Utilization of strawberry and raspberry waste for the extraction of bioactive compounds by deep eutectic solvents

Advances in Extracting Bioactive Compounds from Food and Agricultural Waste and By-Products Using Natural Deep Eutectic Solvents: A Circular Economy Perspective

Due to the urgent need for a transition to sustainable, zero-waste green technology, the extraction of bioactives from food and agricultural by-products and waste has garnered increasing interest. Traditional extraction techniques often involve using organic solvents, which are associated with environmental and health risks. Natural deep eutectic solvents (NADESs) have emerged as a promising green alternative, offering advantages such as low toxicity, biodegradability, and the ability to dissolve a wide range of biomolecules. This review provides a comprehensive overview of recent trends in the application of NADESs for extracting bioactive compounds from sustainable sources. The review explains the composition and principles of preparation and highlights various applications of NADESs in extracting different classes of bioactive compounds, emphasizing their potential to revolutionize extraction processes. By summarizing the latest advancements and trends, this review aims to support research and industrial applications of NADESs, promoting more sustainable and efficient extraction methods in the food and agricultural sectors.

Use of encapsulated pomegranate seed oil in novel coarse and nanosized materials for improving the storage life of strawberry

Different-sized pomegranate seed oil-based emulsions (coarse (CsP) and nanoemulsions (NsP): 1246 and 325 nm) were successfully prepared. Strawberries treated with NsP and CsP showed a significant decrease (p < 0.05) in yeast-mold counts (TMY) by 1.80 log CFU g-1, and mesophilic aerobic bacteria counts (TMAB) decreased (p < 0.05) by 0.91 log CFU g-1, respectively. CsP- and NsP-treated strawberries had a TPC of 74.45 and 82.35 mg GAE kg-1, respectively, while control samples had a TPC of 44.24 mg GAE kg-1. The strawberries treated with NsP exhibited the highest antioxidant capacity with 179.44 mol TEAC g-1. After treatment with a coarse emulsion, severity levels of A. niger and B. cinerea were 60 and 73 % while the nanoemulsion treatment significantly reduced severity levels to 55.3 and 56 %. The coarse and nanoemulsions may have potential use within the food industry owing to their antioxidant and antifungal properties as well as their ability to enhance strawberry quality and function.

Valorisation of Raspberry Seeds in Cosmetic Industry-Green Solutions

The fruit processing industry generates large quantities of by-products well known to be rich in bioactive compounds with numerous nutritional properties and beneficial effects for human health. We developed a strategy to valorise raspberry seeds and obtain valuable ingredients with potential application in cosmetic skincare formulas. Cold press extraction technology was applied to extract oil, and the remaining defatted raspberry seed cake was treated with three proline based deep eutectic solvents (DES) to extract polyphenols. The most potent was proline/citric acid extract, with free and total ellagic acid content (52.4 mg/L and 86.4 mg/L), total phenolic content (TPC, 550.1 mg GAE/L) and radical scavenging activity (RSA, 4742.7 mmol TE/L). After the direct mixing of the extract and after encapsulation with starch as a carrier, the skincare emulsion and microemulsion were characterised by irritation potential (Zein test), transepidermal water loss (TEWL), red blood cell (RBC), and DPPH antioxidant test. The resulting preparations were of improved quality in comparison to the control hand cream, with a low skin irritation effect, lower TEWL, and higher antioxidant potential. This work complies with circular economy principles and green technology standards, and represents the efficient model on how to reuse natural resources through waste minimization.

Nutritional and Phytochemical Characterization of Freeze-Dried Raspberry (Rubus idaeus): A Comprehensive Analysis

