Sustainable and Biomimetic Methodology for Extraction of High-Value-Added Compounds in Almond Hulls.

Almond trees are the most cultivated nut tree in the world. The production of almonds generates large amounts of by-products, much of which goes unused. Herein, this study aimed to develop a green chemistry approach to identify and extract potentially valuable compounds from almond by-products. Initially, a screening was performed with 10 different Natural Deep Eutectic Solvents (NADESs). The mixture lactic acid/glycerol, with a molar ratio 1:1 (1:50 plant material to NADES (w/v) with 20% v/v of water) was identified as the best extraction solvent for catechin, caffeoylquinic acid, and condensed tannins in almond hulls. Subsequently, a method was optimized by a Design of Experiment (DoE) protocol using a miniaturized extraction technique, Microwave-Assisted Extraction (MAE), in conjunction with the chosen NADESs. The optimal conditions were found to be 70 °C with 15 min irradiation time. The optimal extraction conditions determined by the DoE were confirmed experimentally and compared to methods already established in the literature. With these conditions, the extraction of metabolites was 2.4 times higher, according to the increase in total peak area, than the established literature methods used. Additionally, by applying the multiparameter Analytical Greenness Metric (AGREE) and Green Analytical Process Index (GAPI) metrics, it was possible to conclude that the developed method was greener than the established literature methods as it includes various principles of green analytical chemistry.

Method optimization for the extraction of chlorogenic acids from coffee parchment: An ecofriendly alternative.

One of the principal byproducts of coffee roasting is the coffee parchment. It is abundant in bioactive substances, including derivatives of chlorogenic acids, which are well-known for their exceptional antioxidant effects. It is advantageous to use environmentally friendly extraction techniques on such residues since it adds value to the entire coffee production process supply chain. The aim of this work was to assess and enhance the ability of non-conventional extraction techniques to extract derivatives of chlorogenic acid from coffee parchment. A central composite design was used to maximize the recovery of those phenolic compounds. The optimized extraction conditions were with 5 min extraction period, at a temperature of 70 °C, and 80% ethanol in the extractor solvent. In this conditions extraction recovery of chlorogenic acids was of 0.8% by the use of microwave-aided extraction (MAE). The optimized conditions are practical, economical, and ecologically friendly method to extract phenolic compounds and, consequently, underscores the potential for sustainable utilization of coffee parchment, offering a valuable contribution to the development of environmentally conscious strategies within the coffee industry.

Modeling and optimization of microwave-assisted extraction of total phenolics content from mango (Mangifera indica) peel using response surface methodology (RSM) and artificial neural networks (ANN).

Mango (Mangifera indica) is a fruit highly consumed for its flavor and nutrient content. The mango peel is rich in compounds with biological functionality, such as antioxidant activity among others. The influence of microwave-assisted extraction variables on total phenol compounds (TPC) and antioxidant activity (TEAC) of natural extracts obtained from mango peel var. Tommy and Sugar were studied using a response surface methodology (RSM) and Artificial Neural Networks (ANN). TPC of mango peel extract var. Tommy was significantly influenced by time extraction (X1), solvent/plant ratio (X2) and concentration of ethanol (X3) and while mango peel extract var. Sugar was influenced by X2. TEAC by ABTS was significantly influenced by X3. Maximum of TPC (121.3 mg GAE / g of extract) and TEAC (1185.9 µmol Trolox/g extract) for mango peel extract var. Tommy were obtained at X1=23.9s, X2=12.6mL/gand X3=63.2%, and for mango peel extract var. Sugar, the maximum content of TPC (224.86 mg GAE/g extract) and TEAC (2117.7 µmol Trolox/g extract) were obtained at X1=40s, X2=10mL/g and X3=74.9%. The ANN model presented a higher predictive capacity than the RSM (RANN2>RRSM2,RMSEANN

Microwave-Assisted Extraction Optimization and Effect of Drying Temperature on Catechins, Procyanidins and Theobromine in Cocoa Beans.

