High F-value oligopeptides are a type of low molecular weight physiologically active peptides formed when proteases act on food proteins. These peptides are composed of a specific amino acid profile characterized by high levels of branched-chain amino acids and low levels of aromatic amino acids.^[1]

High F-value oligopeptide mixtures are a system of mixed small peptides (or oligopeptides) consisting of 2-9 amino acid residues. This can be explained in two parts: high F-value and oligopeptides. The F-value (Fischer ratio) is the molar ratio of branched-chain amino acids (BCAAs: Val, Ile, Leu) to aromatic amino acids (AAAs: Trp, Tyr, Phe). It is named in honor of the renowned German scholar Fischer J.E., who proposed the "false neurotransmitter hypothesis" in the 1970s. The F-value in the blood of healthy individuals ranges from 3.0 to 3.5, while in patients with liver diseases, it is only 1.0 or lower. High F-value oligopeptides have an F-value greater than 20. Oligopeptides are protein precursors composed of 2-9 amino acids or protein degradation products consisting of 2-9 amino acids, also referred to as small peptides or short peptides. Due to their unique amino acid composition and physiological functions, they have garnered significant attention in the food and pharmaceutical industries.