In Vitro and In Vivo Digestive Fate and Antioxidant Activities of Polyphenols from Hulless Barley: Impact of Various Thermal Processing Methods and β-Glucan

Abstract

The unfavorable bioaccessibility of polyphenols in cereal-based food limits their physiological functions as most polyphenols bind spontaneously to the cell-wall polysaccharides. Effects of β-glucan and various thermal processing methods including flaking and roasting, stir-frying, steam-flash explosion, and popping expansion on the bioaccessibility and antioxidant properties of polyphenols from hulless barley in vitro and in vivo were investigated in this study. The bioaccessibility and antioxidant capacity (via DPPH, •OH, and •O 2 − free radical scavenging, TAC, and FRAP assays) of polyphenol extracts from hulless barley treated by steam-flash explosion and popping expansion increased significantly before and after in vitro digestion compared to those from raw and other processed hulless barley. Further, the total polyphenol content of hulless barley elevated dramatically following hydrolyzing with β-glucanase, which was positively correlated with the antioxidant activity. Additionally, the hulless barley treated with steam-flash explosion exhibited potent antidiabetic effects and antioxidant capacity (via TAC, SOD, GSH-Px, CAT, and MDA assays) in type 2 diabetic rats. The absorption of individual phenolic compounds in the alimentary canal of rats was impacted obviously by thermal processing. This study provides new insights into enhancing the bioaccessibility of the polyphenols and suggests that β-glucans interact with polyphenols and proteins in the hulless barley matrix.

Influence of physicochemical changes and aggregation behavior induced by ultrasound irradiation on the antioxidant effect of highland barley β-glucan

“…Superoxide radicals are relatively weak oxidants, but they can amplify cell damage by producing other kinds of free radicals and oxidants, such as hydrogen peroxide, hydroxyl radicals and singlet oxygen ( Xie et al, 2022 ). Superoxide anions can also indirectly initiate lipid peroxidation to form H 2 O 2 , the precursor of hydroxyl radicals was produced.…”

The phenolics, antioxidant activity and in vitro digestion of pomegranate (Punica granatum L.) peels: an investigation of steam explosion pre-treatment

“…Furthermore, the hydrolyzed amount far exceeded the continued dissolved amount, resulting in a decline in TPC after intestinal digestion. The increase in TPC in the exploded peels was much higher than in the unexploded peels after gastric digestion, suggesting that steam explosion contributed to disconnecting the interaction formed between phenols and other compounds ( 14 ). In addition, the four phenolic compounds in pomegranate peel were easily degraded or transformed during in vitro digestion.…”

“…Qin et al used the steam explosion to extract flavonoids from fig leaves and found that the content of flavonoids from the treated samples was 55.9% higher than that in the control group ( 13 ). Xie et al suggested that steam explosion-treated hulless barley exhibited potent antidiabetic effects and antioxidant capacity ( 14 ). Wan et al reported that steam explosion enhanced the phenolic profiles and antioxidant activity in mung beans ( 15 ).…”

Cymbopogon citratus Essential Oil: Extraction, GC–MS, Phytochemical Analysis, Antioxidant Activity, and In Silico Molecular Docking for Protein Targets Related to CNS

“…Gallic acid was used as standard and for the calculation of the percentage of inhibition the following relation was used: %Inhibition = [Blank − Test]/Blank × 100. A second test to evaluate the antioxidant activity was carried out through the determination of total phenols by the ABTS and Folin–Ciocalteu technique, according to the methodology previously reported [ 28 , 29 , 30 , 31 ]. The same doses mentioned above were used for the test, and the results were reported as equivalents of gallic acid.…”