Cocoa beans (Theobroma cacao L.) are an important source of polyphenols. Nevertheless, the content of these compounds is influenced by post-harvest processes. In this sense, the concentration of polyphenols can decrease by more than 50% during drying. In this study, the process of procyanidins extraction was optimized and the stability of catechins, procyanidins, and theobromine to different drying temperatures was evaluated. First, the effectiveness of methanol, ethanol, acetone, and water as extract solvents was determined. A Box-Behnken design and response surface methodology were used to optimize the Microwave-Assisted Extraction (MAE) process. The ratios of methanol-water, time, and temperature of extraction were selected as independent variables, whereas the concentration of procyanidins was used as a response variable. Concerning the drying, the samples were dried using five temperatures, and a sample freeze-dried was used as a control. The quantitative analyses were carried out by HPLC-DAD-ESI-IT-MS. The optimal MAE conditions were 67 °C, 56 min, and 73% methanol. Regarding the drying, the maximum contents of procyanidins were obtained at 40 °C. To our knowledge, this is the first time that the stability of dimers, trimers, and tetramers of procyanidins on drying temperature was evaluated. In conclusion, drying at 40 °C presented better results than the freeze-drying method.

Combined Pulsed Electric Field and Microwave-Assisted Extraction as a Green Method for the Recovery of Antioxidant Compounds with Electroactive Potential from Coffee Agro-Waste.

Coffee agro-waste is a potential source of polyphenols with antioxidant activity and application in the food and cosmetic trades. The usage of these byproducts persists as a challenge in the industrial landscape due to their high content of purported toxic substances hindering management. This study presents a green extractive process using pulsed electric field (PEF) and microwave assisted extraction (MAE) to recover polyphenols from coffee parchment and two varieties of pulp, posing quick processing times and the use of water as the only solvent. The performance of this process with regard to the bioactivity was assessed through the Folin-Ciocalteu assay, total flavonoid content, DPPH, ABTS and FRAP antioxidant tests. The phenolic composition of the extracts was also determined through HPLC-MS and quantified through HPLC-DAD. When compared to treatment controls, PEF + MAE treated samples presented enhanced yields of total phenolic content and radical scavenging activity in all analyzed residues (Tukey test significance: 95%). The chromatographic studies reveal the presence of caffeic acid on the three analyzed by-products. The HPLC-DAD caffeic acid quantification validated that a combination of MAE + PEF treatment in yellow coffee pulp had the highest caffeic acid concentration of all studied extraction methods.

Design of Functional Powdered Beverages Containing Co-Microcapsules of Sacha Inchi P. huayllabambana Oil and Antioxidant Extracts of Camu Camu and Mango Skins.

Sacha inchi Plukenetia huayllabambana oil (SIPHO) was co-microencapsulated, by spray drying using gum arabic as a coating material, with antioxidant extracts of camu camu (Myrciaria dubia (HBK) McVaugh) (CCSE) and mango (Mangifera indica) (MSE) skins obtained by ultrasound-microwave-assisted extraction (UMAE). The physicochemical characteristics of the microcapsules, such as, particle size, morphology, and moisture, as well as the encapsulation efficiency, the fatty acid composition, and oxidative stability, were determined in order to select the best formulation for the design of functional powdered beverages. The formulation with the highest amounts of ω3 acids and polyphenols was used to prepare a functional powdered beverage that contained ω3 (52.74%), antioxidant activity (324.80 mg AAE/100 g powder), and acceptable sensory attributes.

Non-conventional techniques for the extraction of antioxidant compounds and lycopene from industrial tomato pomace (Solanum lycopersicum L.) using spouted bed drying as a pre-treatment.

