Exploring Microwave Hydrodiffusion and Gravity as an Eco extraction Protocol for Phenolic Extraction from Lettuce: A Step Towards Green Sustainable Processes

Abstract

The current work portraits an innovative approach in the field of botanical extraction using a zero solvent concept of phenolic extraction by implementing microwave hydrodiffusion and the gravity method. Lactuca sativa leaves were used for phenolic extraction without using any solvent and firing microwave power at different power levels (170-510 W). Total phenolic content was chosen as the performance evaluation parameter. Results indicated that a 340 W power level using the Microwave Hydrodiffusion and Gravity (MHG) protocol, comprising of 20 min of microwaving, produced a highly enriched phenolic extract (3,436.55 µg GAE/g of dried extract) when compared to a 24 h Soxhlet extract (496.36 µg GAE/g of dried extract). Phenolic profiling also revealed the richness of the extract produced from the MHG protocol. Improved biological potency by more than 48% in terms of antioxidant activity was observed in the extract produced from MHG. High-Performance Thin-Layer Chromatography (HPTLC) chromatograms revealed no formation of any undesirable adduct as well. The work is an innovative attempt in the field of green sustainable processes, which is the need of the hour for industries.