Several studies have highlighted the beneficial effects of consuming red raspberries on human health thanks to their high content of phytochemicals. However, the products used in these studies, both in the raw or freeze-dried form, were not fully characterized for nutrient and phytochemical composition. In this study, we aimed to determine the nutrient and non-nutrient compounds present in a freeze-dried red raspberry powder widely used by the food industry and consumers. The main sugars identified were fructose (12%), glucose (11%), and sucrose (11%). Twelve fatty acids were detected, with linoleic acid (46%), α-linolenic acid (20%), and oleic acid (15%) being the most abundant. Regarding micronutrients, vitamin C was the main hydro-soluble vitamin, while minerals, potassium, phosphorous, copper and magnesium were the most abundant, with concentrations ranging from 9 up to 96 mg/100 g, followed by manganese, iron and zinc, detected in the range 0.1-0.9 mg/100 g. Phytochemical analysis using UHPLC-DAD-HR-MS detection revealed the presence of Sanguiin H6 (0.4%), Lambertianin C (0.05%), and Sanguiin H-10 isomers (0.9%) as the main compounds. Among anthocyanins, the most representative compounds were cyanidin-3-sophoroside, cyanidin-3-glucoside and cyanidin-3-sambubioside. Our findings can serve as a reliable resource for the food industry, nutraceutical applications and for future investigations in the context of human health.

Alternative Assisted Extraction Methods of Phenolic Compounds Using NaDESs

A renewed understanding of eco-friendly principles is moving the industrial sector toward a shift in the utilization of less harmful solvents as a main strategy to improve manufacturing. Green analytical chemistry (GAC) has definitely paved the way for this transition by presenting green solvents to a larger audience. Among the most promising, surely DESs (deep eutectic solvents), NaDESs (natural deep eutectic solvents), HDESs (hydrophobic deep eutectic solvents), and HNaDESs (hydrophobic natural deep eutectic solvents), with their unique features, manifest a wide-range of applications, including their use as a means for the extraction of small bioactive compounds. In examining recent advancements, in this review, we want to focus our attention on some of the most interesting and novel 'solvent-free' extraction techniques, such as microwave-assisted extraction (MAE) and ultrasound-assisted extraction (UAE) in relation to the possibility of better exploiting DESs and NaDESs as plausible extracting solvents of the phenolic compounds (PCs) present in different matrices from olive oil components, such as virgin olive pomace, olive leaves and twigs, virgin and extra virgin olive oil (VOO and EVOO, respectively), and olive cake and olive mill wastewaters (OMWW). Therefore, the status of DESs and NaDESs is shown in terms of their nature, efficacy and selectivity in the extraction of bioactive phytochemicals such as secoiridoids, lignans, phenolic acids and alcohols. Related studies on experimental design and processes' optimization of the most promising DESs/NaDESs are also reviewed. In this framework, an extensive list of relevant works found in the literature is described to consider DESs/NaDESs as a suitable alternative to petrochemicals in cosmetics, pharmaceutical, or food applications.

Green Extraction of Polyphenols via Deep Eutectic Solvents and Assisted Technologies from Agri-Food By-Products

Polyphenols are the largest group of phytochemicals with important biological properties. Their presence in conveniently available low-cost sources, such as agri-food by-products, has gained considerable attention in their recovery and further exploitation. Retrieving polyphenols in a green and sustainable way is crucial. Recently, deep eutectic solvents (DESs) have been identified as a safe and environmentally benign medium capable of extracting polyphenols efficiently. This review encompasses the current knowledge and applications of DESs and assisted technologies to extract polyphenols from agri-food by-products. Particular attention has been paid to fundamental mechanisms and potential applications in the food, cosmetic, and pharmaceutical industries. In this way, DESs and DESs-assisted with advanced techniques offer promising opportunities to recover polyphenols from agri-food by-products efficiently, contributing to a circular and sustainable economy.

Molecular Guide for Selecting Green Deep Eutectic Solvents with High Monosaccharide Solubility for Food Applications

Monosaccharides play a vital role in the human diet due to their interesting biological activity and functional properties. Conventionally, sugars are extracted using volatile organic solvents (VOCs). Deep eutectic solvents (DESs) have recently emerged as a new green alternative to VOCs. Nonetheless, the selection criterion of an appropriate DES for a specific application is a very difficult task due to the designer nature of these solvents and the theoretically infinite number of combinations of their constituents and compositions. This paper presents a framework for screening a large number of DES constituents for monosaccharide extraction application using COSMO-RS. The framework employs the activity coefficients at infinite dilution (γ_i^∞) as a measure of glucose and fructose solubility. Moreover, the toxicity analysis of the constituents is considered to ensure that selected constituents are safe to work with. Finally, the obtained viscosity predictions were used to select DESs that are not transport-limited. To provide more insights into which functional groups are responsible for more effective monosaccharide extraction, a structure-solubility analysis was carried out. Based on an analysis of 212 DES constituents, the top-performing hydrogen bond acceptors were found to be carnitine, betaine, and choline chloride, while the top-performing hydrogen bond donors were oxalic acid, ethanolamine, and citric acid. A research initiative was presented in this paper to develop robust computational frameworks for selecting optimal DESs for a given application to develop an effective DES design strategy that can aid in the development of novel processes using DESs.

