Extraction of β-carotene from organic phase using ammonium based ionic liquids aqueous solution

Tailor-made solvents for microbial carotenoids recovery

In recent years, microbial carotenoids have emerged as a promising alternative for the pharmaceutical and food industries, particularly in promoting human health due to their potent antioxidant and antimicrobial properties. Microbial carotenoids, particularly those produced by yeast, bacteria, and microalgae, are synthesized intracellularly, requiring the use of solvents for their effective extraction and recovery. The conventional use of toxic volatile organic solvents (VOCs) like hexane, petroleum ether, and dimethyl sulfoxide in the extraction of microbial carotenoids has been common. However, ongoing research is introducing innovative, non-toxic, environmentally friendly tailor-made solvents, such as ionic liquids (IL) and deep eutectic solvents (DES), indicating a new era of cleaner and biocompatible technologies. This review aims to highlight recent advancements in utilizing IL and DES for obtaining carotenoids from microorganisms. Additionally, we explore the utilization of in silico tools designed to determine the solubilities of microbial carotenoids in tailor-made DES and ILs. This presents a promising alternative for the scientific community, potentially reducing the need for extensive experimental screening of solvents for the recovery of microbial carotenoids in the separation processing. According to our expert perspective, both IL and DES exhibit a plethora of exceptional attributes for the recovery of microbial carotenoids. Nevertheless, the current employment of these solvents for recovery of carotenoids is restricted to scientific exploration, as their feasibility for practical application in industrial settings has yet to be conclusively demonstrated. KEY POINTS: • ILs and DES share many tailoring properties for the recovery of microbial carotenoids • The use of ILs and DES for microbial carotenoid extraction remains driven by scientific curiosity. • The economic feasibility of ILs and DES is yet to be demonstrated in industrial applications.

Green Solvents: Emerging Alternatives for Carotenoid Extraction from Fruit and Vegetable By-Products

Carotenoids have important implications for human health and the food industry due to their antioxidant and functional properties. Their extraction is a crucial step for being able to concentrate them and potentially include them in food products. Traditionally, the extraction of carotenoids is performed using organic solvents that have toxicological effects. Developing greener solvents and techniques for extracting high-value compounds is one of the principles of green chemistry and a challenge for the food industry. This review will analyze the use of green solvents, namely, vegetable oils, supercritical fluids, deep eutectic solvents, ionic liquids, and limonene, combined with nonconventional techniques (ultrasound-assisted extraction and microwave), for carotenoid extraction from fruit and vegetable by-products as upcoming alternatives to organic solvents. Recent developments in the isolation of carotenoids from green solvents and their inclusion in food products will also be discussed. The use of green solvents offers significant advantages in extracting carotenoids, both by decreasing the downstream process of solvent elimination, and the fact that the carotenoids can be included directly in food products without posing a risk to human health.

Radix Pueraria Flavonoids Assisted Green Synthesis of Reduced Gold Nanoparticles: Application for Electrochemical Nonenzymatic Detection of Cholesterol in Food Samples

Using radix pueraria flavonoids (RPFs) as a reducing and stabilizing agent, we report a simple, cost-effective, and ecologically friendly green synthesis technique for gold nanoparticles (AuNPs) in the present study. Ultraviolet-visible (UV) spectroscopy, transmission electron microscopy (TEM), Fourier transform infrared (FTIR), and X-ray diffraction (XRD) investigations were used to characterize the AuNPs. The results demonstrated that the produced AuNPs were nearly spherical and that their particle sizes had a mean diameter of 4.85 ± 0.75 nm. The "Green" AuNPs, exhibiting remarkable peroxidase-like activity and Michaelis-Menten kinetics with high affinity for H₂O₂ and 3,3',5,5'-tetramethylbenzidine (TMB), were effectively applied to the fabrication of a sensitive nonenzymatic enhanced electrochemical sensor for the detection of cholesterol (Cho). Under optimum circumstances, it was possible to establish two linear ranges of 1-100 and 250-5000 μmol/L with a detection limit of 0.259 μmol/L (signal/noise ratio (S/N) = 3). The suggested sensor was utilized with satisfactory findings to determine the amount of Cho in food samples.

