Effects of thermal processing on antioxidant activities, amino acid composition and protein molecular weight distributions of jasmine rice bran protein hydrolysate

Abstract

This research aimed to evaluate the effects of thermal processing on the amino acid composition, molecular weight distribution (MW) and antioxidant activities of Jasmine rice bran protein hydrolysates (JBH). JBH was prepared by enzymatic hydrolysate (alcalase and flavourzyme at a ratio of 9.81:90.19, 2.84% w/w) for 60 min. JBH samples were treated as follows: non-heat (NJBH), pasteurisation (72°C, 15 min; PJBH) and sterilisation (121°C, 15 min; SJBH). For SJBH treatment, the browning index and fluorescence intensity increased (P < 0.05). FTIR showed that thermal process changed the intensities and location of some bands. Thermal processing affected MW by decreasing it from high MW (>10 kDa) to medium (3-10 kDa) and low MW (<3 kDa). Val, Met, Ile and Leu contents increased after thermal processing. Compared with NJBH, the IC 50 values of ABTS and FRAP of SJBH were not significantly different, while the IC 50 of DPPH increased (P ≥ 0.05).

Anti-Obesity and Anti-Hyperglycemic Effects of Meretrix lusoria Protamex Hydrolysate in ob/ob Mice

“…In this study, we demonstrated that MLPH had anti-obesity and anti-hyperglycemic effects in an ob / ob mouse model. The antioxidant activity of hydrolysates depends on their molecular weight distribution [ 30 ]. In this study, protamex, alcalase, and flavourzyme hydrolysates from M. lusoria with low-molecular-weight peptides (≤1 kDa) were found to have lower IC 50 values, corresponding to higher scavenging activity for DPPH and ABST radicals.…”

“…The mobile phase for the analysis was distilled water and MeOH containing 0.1% formic acid, flowing from 10–100% methanol ( v / v ) at 1 mL/min flow rate for 40 min under a gradient system. Following the highest yield and activity analysis, the most potent peptide sub-fraction was purified by RP-HPLC on a C18 analytical column (YMC-Triart C18 ExRs) with the same MeOH containing 0.1% formic acid at a flow rate of 1 mL/min for 40 min [ 30 ].…”

Optimization of Enzymatic Hydrolysis by Alcalase and Flavourzyme To Enhance the Antioxidant Properties of Jasmine Rice Bran Protein Hydrolysate

“…The JB was defatted as described by Hunsakul, Laokuldilok, Prinyawiwatkul and Utama-ang 20 . In brief, 100 g of defatted rice bran was dispersed in 1 L of 0.05 M NaOH.…”

Recent findings on the cellular and molecular mechanisms of action of novel food-derived antihypertensive peptides

“…This was demonstrated in a study where ultrasound treatment of watermelon seed and mung bean proteins prior to enzyme hydrolysis enhanced the hydrophobicity and release of peptides with terminal aromatic amino acids all of which influenced their stability, bioavailability, and bioactivity (such as radical scavenging and antihypertensive properties ( Jiang et al, 2021 , Wen et al, 2020 , Xie et al, 2020 ). On the other hand, the use of procedures such as microwaves and other thermal techniques for peptide preparation have been shown to affect the functionality of the peptides, by changing the native physicochemical properties of the peptide which affects their stability and bioactivities ( Hunsakul, Laokuldilok, Prinyawiwatkul, & Utama-ang, 2021 ). Considering the better functionality of low molecular weight peptides, a combination of two or more hydrolyzing enzymes is likely to generate shorter chain peptides compared to using one enzyme ( Aluko, 2015 ).…”