Deep Eutectic Solvents-Based Ultrasound-Assisted Extraction of Antioxidants from Kudingcha (llex kudingcha C.J. Tseng): Process Optimization and Comparison with Other Methods

Kudingcha (KDC) is an important tea substitute containing abundant antioxidants. Herein, a ultrasonic-assisted extraction (UAE) technique based on deep eutectic solvents (DESs) was applied to optimize the total phenolic/total flavonoid content (TPC/TFC) from the KDC extracts. Results indicated that DES composed of L-proline and glycerol (Pro-Gly) had excellent extraction performance for TPC, TFC, ABTS•+ and FRAP, which were significantly better than other solvents. Response surface methodology (RSM) was used to obtain optimal extraction parameters for simultaneously maximizing the TPC, TFC and antioxidant activity. Results revealed that water content in Pro-Gly, liquid to solid ratio (L/S), ultrasonic temperature and extraction time were the major influence factors of the TPC, TFC, ABTS•+ and FRAP of the KDC extracts. The optimal conditions included water content in Pro-Gly of 46.4%, L/S of 25:1 (mL/g), ultrasonic temperature of 55 °C and extraction time of 50 min. Meanwhile, HPLC-MS/MS was adopted to identify the KDC extracts, which revealed the presence of major phytochemicals, including 5-chlorogenic acid, 4,5-dicaffeoylquinic acid, 3,5-dicaffeoylquinic acid, 3,4-dicaffeoylquinic acid, kaempferol 3-rutinoside, myricetin and isorhamnetin. Moreover, UAE-Pro-Gly achieved further higher individual phenolics contents, TPC, TFC, ABTS•+ and FRAP than other methods. In conclusion, UAE-Pro-Gly is a highly efficient method for extraction of phenolic antioxidants from KDC.

Strawberry Fragaria x ananassa cv. Festival: A Polyphenol-Based Phytochemical Characterization in Fruit and Leaf Extracts

Berry fruits are an important dietary source of health-promoting antioxidant polyphenols. Interestingly, berry leaves of diverse species, including strawberries, have shown higher bioactive phytochemical content in the leaves than in the fruit. Moreover, the vegetative part of the plants is usually discarded, representing a presumably large source of underutilized bioactive biomass. In this investigation, the polyphenol profiles of tropical highland strawberry (Fragaria x ananassa cv. Festival) leaves and fruits were compared by high-performance liquid chromatography coupled with a diode array detector (UHPLC-DAD) and mass spectrometry (HPLC-MS). The total polyphenol strawberry leaf extracts exhibited a 122-fold-higher total polyphenol content and 13-fold higher antioxidant activity (ORAC) than strawberry fruits, and they showed evidence of possible photoprotective effects against UV damage in human melanoma cells (SK-MEL-28) and in murine embryo fibroblasts (NIH/3T3), together with promising anti-proliferative activities against the same melanoma cells. Seven polyphenols were confirmed by HPLC-DAD in the leaf extracts, with differences depending on fraction solubility. Moreover, three substituted quercetin derivatives, three substituted kaempferol derivatives, two anthocyanins, and catechin were confirmed in the soluble fraction by HPLC-MS. Given their higher total polyphenol content and bioactive activities, underutilized strawberry Festival leaves are a potential source of apparently abundant biomass with prospective bioactive applications.

