Response surface modeling and optimization of the extraction conditions using lactic acid‐based deep eutectic solvents as green alternative extraction media for Mentha pulegium

Abstract

Introduction Most recurrently available organic solvents are toxic and inflammable and pose high risks to human health. Natural deep eutectic solvents (NADESs) have been developed as promising green alternatives. Objective We aimed to extract polyphenolic compounds from Mentha pulegium using lactic acid‐based deep eutectic solvents. Extraction parameters were optimized by response surface methodology. Material and Methods Combined with ultrasound‐assisted extraction, three different lactic acid‐based deep eutectic solvents were investigated for the extraction of polyphenols. Methanol (80%, v/v) was used for comparison. The optimized influencing factors were: water content in solvent, extraction time, and temperature. The design was adopted including 17 experiments with three center points. Results All NADESs tested showed an excellent extraction efficacy compared to 80% methanol. Under the optimized conditions, with 45% of water, at 30°C, and for extraction 90 min, the highest extraction yields were recorded using lactic acid:sodium acetate (3:1), achieving 173.35 ± 0.02 mg gallic acid equivalents (GAE)/g dry weight (dw) of polyphenols and 95 ± 0.09% antioxidant activity. After extraction for 90 min at 80°C with 18% of water, we obtained 164.06 ± 0.01 mg GAE/g dw and 94 ± 0.02% antioxidant activity using lactic acid:glucose (5:1). Efficient recovery (64.92 ± 0.01 mg GAE/g dw and 97 ± 0.1% antioxidant activity) was achieved using lactic acid:glycine (3:1) with 31% of water, at 35°C, and extraction for 30 min. Conclusion Our results indicate that with optimized parameters, the proposed natural solvents are excellent alternatives to chemical ones for the extraction of phenolic compounds.

Optimization of Cyclodextrin-Assisted Extraction of Phenolics from Helichrysum italicum for Preparation of Extracts with Anti-Elastase and Anti-Collagenase Properties

“…It is important to note the possibility that LA may form a eutectic mixture with amino acids present in the plant material, thus enhancing the extraction yield. However, the LA content used in this study (up to 2%) was rather low in comparison to the LA content in other studies that used up to 65% of LA-based eutectic solvent [ 50 ]. Thus, even if formation of such a mixture occurred in the extraction medium, its content would have been too low to significantly affect the outcome of the extraction.…”

Elaboration and Characterization of Natural Deep Eutectic Solvents (NADESs): Application in the Extraction of Phenolic Compounds from pitaya

“…Alternative solvents, substitutes for ethanol, and solvents with high toxicity have been the focus of several studies about their use for the extraction of bioactive compounds [ 71 , 72 , 73 , 74 ], with promising results. In this sense, NADESs obtained from natural sources, such as choline, amino acids, and organic acids, are favorable alternatives for use.…”

Green subcritical water extraction of Mentha x rotundifolia leaves collected in different annuities

“…Although solid-liquid extraction (SLE) is the most widely used procedure to obtain bioactive extracts because of their undeniable advantages in terms of simplicity and affordability, advanced extraction techniques such as microwave-assisted extraction (MAE), ultrasound-assisted extraction (UAE) and subcritical water extraction (SWE), are gaining importance as efficient alternatives for bioactive extraction [10]. While UAE [11][12][13][14] and MAE [8,11,15] have been previously described to provide improved performance for the extraction of Mentha bioactives, SWE has been scarcely applied for this purpose.…”