essential-oils
Essential oils are hydrophobic volatile organic compounds extracted from plant material that carry the characteristic fragrance or essence of the source plant. In plant science, they are studied for their roles in plant defense, pollinator attraction, and stress response, as well as for understanding the biosynthetic pathways — such as the terpenoid and phenylpropanoid routes — that produce these compounds. Research into essential oils also informs breeding, agronomy, and phytochemistry efforts aimed at optimizing the yield and composition of aromatic crops.
open_in_new WikipediaPubMed · 2026-04-30
Researchers compared the chemical profiles of essential oils and hydrosols — the aromatic water left over after steam distillation — from seven common herb species in the mint family. They found that hydrosols are chemically distinct from essential oils, carrying more water-friendly aromatic compounds that make them useful ingredients in their own right.
Hydrosols from all seven herb species showed a higher relative proportion of polar, water-soluble oxygenated compounds (such as alcohols and oxides) compared to their matched essential oils.
Essential oils were dominated by less polar, highly volatile compounds including monoterpene hydrocarbons and certain esters and ketones — categories less prominent in hydrosols.
Across all seven Lamiaceae species tested — including lavender, peppermint, oregano, and three sage varieties — oxygenated monoterpenes were the dominant chemical class in both distillation products.
