Sustainable green extraction of anthocyanins and carotenoids using deep eutectic solvents (DES): A review of recent developments

Recently, deep eutectic solvents (DES) have been extensively researched as a more biocompatible and efficient alternative to conventional solvents for extracting pigments from natural resources. The efficiency of DES extraction for the anthocyanin and carotenoid can be enhanced by microwave-assisted extraction (MAE) and/or ultrasound-assisted extraction (UAE) techniques. Apart from the extraction efficiency, the toxicity and recovery of the pigments and their bioavailability are crucial for potential applications. A plethora of studies have explored the extraction efficiency, toxicity, and recovery of pigments from various natural plant-based matrices using DES. Nevertheless, a detailed review of the deep eutectic solvent extraction of natural pigments has not been reported to date. Additionally, the toxicity, safety, and bioavailability of the extracted pigments, and their potential applications are not thoroughly documented. Therefore, this review is designed to understand the aforementioned concepts in using DES for anthocyanin and carotenoid extraction.

Characterizing date seed polysaccharides: A comprehensive study on extraction, biological activities, prebiotic potential, gut microbiota modulation, and rheology using microwave-assisted deep eutectic solvent

This study investigated the biological activities, prebiotic potentials, modulating gut microbiota, and rheological properties of polysaccharides derived from date seeds via microwave-assisted deep eutectic solvent systems. Averaged molecular weight (246.5 kDa) and a monosaccharide profile (galacturonic acid: glucose: mannose: fructose: galactose), classifying MPS as a heteropolysaccharide. MPS, at concentrations of 125-1000 µg/mL, demonstrates increasing free radical scavenging activities (DPPH, ABTS, MC, SOD, SORS, and LO), potent antioxidant potential (FRAP: 51.2-538.3 µg/mL; TAC: 28.3-683.4 µg/mL; RP: 18.5-171.2 µg/mL), and dose-dependent antimicrobial activity against common foodborne pathogens. Partially-purified MPS exhibits inhibition against α-glucosidase (79.6 %), α-amylase (85.1 %), and ACE (68.4 %), along with 80 % and 46 % inhibition against Caco-2 and MCF-7 cancer cells, respectively. Results indicate that MPS fosters the growth of beneficial fecal microbiota, including Proteobacteria, Firmicutes, and Actinobacteria, supporting microbes responsible for major SCFAs (acetic, propionic, and butyric acids) production, such as Ruminococcus and Blautia.

Comparison of green solvents for the revalorization of orange by-products: Carotenoid extraction and in vitro antioxidant activity

Orange peels contain a considerable number of bioactive compounds such as carotenoids, that can be used as ingredients in high-value products. The aim of this study was to compare orange peel extracts obtained with different green solvents (vegetable oils, fatty acids, and deep eutectic solvents (DES)). In addition, the chemical characterization of a new hydrophobic DES formed by octanoic acid and l-proline (C8:Pro) was performed. The extracts were compared in terms of carotenoid extraction, antioxidant activity by three methods, color, and environmental impact. The results confirmed that the mixture of C8:Pro is a DES and showed the highest carotenoid extraction (46.01 µg/g) compared to hexane (39.28 µg/g). The antioxidant activity was also the highest in C8:Pro (2438.8 µM TE/mL). Finally, two assessment models were used to evaluate the greenness and sustainability of the proposed extractions. These results demonstrated the potential use of orange peels in the circular economy and industry.

Antioxidant capacity of an ethanolic extract of Elaeagnus x submacrophylla Servett. leaves

In this study, we investigated the ethanolic extraction of the leaves of a very common but little studied plant species, Elaeagnus x submacrophylla Servett. and the opportunity of generating an antioxidant ingredient. The phytochemical profile of an ethanolic extract is also described here using gas chromatography and ultra-performance liquid chromatography, both combined with mass spectrometry (GC-MS and UPLC-MS), highlighting the presence of flavonoids, saponins, triterpenoids and a set of volatile compounds. Through in vitro assays (DPPH, ABTS, ORAC), the free radical scavenging capacity of the ingredient was then investigated (from 0.25 to 1.75 mmol TE/g) and compared with well-known standard antioxidants (BHT, gallic acid, quercetin, Trolox and vitamin C). In addition, in cellulo antioxidant capacity was performed using mice fibroblasts, revealing an activity equivalent to 50 mg/L of quercetin when tested the ethanolic extract in the concentration range of 50-300 mg/L, suggesting a synergistic combination effect of the identified phytochemicals. These results support the use of Elaeagnus x submacrophylla as a source of antioxidant ingredients.

Sustainable strategies for using natural extracts in smart food packaging

The growing demand for sustainable and eco-friendly food packaging has prompted research on innovative solutions to environmental and consumer health issues. To enhance the properties of smart packaging, the incorporation of bioactive compounds derived from various natural sources has attracted considerable interest because of their functional properties, including antioxidant and antimicrobial effects. However, extracting these compounds from natural sources poses challenges because of their complex chemical structures and low concentrations. Traditional extraction methods are often environmentally harmful, expensive and time-consuming. Thus, green extraction techniques have emerged as promising alternatives, offering sustainable and eco-friendly approaches that minimise the use of hazardous solvents and reduce environmental impact. This review explores cutting-edge research on the green extraction of bioactive compounds and their incorporation into smart packaging systems in the last 10 years. Then, an overview of bioactive compounds, green extraction techniques, integrated techniques, green extraction solvents and their application in smart packaging was provided, and the impact of bioactive compounds incorporated in smart packaging on the shelf lives of food products was explored. Furthermore, it highlights the challenges and opportunities within this field and presents recommendations for future research, aiming to contribute to the advancement of sustainable and efficient smart packaging solutions.

Towards green extraction of bioactive natural compounds

The increasing interest in natural bioactive compounds is pushing the development of new extraction processes that may allow their recovery from a variety of different natural matrices and biomasses. These processes are clearly sought to be more environmentally friendly than the conventional alternatives that have traditionally been used and are closely related to the 6 principles of green extraction of natural products. In this trend article, the most critical aspects regarding the current state of this topic are described, showing the different lines followed to make extraction processes greener, illustrated by relevant examples. These include the implementation of new extraction technologies, the research on new bio-based solvents, and the development of new sequential process and biorefinery approaches to produce a full valorization of the natural sources. Moreover, the future outlook in the field is presented, in which the main areas of evolution are identified and discussed.

Aqueous enzymatic extraction of macauba (Acrocomia aculeata) pulp oil: A green and sustainable approach for high-quality oil production

Aqueous enzymatic extraction (AEE) of macauba pulp oil (MPO) was performed in this study with five commercial enzymatic pools. The chemical, nutritional, and thermal properties of the oils with high oil efficiency by AEE were evaluated and compared with mechanical pressing (MP) and organic solvent extraction (SE). Among the AEE processes, the pectinase pool (at pH 5.5 and 50 °C) exhibited the highest process efficiency (88.6 %). The oils presented low acidity values (0.4-3.1 %) and low molar absorptivities, indicating minimal oil degradation. Bioactive compounds, such as carotenoids, were found in MPO. The iodine index and the fatty acid profile of the oils revealed a high content of unsaturated fatty acids, particularly oleic and linoleic acids, with excellent nutritional scores, as evidenced by anti-atherogenicity and anti-thrombogenicity indices. These findings emphasized that AEE is an eco-friendly approach for extracting high-quality MPO with beneficial health compounds for food products.

