Green extraction processes of natural products as tools for biorefinery

Abstract

This review introduces a new and innovative area in the frontiers of chemistry, biology and processing: green extraction with special emphasis on natural products processing. Green extraction is a part of the sustainable development and industrial strategy; its history, concept, principles, and fundamentals are described. We pay special attention to the strategies and the tools available to make biorefinery greener. This review presents the innovative research in this area in the past five years in terms of innovative techniques (microwave, ultrasound, instantaneous pressure drop, supercritical fluid extraction, pressing) applied to green extraction of natural products with special examples applied to biorefinery concept.

Ultrasound versus microwave as green processes for extraction of rosmarinic, carnosic and ursolic acids from rosemary

“…Some extraction processes, particularly conventional ones, are sometimes accompanied by several drawbacks, such as the use of harmful solvents, degradation of compounds of interest due to high temperature, long extraction time, difficulty to implement or high economic and energetic costs. That way, during the last few years, concepts of ''Green chemistry'' and ''eco-extraction'' emerged [22,23]. Extraction processes have been studied to be more energy saving, safe for users and environmental friendly than yesterday, without reducing extraction efficiency.…”

“…To evaluate those innovative processes, results are compared to conventional solid/liquid extraction (reflux extraction and maceration). Within the objectives of green extraction [22,23], all extractions were performed in a mixture of ethanol/water (90/10, v/v). Results are compared quantitatively on the basis of extraction yield and on the contents of RA, CA and UA in the extracts.…”

Optimization of Subcritical Water Extraction of Resveratrol from Grape Seeds by Response Surface Methodology

“…The concentration of RES in the A general definition of green chemistry is the invention, design, and application of chemical products and processes to reduce or to eliminate the use and generation of hazardous substances [34]. In the case of the green extraction of natural products, the process also should reduce energy consumption and extraction time, allow for the use of alternative solvents, obtain useful co-products, and ensure a safe and high quality of product [35]. In our research, the SWE process of RES from grape seeds was consistent with the above principles.…”

Comparison of the Efficiency of Different Extraction Methods on Antioxidants of Maltease Orange Peel

“…In fact, this method is accelerated by using ultrasound and microwave energy. The intensification of extraction efficacy using ultrasound has been attributed to the propagation of ultrasound pressure waves through the solvent and resulting cavitation phenomena [37] . A cavitation bubble can be generated close to the plant material surface, then during a compression cycle, this bubble collapses and a micro jet directed toward the plant matrix is created.…”

“…The high pressure and temperature involved in this process will destroy the cell walls of the plant matrix and its content can be released into the medium. This phenomenon seems responsible for cell wall destruction and further release of the cellular content into the surrounding media [37,38] . However, microwave irradiation accelerates the rupture of cells by causing a sudden temperature rise and internal pressure increase in the plant or fruit cell walls [39] .…”