Stillage Waste from Strawberry Spirit Production as a Source of Bioactive Compounds with Antioxidant and Antiproliferative Potential

The production of fruit distillates generates solid residues which are potentially rich in bioactive compounds worthy of valorization and exploitation. We report herein the in vitro antioxidant and antiproliferative properties of an extract obtained from the waste of fermented strawberry distillate production. The main low molecular weight phenolic components of the extract were identified as ellagic acid and p-coumaric acid using spectroscopic and chromatographic analysis. The extract exhibited high antioxidant properties, particularly in the ferric reducing/antioxidant power (FRAP) assay, and a high total phenolic content (TPC). It was also able to induce an antiproliferative effect on different human cancer cell lines. A strong decrease in viability in human promyelocytic leukemia (HL-60) cells through a rapid and massive apoptosis were observed. Moreover, at an early time (<30 min), reactive oxygen species (ROS) production and inactivation of the extracellular signal-regulated kinase (ERK)/mitogen-activated protein kinases (MAPK) pathway were detected. Notably, the antiproliferative activity of the sample was comparable to that observed with an analogous extract prepared from unfermented, fresh strawberries. These results bring new opportunities for the valorization of fruit distillery by-products as low-cost resources for the design of bioactive formulations of comparable value to that from fresh food.

Towards food circular economy: hydrothermal treatment of mixed vegetable and fruit wastes to obtain fermentable sugars and bioactive compounds

Due to processing activity, fruits and vegetables generate notable amounts of wastes at the processing, retail, and consumption level. Following the European goals for reducing food wastes and achieving a circular economy of resources, these biowastes should be valorized. In this work, hydrothermal hydrolysis at different conditions (temperatures, times, waste/water ratio, pH values) were tested to treat for first time; biowastes composed of mixed overripe fruits or vegetables to maximize the extraction of fermentable sugars that can be used as substrates in bioprocesses. Experimental data were fitted by a model based on irreversible first-order reactions, and kinetic constants were obtained. When hydrolysis of fruit wastes was carried out at 135 °C and pH 5 during 40 min, more than 40 g of reducing sugars per 100 g of waste (dry weight) could be obtained (represents an extraction of 97% of total carbohydrates). Concentrations of inhibitor compounds (HMF, furfural, acetic acid) in the hydrolysates were very low and, as example, a fermentation to obtain bioethanol was successfully carried out with an efficiency above 95%. Additionally, the production by hydrothermal treatment of bioactive compounds was investigated and the best results obtained were 92% DPPH inhibition and 12 mg GAE/g (dry weight) for antioxidant activity and phenolic compounds, respectively. These values are similar or even higher than those reported in literature using specific parts of fruits and vegetables.

Optimization of ultrasound-assisted extraction of phenolics from Asparagopsis taxiformis with deep eutectic solvent and their characterization by ultra-high-performance liquid chromatography-mass spectrometry

Asparagopsis taxiformis is a significant source of phenolics. Owing to the incessant demand of green extraction procedures for phenolics from A. taxiformis, ultrasound-assisted extraction (UAE) using deep eutectic solvents (DESs) was optimized. Among the tested DESs, betaine-levulinic acid afforded the highest total phenolic content (TPC). Moreover, the optimal extraction conditions elucidated from single-factor and response surface methodologies comprised a 52.41°C ultrasonic temperature, 46.48% water content of DES, and 26.99 ml/g liquid-to-solid ratio. The corresponding TPC (56.27 mg GAE/100 g DW) and antioxidant ability fitted the predicted values. UAE afforded superior TPC and antioxidant abilities with DESs than with traditional solvents. Using UHPLC-MS, seven phenolic acids, 18 flavonoids, and two bromophenols were identified and quantified. DES-UAE afforded the highest phenolic compound number (26) and sum of contents. These results disclose the high extraction efficiency of DES-UAE for A. taxiformis phenolics and provide a basis for the higher-value application of this species.