Trends in extracting Agro-byproducts' phenolics using non-thermal technologies and their combinative effect: Mechanisms, potentials, drawbacks, and safety evaluation

The agro-food industries generate significant waste with adverse effects. However, these byproducts are rich in polyphenols with diverse bioactivities. Innovative non-thermal extraction (NTE) technologies (Naviglio extractor®, cold plasma (CP), high hydrostatic pressure (HHP), pulse-electric field (PEF), ultrasound-assisted extraction (UAE), etc.) and their combinative effect (integrated UAE + HPPE, integrated PEF + enzyme-assisted extraction, etc.) could improve polyphenolic extraction. Hence, this article comprehensively reviewed the mechanisms, applications, drawbacks, and safety assessment of emerging NTE technologies and their combinative effects in the last 5 years, emphasizing their efficacy in improving agro-byproduct polyphenols' extraction. According to the review, incorporating cutting-edge NTE might promote the extraction ofmore phenolic extractfrom agro-byproducts due to numerous benefits,such as increased extractability,preserved thermo-sensitive phenolics, and low energy consumption. The next five years should investigate combined novel NTE technologies as they increase extractability. Besides, more research must be done on extracting free and bound phenolics, phenolic acids, flavonoids, and lignans from agro by-products. Finally, the safety of the extraction technology on the polyphenolic extract needs a lot of studies (in vivo and in vitro), and their mechanisms need to be explored.

Kappaphycus alvarezii as a renewable source of kappa-carrageenan and other cosmetic ingredients

Kappa-carrageenan is one of the most traded marine-derived hydrocolloids used in the food-and-beverage, pharmaceuticals, and personal care/cosmetics industries. K. alvarezii (previously known as Kappaphycus alvarezii) is arguably the most important natural producer based on annual production size and near-homogeneity of the product (i.e., primarily being the kappa-type). The anticipated expansion of the kappa-carrageenan market in the coming years could easily generate >100,000 MT of residual K. alvarezii biomass per year, which, if left untreated, can severely affect the environment and economy of the surrounding area. Among several possible valorization routes, turning the biomass residue into anti-photoaging cosmetic ingredients could potentially be the most sustainable one. Not only optimizing the profit (thus better ensuring economic sustainability) relative to the biofuels- and animal feed-routes, the action could also promote environmental sustainability. It could reduce the dependency of the current cosmetic industry on both petrochemicals and terrestrial plant-derived bioactive compounds. Note how, in contrast to terrestrial agriculture, industrial cultivation of seaweeds does not require arable land, freshwater, fertilizers, and pesticides. The valorization mode could also facilitate the sequestration of more greenhouse gas CO2 as daily-used chemicals, since the aerial productivity of seaweeds is much higher than that of terrestrial plants. This review first summarizes any scientific evidence that K. alvarezii extracts possess anti-photoaging properties. Next, realizing that conventional extraction methods may prevent the use of such extracts in cosmetic formulations, this review discusses the feasibility of obtaining various K. alvarezii compounds using green methods. Lastly, a perspective on several potential challenges to the proposed valorization scheme, as well as the potential solutions, is offered.

Taguchi approach for assessing supercritical CO2 (sCO2) fluid extraction of polyhydroxyalkanoate (PHA) from Chlorella Vulgaris sp. microalgae

This research explicitly investigates the utilization of Chlorella Vulgaris sp. microalgae as a renewable source for lipid production, focusing on its application in bioplastic manufacturing. This study employed the supercritical fluid extraction technique employing supercritical CO2 (sCO2) as a green technology to selectively extract and produce PHA's precursor utilizing CO2 solvent as a cleaner solvent compared to conventional extraction method. The study assessed the effects of three extraction parameters, namely temperature (40-60 °C), pressure (15-35 MPa), and solvent flow rate (4-8 ml/min). The pressure, flowrate, and temperature were found to be the most significant parameters affecting the sCO2 extraction. Through Taguchi optimization, the optimal parameters were determined as 60 °C, 35 MPa, and 4 ml/min with the highest lipid yield of 46.74 wt%; above-average findings were reported. Furthermore, the pretreatment process involved significant effects such as crumpled and exhaustive structure, facilitating the efficient extraction of total lipids from the microalgae matrix. This study investigated the microstructure of microalgae biomatrix before and after extraction using scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). Fourier-transform infrared spectroscopy (FTIR) was utilized to assess the potential of the extracted material as a precursor for biodegradable plastic production, with a focus on reduced heavy metal content through inductively coupled plasma-optical emission spectrometry (ICP-OES) analysis. The lipid extracted from Chlorella Vulgaris sp. microalgae was analysed using gas chromatography-mass spectrometry (GC-MS), identifying key constituents, including oleic acid (C18H34O2), n-Hexadecanoic acid (C16H32O2), and octadecanoic acid (C18H36O2), essential for polyhydroxyalkanoate (PHA) formation.

Resource-Efficient Use of Residues from Medicinal and Aromatic Plants for Production of Secondary Plant Metabolites

Although people's interest in green and healthy plant-based products and natural active ingredients in the cosmetic, pharmaceutical, and food industries is steadily increasing, medicinal and aromatic plants (MAPs) represent a niche crop type.It is possible to increase cultivation and sales of MAPs, by utilizing plant components that are usually discarded. This chapter provides an overview of studies concerning material flows and methods used for sustainable production of valuable metabolites from MAPs between 2018 and 2023. Additionally, it describes new developments and strategies for extraction and isolation, as well as innovative applications. In order to use these valuable resources almost completely, a systematic recycling of the plant material is recommended. This would be a profitable way to increase sustainability in the cultivation and usage of MAPs and provide new opportunities for extraction in plant science.

From feed to functionality: Unravelling the nutritional composition and techno-functional properties of insect-based ingredients

In recent years, there has been a growing interest in using insects as a sustainable resource for biorefinery processes. This emerging field aims to convert insect biomass into valuable products while minimizing waste. The integration of emerging green technologies and the efficient extraction of high-value compounds from insects offer promising avenues for addressing the growing demand for sustainable food production and resource utilization. The review examines the impact of dietary modifications on the nutritional profile of insects. It highlights the potential for manipulating insect feed to optimize protein quality, amino acid profile, lipid content and fatty acid composition. Additionally, innovative green processing technologies such as ultrasound, high pressure processing, pulsed electric fields, cold plasma and enzymatic hydrolysis are discussed for their ability to enhance the extraction and techno-functional properties of insect-based ingredients. The review finds that dietary modifications can impact the nutritional composition of insects, allowing the customization of their nutrient content. By optimizing the insect feed, it is possible to increase the quantity and improve the quality of essential nutrients like proteins or lipids in the derived ingredients. Moreover, alternative processing technologies can improve the techno-functional properties (e.g., solubility, water and oil holding capacities, among others) of insect-based ingredients by modifying proteins' conformation. By harnessing these strategies, researchers and industry professionals can unlock the full potential of insects as a sustainable and nutritional food source, paving the way for innovative insect-based food products.

Recovering rhamnogalacturonan-I pectin from sugar beet pulp using a sequential ultrasound and microwave-assisted extraction: Study on extraction optimization and membrane purification

This research focuses on the integrated recovery of rhamnogalacturonan-I (RG-I) pectin from sugar beet pulp (SBP). First, the extraction of RG-I pectin through sequential ultrasound-assisted extraction (UAE) and microwave-assisted extraction (MAE) was assessed. Optimization using a response surface methodology identified the optimal conditions as initial pH 4, 10 min of UAE, and 157 °C for MAE, achieving a 66.0 % recovery of pectooligosaccharides (POS). Additionally, purification through continuous diafiltration and concentration via ultrafiltration of the POS using membranes with different molecular weight cut-offs (MWCO) was explored. In contrast to previous research using discontinuous diafiltration, the use of continuous diafiltration allowed a decrease in the extract viscosity and obtained higher yields using a higher MWCO membrane. The refined RG-I pectin solids exhibited a high global yield (39-40 g pectin/100 g SBP), and high-methoxyl characteristics, as well as purity levels (70-80 %) similar to commercial prebiotics.

