Elucidation of the Effects of Heat Treatment on Polyphenolic Compounds in Highland Barley and Their Potential Mechanisms of Action in Improving Hypertension Using Targeted Metabolomics, Network Pharmacology, and Molecular Docking.

This study aims to systematically elucidate the influence of various heat treatment methods on the phenolic compounds in highland barley and their potential antihypertensive processes via chemical, in vitro bioactivity, and bioinformatics prediction analyses. This work employed UHPLC-Q Exactive HFX-MS/MS targeted metabolomics technology to ascertain metabolites in barley treated with five different thermal conditions: steaming (ST), boiling at atmospheric pressure (BO), boiling at high pressure (PO), extrusion puffing (EX), and sand-roasting (SR). The data revealed 252 phenolic metabolites, comprising 19 phenolic acids and 233 flavonoids. Moreover, it was observed that, in comparison to the untreated group, various heat treatments yielded substantial differences in the profiles of phenolic compounds. Notably, extrusion puffing (EX) exhibited superior performance: it increased specific flavonoid glycosides such as Clitorin and Quercetin 3-O-rutinoside-(1-2)-O-rhamnoside, while also improving direct antioxidant capabilities such as DPPH and FRAP. In addition, network pharmacology analysis of differentially expressed metabolites in the puffed group identified 44 potential targets, including TNF, IL-6, MMP-9, HIF-1A, and ACE. The KEGG and GO enrichment analyses revealed a substantial enrichment of these targets in classic hypertension-related pathways, including lipid metabolism, atherosclerosis and fluid shear stress. The molecular docking findings indicated that Apigenin 7-O-(2G-rhamnosyl) gentiobioside had significant binding affinities for the target proteins MMP9 and ACE. This study demonstrated that EX is an efficient processing method, with highland barley polyphenols showing potential antihypertensive activity. The findings provide a novel theoretical foundation and research direction for optimizing highland barley processing to maximize functional component utilization and elucidate its food-derived antihypertensive mechanisms.