Rubber and latex extraction processes for Taraxacum kok-saghyz

Natural rubber (NR) has unique properties which are unmatched by synthetic rubber and is used in over 50,000 products. The only commercial source of NR is the Para rubber tree (Hevea brasiliensis) which is insecure because of increasing demand, price instability, high labor costs, trade politics, competition with other crops, deforestation bans preventing new H. brasiliensis acreage, and disease. Taraxacum kok-saghyz, rubber root dandelion, produces NR quite similar to that from H. brasiliensis. One of the major challenges in turning T. kok-saghyz into an industrial rubber-bearing crop is the lack of an environmentally friendly and cost-effective process for rubber extraction proven at commercial scale. Rubber in T. kok-saghyz is present as latex and solid rubber threads. If the latex form is not required, the better option is to recover all the NR as solid rubber after drying the roots. This review summarizes latex extraction (flow and blender methods) and solid rubber extraction (wet milling, enzyme digestion, solvent extraction, and dry milling processes) from T. kok-saghyz and their effects on NR yield and quality (molecular weight and purity). The current challenges and future perspectives for improving T. kok-saghyz NR extraction processes are discussed. •An alternative to Hevea brasiliensis, the only commercial source of NR, is needed.•Taraxacum kok-saghyz produces NR quite similar to that from H. brasiliensis.•Environmentally friendly and cost-effective processes for NR extraction are necessary.•Rubber in T. kok-saghyz is present as latex and solid rubber threads.•For economic viability, the crop should be exploited in the biorefinery context.