Optimizing green approach to enhanced antioxidants from Thai pigmented rice bran using deep eutectic solvent-based ultrasonic-assisted extraction

Deep eutectic solvents (DES) have garnered significant attention as extraction media owing to their commendable attributes of being environmentally sustainable and the inherent adaptability of DES's versatile physical and chemical characteristics. The present study investigated the effects of deep eutectic solvents on the total contents of anthocyanin, phenolic, and flavonoids, as well as the antioxidant activity of Thai pigmented rice bran extract. The optimal extraction parameters for deep eutectic solvent-based ultrasonic-assisted extraction (DES-UAE) were also determined using the response surface methodology (RSM). The optimal conditions for the extraction of anthocyanins and other antioxidants from pigmented rice bran using a deep eutectic solvent were choline chloride: ethylene glycol (Ch:Eg) at a 1:2 ratio, mixed with 20 % water as a solvent. The ultrasonic-assisted extraction (UAE) at 37 kHz of frequency, 50 °C of temperature, 40 min of extraction time, and a 1:6 g/mL of solid-to-solvent ratio yielded a total anthocyanin content of 4.55 ± 0.09 mg C3G/g DW, a total phenolic content of 26.49 ± 0.62 mg GAE/g DW, a total flavonoid content of 6.57 ± 0.55 mg QE/g DW, and a percent inhibition of DPPH radical of 77.83 ± 1.51. By comparing the antioxidant content that was extracted from three cultivars of pigmented rice, it was found that Leum Pua black rice bran provided significantly higher antioxidant content compared to Hom Nin purple rice bran and Mali Dang red rice bran. This research suggests an achievable, eco-friendly, and effective method for preparing high-quality, consumer-safe Thai rice bran as a raw material for nutraceuticals.

Ultrasound-assisted extraction of bioactive pigments from Spirulina platensis in natural deep eutectic solvents

Spirulina platensis biopigments have been documented as a potential source of nutritional, physiological, and pharmacological purposes due to the presence of bioactive pigments, total phenolic content (TPC) and the consequent antioxidant activity that these compounds present. Bioextracts market has increased in the last decades and is a key option for replacing fossil-derived products and promote the transition for a bio-based economy. To take advantage of these compounds more effectively, optimized extraction processes must be researched and used in biomass sources. The present study focused on optimizing the ultrasound-assisted extraction (UAE) using response surface methodology. Three factor and three level Box-Behnken design was used to optimize the extraction of bioactive pigments, and to investigate the effects of three independent variables, x 1: extraction temperature (40-60 °C), x 2: extraction cycle time (20-40 min), and x 3: solvent-to-biomass ratio (50-70 mL/mg) on total pigment yield, antioxidant assay, and TPC (dependent variables). A second-order polynomial model was used for predicting the responses. Statistically, the model was validated using an analysis of variance. Results revealed that ultrasound-assisted temperature, time, and solvent-to-biomass ratio had a significant (p < 0.05) influence on the total pigment yield, while temperature and solvent-to-biomass ratio had a significant influence in the antioxidant activity, and temperature significantly influenced the total pigment yield. For total pigment yield, antioxidant activity, and total phenol content, theR 2 values of the models generated were 0.8627, 0.8460, and 0.9003, respectively, indicating that the models developed based on second-order polynomials were satisfactorily accurate for analyzing interactions between parameters. Desirability functions showed that the optimal extraction parameters were temperature: 60 °C, extraction cycle time: 20 min; and a solvent-to-biomass ratio of 70 mL/mg. Under optimal conditions, experimental values for total pigment yield, total phenol content expressed as gallic acid equivalent (GAE), and antioxidant activity expressed as Trolox equivalent (TRE) were: 165.19 ± 1.01 mg/g Dry Matter (DM), 36.50 ± 0.98 mg GAE/g DM, and 37.98 ± 0.58 mg TRE/g DM, respectively. The experimental values showed a good agreement with the predicted values with residual standard low 1% under optimum conditions. This optimized ultrasound-assisted method in natural eutectic solvents is effective and scalable to a green extraction of the bioactive pigments from Spirulina platensis with potential application to food, pharmaceutical, functional materials, and packaging.

Quantification of polycyclic aromatic sulfur heterocycles in fine airborne urban particles (PM2.5) after multivariate optimization of a green procedure

Polycyclic aromatic sulfur heterocycles (PASHs), such as benzothiophenes (BT), dibenzothiophenes (DBT) and benzonapthothiophenes (BNT), can be emitted from vehicular traffic and deposited in fine particles matter (PM2.5). The presence of these compounds in PM2.5 is an environmental concern due to air pollution and its toxic properties. In this study, a green microscale solid-liquid extraction method was developed to determine twenty-three PASHs in PM2.5. A simplex-centroid mixture design was applied to optimize the extraction solvent. A full factorial design was used for preliminary evaluation of the factors that influence the extraction process (extraction time, sample size, and solvent volume) and then a Doehlert design for the significant parameters. The optimal extraction conditions based on the experimental design were: sample size, 4.15 cm2; 450 μL of toluene:dichloromethane (80:20,v/v); and extraction duration, 24 min. High sensitivity (LOD < 0.66pg m-3 and LOQ < 2.21 pg m-3) and acceptable recovery (82.8-120 %), and precision (RSD 3.6-14.0 %) were obtained. The greenness of the method was demonstrated using the Analytical GREEnness (AGREE) tool. The method was applied for analyzing PASHs in PM2.5 samples collected in three time intervals per day from years with different sulfur contents in the diesel: S-500 (≤500 ppm sulfur) and S-50 (≤50 ppm sulfur). Fourteen PASHs were quantified with the highest concentrations observed for 2,8-DMDBT and 4,6-DMDBT, which are recalcitrant compounds. The ANOVA test indicated significant differences between sampling periods during the day. The reduction of diesel S-500 to S-50 corresponded to a 28 % decrease in the total sum of PASHs (∑PASHs) evaluated. Spearman's rank correlations allowed for verifying that BTs and DBTs were highly correlated, suggesting that they were derived from similar sources. A weak correlation of 2,1-BNT and 2,3-BNT with BTs and DBTs indicates that these compounds are a chemical proxy for the emission of diesel engines during the combustion process.

Bioactive compounds recovery by freeze concentration process from winemaking by-product

Grape pomace is the main solid residue of wine industry, containing high amounts of phenolic compounds. Considering its high potential, an extraction procedure was optimized for maximal recovery of anthocyanins from grape pomace (Vitis vinifera L.) using citric acid as a generally recognized as safe (GRAS) acidulant in water. Volume of solvent (3.2-36.8 mL), time (14.4-165.6 min) and pH of solvent (1.12-4.48) were the studied variables. Furthermore, the best condition to obtain extract rich in anthocyanins was submitted to the gravitational block freeze concentration process. The performance of the process was evaluated and cryoconcentrated and ice fractions were analyzed for physicochemical properties, bioactive compounds content, and antioxidant activity. Interaction, linear, and quadratic effects for volume and pH of solvent were significant by analysis of variance (ANOVA). The experimental design allowed the prediction for maximal recovery of anthocyanins (10 mL of solvent at pH 1.8). The bioactive composition of the optimized grape pomace extract was influenced by the cryoconcentration process. After three cycles using gravitational block freeze concentration, the total phenolics and monomeric anthocyanins were approximately 4 and 5 times higher than the initial condition of the extract, respectively. Consequently, an increase in antioxidant activity was observed. The increase in the concentration of bioactive compounds reached a process efficiency of 93% (stage 1) for phenolic compounds and 91% (stage 2) for anthocyanins. Therefore, the final water-based optimized method is safe and has a low cost and the concentrated extract certainly showed higher concentrations of total phenolics and anthocyanins, compared to the initial extract. The proposed clean extraction method and cryoconcentration technique can be considered important strategies for recovering and valuing grape pomace components, improving the approach to the circular economy concept in the wine industry.

Sustainable valorization of pitaya (Hylocereus spp.) peel in a semi-continuous high-pressure hydrothermal process to recover value-added products

This study evaluated the use of a semi-continuous high-pressure hydrothermal process for the recovery of value-added products from pitaya peel. The process was carried out at 15 MPa, a water flow rate of 2 mL/min, a solvent-to-feed ratio of 60 g water/g pitaya peel, and temperatures ranging from 40 to 210 °C. The results show that extraction temperatures (between 40 and 80 °C) promoted the recovery of betacyanin (1.52 mg/g), malic acid (25.6 mg/g), and citric acid (25.98 mg/g). The major phenolic compounds obtained were p-coumaric acid (144.63 ± 0.42 µg/g), protocatechuic acid (91.43 ± 0.32 µg/g), and piperonylic acid (74.2 ± 0.31 µg/g). The hydrolysis temperatures (between 150 and 210 °C) could produce sugars (18.09 mg/g). However, the hydrolysis process at temperatures above 180 °C generated Maillard reaction products, which increased the total phenolic compounds and antioxidant activity of the hydrolysates. Finally, the use of semi-continuous high-pressure hydrothermal process can be a sustainable and promising approach for the recovery of value-added compounds from pitaya peel, advocating a circular economy approach in the agri-food industry.

