Comparison of extraction methods for active biomolecules using sub-critical dimethyl ether and n-butane

Abstract

Several extraction methods are used to isolate natural compounds, and recent approaches utilize subcritical or supercritical extraction media. In this paper we compare extraction methods based on subcritical eluents, dimethyl ether (sC-DME) and n-butane (sC-nB), under mild conditions, using coffee beans and powder as an exemplary raw material. The parameters to be controlled to improve the extraction are considered, and the resulting data discussed. The results obtained display higher selectivity of sC-DME for caffeine (1.9%w/w sC-DME vs. 1.7%w/w sC-nB, on dry extract) and a good yield (0.479 mg/g of caffeine from green coffee beans) compared to, e.g., supercritical carbon dioxide (SC-CO2), which shows 0.32 mg/g of caffeine at higher pressure and temperature (25 MPa, 40 °C). We also discuss some technical implementations for optimizing the use of sub-critical eluents through proper combinations of pressure and temperature. We show that extraction processes based on sub-critical eluents are easy to operate and efficient, and can be easily automated.

Staphylococcus aureus/Staphylococcus epidermidis from skin microbiota are balanced by Pomegranate peel extract: An eco-sustainable approach

“…The extract was obtained from the internal and external pomegranate peel, through an eco-sustainable extraction method with low environmental impact according to Ciulla et al [ 25 ]. The extraction of pomegranate peel was performed under two different conditions: Dimethyl Ether (DME) and n-butane.…”

Extraction and Separation of Natural Products from Microalgae and Other Natural Sources Using Liquefied Dimethyl Ether, a Green Solvent: A Review

“…Liquefied DME enables catechin extraction while completely removing caffeine. Ciulla et al also demonstrated higher extraction rates of caffeine from coffee beans and powder using liquefied DME rather than using scCO 2 -based extraction methods [184].…”