This study aimed to use the non-conventional microwave-assisted extraction (MAE) and pressurized liquid extraction (PLE) techniques for recovering bioactive compounds from tomato pomace, a valuable agro-industrial waste. The raw material was previously dried using a spouted bed dryer and then submitted to extraction with green solvents. A response surface methodology (RSM) performed the optimization of MAE and PLE. Next, the yield and the antioxidant activity results were maximized, and the lycopene content of the optimum MAE and PLE extracts was assessed by high-performance liquid chromatography (HPLC). Additionally, a fraction of raw material was oven dried as a comparison. The PLE extract exhibited the highest antioxidant activity, whereas the MAE extract showed the highest lycopene content (59.66 µg lycopene/g extract), which represents a 66.93% lycopene recovery compared to a standard technique with acetone. The remarkable results show that the non-conventional drying and extraction techniques were effective in valorizing this neglected material.

Antioxidant Capacity and Antiplatelet Activity of Aqueous Extracts of Common Bean (Phaseolus vulgaris L.) Obtained with Microwave and Ultrasound Assisted Extraction.

Phaseolus vulgaris L. has beneficial effects on several chronic non-communicable diseases (e.g., cardiovascular diseases) related to oxidative stress. This redox state may influence platelet activation and aggregation; which is crucial in thrombus formation. In this work, the antiplatelet and antioxidant potential of aqueous extracts obtained by green processes, microwave-assisted extraction and ultrasound-assisted extraction, from 25 landraces of common beans were investigated. Phenol content and antioxidant potential were determined using the Folin-Ciocalteu method, total monomeric anthocyanin and ORAC assay, respectively. The antiplatelet potential of the extracts was explored by turbidimetry. Microwave extraction showed higher phenol content and antioxidant activity in most extracts. Soja landrace extract obtained by microwave-assisted extraction showed higher phenol content and antioxidant activity (893.45 ± 87.30 mg GAE/g and 35,642.85 ± 2588.88 ORAC µmolTE/g, respectively). Although most of the extracts obtained by microwave-assisted extraction showed antiplatelet activity, the extract of Hallado Aleman landrace obtained by ultrasound-assisted extraction (IC50 = 0.152 ± 0.018 mg/mL) had the highest antiplatelet potential. The extraction method, MAE and UAE, influences the biological potential of the beans, specifically the antiplatelet activity and antioxidant activity. The functional value of this legume for direct consumption by the population was evidenced, as well as its inclusion in food formulations.

Microwave-assisted extraction and content determination of astilbin in Lysiphyllum strychnifolium stems

Abstract Lysiphyllum strychnifolium (Craib) A. Schmitz. (in Thai name, Ya nang daeng) has been traditionally used to treat fever, alcohol intoxication, cancer, allergies, and blood toxins. It can be used as a health-promoting herbal tea and contains hydroalcoholic extracts. The purpose of the present study was to develop a microwave-assisted extraction method for astilbin in L. strychnifolium stems. HPLC was used to determine astilbin content. Three extraction conditions were optimized: types of solvent, microwave power levels, and the number of extraction cycles. Water:methanol (40:60) was the best solvent for astilbin extraction from L. strychnifolium stems using 450 watts and six microwave-assisted extraction cycles. This technique offers important advantages over conventional methods, such as shorter extraction times, substantial energy savings, and a reduced environmental burden.

Latest Insights on Novel Deep Eutectic Solvents (DES) for Sustainable Extraction of Phenolic Compounds from Natural Sources.

Phenolic compounds have long been of great importance in the pharmaceutical, food, and cosmetic industries. Unfortunately, conventional extraction procedures have a high cost and are time consuming, and the solvents used can represent a safety risk for operators, consumers, and the environment. Deep eutectic solvents (DESs) are green alternatives for extraction processes, given their low or non-toxicity, biodegradability, and reusability. This review discusses the latest research (in the last two years) employing DESs for phenolic extraction, solvent components, extraction yields, extraction method characteristics, and reviewing the phenolic sources (natural products, by-products, wastes, etc.). This work also analyzes and discusses the most relevant DES-based studies for phenolic extraction from natural sources, their extraction strategies using DESs, their molecular mechanisms, and potential applications.

Microwave Assisted Extraction of Bioactive Carbohydrates from Different Morphological Parts of Alfalfa (Medicago sativa L.).

