The main components of gluten powder are wheat gluten and alcohol soluble protein, as well as small amounts of starch, fat, minerals, etc. (Table 1) . Wheat gluten is a protein formed by the polymerization of polypeptide bonds through intermolecular disulfide bonds. It has a large molecular weight, is fibrous, and highly cross-linked in a branching manner. Its structure is irregular, and the molecule contains many β - folded structures, rich in glutamine (Gln) and cysteine (Cys). Alcohol soluble protein is a monomeric protein with a molecular weight of approximately 35 kD, spherical in shape, insoluble in water and anhydrous ethanol, but soluble in 70% to 80% ethanol solution. Its characteristics are that it has more proline and amide, more non-polar side chains than polar side chains, no subunit structure within the molecule, and no disulfide bonds between peptide chains. Single peptide chains are connected by hydrogen bonds, hydrophobic bonds, and intramolecular disulfide bonds, forming a compact three-dimensional structure. Under low pH conditions, alcohol soluble proteins can be classified into four types based on their electrophoretic mobility: alpha, beta, gamma, and omega. Among them, alpha alcohol soluble proteins have the highest fluidity, while omega alcohol soluble proteins have the worst fluidity.

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