Comparison between Pressurized Liquid Extraction and Conventional Soxhlet Extraction for Rosemary Antioxidants, Yield, Composition, and Environmental Footprint.

Mathilde Hirondart,Mathilde Hirondart,Mathilde Hirondart,Mathilde Hirondart,Anne Sylvie Fabiano-Tixier,Anne Sylvie Fabiano-Tixier,Anne Sylvie Fabiano-Tixier,Anne Sylvie Fabiano-Tixier,Natacha Rombaut,Natacha Rombaut,Natacha Rombaut,Natacha Rombaut,Farid Chemat,Farid Chemat,Antoine Bily,Antoine Bily,Antoine Bily

doi:10.3390/foods9050584

Abstract

Nowadays, “green analytical chemistry” challenges are to develop techniques which reduce the environmental impact not only in term of analysis but also in the sample preparation step. Within this objective, pressurized liquid extraction (PLE) was investigated to determine the initial composition of key antioxidants contained in rosemary leaves: Rosmarinic acid (RA), carnosic acid (CA), and carnosol (CO). An experimental design was applied to identify an optimized PLE set of extraction parameters: A temperature of 183 °C, a pressure of 130 bar, and an extraction duration of 3 min enabled recovering rosemary antioxidants. PLE was further compared to conventional Soxhlet extraction (CSE) in term of global processing time, energy used, solvent recovery, raw material used, accuracy, reproducibility, and robustness to extract quantitatively RA, CA, and CO from rosemary leaves. A statistical comparison of the two extraction procedure (PLE and CSE) was achieved and showed no significant difference between the two procedures in terms of RA, CA, and CO extraction. To complete the study showing that the use of PLE is an advantageous alternative to CSE, the eco-footprint of the PLE process was evaluated. Results demonstrate that it is a rapid, clean, and environmentally friendly extraction technique.

Highlights

In the field of raw material extraction, the first challenge consists of determining the potential of the plant matrix that means what can be extracted and valorized
In this study we focused on rosemary (Rosmarinus Officinalis L.), which is mostly studied and used used in the food industry due to its richness in antioxidants’ compounds [11,12], in the food industry due to its richness in antioxidants’ compounds [11,12], rosmarinic rosmarinic acid (RA), carnosic acid (CA), and carnosol (CO) (Figure 1)
To determine the solvent that maximized the extraction of both Rosmarinic acid (RA) and CA, Pressurized Liquid Extraction (PLE) was performed with various percentages of ethanol in water: 0, 20, 40, 60, 80, and 100% (g/g)

Summary

Introduction

In the field of raw material extraction, the first challenge consists of determining the potential of the plant matrix that means what can be extracted and valorized. The chemical composition of the plant material may highly vary depending on the local environmental conditions, development stages, plant part, harvesting season, the technique used for drying, and the storage condition. For each batch of plant material used for industrial extraction, an analysis has to be performed to determine the amount of available extractives. An analytical procedure for antioxidants from plants or spices comprises two steps: Extraction (Soxhlet, maceration, percolation) followed by analysis (spectrophotometry, high performance liquid chromatography coupled or not to mass spectrometry (HPLC-MS), gas chromatography coupled or not to mass spectrometry (GC–MS)). 22 of of after only to 30 min, extraction takes at least several hours.

Objectives

Results

Conclusion