Recent advancement in ultrasound-assisted novel technologies for the extraction of bioactive compounds from herbal plants: a review

Herbal plants comprise potent bioactives, and they have a potential for the development of functional foods. Ultrasonication technology can be used to enhance the efficiency and quality of these bioactivities. The present review discussed the ultrasound-assisted novel extraction technologies (supercritical carbon dioxide (CO2) and high pressurized liquid), including mechanistic understanding, influencing factors, extract process efficiency, and the recovery of bioactives with an industrial perspective. The strong observations of this study are the novel ultrasound-induced extraction process variables, such as ultrasound amplitude, sonication time, temperature, solid-solvent ratio, and pressure, are significantly influenced and must be optimized for maximum recovery of bioactives. The novel green technologies (ultrasound and assisted) could remarkably improve the extraction efficiency and enhance the quality of green extract. This review will support technological understanding about the impact on process parameters for the extraction of bioactives for the development of functional foods and nutraceuticals.

Anar Phali (Opuntia ficus) juice extract as a novel pollution-free source of natural betalain dye for wool yarn

Green products such as plant pigments in all filed are gaining fame globally due to their excellent ayurvedic and biological characteristics. In this study, microwave rays have been employed for the isolation of colorants from Anar Phali while bio-mordant have been included to get color-fast shades. The colorant was isolated in an acidic medium before and after microwave rays for 2 min. For getting darker shades with different tints, sustainable chemical and plant-based extracts as bio-mordant have been employed before and after bio coloration of wool yarn at given conditions. CIE Lab system computed in Colori-spectrophotometer (CS-410) was used to observe the change in color depth and tonal variation of dyed fabrics, and ISO standard methods have been employed to rate the colorfastness to light, washing, and rubbing at grey scale. It is concluded that microwave rays have an excellent sustainable efficacy to isolate colorant from Anar Phali powder for wool dyeing, whereas the addition of bio-mordants has made the process more sustainable and eco-friendly.

Preparation, development, and scale-up of standardized pentacyclic triterpenoid-rich extract from Centella asiatica (L.) Urb. and study of its wound healing activity

This pilot-scale study of an innovative green extraction method shows increased biomarker content in plant extracts. Moreover, green extraction methods decrease the effects on the environment and human health and promote industrial growth. This study optimized the process conditions to obtain a pentacyclic triterpenoid-rich extract (PRE) from Centella asiatica (L.) Urb., which contains asiatic acid, madecassic acid, asiaticoside, and madecassoside, and evaluated its biological activities. PRE preparation was scaled up from laboratory to pilot scale. In the pilot scale, a combination of microwave-assisted extraction with an irradiation power of 4 kW and an ultrasonic-assisted extraction at 0.55 kW was used for C. asiatica extraction. The total pentacyclic triterpene content was 106.02 mg/g of crude extract. Then, the C. asiatica extract was fractionated by a macroporous resin (Diaion® HP-20). The PRE preparation method used 50% and 75% EtOH fractions. This PRE produced a high content of pentacyclic triterpenoids at 681.12 mg/g of crude extract. It presented a high anti-inflammatory effect with an IC50 value of 23.88 μg/mL for nitric oxide inhibition and induced wound healing processes (proliferation, migration, and collagen synthesis) in human dermal fibroblast cells. The information gained from this study can advance the industrial extraction of physiologically active substances from various plant sources for use as medicines or components of supplemental food and cosmeceutical products.

A green extraction strategy for the detection of antioxidants in food simulants and beverages migrated from plastic packaging materials

Antioxidants, widely utilized in the food packaging field, have a risk of migrating into foodstuffs and eventually entering the human body. In this work, a novel method was established for green extraction and determination of antioxidants in food simulants migrated from plastic packaging materials. It was found that the antioxidants could be extracted directly from food simulants by in-situ formation of hydrophobic deep eutectic solvents with low toxic medium-chain fatty alcohols. Under the optimal conditions, the limit of detection was 0.15 to 0.25 µg/L, and the limit of quantification was 0.5 to 1.0 µg/L for the antioxidants. The extraction reaches equilibrium in 2 min. Importantly, butylated hydroxytoluene was detected in two types of the surveyed food contact materials. The established method shows high sensitivity, high enrichment factor, and strong anti-interference ability, and can be used for the separation and enrichment of ultra-trace antioxidants in foodstuffs.

Supercritical CO2 extraction of spices: A systematic study with focus on terpenes and piperamides from black pepper (Piper nigrum L.)

Black pepper (P. nigrum L.) is considered one of the most valuable spices and a promising candidate in natural product research. In this study, the influence of different combinations of pressures (100-300 bar) and temperatures (40-60 °C) on the supercritical CO₂ (SC-CO₂) recovery of several key compounds from black pepper was evaluated systematically. The extraction curves showed that terpenes were recovered in a short time under all studied conditions. In contrast, higher pressure values were required to extract piperamides efficiently. Furthermore, the differences in the extraction kinetics of piperine, piperettine, pellitorine, guineensine, and N-isobutyl-2,4,14-eicosatrienamide were linked with several structural features, such as the nature of the amine group or the terminal part of the fatty acid. The data from the isocratic experiments represented the starting point for designing a two-step pressure gradient SC-CO₂ process in which one terpene-rich and one piperamide-rich product were successively obtained.

Bioactivities and green advanced extraction technologies of ginger oleoresin extracts: A review

Zingiber officinale Roscoe is an excellent source of bioactive compounds, mainly gingerols and shogaols compounds, that associated with various bioactivities including antioxidant, anticancer, anti-inflammatory, antimicrobial, and antibiofilm. Zingiber officinale Roscoe found its application in the food, pharmaceutical, and cosmeceutical industries. The demand for a high quality of ginger oleoresin extracts based on the contents of gingerols and shogaols compounds for a health-benefit has dramatically increased. Various extraction techniques, including the conventional and advanced extraction techniques for gingerols and shogaols have been reported based on the literature data from 2012 to 2022. The present review examines the functional composition and bioactivities of Zingiber officinale Roscoe and the advanced green extraction technologies. Some variations in the quantity and quality of gingerols and shogaols compounds are because of the extraction method employed. This review provides a depth discussion of the various green advanced extraction technologies and the influences of process variables on the performance of the extraction process. Lower temperature with a short exposure time such as ultrasound-assisted and enzyme-assisted extraction, will lead to high quality of extracts with high content of 6-gingerol. High thermal processing, such as microwave-assisted and pressurized liquid extraction, will produce higher 6-shogaol. Meanwhile, supercritical fluid extraction promotes high quality and the safety of extracts by using non-toxic CO2. In addition, challenges and future prospects of the extraction of ginger oleoresin have been identified and discussed. The emerging green extraction methods and technologies show promising results with less energy input and higher quality extracts than conventional extraction methods.

Cellulose nanocrystals from Siam weed: Synthesis and physicochemical characterization

The use of biomass for the development of environmentally friendly and industrially useful materials is still attracting global interest. Herein, cellulose nanocrystals were prepared from Siam weed. The production steps involved dewaxing the biomass sample, bleaching treatment, alkali treatment and acid hydrolysis. The resulting cellulose nanocrystals were characterized using Fourier transformed infrared (FTIR) spectroscopy, X-ray diffraction (XRD) spectroscopy, thermo-gravimetric analysis (TGA), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and dynamic light scattering (DLS) technique. Chemical composition results showed that Siam weed contained 39.6% cellulose, 27.5% hemicellulose, 28.7% lignin and 4.2% extractive. FTIR spectrum confirmed the presence of cellulose and absence of lignin and hemicellulose while XRD analysis revealed that the cellulose nanocrystals have crystallinity index of 66.2% and particle size of 2.2 nm. TGA revealed that thermal stability of raw Siam weed is lower than that of its cellulose nanocrystals due to the presence of the non-cellulosic component with lower temperature of degradation. SEM revealed that degradation of cellulosic chain had occurred. TEM confirmed that the crystal size is in the nanoscale with an average size <100 nm. DLS data revealed a nanocellulose with an average hydrodynamic size of 213 nm and a zeta potential at -9.57 mV.

