Cov khoom siv roj tseem ceeb feem ntau suav nrog cov ntsiab lus xws li cov roj yam tseem ceeb, cov roj nqa khoom, thiab hydrosols. Nws yog ib qho tseem ceeb uas yuav tsum nco ntsoov tias tam sim no tsis muaj cov qauv nruj hauv tebchaws kom paub qhov txawv ntawm cov ntsiab lus no; kev sib txawv nyob ntawm ntau yam ntawm kev lag luam thiab kev paub txog pej xeem.
Ib qho tseem ceeb roj yog hais txog 100% cov roj yam tseem ceeb, feem ntau muaj npe tom qab cov nroj tsuag (xws li, roj sawv, roj lavender, roj camellia). Vim lawv cov purity siab, lawv tsis haum rau daim ntawv thov ncaj qha rau ntawm daim tawv nqaij, vim qhov no tuaj yeem ua rau lub nra yooj yim rau ntawm daim tawv nqaij, ua rau muaj kev fab tshuaj lossis txawm tias kub hnyiab. Ua ntej siv, cov roj nqa thiab ib qho tseem ceeb roj yuav tsum tau muab sib xyaw thiab diluted raws li cov lus qhia ua ntej thov ncaj qha rau ntawm daim tawv nqaij siv zaws lossis lwm txoj kev.
Cov roj tseem ceeb yog cov sib xyaw ntawm ntau cov roj tseem ceeb ntawm cov nroj tsuag raws li lawv cov khoom sib txawv. Feem ntau, lawv cov ntsiab lus active ingredient yog nyob ib ncig ntawm 3%, thaum lub tseem ceeb tivthaiv yog ib tug cab kuj roj siv rau blending. Cov neeg siv khoom tuaj yeem siv cov roj tseem ceeb ncaj qha rau ntawm daim tawv nqaij ntawm lub ntsej muag, caj npab, ceg, thiab lwm yam, raws li cov lus qhia ntawm cov khoom.
Cov roj nqa khoom, tseem hu ua cov roj hauv paus lossis cov roj sib xyaw, tsis yog - cov roj tsis hloov pauv tau los ntawm cov noob thiab txiv hmab txiv ntoo ntawm ntau yam nroj tsuag los ntawm kev nias thiab rho tawm. Lawv yog cov nroj tsuag -raws li nruab nrab roj siv los muab ib los yog ntau tshaj siab -concentration ib qho tseem ceeb roj. Lawv yog cov mob me me thiab yooj yim nqus los ntawm lub cev, thiab tuaj yeem siv ib leeg ua cov roj tu tawv nqaij lossis cov roj zaws.
Hydrosols, tseem hu ua dej -raws li cov roj yam tseem ceeb, yog 100% saturated distillates sib cais thaum lub sij hawm distillation thiab rho tawm cov roj yam tseem ceeb. Ntxiv nrog rau qhov muaj me me ntawm cov roj yam tseem ceeb, lawv kuj muaj dej - cov tshuaj soluble los ntawm cov nroj tsuag. Piv nrog rau cov roj yam tseem ceeb, hydrosols muaj qhov qis dua thiab yooj yim dua los ntawm daim tawv nqaij.