Despite the nutritional properties of alfalfa, its production is mainly for animal feed and it is undervalued as a food source. In this study, the valorization of alfalfa as a potential source of bioactive carbohydrates [inositols, α-galactooligosaccharides (α-GOS)] is presented. A Box-Behnken experimental design was used to optimize the extraction of these carbohydrates from leaves, stems, and seeds of alfalfa by solid-liquid extraction (SLE) and microwave-assisted extraction (MAE). Optimal extraction temperatures were similar for both treatments (40 °C leaves, 80 °C seeds); however, SLE required longer times (32.5 and 60 min vs. 5 min). In general, under similar extraction conditions, MAE provided higher yields of inositols (up to twice) and α-GOS (up to 7 times); hence, MAE was selected for their extraction from 13 alfalfa samples. Pinitol was the most abundant inositol of leaves and stems (24.2-31.0 mg·g-1 and 15.5-22.5 mg·g-1, respectively) while seed extracts were rich in α-GOS, mainly in stachyose (48.8-84.7 mg·g-1). In addition, inositols and α-GOS concentrations of lyophilized MAE extracts were stable for up to 26 days at 50 °C. These findings demonstrate that alfalfa is a valuable source of bioactive carbohydrates and MAE a promising alternative technique to obtain functional extracts.

Bio-Based Active Packaging: Carrageenan Film with Olive Leaf Extract for Lamb Meat Preservation.

Carrageenan-based active packaging film was prepared by adding olive leaf extract (OLE) as a bioactive agent to the lamb meat packaging. The OLE was characterized in terms of its phenolic compounds (T.ph), antioxidant activity (AA), oleuropein, and minimum inhibitory concentration (MIC) against Escherichia coli. The film's formulation consisted of carrageenan, glycerol as a plasticizer, water as a solvent, and OLE. The effects of the OLE on the thickness, water vapor permeability (WVP), tensile strength (TS), elongation at break (EB), elastic modulus (EM), color, solubility, and antimicrobial capacity of the carrageenan film were determined. The OLE had the following excellent characteristics: the T.ph value was 115.96 mgGAE∙g-1 (d.b), the AA was 89.52%, the oleuropein value was 11.59 mg∙g-1, and the MIC was 50 mg∙mL-1. The results showed that the addition of OLE increased the thickness, EB, and WVP, and decreased the TS and EM of the film. The solubility was not significantly affected by the OLE. The color difference with the addition of OLE was 64.72%, which had the benefit of being a barrier to oxidative processes related to light. The film with the OLE was shown to have an antimicrobial capacity during the storage of lamb meat, reducing the count of psychrophiles five-fold when compared to the samples packed by the control and commercial films; therefore, this novel film has the potential to increase the shelf life of lamb meat, and as such, is suitable for use as active packaging.

Carrageenan-Based Films Incorporated with Jaboticaba Peel Extract: An Innovative Material for Active Food Packaging.

This research investigated the bioactive potential of jaboticaba peel extract (JPE) and proposed an innovative material for food packaging based on carrageenan films incorporated with JPE. The extract was obtained through microwave assisted extraction (MAE) according to central composite rotational design and the optimized conditions showed a combined antimicrobial and antioxidant actions when the extraction process is accomplished at 80 °C and 1 min. The carrageenan film incorporated with JPE was manageable, homogeneous and the presence of JPE into film increased the thickness and improved the light barrier of the film. The results of solubility and mechanical properties did not show significant differences. The benefit of using MAE to improve the recovery of bioactive compounds was demonstrated and the carrageenan film with JPE showed a great strategy to add additives into food packaging.

