Differences in sex among cattle are associated with distinct physiological traits and endocrine profiles, which significantly influence meat quality and flavor characteristics. This study is the first to explore the effect of sex on meat quality, volatile flavor, and metabolites in Yanbian yellow cattle. Volatile and non-volatile metabolites in the longissimus dorsi muscle were comprehensively profiled using gas chromatography–ion mobility spectrometry (GC-IMS) and liquid chromatography–tandem mass spectrometry (LC-MS/MS). The results revealed that the fatty acid content (SFA, MUFA, PUFA) in the triceps brachii and longissimus dorsi muscles of cows was significantly higher than that of bulls (p < 0.05). In contrast, bulls showed elevated levels of total amino acids and non-essential amino acids (p < 0.05). Volatile flavor analysis revealed 35 discovered compounds, including alcohols, ketones, aldehydes, and esters. Notably, alcohols and aldehydic flavor compounds in the longissimus dorsi were substantially more prominent in cows, whereas ketonic compounds were predominantly higher in bulls. The study also identified key metabolic pathways—including lipid metabolism, protein and amino acid metabolism, and glycolysis—that are predominantly associated with meat quality. These findings provide a theoretical basis for further elucidating the molecular mechanisms regulating flavor formation in Yanbian yellow cattle.

The global burden of hypertension continues to rise, highlighting an urgent need for effective therapeutic strategies. Angiotensin-converting enzyme (ACE) is central to blood pressure regulation, but commonly used synthetic ACE inhibitors often have adverse side effects, spurring the search for safer natural alternatives. The aim of this study was to investigate Yanbian cattle hemoglobin as a novel precursor for ACE inhibitory peptides. The <1 kDa fraction was identified as exhibiting the highest inhibitory activity through the systematic screening of hydrolysates across multiple molecular weight ranges. LC-MS/MS analysis identified 1980 peptides, of which four were selected for further experiments. Solid-phase synthesis confirmed that NFGYDL exhibited the strongest ACE inhibition (IC₅₀ = 54.95 μM). Inhibition kinetics showed FHDYL acted as a mixed-type inhibitor, DLGHF and NFGYDL as competitive inhibitors and GFHLD as a non-competitive inhibitor. Molecular dynamics simulations validated the stable binding of these bovine blood-derived peptides to the ACE complex. HUVEC functional assays demonstrated that four peptides significantly increased angiotensin II-induced nitric oxide production and endothelin-1 levels, suggesting their potential antihypertensive activity. These findings suggested that bovine blood is a promising natural source of ACE-inhibitory peptides and holds potential for application as a functional component in functional foods targeting hypertension management.