Solvents effect on phenolics, iridoids, antioxidant activity, antibacterial activity, and pancreatic lipase inhibition activity of noni (Morinda citrifolia L.) fruit extract

This study focused on the relationship between content levels of phytochemicals and the biological activities of noni (Morinda Citrifolia L.) fruit extracts (NFEs) prepared with traditional solvents and deep eutectic solvents (DESs). The results indicated the total phenolic content in Bet-Gly (Betaine: Glycerol) extracts (11.89 mg GAE/g DW) and total iridoid content in 70% ethanol extracts (26.38 mg CE/g DW) were the highest. A total of 17 compounds were identified and quantified in NFEs. Traditional solvent extracts, except ethyl acetate, exhibited higher antioxidant activities than DESs. Three DES extracts showed higher activities against pancreatic lipase than traditional solvent extracts. Multivariate analysis revealed that the type of extraction solvent exerts a significant influence on the phytochemical compositions and biological activities of NFEs. This study provided valuable information on the efficient extraction of phytochemicals from noni fruits and DESs are promising green solvent for the extraction of bioactive compounds from noni fruits.

Optimization of Deep Eutectic Solvent Extraction of Phenolic Acids and Tannins from Alchemilla vulgaris L

Alchemilla vulgaris L. is a good source of antioxidant components with an emphasis on phenolic acids and tannins. In this study, gallic acid, ellagic acid, and hydrolyzable tannins (HT) were extracted from this plant with different deep eutectic solvents (DESs), varying the amount of added H2O, temperature and extraction time. Seventeen DESs (n = 3) were used for the extraction, of which choline chloride:urea (1:2) proved to be the most suitable. The selection of the best solvent was followed by the examination of the influence of the extraction type and parameters using response surface methodology (RSM). Gallic acid content was in the range of 0.00-1.89 µg mg-1, ellagic acid content was 0.00-12.76 µg mg-1 and hydrolyzable tannin (HT) content was 3.06-181.26 µgTAE mg-1, depending on the used technique and the extraction conditions. According to the results, extraction by stirring and heating was the most suitable since the highest amounts of gallic acid, ellagic acid, and HT were extracted, and the obtained optimal values using response surface methodology (RSM) are confirmed by experimentally obtained values.

Impact of Eutectic Solvents Utilization in the Microwave Assisted Extraction of Proanthocyanidins from Grape Pomace

The extraction of proanthocyanidins (PACs), despite being an important and limiting aspect of their industrial application, is still largely unexplored. Herein, the possibility of combining eutectic solvents (ESs) with microwave assisted extraction (MAE) in the extraction of PACs from grape pomace (GP) is explored, aiming to improve not only the extraction yield but also the mean degree of polymerization (mDP). The combination of choline chloride with lactic acid was shown to be the most effective combination for PACs extraction yield (135 mg_PAC/g_GP) and, despite the occurrence of some depolymerization, also enabled us to achieve the highest mDP (7.13). Additionally, the combination with MAE enabled the process to be completed in 3.56 min, resulting in a considerably reduced extraction time.

Influence of Raspberry and Its Dietary Fractions on the In vitro Activity of the Colonic Microbiota from Normal and Overweight Subjects

Raspberry is a source of dietary fibre and phenolic compounds, which are metabolised by the gut microbiota, resulting in the production of short chain fatty acids (SCFAs) and phenolic catabolites; but the formation of these compounds depends on the microbiota composition. The aim of this study was to investigate whether the raspberry and its fractions (phenolic extract, total and insoluble dietary fibre) affect the microbial activity depending on the body weight condition. For this, in vitro fermentations of raspberry fractions were carried out using faeces from normal-weight (NW) and overweight volunteers (OW) during 48 h, and phenolic catabolites and SCFAs were analysed at 0, 6, 24 and 48 h. The whole raspberry and the phenolic extract produced greater quantities of urolithins and total SCFAs when compared with fibre fractions, reaching the highest amount between 24 and 48 h. The body weight condition was an important factor, since faeces from NW led to greater production of urolithins from non-extractable phenolic compounds bound to fibre fractions, whereas in OW the urolithins production was higher from the fractions with more extractable polyphenols. In summary, the whole raspberry has been shown to have a prebiotic effect, mainly due to its phenolic compounds content rather than its fibre content.