Extracción por microondas libre de solvente del aceite esencial de naranja (Citrus sinensis), y el efecto de las condiciones de proceso en su rendimiento, composición y actividad antimicrobiana

RESUMEN La extracción asistida por microondas (MAE por sus siglas en inglés) es una técnica eco amigable relativamente nueva que ha recibido una atención creciente debido a su menor tiempo de extracción y consumo de energía, mayor rendimiento de compuestos de interés y menor consumo de disolvente; a diferencia de técnicas convencionales de extracción, que implican elevados gastos de energía y tiempo. Así mismo, subproductos de industrias como cáscaras de cítricos, son desechados en grandes cantidades, no aprovechándose las propiedades funcionales sus compuestos. En esta investigación se realizó la extracción de aceite esencial a partir de cáscara de naranja, por microondas libre de solventes (SFME por sus siglas en inglés), a diferentes condiciones de potencia (400, 800 W, y sus combinaciones). El objetivo fue evaluar el efecto de las diferentes condiciones de proceso sobre el rendimiento del aceite esencial extraído, sobre su composición química y actividad antimicrobiana. Los más altos rendimientos de extracción correspondieron a los aceites extraídos a 400 W y a 800/400 W, siendo este último el que conllevó un menor gasto de energía y emisión de CO2. En general, todos los aceites extraídos presentaron los mismos compuestos mayoritarios (limoneno, β- mirceno, linalool y α- pineno), mientras que el aceite sometido a 400 W, presentó cantidades menores de 0,23% de 5 compuestos minoritarios adicionales. Sobre la actividad antimicrobiana, se detectó mayor actividad contra Listeria monocytogenes (ATCC 19115) respecto a Escherichia coli (ATCC 8739) en todos los tratamientos.

ABSTRACT Microwave assisted extraction (MAE) is a relatively new ecofriendly technique that has received increasing attention due to its reduced extraction time and energy consumption, higher yield and lower solvent consumption; unlike conventional extraction techniques, which involve higher energy costs and greater time. Likewise, industry by-products such as citrus peels are disposed of in large quantities, thus functional properties of their compounds are left unused. In the present investigation, solvent-free microwave extraction (SFME) was used to obtain orange peel essential oil at different power conditions (400, 800 W, and their combinations). The aim was to evaluate the effect of the process on the yield, composition and antimicrobial activity of the essential oil obtained. The highest extraction yields were obtained using powers of 400 and 800/400 W, corresponding the minor energy and CO2 emission generated to the latter. In general, all oils had the same major components (limonene, β- myrcene, linalool and α- pinene), with the oil obtained at 400 W having, in addition, five minor compounds, in amounts less than 0.23%. Regarding antimicrobial activity, in general, greater activity against L. monocytogenes (ATCC 19115) was detected in comparison with E. coli (ATCC 8739) in all treatments.

Development of a microwave-assisted extraction method for the recovery of bioactive inositols from lettuce (Lactuca sativa) byproducts.

A microwave-assisted extraction (MAE) method was developed for the extraction of bioactive inositols (D-chiro- and myo-inositols) from lettuce (Lactuca sativa) leaves as a strategy for the revalorization of these agrofood residues. Gas chromatography-mass spectrometry was selected for the simultaneous determination of inositols and sugars (glucose, fructose, and sucrose) in these samples. A Box-Behnken experimental design was used to maximize the extraction of inositols based on the results of single factor tests. Optimal conditions of the extraction process were as follows: liquid-to-solid ratio of 100:1 v/w, 40°C, 30 min extraction time, 20:80 ethanol:water (v/v), and one extraction cycle. When compared with conventional solid-liquid extraction (SLE), MAE was found to be more effective for the extraction of target bioactive carbohydrates (MAE 5.42 mg/g dry sample versus SLE 4.01 mg/g dry sample). Then, MAE methodology was applied to the extraction of inositols from L. sativa leaves of different varieties (var. longifolia, var. capitata and var. crispa). D-chiro- and myo-inositol contents varied between 0.57-7.15 and 0.83-3.48 mg/g dry sample, respectively. Interfering sugars were removed from the extracts using a biotechnological procedure based on the use of Saccharomyces cerevisiae for 24 h. The developed methodology was a good alternative to classical procedures to obtain extracts enriched in inositols from lettuce residues, which could be of interest for the agrofood industry.

