Development of novel processes for aqueous extraction of natural rubber from Taraxacum kok-saghyz (TK)

Authors: RAMIREZ-CADAVID, DAVID - Ohio Agricultural Research & Development Center; CORNISH, KATRINA - Ohio Agricultural Research & Development Center; Hathwaik, Upul; KOZAK, ROBERT - Atlantic Biomass Conversions, Inc; McMahan, Colleen; MICHEL, FREDERICK - Ohio Agricultural Research & Development Center

Submitted to: Journal of Chemical Technology & Biotechnology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/7/2019
Publication Date: 4/7/2019
Citation: Ramirez-Cadavid, D., Cornish, K., Hathwaik, U.I., Kozak, R., McMahan, C.M., Michel, F. 2019. Development of novel processes for aqueous extraction of natural rubber from Taraxacum kok-saghyz (TK). Journal of Chemical Technology & Biotechnology. 94(8):2452-2464. https://doi.org/10.1002/jctb.6027.
DOI: https://doi.org/10.1002/jctb.6027

Interpretive Summary: Alternative rubber-producing crops can supply a strategic raw material while providing benefit to American farmers. One of the crops under development as a US source of rubber and inulin (a carbohydrate) is Kazakh dandelion (TK). TK stores rubber and inulin in root tissues, and both are closely associated with root biomass. Therefore, efficient and effective extraction processes are needed. In this study, a series of water-based extraction processes were evaluated for separation of rubber and inulin from root tissues. The best results included alkaline (basic) pretreatments, and enzyme digestion of root tissues. This process resulted in TK rubber recovery at high yield and quality.

Technical Abstract: Natural rubber (NR) is a raw material essential to the modern economy. Taraxacum kok-saghyz (TK) is a rubber-producing plant currently being developed as an alternative source of NR. Rubber is formed in the roots in TK and exists in mostly solid form. Processes for the extraction of rubber from TK at high yield and sufficient purity to meet industry standards (=99.8%) have yet to be developed. In this study, water extraction, enzymatic hydrolysis, milling and alkaline treatments were used in various combinations to extract and purify TK rubber. Water extraction of inulin followed by enzymatic digestion, with and without alkaline pretreatment, yielded the most rubber and the highest purity (best case, 99.4%). More rubber was extracted from chopped roots than whole roots, but the rubber was less pure. Alkaline pretreatment did not adversely affect rubber quality and improved yield. However, while alkaline purification post-treatment of extracted crude rubber further increased rubber purity, it reduced rubber molecular weight. Thus, water extraction of inulin followed by alkaline pretreatment and/or enzymatic digestion form the basis for aqueous processes that could be used for large scale, efficient extraction of TK rubber of purity and quality sufficient to meet industry standards.