Vegetable Oil-Ionic Liquid-Based Emulsion Liquid Membrane for the Removal of Lactic Acid from Aqueous Streams: Emulsion Size, Membrane Breakage, and Stability Study

In this study, we present a highly stable vegetable oil ionic liquid (IL)-based emulsion liquid membrane (VOILELM) for the removal of lactic acid from water streams. The system developed as a part of this work comprises a non-ionic surfactant Span 80, sodium hydroxide as an internal stripping agent, sunflower canola oil as a green diluent, and IL-tetramethylammonium acetate [TMAm][Ac]-as a carrier. VOILELM stability was evaluated in terms of breakage, emulsion diameter, and standalone stability. The effect of various parameters, namely, concentration of the surfactant, concentration of the internal stripping agent, concentration of the carrier, phase ratio, homogenizer speed, and homogenization time, on the VOILELM stability was studied. The results revealed that VOILELM was highly stable, with 1.34% minimum breakage, 1.16 μm emulsion diameter, and 131 min standalone stability. The optimal process parameters were 0.1 wt % Span 80, 0.1 M NaOH, 0.3 wt % IL, 0.25 phase ratio, 5000 rpm homogenizer speed, and 5 min homogenization time. At these optimized conditions, 96.08% lactic acid extraction efficiency was achieved. Thus, a highly effective VOILELM was developed, with minimal breakage and emulsion diameter and maximum stability.

Screening of Suitable Ionic Liquids as Green Solvents for Extraction of Eicosapentaenoic Acid (EPA) from Microalgae Biomass Using COSMO-RS Model

Omega-3 poly unsaturated fatty acids (PUFA) particularly eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA), have many health benefits including reducing the risk of cancer and cardiovascular disease. Recently, the use of ionic liquids (ILs) in lipid extraction from microalgae provides the potential to overcome common drawbacks, offers several other benefits. To date, very limited researches are available to focus on extracting microalgae lipid and PUFA in particular by using ILs. The objective of current work is to screen the potential ILs that can be applied in EPA extraction. In this study, fast ILs screening was performed with the help of a conductor like screening model for real solvents (COSMO-RS) and the ILs with higher capacity values for use in extraction of EPA were compared. According to the results, the highest capacity for EPA extraction among 352 screened cation/anion combinations belongs to [TMAm][SO₄]. It is expected to achieve a higher yield of EPA once applying this combination as the solvent in the process of extraction. ILs with small anions were observed to have higher capacities, as well possessing higher charge density compared to larger ones, and therefore, they are more preferable for extraction purposes. Moreover, shorter alkyl chain cations are preferred when using imidazolium-based IL, which agrees with experimental data.

Ionic Liquid Based Nanocarriers for Topical and Transdermal Drug Delivery

In the pharmaceutical industry, there are challenges in topical and transdermal administration of drugs, which are sparingly soluble in water and most organic solvents. Ionic liquids (ILs) have been found to be very effective for dissolution of sparingly soluble drugs. However, hydrophilic IL-borne drugs cannot penetrate into or across the skin because of the highly hydrophobic barrier function of the outer skin. In this chapter we report a novel IL-in-oil (IL/o) microemulsion (ME) that is able to dissolve a significant amount of sparingly soluble drug, acyclovir, in the IL core while the continuous oil phase can provide the desired features for topical/transdermal transport through the skin. The ME is composed of a blend of the nonionic surfactants polyoxyethylene sorbitan monooleate (Tween 80) and sorbitan laurate (Span 20), isopropyl myristate (IPM) as an oil phase, and the IL [C1mim][(MeO)2PO2] (dimethylimidazolium dimethylphosphate) as a dispersed phase. The size and size distribution of the aggregates in the MEs were characterized by dynamic light scattering, showing formation of the nanocarrier in the size range 8–34 nm. In vitro drug permeation studies into and across the skin showed that the IL/o ME increased drug administration compared with other formulations. The safety profile of the new carrier was evaluated using a cytotoxicity assay on the human epidermal model LabCyte. We believe that these IL-assisted nonaqueous MEs can serve as a versatile and efficient nanodelivery system for sparingly soluble drug molecules.