Spinning of Peanut Protein Fibers1

Abstract

Abstract Raw Altika peanuts were blanched, partially defatted, ground and the protein was removed using an aqueous alkaline extraction, precipitated at pH 4.0 and freeze dried to yield a protein concentrate with 85.5% protein, 3.1% fat and 2.0% ash on a dry weight basis. Peanut protein concentrate was used to produce dope solutions for the spinning of fibers. Viscosity of dope solutions increased rapidly with increases in protein concentration from 11 to 14%; the highest protein concentration gelled within a short time after mixing. Dope solution viscosity increased with increasing NaOH concentration from 0.85% to 0.90%. Higher NaOH concentrations, up to 1.05%, however, resulted in a continued decrease in dope viscosity. Dope viscosity increased as a function of maturation time, especially at NaOH concentrations that yielded the highest viscosities. The best conditions for spinning peanut protein fibers were: 1) dope pH 11.4, 2) maturation time of 12 hours for a 13.0% protein dope or 2 hours for 13.5% protein dope, 3) coagulating bath conditions of 2N acetic acid and 20% NaC1, and 4) dope extrusion pressure of 15 psi. Suitability of dope solutions for spinning depended on the interaction between protein concentration, pH and dope maturity.