A comparative study of three drying methods on the phenolic profile and biological activities of Salvia absconditiflora

Drying method is one of the most important steps in the preparation of plant materials for phytochemical analysis and biological evaluation. In this sense, this research endeavoured to evaluate the effects three drying methods (oven, freeze, and shade drying) on phytochemical component, antioxidant, and enzyme inhibitory effects of Salvia absconditiflora Greuter & Burdet. Antioxidant activities were screened by phosphomolybdenum, DPPH, ABTS, FRAP, CUPRAC, and metal chelating activity. Enzyme inhibitory effects were assessed against cholinesterases (AChE, BChE), tyrosinase, -amylase, and -glucosidase. Drying methods were found to affect the chemical component and biological properties. Shade drying showed the highest TPC (99.33mgGAE/g) and TFC (46.88mgRE/g) followed by oven (58.15mgGAE/g for TPC, 40.65 for TFC), and freeze drying (43.73mgGAE/g for TPC, 36.68mgRE/g for TFC). The main phenolic compound characterized by HPLC was rosmarinic acid, which was observed to be highest following shade drying. Shade drying contained highest total bioactive compounds and exhibited the strongest antioxidant properties. The enzyme inhibitory effects of S. absconditiflora performed using different depends were dependent on the drying methods. Our results tend to suggest that shade drying was most suitable for S. absconditiflora because of possessing the highest rosmarinic acid and biological properties