Analytical approaches applied to the analysis of apprehended formulations of anabolic androgenic steroids.

Anabolic androgenic steroids (AASs) comprise a class of synthetic androgens resulting from chemical modifications of testosterone, known for their illicit consumption, which can result inextensive side effects. Extraction procedures applied to the analysis of their formulations are still limited to a few methodologies, despite the increasing numbers of confiscations of AASs. In this sense, the aims of this work were to evaluate the extraction of active ingredients from formulations of anabolic agents using solid-liquid or liquid-iquid, ultrasonic bath, ultrasonicprobe, and microwave-assisted extraction. The results indicated that the extraction procedures influenced the detected concentration of AASs, as the use of ultrasonic probe and microwave irradiation increased the overall extraction of anabolic agents compared with solid-liquid, liquid-liquid, and ultrasonic bath. Regarding oxymetholone, for instance, the microwave-assisted extraction and ultrasonic probe extracted, respectively, 37.46 ± 1.36 and 35.69 ± 0.98 mg/tablet, while solid-liquid extracted 29.63 ± 0.40 mg/tablet of the activeingredient. Therefore, alternative methods such as microwave-assisted extraction or theultrasonic probe could be used for the analysis of formulations of AASs assisting with the identification of illicit and toxic components.

Systematic evaluation of sample preparation for fractionation of phytohormone salicylic acid in fresh leaves.

The determination of salicylic acid (SA), an important phytohormone responsible for stress signaling in plants, is of great importance in agricultural studies. However, a critical evaluation of the procedures for the extraction of the analytes and hydrolysis of the conjugated forms of SA is lacking in the literature and the available alternatives are complex, time-consuming, and laborious. In this study, the sample preparation methods for SA fractionation were critically evaluated to develop a simpler and faster alternative procedure. Microwave-assisted extractions were carried out with 2.0 g of fresh leaves and 8.0 mL of a 75% v/v ethanol:water solution at 40 °C for 10 min, followed by alkaline hydrolysis using 100 µL of 0.1 mol L-1 NaOH at 80 °C for 60 min. Free and total SA were determined in crude and hydrolyzed extracts, respectively, by fluorimetry after chromatographic separation of the sample matrix under isocratic elution (25% v/v acetonitrile/phosphate buffer) using a C18 column. Recovery experiments using methyl salicylate and acetylsalicylic acid model compounds demonstrated that the soft microwave-assisted extraction did not decompose the SA derivatives and that alkaline hydrolysis was quantitative. The proposed procedure was successfully applied for fractionation of SA in sugarcane, corn, and soybean leaves with extraction and hydrolysis yields up to 70 and 20% higher than those achieved in previously proposed approaches, respectively. The developed procedure is a simple, fast, and reliable alternative for SA fractionation in crude extracts without sample clean-up, and utilizes dilute reagents and green solvents.

Microwave-Assisted Extraction of Ricinine from Ricinus communis Leaves.

The alkaloid ricinine (3-cyano-4-methoxy-N-methyl-2-pyridone) is found in different parts of the Ricinus communis plant and is known to possess several bioactive properties, including strong antioxidant activity. In this study, a new microwave-assisted extraction (MAE) method was developed for the recovery of ricinine from R. communis leaves. The extraction variables studied were extraction temperature (between 125 °C and 175 °C), microwave power (between 500 W and 1000 W), extraction time (between 5 min and 15 min), extraction solvent (between 10% and 90% of EtOAc in MeOH), and solvent-to-sample ratio (between 25:1 mL and 50:1 mL of solvent per gram of the sample). On studying the effects of extraction variables, both solvent and liquid-to-solid ratio were found to exhibit the highest effects on ricinine recovery. A fast (15 min) microwave-assisted extraction method was developed (high temperatures can be applied because the stability of ricinine is proven in the literature), allowing for the recovery of ricinine from R. communis leaves. The study revealed that R. communis leaves had almost 1.5 mg g-1 (dried weight) of ricinine.

