Study on extraction conditions and characteristics of protein from burdock roots

Abstract

Burdock (Arctium lappa L.), which belongs to the Compositae family, possesses significant medicinal and nutritional value. Burdock root is abundant in proteins and essential amino acids. In this study, proteins from burdock roots were extracted by alkali extraction and acid sedimentation, and the optimal conditions for protein extraction from burdock roots and protein characteristics were explored. The optimal conditions for protein extraction with a yield rate of 9.03% were 40°C extraction temperature, pH 8.0, a solid–liquid ratio of 1:25 (g/mL), and extraction time of 65 minutes. Single-factor and orthogonal tests on the extraction rate of burdock proteins under different conditions found that the extraction rate of protein from burdock roots were influenced by pH, extraction temperature, solid–liquid ratio, and extraction time, in this order. The solubility and gelation properties of burdock protein were similar to those of soybean protein; however, burdock protein demonstrated 1.2 times the oil absorption capacity and half the water retention capacity of soybean protein. Analysis of the amino acid contents of burdock protein revealed that burdock root contains significant essential and non-essential amino acids, with valine content being the highest.

Keywords

• acid precipitation
• alkali extraction
• amino acid content
• burdock
• protein characteristics
• protein extraction.