is it safe to oven-dry medicinal plant samples (legumes and leaf parts) under 30°C?Provided that the plant's growing temperature is around this temperature.
Some stated that it must be below 40°C to avoid any changes on the phytochemicals within.
Yes, you can dry at this temperature. you can go up to 45-50 degree under vacuum. majority of the phytochemicals stable up to 50c. Incase your molecules of choice are heat sensitive then use below 40c under vacuum.
It depends to the type of secondary metabolites you are working on;
if the target is essential oil then your temp. limit is around 45 C to reduce the volatile content loss. If it is an alkaloid go up to 60-70 C. In case of glycosides, you should choose 50-60 C to stop enzymes activity. In case of vitamins choose 80 C to minimize oxidation.
Yeah Sir @Phillip Morris, i expect there will be differences between the dry.and fresh wet sample. In addition, i am planning to find whether is it just the phytochemicals contribute to antibacterial property or does protein helps. Apparently protein,pandanin in P. amaryfollious is antiviral.
Hope my project is working provide the extraction method must be on point.