Microwave-assisted extraction and differential scanning calorimetry in the chemical identification of sliming agents apprehended in the south region of Brazil.

Over the past decades, consume of slimming agents considerably increased in several countries, including Brazil, due to weight-loss and stimulant properties. Since these drugs are controlled to prevent illicit and indiscriminate use, there is a parallel illegal market that uses the Internet and irregular pharmacies in order to distribute these formulations. Slimming agents produced by these illegal sources are known for being manufactured with little or none quality control resulting in uncertain and unknown formulations. For forensic purposes, apprehended pharmaceuticals have to undergo a process of chemical identification that can be difficult due to its complex matrix. In this sense, application of assisted energies in the extraction step such as microwave irradiation can be a promising method to increase the recuperation of the target molecules of the sample. Therefore, the aim of this research was to identify four slimming agents apprehended in Brazil by means of visual inspection, Fourier Transform Infrared Spectroscopy, Differential Scanning Calorimetry and Gas Chromatography - Mass Spectrometry. Moreover, the efficiency of solid-liquid extraction and microwave-assisted extraction was compared. It should be noted that our work was one of the few to use Differential Scanning Calorimetry and the application of microwave irradiation in the analysis of apprehended materials. Results showed that the majority of the samples was counterfeit being composed of one or several adulterants or contaminants. Initially, visual inspection resourcefully screened the slimming agents for possible signs of falsification, however it failed to detect fraudulent products that were very similar to veridical medicines. Sequentially, Fourier Transform Infrared Spectroscopy detected functional groups present in the samples while the presence or absence of the alleged active ingredients were successfully measured with Differential Scanning Calorimetry and, thus, providing a full chemical screening of the apprehended materials. Gas Chromatography- Mass Spectrometry confirmed the presence of adulterants such as caffeine, fluoxetine and phenolphthalein as well as contaminants such as sulfurol in the falsified samples. Finally, comparison of extraction procedures indicated that microwave-assisted extraction increased the recovery of compounds detected in chromatographic analysis to a greater extent than solid-liquid extraction.

State-of-the-Art Extraction Methodologies for Bioactive Compounds from Algal Biome to Meet Bio-Economy Challenges and Opportunities.

Over the years, significant research efforts have been made to extract bioactive compounds by applying different methodologies for various applications. For instance, the use of bioactive compounds in several commercial sectors such as biomedical, pharmaceutical, cosmeceutical, nutraceutical and chemical industries, has promoted the need of the most suitable and standardized methods to extract these bioactive constituents in a sophisticated and cost-effective manner. In practice, several conventional extraction methods have numerous limitations, e.g., lower efficacy, high energy cost, low yield, etc., thus urges for new state-of-the-art extraction methodologies. Thus, the optimization along with the integration of efficient pretreatment strategies followed by traditional extraction and purification processes, have been the primary goal of current research and development studies. Among different sources, algal biome has been found as a promising and feasible source to extract a broader spectrum of bioactive compounds with point-of-care application potentialities. As evident from the literature, algal bio-products includes biofuels, lipids, polyunsaturated fatty acids, pigments, enzymes, polysaccharides, and proteins. The recovery of products from algal biomass is a matter of constant development and progress. This review covers recent advancements in the extraction methodologies such as enzyme-assisted extraction (EAE), supercritical-fluid extraction (SFE), microwave-assisted extraction (MAE) and pressurized-liquid extraction (PLF) along with their working mechanism for extracting bioactive compounds from algal-based sources to meet bio-economy challenges and opportunities. A particular focus has been given to design characteristics, performance evaluation, and point-of-care applications of different bioactive compounds of microalgae. The previous and recent studies on the anticancer, antibacterial, and antiviral potentialities of algal-based bioactive compounds have also been discussed with particular reference to the mechanism underlying the effects of these active constituents with the related pathways. Towards the end, the information is also given on the possible research gaps, future perspectives and concluding remarks.