In-tube gel electromembrane extraction: A green strategy for the extraction of narcotic drugs from biological samples

The development of green and miniature extraction methods is always a major and controversial challenge in the field of sample preparation. In this work, in-tube gel electromembrane extraction (IT-G-EME) was developed as a miniaturized extraction device for the extraction of six narcotic drugs (codeine, oxycodone, hydrocodone, tramadol, thebaine, and noscapine) from biological samples. A transparent capillary tube (∼6 cm) was used as a microextraction unit. The middle part of the tube was filled with a narrow plug (∼3 mm) of the agarose gel (3.0% w/v) as a membrane and the other sides were filled with aqueous extractant solution (pH 2.0, 20 µL) and sample solution (pH 5.0, 200 µL). By applying electrical potential (400 V), the target drugs with positive charge were migrated from sample solution toward the extractant solution through gel membrane during short extraction time (5 min). Then, the enriched analytes in extractant solution was analyzed by HPLC-UV. Under the optimized conditions, the calibration curves were linear within the permissible range of 10.0-1500 ng/mL (r² ≥ 0.991). Limits of detection and extraction recoveries were in the range of 3.0-4.5 ng/mL and 61.9-86.9%, respectively. On the basis of four replications, the repeatability of the method was also evaluated in terms of intra- and inter-day RSDs (%), which did not exceed from 6.6 and 7.9%, respectively in aqueous media. The figures of merit were also assessed in biological samples. Eventually, the developed method was profitably used for simultaneous determination of narcotic drugs in the real urine and plasma samples.

Ultrasound-assisted green extraction methods: An approach for cosmeceutical compounds isolation from Macadamia integrifolia pericarp

This study aimed was to examine the potential of several green extraction methods to extract cosmetic/cosmeceutical components from Macadamia integrifolia pericarps, which were a by-product of the macadamia nut industry. M. integrifolia pericarps were extracted by conventional solvent extraction process using 95% v/v ethanol and various green extraction methods, including infusion, ultrasound, micellar, microwave, and pulsed electric field extraction using water as a clean and green solvent. The extracts were evaluated for total phenolic content using Folin-Ciocalteu method.The antioxidant activities were evaluated by 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), ferric reducing/antioxidant power, and ferric-thiocyanate method. The anti-skin ageing activities were investigated by means of collagenase, elastase, and hyaluronidase inhibition using enzyme-substrate reaction assay. The irritation profile of the extracts was evaluated by the hen's egg test-chorioallantoic membrane (HET-CAM) test. The results noted that ultrasound-assisted extraction yielded the significantly highest extract amount with the significantly highest total phenolic content (p < 0.05), especially when the extraction time was 10 min. The aqueous extract from ultrasound-assisted extraction possessed the most potent antioxidant and anti-skin ageing activities (p < 0.05). Its antioxidant activities were comparable to ascorbic acid and Trolox, whereas the anti-skin ageing activities were equivalent to epigallocatechin-3-gallate and oleanolic acid. Besides, the extract was safe since it induced no irritation in the HET-CAM test. Therefore, ultrasound-assisted extraction was suggested as an environmentally friendly extraction method for M. integrifolia pericarp extraction and further application in the cosmetic/cosmeceutical industries.

Utilization of natural deep eutectic solvents and ultrasound-assisted extraction as green extraction technique for the recovery of bioactive compounds from date palm (Phoenix dactylifera L.) seeds: An investigation into optimization of process parameters

The green extraction of bioactive compounds from date seeds was investigated using seven natural deep eutectic solvents (NADES) coupled with ultrasound-assisted extraction (UAE). The seven NADESs mainly consisted of choline chloride as hydrogen bond acceptors (HBA) and four sugars, two organic acids, and one polyalcohol as hydrogen bond donors (HBD) were utilized in this study. When the extraction efficiency of the NADESs was compared to that of the conventional solvents, all the NADESs showed superior bioactive compounds recovery efficacy. The lactic acid-based NADES had the highest extraction efficiency and was further optimized using the response surface method and Box-Behnken design. A four-factors including extraction time (10, 20, and 30 min), ultrasound amplitude (70, 80, and 90 %), % NADES content (30 %, 50 %, and 70 %) and solid-to-solvent ratio (1:30, 1.5:30, and 2:30 g/ml) each at three levels (-1, 0 and 1) using Box-Behnken design was applied. The % NADES content and the solid-to-solvent ratio were the major factors influencing the extraction efficiency of the total phenolic content (TPC) and the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity. The optimum extraction conditions included an extraction time of 15 min, ultrasound amplitude of 90 %, % NADES content of 70 % and solid-to-liquid ratio of 1:30 g/ml. The experimental values for TPC and DPPH at optimum extraction conditions were 145.54 ± 1.54 (mg GAE/g powder) and 719.19 ± 2.09 (mmol TE/g powder), respectively. The major phenolic compounds observed in the date seeds extracted using ChCl-LA were 3,4-dihydroxybenzoic acid, catechin and caffeic acid. This study reveals that the extraction of date seeds with NADES in combination with UAE technique was able to recover significantly higher amounts of phenolic compounds which could find useful applications in the food, pharmaceutical, and cosmetics industries.

Pomegranate peel phenolics: One step water extraction, in vitro antiproliferative activity, and effect on sensory attributes of muffins and cheese

Pomegranate is one of the richest fruits species in bioactive compounds, including its non-edible parts. In this work, a simple, rapid and environmentally-friend is described. It allowed the recovery of 108 mg of bioactive per gram of enriched extract from pomegranate peel (PomPE). The quality of PomPE was assessed in terms of antiproliferative activity and its influence on the sensory attributes on muffins and cheese was evaluated. Results showed an IC50 of ∼ 50 µg/ml, which was equal to extract obtained by ethanol 70%. The incorporation of PomPE in muffins formulation improved some sensory attributes by 10%. However, overall, the supplementation of cheese led to a decrease of the sensory parameters. The results concluded that the described method could be an alternative to the conventional techniques to obtain enriched extract with high potential of valorization in food and pharmaceutical sectors.

Chemometric approach for the spectrophotometric determination of chloramphenicol in various food matrices: Using natural deep eutectic solvents

A novel, simple and green temperature controlled-natural deep eutectic solvent emulsification liquid-liquid microextraction (TC-NADES-LLME) coupled with UV-vis spectrophotometry was optimized for preconcentration and measurement of chloramphenicol (CAP) in eggs, milks honeys and chicken meat. Four different NADES were prepared and investigated for the efficient extraction of CAP. The important parameters (pH, NADES-3 vol, Fe(III) amount and extraction temperature) affecting the extraction efficiency of the TC-NADES-LLME procedure were investigated and optimized using a chemometric approach. In this study, Fe(III), NADES-3 and extraction temperature were used as complexing agent, extraction solvent and emulator accelerator, respectively. Using optimized values, the linear range of the TC-NADES-LLME procedure was in the range of 0.1-300 µg L^-1 with a coefficient of determination of 0.9991. The detection limit and enhancement factor were 0.03 µg L^-1 and 285, respectively. The precision of the method has been confirmed in repeatability and reproducibility studies. Relative standard deviation of these studieswas<4.2 %. The matrix effect was investigated by adding three different CAP concentrations to the selected samples, and the results indicated the low matrix effect of the method. The TC-NADES-LLME procedure was successfully applied to determine and extract CAP in the selected samples.

