Submitted to: Industrial Crops and Products
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 28, 2005
Publication Date: January 23, 2006
Citation: Laszlo, J.A., Compton, D.L., Li, X.-L. 2006. Feruloyl esterase hydrolysis and recovery of ferulic acid from jojoba meal. Industrial Crops and Products. 23:46-53. Interpretive Summary: Seeds of the jojoba plant are a source of valuable waxes used in skin and hair care products. The defatted meal, while rich in protein, cannot be fed to animals unless a toxic fraction, dubbed simmondsin, is first removed. Finding high-value uses for simmondsin would significantly improve the economics of the meal extraction process. The present work demonstrates that valuable ferulic acid can be recovered from simmondsin by treatment with an enzyme. Ferulic acid was shown to be readily converted to an ester, which allows it to be used as well in cosmetics and sun care products. The identification of simmondsin as a useful source of ferulic acid should increase the potential that defatted jojoba meal can be used for animal feed, thereby increasing the profitability of jojoba growers and processors.
Technical Abstract: There is growing interest in recovering ferulic acid from plant sources for use as feedstock for several high-value applications. The feruloyl esterase domain of the Clostridium thermocellum cellulosomal xylanase was employed to hydrolyze ferulic acid from defatted jojoba meal. Esterase treatment produced 6.7 g of ferulic acid per kg of jojoba meal. The predominant source (86%) of the ferulate was found to originate from the meal's water-soluble simmondsin fraction. Seven feruloyl simmondsin species from jojoba meal were identified by liquid chromatography'mass spectroscopy. Only one species, a didemethylsimmondsin ferulate, displayed a turnover rate with the enzyme distinctly faster than the other feruloyl simmondsins. Complete hydrolysis of all feruloyl simmondsin species was achieved in 24-48 h at 60°C with a 100:1 meal:enzyme weight ratio. Ferulic acid was efficiently recovered from the medium by ethyl acetate extraction. The recovered ferulic acid was readily converted to ethyl ferulate, demonstrating a facile procedure for producing a valuable product from defatted jojoba meal.