydroxyl radical scavenging activity ( IC 50 value of 1.159 mg/mL) and ferrous ion chelating activity ( IC 50 value of 0.391 mg/mL) of broken rice protein hydrolysate at DH of 20.17% 41 . In the present study, protein hydrolysate of RRF‐105 exhibited the best antioxidant property at 30.66% DH.…”

“…The results indicate that specific peptide structures with high metal binding affinity (e.g., -SH or/and L-Cys) might be formed by alcalase hydrolysis. 41 Sarteshnizi et al 8 reported that the potent metal ion chelating activity of fish protein hydrolysate fraction is attributed to its elevated concentration of histidine, which possesses an imidazole ring capable of chelating metals.…”

Monascus Red Pigment Liposomes: Microstructural Characteristics, Stability, and Anticancer Activity

“…The cells' viability was measured by the method described by Ren et al [22] with slight modification. Five different concentrations of MRPs and MRPL suspension (0.02, 0.04, 0.08, 0.16, and 0.32 mg/mL) were filtered by 0.22 µm filter to remove bacteria.…”

Complex coacervation of soy protein isolate‐limited enzymatic hydrolysates and sodium alginate: Formation mechanism and its application

“…As shown in Figure 4 , the lipid antioxidant capacity increased with the increase of concentrations (0–10 mg/ml). The enzymatic hydrolysis disrupted the intrinsic structure of soy protein, which led to the exposure of active amino acid residues that could react with oxidants (Ren et al, 2021 ). Therefore, enzymatic hydrolysis has a positive influence in improving the resistance to oxidation.…”