Abstract: Barley malt roots as a byproduct of malt product was analyzed for proximate chemical composition according to the national standards. Meanwhile, the extraction of alkali-soluble protein from barley malt roots was optimized by orthogonal array design method. Barley malt roots contained 29.2% protein, 6.9% ash, 6.42% water, 1.4% fat and 10.7% crude fiber. The optimal conditions for protein extraction were found to be extraction at 40 ℃ and pH 9.0 for 60 min with a solid-to-solvent ratio of 1:25 (g/mL), resulting in a protein yield of 63.5%. The optimized procedure provided a simple and high-yield method for protein extraction from barley malt roots.

Key words: barley malt roots, protein, extraction, orthogonal array design