PURIFICATION AND CHARACTERIZATION OF PROTEIN CONCENTRATES FROM JOJOBA (SIMMONDSIA CHINESIS) PRESSED MEAL.

Abstract

Jojoba, Simmondsia chinesis, a shrub native to the Sonoran Desert, has seeds with a high percentage of oil. The oil, which has properties similar to sperm whale oil, is expressed with heat and pressure, leaving behind a pressed meal rich in protein and carbohydrate. High concentration of a cyanoglycoside, simmondsin, and polyphenolic compounds in the meal make it unusable for animal or human consumption. Commercial means of protein extraction were improved by washing the protein concentrate with methanol, acetone, and acidic methanol to remove sugars, polyphenolic components and simmondsin. A concentrate with 85% protein, less than 0.3% polyphenolic compounds, and less than 1% simmondsin resulted. The foamability, water absorption, oil absorption, gelation, emulsification and nitrogen solubility were comparable to other plant protein concentrates. Fewer than 15 proteins in the pressed meal and concentrates were detected using PAGE (12.5% T, 2.4% C) in a Laemmli discontinuous system. The proteins were deficient in the sulfur amino acids, and marginal in threonine and lysine. The amino acid imbalance might be partially responsible for poor weight gain and other toxicity symptoms reported previously.