Solvent effects on the wood delignification with sustainable solvents

Solutions of a pure organic solvent acidified with 1% sulfuric acid, and some of their aqueous mixtures were used for lignin extraction in the Pinus radiata sawdust delignification. Organic acid solvents including acetic, lactic and citric acids as well as non-acidic compounds such as γ-valerolactone, 2-methyltetrahydrofuran, glycerol and ethylene glycol were studied. Crude lignin extractions yields (%) ranging between ca. 5-50% were obtained, from which ethylene glycol (33%), γ-valerolactone (48%) and propylene carbonate (52%) showed the greatest effectiveness. The effect of added water on the lignin extraction was investigated in mixtures of an organic solvent with a variable water content (75%w/w, 50% w/w, 25%w/w and 10% w/w) where it was observed that the yield of extraction decreased with the increased water content. Moreover, the purity of extracted lignins were analyzed by spectroscopic methods (UV and IR). Kamlet-Taft solvent polarity parameters, were determined with the solvatochromic probes 4-nitroaniline, N,N-diethyl-4-nitroaniline, Nile Red and 6-propionyl-2-N,N-dimethylaminonaphthalene (PRODAN), and then correlated to lignin extraction yields to explain the influence of the solute-solvent interactions on biomass delignification. A reasonable correlation was found between the medium polarizability-dipolarity π* and the effectiveness of the solvent mixture on the extraction of lignin wood.

Generation and characterization of nanobubbles in ionic liquid for a green extraction of polyphenols from Carya cathayensis Sarg

Nanobubbles (NBs) generated-nanojets membrane poration have gained enormous attention. In this study, NBs were fabricated as a novel green approach to assist ionic liquid (IL) [C₄C₁im][BF₄] extraction of polyphenols from Carya cathayensis Sarg. husk. NBs were successfully generated with mean size of 85.47 ± 5 nm, zeta potential of +39 ± 2.24 mV, and concentration of 21.15 ± 0.75 × 10⁸ particles/mL (stable for over 48 h in IL solution). Compared to common solutions extract, IL-NBs extract showed significantly higher (p < 0.05) antioxidant activity and polyphenols yields with a total polyphenol, total flavonoid, and total tannins contents of 85.67 ± 2.05 mg GAE/g DW, 42.44 ± 1.17 mg CE/g DW, and 8.2 ± 0.05 mg TAE/g DW, respectively. The SEM results confirmed that NBs' nanojets caused morphological destruction of the husk powder. Overall, IL-NBs solution showed better extraction efficiency of polyphenols than other solutions, giving insight into a new "green" nanotechnology-based extraction method.

Dataset of ultrasound-assisted extraction of anthocyanin from the petals of Clitoria ternatea using Taguchi method and effect of storage conditions on the anthocyanin stability

Anthocyanins are natural water-soluble colourants with a number of reported health benefits and are an excellent alternative to artificial dyes. Anthocyanins from Clitoria ternatea were obtained using ultrasound-assisted extraction with glycerol-water (60:40 w/v). The anthocyanins in the extract were measured at wavelength 550 and 700 nm using a UV-visible spectrophotometer and expressed in terms of total anthocyanins content (TAC). Taguchi method was employed to optimize the extraction parameters that include the extraction time (30 to 50 min), extraction temperature (40 to 60 °C), and solvent to solid ratio (10:1 to 30:1), with TAC as the response. The obtained data showed the optimum extraction parameters as 30 min extraction time, 50 °C extraction temperature, and 10:1 solvent to solid ratio. The anthocyanin's storage stability was analyzed for 7 days at varying storage temperatures and exposure to light. The present dataset in this article indicated the glycerol-water system as a green alternative for anthocyanin extraction and acted as a storage medium. Furthermore, our methodology can be applied to optimize the anthocyanins extraction process, manipulate storage conditions and improve the extract quality.

Chondrus crispus treated with ultrasound as a polysaccharides source with improved antitumoral potential

Ultrasound-assisted extraction was used to recover gelling biopolymers and antioxidant compounds from Chondrus crispus with improved biological potential. The optimal processing conditions were evaluated using a Box-Behnken design, and the impact on the biological and thermo-rheological properties of the carrageenan fraction and on the bioactive features of the soluble extracts were studied. The optimum extraction parameters were defined by extraction time of ~34.7 min; solid liquid ratio of ~2.1 g/100 g and ultrasound amplitude of ~79.0% with a maximum power of 1130 W. The dependent variables exhibited maximum carrageenan yields (44.3%) and viscoelastic modulus (925.9 Pa) with the lowest gelling temperatures (38.7 °C) as well as maximum content of the extract in protein (22.4 mg/g), gallic acid (13.4 mg/g) and Trolox equivalents antioxidant capacity (182.4 mg TEAC/g). Tested hybrid carrageenans exhibited promising biological activities (% of growth inhibition around 91% for four human cancer cellular lines: A549; A2780; HeLa 229; HT-29).

Microwave hydrothermal processing of Undaria pinnatifida for bioactive peptides

Microwave hydrothermal processing was employed to obtain valuable gelling or bioactive fractions from U. pinnatifida, assessing the processing conditions following a biorefinery concept. It was identified a relevant impact on the antioxidant properties, sulfate, protein and oligosaccharides content, with the highest values above 200 °C, although the maximum in fucose was obtained at 160 °C. The lowest temperature involved the highest minerals and sulfate content of the solid phases. Rheology indicated that hydrothermal treatment at 160 °C is adequate to extract alginates with structural and viscoelastic properties similar to those commercially available. The incorporation of the hydrothermal residual solids in the proposed alginate matrices favored the development of systems with potential non-food applications applications. Selected extracts, after an intensification stage using ultrasound, featured interesting biological activities for two human cancer cell lines (A2780; HeLa 229) with percentage of cellular inhibition > 83 and 57%, without positive effects on A549 and HCT-116.

Novel extraction of polyphenols from sour cherry pomace using natural deep eutectic solvents - Ultrafast microwave-assisted NADES preparation and extraction

In this work, new approaches for the green extraction of polyphenols from sour cherry pomace were explored. Three Natural Deep Eutectic Solvents (NADES) systems based on choline chloride (ChCl) as a hydrogen bond acceptor (HBA) and malic acid, urea, and fructose (MalA, Ur, and Fru) as hydrogen bond donors (HBD) were used. NADES systems were prepared by heating and stirring (H&S), ultrasound (US), and microwave (MW) methods. It was found that MW-assisted preparation was the fastest requiring less than 30 s. Polyphenol extraction from cherry pomace was performed also by three mentioned methods, and compared with conventional methods. MW extraction was the most rapid with less than 5 min necessary for the extract preparation. All three NADES systems were highly efficient for anthocyanin extraction, but the most efficient was ChCl:MalA system. Extract based on ChCl:MalA system was for 62.33% more efficient for anthocyanin extraction comparing with the conventional solvent.

Green non-conventional techniques for the extraction of polyphenols from agricultural food by-products: A review

Food processing industry is accompanied with the generation of a great production of wastes and by-products exceptionally rich in bioactive compounds (especially phenolics), with antioxidant activity. The recovery of these health molecules constitutes a key point for the valorization of by-products, with the possibility of creating new ingredients to be used for the formulation of food and cosmetic products. One of the main limitations to reuse by-products is linked to the high cost to obtain bioactive compounds, consequently in order to exploit these resources commercially valuable it is necessary to develop innovative, economic and environmentally friendly extraction strategies. These extraction methods should be able to reduce petroleum solvents, energy consumption and chemical wastes, protecting both environment and consumers and ensuring safe and high-quality final products. The purpose of this review is to summarize current knowledge and applications of the new extraction techniques such as supercritical fluid extraction, pressurized liquid extraction, ultrasound assisted extraction applied to polyphenols extraction from agricultural food by-products. Particular attention has been paid to theoretical background, highlighting mechanisms and safety precautions. Authors concluded that relevant results of these techniques represent an opportunity to industrial scale-up, improving the extraction yields, minimizing time, costs and environmental impact.

