Using response surface methodology to maximize heat assisted extraction of rosmarinic acid in three medicinal and aromatic plants
Conference Paper
Overview
Overview
abstract
The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) and FEDER under Programme PT2020 for financial support to CIMO (UID/AGR/00690/2013), M. Carocho’s post-doc grant (SFRH/BPD/114650/2016), L. Barros contract. To Xunta de Galicia for M.A. Prieto’s grant. This work is funded by the European Regional Development Fund (ERDF) through the Regional Operational Program North 2020, within the scope of Project NORTE-01-0145-FEDER-023289: DeCodE; and the FEDER-Interreg España-Portugal programme for financial support through the project 0377_Iberphenol_6_E.
The increasing awareness of consumers, which prefer food with natural additives, shifted the industry to pursue natural counterparts for food additives. Among them, one preservative, E392, is obtained from the rosemary plant (Rosmarinus officinalis L.), with its main preserving molecule being rosmarinic acid (RA). Given its expensive and costly extraction, alternative plants should be pursued. In this work, heat assisted extraction with varying hydroalcoholic mixtures as solvent (S, ethanol proportion in % from 0 to 100), temperatures (T, from 25 to 85ºC) and times (t, from 20 to 120 min) were tested in rosemary, basil (Ocimum basilicum L.) and sage (Salvia officinalis L.). A response surface methodology was used to define the optimum extraction conditions to maximize the RA content, using a circumscribed central composite design of three variables with five levels. The extraction results were expressed in three response format values (Y): Y1, mg of RA (determined through -HPLC-DAD) per g of leave (L) dry matter (mg RA/g L dw), specifically used to analyse the content of the plants in RA; Y2, mg of RA obtained in the extracted dried weight residue (R; mg RA/g R) to measure the purity of R; and Y3 in g R/g P dw, which provides information regarding the extraction yield in R. For rosemary, the optimal global conditions were at 87.18±6.97 min, 85.00±8.50ºC, and 39.09±0.78% of ethanol, producing 23.28±0.70 mg RA/g L dw (Y1), 82.59±4.13 mg RA/g R (Y2), and 0.31±0.02 g R/g P dw (Y3). For basil, these were at 98.44±3.94 min, 85.00±0.85ºC, and 44.91±3.59% of ethanol, producing 28.61±1.14 mg RA/g L dw (Y1), 111.74±11.17 mg RA/g R (Y2), and 0.32±0.04 g R/g P dw (Y3). And for sage at 120.00±6.00 min, 85.00±1.70ºC, and 47.25±0.47% of ethanol, producing 28.895±2.3 mg RA/g L dw (Y1), 126.63±5.07 mg RA/g R (Y2), and 0.33±0.03 g R/g P dw (Y3).
In brief, the obtained results show the potential of several plants as a source of RA, with potential uses in the food industry and others.
