Thank you for your questions, Margaret. Although I could find few dandelion root-specific answers, I think we can draw some conclusions about nutrients retained or destroyed during cooking.

Dandelions are known sources of vitamins A, C, K, folate, calcium and potassium. The fat-soluble vitamins A and K and the minerals calcium and potassium are stable and not affected by cooking. Water-soluble vitamins are sensitive to heat and may be reduced by boiling or steaming.

The roots are rich in inulin, a soluble fiber, which may be increased with boiling or steaming, particularly steaming. This evidence was reported in inulin-rich foods other than dandelion.

Taraxasterol (TS) in dandelion root, also found in legumes, cereals, nuts, seeds and plant oils, is anti-inflammatory, anti-oxidative, and anti-carcinogenic. Studies did not specify whether samples were raw or cooked however water and heat appear to be used in the extraction process. I would conclude cooking does not negatively affect this compound.

Chlorogenic acid (CGA) is the richest phenolic component of dandelion with potent antioxidant capacity. It is water-soluble and some studies show improved bioactivity with boiling or steaming. CGA content, also found in coffee beans, is reduced in the roasting process.

In general, the consensus is that dandelion root can be consumed similar to other root vegetables such as the carrot. The nutrition content may vary slightly depending on whether it is a water or fat-soluble nutrient. Drying or roasting for tea or adding to a smoothie, soup or salad will provide nutrition benefits, regardless of being cooked or raw.

Other resources/references:

https://health.clevelandclinic.org/dandelion-health-benefits

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5553762/
https://pubmed.ncbi.nlm.nih.gov/38425109/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6162770/