Castanea sativa shells: A review on phytochemical composition, bioactivity and waste management approaches for industrial valorization

Castanea sativa is an outstanding species that represents a valuable natural resource for rural populations. C. sativa shells (CSS), an abundant agro-industrial by-product generated during chestnut peeling process, is commonly discarded or used as fuel. Nevertheless, CSS produced are not depleted by this application and huge amounts are still available, being particularly rich in bioactive compounds (polyphenols, vitamin E, lignin and oligosaccharides) with health benefits. Phytochemical studies reported not only antioxidant and antimicrobial activities, but also anti-inflammatory, anticancer, hypolipidemic, hypoglycemic and neuroprotective activities. The application of a suitable extraction technique is required for the isolation of bioactive compounds, being green extraction technologies outstanding for the industrial recovery of chestnut shells' bioactive compounds. CSS were highlighted as remarkable sources of functional ingredients with promising applications in food and nutraceutical fields, mainly as natural antioxidants and effective prebiotics. This review aims to summarize the phytochemical composition and pro-healthy properties of CSS, emphasizing the sustainable extraction techniques employed in the recovery of bioactive compounds and their potential applications in food and nutraceutical industries.

Sonication-synergistic natural deep eutectic solvent as a green and efficient approach for extraction of phenolic compounds from peels of Carya cathayensis Sarg

An excellent high-efficiency natural deep eutectic solvent (NADES, ChCl-MA) was screened out and integrated with pulse-ultrasonication technique for extracting phenolic compounds from Carya cathayensis Sarg. peels (CCSPs). Single factor experiment combined with response surface methodology (RSM) using Box-Behnken design (BBD) were employed to investigate significant factors and optimize their influence on extraction of phenolic compounds. Significant synergistic effect triggered by ChCl-MA based pulse-ultrasonication over other methods used alone were proved by comparative study concerning a variety of bioactive components and antioxidant activities. The second-order kinetic model was developed and validated (R² > 0.99) to describe the extraction process and its mechanism; and second-order kinetic extraction rate constant (k), saturation concentration (C_s), and initial extraction rate (h) were calculated. FT-IR, DSC and SEM results further demonstrated synergistic effect and influence during extraction. Overall, this study provided a green and high-efficiency alternative for the recovery of various phenolics compounds from plant source by-products.

Three way ANOVA for emulsion of carotenoids extracted in flaxseed oil from carrot bio-waste

The juice expelled from carrot, a globally produced root vegetable, leavesbehind carrot pomace (a bio- and horticultural waste) which is potentially rich source of micro-nutrients and carotenoids.However, it is discarded as waste or used as animal feed. It holds potential to be channelized to food chain by a couple of technological interventions. In this regard, present work was aimed at preparing stable emulsion based delivery system for 'green' carotenoids extracted from carrot-pomace in flaxseed oil (a green solvent), and at maximizing the amount of core material so that the resultant emulsion can potentially be used as a source of both carotenoids and omega-3 fatty acid of flaxseed oil origin. The study used natural emulsifier. Preparation of oil-in-water emulsion was optimized using 3³ factorial experiment by varying levels of extract containing carotenoid (30-40%), whey protein concentrates (WPC-80) and lactose. The optimized emulsion (CREm) was selected on the basis of particle size, zeta potential, color values (L*, a*, b*) and viscosity statistically analyzed via three-way ANOVA using Proc GLM of SAS 9.3 (described in detail in this paper); the respective values of these parameters being 120.03 ± 8.20 nm, -16.57 ± 0.49 mV, 75.11 ± 0.04, 9.66 ± 0.32, 50.29 ± 0.62, and 0.124 ± 0.0115 Pa.s for CREm. CREm contained 35% flaxseed oil, 10% WPC-80 and 5% lactose and showed good centrifugal and gravitational stability (15 days). It was analyzed for total carotenoid content, antioxidant activities (ABTS (2,2-azinobis-(3-ethylbenzthiazoline-6sulfonic acid), DPPH (2,2-Diphenyl-1-picrylhydrazyl) and FRAP (Ferric reducing antioxidant power assay)) and microstructure.

Extracts of medicinal plants with natural deep eutectic solvents: enhanced antimicrobial activity and low genotoxicity

Natural deep eutectic solvents (NADES) are a new alternative to toxic organic solvents. Their constituents are primary metabolites, non-toxic, biocompatible and sustainable. In this study four selected NADES were applied for the extraction of two medicinal plants: Sideritis scardica, and Plantago major as an alternative to water-alcohol mixtures, and the antimicrobial and genotoxic potential of the extracts were studied. The extraction efficiency was evaluated by measuring the extracted total phenolics, and total flavonoids. Best extraction results for total phenolics for the studied plants were obtained with choline chloride-glucose 5:2 plus 30% water; but surprisingly these extracts were inactive against all tested microorganisms. Extracts with citric acid-1,2-propanediol 1:4 and choline chloride-glycerol 1:2 showed good activity against S. pyogenes, E. coli, S. aureus, and C. albicans. Low genotoxicity and cytotoxicity were observed for all four NADES and the extracts with antimicrobial activity. Our results confirm the potential of NADESs for extraction of bioactive constituents of medicinal plants and further suggest that NADES can improve the effects of bioactive extracts. Further studies are needed to clarify the influence of the studied NADES on the bioactivity of dissolved substances, and the possibility to use such extracts in the pharmaceutical and food industry.

A novel sustainable approach for the extraction of value-added compounds from Hibiscus sabdariffa L. calyces by natural deep eutectic solvents

Hibiscus sabdariffa L. is widely acknowledged as an important source of value-added compounds as natural pigments and bioactive compounds whose isolation is of great interest in food industry. Due to the incessant demand of green extraction procedures, NADESs have emerged in the last years as new green solvents alternative to the conventional organic ones. The feasibility of NADESs for the extraction of value-added compounds of H. sabdariffa has been assessed in this work for the first time. An extraction technique based on microwave assisted extraction (MAE) and the use of NADESs was proposed testing different deep eutectic solvents based on choline chloride (ChCl). Among them, oxalic acid based NADES exhibited a great selectivity for anthocyanins in particular as well as higher extraction yields of bioactive compounds was also observed, even greater than those observed by methanol. The effect of extraction variables such as liquid-solid ratio, temperature and water percentage were studied by Box-Behnken design and a response surface methodology. The statistical program pointed out the liquid-solid ratio of 1:30 mL mg^-1, temperature of 75 °C and a water percentage of 55% as the conditions to maximize extraction within the experimental domain. Hence, NADES composed by oxalic acid and choline chloride resulted to be an effective green alternative tailor-made solvent to carry out selective extractions of value-added compounds from H. sabdariffa.

Ultrasound processing of coffee silver skin, brewer's spent grain and potato peel wastes for phenolic compounds and amino acids: a comparative study

Awareness towards utilizing food-processing by-products are increasing in health as well as environmental purview. Coffee silver skin (CSS), potato peel (PP) and brewer's spent grain (BSG) are voluminous by-products in their respective processing industries. The present study compared these three by-products for their prospective utilization in producing polyphenols-rich aqueous extracts by using ultrasound-assisted extractions (UAE). A probe-type sonicator was used for ultrasound treatments. The total phenolic contents in the extracts were assessed by Folin-Ciocalteu assay, while the phenolic profiles of the extract was characterized by LC-Q-TOF mass spectrometry. The microstructure of the samples after UAE was evaluated by scanning electron microscopy (SEM). Ultrasound treatment enhanced the rate of extraction and recovered 2.79, 2.12 and 0.66 mg gallic acid equivalents/g of TPC from CSS, PP and BSG, respectively in 30 min, which correspond to recoveries of 97.6%, 84.5% and 84.6%, respectively, compared to conventional solid-liquid extractions carried out for 24 h. The extraction yield was dependent on the particle size of the raw materials and the highest yield was obtained from the materials with 100-250 µm particle size. The SEM imaging revealed that ultrasound treatment caused prominent tissue damage. Extracts contained mainly hydroxycinnamic acid derivatives of phenolic acids. PP and CSS had the highest amounts of umami free amino acids (0.13 mg/g in each), while BSG contained the highest amount of essential amino acids (92 mg/g). The present work shows that CSS, PP and BSG are good sources of polyphenols and UAE can be employed to enhance the extraction efficiency as means of a green approach.

