Extractable latex yield from Taraxacum kok-saghyz roots is enhanced by increasing rubber particle buoyancy

Authors: KING-SMITH, NATHANIE - The Ohio State University; MOLNAR, KRISTOF - The Ohio State University; BLAKESLEE, JOSHUA - The Ohio State University; McMahan, Colleen; PILLAI, ASWATHY - Collaborator; MUTALKHANOV, MEIRAMBEK - Al-Farabi Kazakh National University; PUSKAS, JUDIT - The Ohio State University; CORNISH, KATRINA - The Ohio State University

Submitted to: Industrial Crops and Products
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/22/2023
Publication Date: 10/28/2023
Citation: King-Smith, N., Molnar, K., Blakeslee, J., McMahan, C.M., Pillai, A., Mutalkhanov, M., Puskas, J., Cornish, K. 2023. Extractable latex yield from Taraxacum kok-saghyz roots is enhanced by increasing rubber particle buoyancy. Industrial Crops and Products. 206. Article 117698. https://doi.org/10.1016/j.indcrop.2023.117698.
DOI: https://doi.org/10.1016/j.indcrop.2023.117698

Interpretive Summary: Introduction of domestic natural rubber-producing crops requires efficient processing methods for extraction of latex and rubber. Extraction of latex in the liquid form is required for production of dipped goods including gloves and many medical devices. Taraxacum-kok saghyz (rubber dandelion) is a promising crop for rubber production in temperate climates, but extraction of its latex has been challenging. Here, a simple process modification, i.e. addition of EDTA, a common water treatment chemical, resulted in increased yields of liquid latex, in some cases of 3 fold more latex.

Technical Abstract: The tropical rubber tree, Hevea brasiliensis, is relied on solely for the world’s natural rubber (NR) supply. Hevea can only be cultivated? in narrow geographic regions and is a clonal plant, making it highly vulnerable to disease. Future increased rubber demands require a substantial increase in Hevea acreage, but this is not possible without massive deforestation. Alternative rubber crops able to grow in temperate climates will be the solution to this supply problem. Taraxacum kok-saghyz (TK) is a leading alternative rubber-producing plant that produces NR latex in laticifers within its roots. TK can be grown in temperate regions, such as the northern United States, as the basis of a domestic rubber production industry. To support such an industry, efficient, scalable rubber extraction techniques are needed. In this study, aqueous extraction was used to recover TK latex (TNRL) from three harvests of greenhouse-produced TK roots with a new process? that improves rubber particle buoyancy in root homogenate by chelation. The new method includes harvest, cleaning, and homogenization of freshly harvested roots, followed by centrifugation, vacuum collection, and purification of the latex. Treatment of homogenate with EDTA, a divalent cation chelator, allowed more than twice as much latex to be extracted from the fresh homogenate. EDTA-treated rubber particles contained lower concentrations of divalent cations than untreated ones in fresh homogenate and homogenate stored for two weeks. Long term (three months) storage of root homogenate yielded more latex than fresh homogenate and had low divalent cation rubber particle concentrations, indicating that heavy cations had slowly leached from the particles into the aqueous medium. Rubber particle size was larger in this treatment suggestive of rubber particle agglomeration. Molecular characterization of purified latex established that the TNRL was of the high molecular weight needed for product manufacturing.