Application of natural deep eutectic solvents for the “green”extraction of vanillin from vanilla pods

Abstract

In recent years, a new type of solvents, natural deep eutectic solvents (NADES), have been developed and are gaining popularity as an alternative "green solvent" to conventional organic solvents. The traditional extraction of flavor or fragrance from plant materials such as vanillin is a tedious procedure that involves the use of organic solvents. In this case the solubility of vanillin and its extractability from vanilla pods in 14 NADES was evaluated. The solubility in some NADES such as lactic acid: propanediol (620 mg/mL) and lactic acid: fructose (320 mg/ mL) was found to be almost similar to that of organic solvents e.g. methanol (632.94 mg/mL) or ethanol (375.81 mg/mL). Interestingly, the extractability of vanillin from vanilla pods did not reflect the results observed for the solubility tests. Some NADES with constituents that are suitable as food ingredients such as citric acid-fructose-glucose (CAFG), fructose-glucose (FG), malic acid-glucose (MAG), and malic acid-fructose-glucose (MAFG), showed a higher extraction power (7.6, 10.1, 16.7, and 16.3 mg/g DW, respectively) than ethanol (4.4 mg/g DW). The discrepancy between solubility and extractability might be due to differences in the interaction with the matrix depending on the NADES. The effect of water content in some NADES on the extractability of vanillin was also studied. With the high extraction capacity and the absence of toxicity of their components, NADES are very suitable for extraction of flavours and fragrances used in food and cosmetics. plants. 4 However, in terms of quality, natural vanilla has a superior aroma and fragrance performance than pure vanillin. This is due to the presence of various minor compounds in the pods that give special notes to the vanilla flavor. The highest quality vanilla extract is obtained from vanilla pods using the percolation or oleoresin method. 5The percolation method consists of circulating aqueous ethanol (35-50%, v/v) over the pods, under vacuum. This process takes betweenThis is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.

New Preparation Method Using Microwave, Kinetics, In Vitro Dissolution‐Diffusion, and Anti‐Inflammatory Study of Diclofenac‐ Proline Co–Crystal

“…These data confirm that the DPC had an improved dissolution profile from that of DA significantly in the intestinal pH. LP in physical mixture also pushed the dissolution rate due to its properties as a deep eutectic solvent in the solution, which has been established in many reports . However, DPC remain superior by increasing the DA dissolution rate compared to DA alone and physical mixture.…”

Extraction of Natural Fragrance Ingredients: History Overview and Future Trends

“…In green chemistry, ILs have been used for diverse purposes including for the extraction of natural compounds from biomass: ILs were notably successfully combined with microwave‐assisted extraction (ILMAE) to extract medicinal alkaloids from lotus leaf or polyphenolic compounds from medicinal plants, or with ultrasonic‐assisted extraction (ILUAE) to extract piperine from white pepper . Such IL‐based method are particularly advantageous as the required extraction time may be significantly reduced through the combinational use of intensification techniques .…”

“…DESs are called NaDESs (Natural Deep Eutectic Solvents) when they are bio‐based, that is, when both their components are plant primary metabolites (for example small organic acids or bases, sugars, alcohols, amines and amino acids) that in different combinations and specific molar ratios form liquids at ambient temperature …”

“…Furthermore, they possess a real potential to be considered as green solvents for extraction as they display high solubilization power of both polar and nonpolar molecules . Their polarity ranging between that of water and alcohols, they have been reported to extract a wide variety of compounds from plant origin: NaDES have already been used to extract phenolic compounds from safflower or anthocyanins from rose periwinkle . González et al.…”

Environmentally Benign Deep Eutectic Solvent for Synthesis of 1,3‐Thiazolidin‐4‐ones

“…The melting point of resulting mixture is lower than their individual components due to charge delocalization occurring through hydrogen bonding between halide ion and hydrogen donor component ,. Choline Chloride based Deep Eutectic Solvents have been effectively used for Knoevenagel condensation, Spirooxoindole synthesis, benzylation of phenol, Clauson‐Kaas reaction, Pictet‐Spengler reaction, N ‐alkylation of amines, Perkin reaction, removal of residual KOH content from biodiesel, Paal‐Knorr reaction, synthesis of multisubstituted cyclohexa‐1,3‐dienamines, deacidification of palm oil, extraction of vanillin, pretreatment of rice straw for butanol fermentation and extraction of phenolic compounds from oil mixtures …”