Application of deep eutectic solvents for the extraction of phenolic compounds from extra-virgin olive oil

A HPLC-DAD/ESI-MS method has been developed and validated for the analysis of the most representative phenolic compounds in extra-virgin olive oil (EVOO) samples using a green extraction approach based on deep eutectic solvents (DESs) at room temperature. We examined ten DESs based on choline chloride and betaine in combination with different hydrogen bond donors comprising six alcohols, two organic acids, and one urea. Five phenolic compounds, belonging to the classes of secoiridoids and phenolic alcohols, were selected for the evaluation of extraction efficiency. A betaine-based DES with glycerol (molar ratio 1:2) was found to be the most effective for extracting phenolic compounds as compared to a conventional solvent. The optimization of the extraction method involved the study of the quantity of water to be added to the DES and evaluation of the sample-to-solvent ratio optimal condition. Thirty percent of water added to DES and sample to solvent ratio 1:1 (w/v) were selected as the best conditions. The chromatographic method was validated by studying LOD, LOQ, intraday and interday retention time precision, and linearity range. Recovery values obtained spiking seed oil sample aliquots with standard compounds at 5 and 100 μg/g concentration were in the range between 75.2% and 98.7%.

Dataset on the phytochemicals, antioxidants, and minerals contents of pecan nut cake extracts obtained by ultrasound-assisted extraction coupled to a simplex-centroid design

This article contains a dataset related to the research published in “The potential of the pecan nut cake as an ingredient for the food industry” [1]. A three-component simplex-centroid mixture design coupled with response surface methodology (RSM) was applied to generate statistical models and to analyze the dataset. The method was also applied to evaluate the effect of different solvents (ethanol, water, and acetic acid) on the extraction of bioactive compounds of pecan nut cake (PNC) and its antioxidant activity. Furthermore, simultaneous optimization of the solvent mixture was carried out to predict the optimum point with the best combination of solvents to obtain an extract with enhanced phytochemical composition, as well as high in vitro antioxidant activity. The maximization of total phenolic compounds, condensed tannins, and antioxidant activity of the PNC was predicted by the desirability function. A total of 80 interactions were run to provide the best condition for optimization. The combined use of the different solvents enables a higher recovery of the compounds than their isolated use. This dataset may help other researchers on the application of a mixture design to recover phytochemicals from a broad range of co-products such as defatted meals and other nut cakes, which are sometimes discarded as waste by many industries.

Enabling technologies for the extraction of grape-pomace anthocyanins using natural deep eutectic solvents in up-to-half-litre batches extraction of grape-pomace anthocyanins using NADES

Bioactive compounds should be extracted using alternative solvents and enabling technologies, in accordance with green extraction principles. The aim of this study is to develop an eco-friendly extraction method for grape-pomace anthocyanins on a larger scale. From a preliminary screening of 8 different natural deep eutectic solvents (NADES), a combination of choline chloride:citric acid was selected because of its price, physicochemical properties, and anthocyanin recovery and stability. The effects of multimode-microwave (MW), and low-frequency-ultrasound (US) irradiation (used alone or simultaneously), as well as that of process parameters on extraction efficiency have been investigated in order to maximise anthocyanin extraction yield. The best conditions were found to be: simultaneous ultrasound/microwave-assisted extraction (UMAE) (MW power at 300 W, US power 50 W), for 10 min with 30% (v/v) of water. This gave 1.77 mg g_dw^-1 of anthocyanins. Anthocyanins were efficiently recovered from NADES, which were recycled. The optimised procedure was scaled up to a half-litre batch.

Valorization of papaya (Carica papaya L.) agroindustrial waste through the recovery of phenolic antioxidants by supercritical fluid extraction

In this work, supercritical fluid extraction (SFE) for the recovery of phenolic antioxidants from papaya agroindustrial waste (seeds) was explored, making use of neat supercritical CO₂ and CO₂ added with ethanol (CO₂-EtOH). A full factorial design played on in order to evaluate the effect of CO₂ extraction parameters (temperature between 40 and 60 °C, and pressure between 10 and 30 MPa) on yield and total phenols content (TPC), then ethanol was applied as a co-solvent and its effect on the recovery of phenolics was analyzed. The SFE was compared to the conventional extraction using ethanol. The antioxidant activity of all extracts was evaluated, and the phenolic composition in selected extracts was assessed by HPLC-ESI-MS. The highest extraction yields (21.02-26.46%) and TPC (15.34-34.23 mgGAE/g) were found in extracts obtained with CO₂-EtOH and ethanol. Good and selective phenolic recovery was obtained by using CO₂-EtOH, (44.81% of TPC recovered). The CO₂-EtOH extracts showed high radical scavenging activity and higher antioxidant effect against lipid oxidation. Some phenolic acids and flavonoids were observed in the extracts with better antioxidants properties. The results showed that SFE is a suitable green technology for the phenolic recovery from papaya agroindustrial waste, and also an alternative for its valorization.

Sustainable approach for lycopene extraction from tomato processing by-product using hydrophobic eutectic solvents

Lycopene, a non-polar antioxidant compound with important effects on human health and wide commercial applications, was extracted from tomato processing wastes using innovative hydrophobic eutectic mixtures (HEMs) replacing traditional organic solvents. HEMs were prepared using DL-menthol as hydrogen-bond acceptor (HBA) and lactic acid as hydrogen-bond donor (HBD), and the ultrasound-assisted extraction (UAE) was optimized using a Box-Behnken design to evaluate extraction conditions: extraction temperature (°C), molar ratio of eutectic mixture (moles HBA: mol HBD), solvent to sample ratio (volume to mass, mL/g), and extraction time (min), with lycopene extraction yield (µg/g d.w.) as the response variable. Optimization of parameters was performed using response surface methodology, and the optimized extraction conditions were determined to be 70 °C, 8:1 mol HBA/mol HBD, 120 mL/g solvent: sample, and 10 min. The experimental optimal yield was 1446.6 µg/g, in agreement with the predicted optimal yield, indicating the validity of the model. This new technique for lycopene extraction, using a HEM as extraction solvent in replacement of hazardous organic solvents, and tomato pomace as source material, represents a viable and more sustainable approach for obtaining a high value-added bioactive compound, and can contribute towards the development of greener extraction processes.

Optimization of green extraction methods for cinnamic acid and cinnamaldehyde from Cinnamon (Cinnamomum cassia) by response surface methodology

The major compounds of cinnamon are cinnamic acid and cinnamaldehyde, for which the conditions of microwave-assisted extraction (MAE), ultrasound-assisted extraction (UAE), and reflux extraction (RE) were optimized using response surface methodology for comparing their efficiencies in terms of extraction yield, consumption of time and energy, and CO2 emission. The results indicated MAE superiority to UAE and RE owing to the highest yield of target compounds (total yield: 0.89%, cinnamic acid: 6.48 mg/100 mL, and cinnamaldehyde: 244.45 mg/100 mL) at optimum MAE conditions: 59% ethanol, 147.5 W microwave power and 3.4 min of extraction time. RE resulted in comparable yields with the highest consumption of time, energy, and solvent, and least CO2 emission. Therefore, it is concluded that MAE is the most efficient method for green extraction of cinnamic acid and cinnamaldehyde from cinnamon powder compared to UAE and RE.

An updated review on use of tomato pomace and crustacean processing waste to recover commercially vital carotenoids

Globally, the amount of food processing waste has become a major concern for environmental sustainability. The valorization of these waste materials can solve the problems of its disposal. Notably, the tomato pomace and crustacean processing waste presents enormous opportunities for the extraction of commercially vital carotenoids, lycopene, and astaxanthin, which have diverse applications in the food, feed, pharmaceuticals, and cosmetic industries. Moreover, such waste can generate surplus revenue which can significantly improve the economics of food production and processing. Considering these aspects, many reports have been published on the efficient use of tomato and crustacean processing waste to recover lycopene and astaxanthin. The current review provides up-to-date information available on the chemistry of lycopene and astaxanthin, their extraction methods that use environmentally friendly green solvents to minimize the impact of toxic chemical solvents on health and environment. Future research challenges in this context are also identified.