Effect of chia seed mucilage/bacterial cellulose edible coating on bioactive compounds and antioxidant activity of strawberries during cold storage

This study aimed to investigate the effect of chia seed mucilage (CSM) - bacterial cellulose nano-fiber (CNF) edible coating on bioactive compounds and antioxidant enzyme activity of strawberries. Strawberries were coated with CSM containing 0.6 and 8.0% (w/w) of CNF. The content of total phenol, flavonoids, anthocyanin, ascorbic acid, protein content, antioxidant activity and the activity of polyphenol oxidase, peroxidase, superoxide dismutase and phenylalanine ammonia-lyase enzymes were evaluated. The use of CSM - CNF edible coatings further preserved the phenolic, flavonoid, ascorbic acid and antioxidant activity of strawberries, and this effect was more evident in the CSM-coated sample containing CNF; However, the accumulation of anthocyanins in the coated samples was lower than the control sample. The activity of polyphenol oxidase and peroxidase enzymes, which lead to the degradation of phenolic compounds and brown color in the product, was also effectively controlled by the edible coating.

Effects of aerosolized citric acid-radio frequency as a pretreatment on hot-air drying characteristics of banana

The effects of aerosolized citric acid-radio frequency (RF) pretreatment were evaluated on the quality characteristics of hot air-dried banana. The results showed that increasing the RF intensity elevated the total phenolic content (TPC), shrinkage, and color changes, while the TPC and color changes decreased with increasing the RF exposure duration. A rise in the RF intensity reduced the rehydration ratio (RR) and firmness of the samples. Aerosolization of citric acid rendered the preservation of the phenolic compounds of the samples to a higher extent, and TPC decreased from 311 ± 3.4 mg/g in fresh banana to 252.1 ± 4.24 mg/g in the samples treated with a RF of 27.12 Hz for 40 min, 280.5 ± 8.1 mg/g in the ones treated with 1% aerosolized citric acid for 40 min, and 162.5 ± 10.8 mg/g in the ones with no pretreatment. According to scanning electron microscopy (SEM), the application of aerosolized citric acid pretreatment caused tissue softening and the formation of cell holes in the samples. Cell wall collapse and damage were severe when RF was in use, which caused the blockage of some microchannels within the tissue. The Page model with the highest determination coefficient (R 2) and the lowest root-mean-squared error (RMSE) and chi-square (χ 2) was selected as the best model.

Bioactive Compounds from Agricultural Residues, Their Obtaining Techniques, and the Antimicrobial Effect as Postharvest Additives

Agricultural vegetable products always seek to meet the growing demands of the population; however, today, there are great losses in supply chains and in the sales stage. Looking for a longer shelf life of fruits and vegetables, postharvest technologies have been developed that allow an adequate transfer from the field to the point of sale and a longer shelf life. One of the most attractive methods to improve quality and nutritional content and extend shelf life of fruits and vegetables is the incorporation of bioactive compounds with postharvest technologies. These compounds are substances that can prevent food spoilage and the proliferation of harmful microorganisms and, in some cases, act as a dietary supplement or provide health benefits. This review presents an updated overview of the knowledge about bioactive compounds derived from plant residues, the techniques most used for obtaining them, their incorporation in edible films and coatings, and the methods of microbial inhibition.

LC-Q-Orbitrap-MS/MS Characterization, Antioxidant Activity, and α-Glucosidase-Inhibiting Activity With In Silico Analysis of Extract From Clausena Indica (Datz.) Oliv Fruit Pericarps

Clausena indica (Datz.) Oliv fruit pericarps (CIOPs) is an important agro-industrial by-product rich in active components. In this article, the effects of traditional and green deep eutectic solvents (DESs) on the high-performance liquid chromatography (HPLC) characterization, antioxidant activities, and α-glucosidase-inhibitory activity of phenolic extracts from CIOPs were investigated for the first time. The results showed that ChCl-Gly and Bet-CA had higher extraction efficiency for the total phenolic content (TPC, 64.14-64.83 mg GAE/g DW) and total flavonoid content (TFC, 47.83-48.11 mg RE/g DW) compared with the traditional solvents (water, methanol, and ethyl acetate). LC-Q-Orbitrap-MS/MS was adopted to identify the phenolic compositions of the CIOPs extracts. HPLC-diode array detection (HPLC-DAD) results indicated that arbutin, (-)-epigallocatechin, chlorogenic acid, procyanidin B1, (+)-catechin, and (-)-epicatechin were the major components for all extracts, especially for deep eutectic solvents (DESs). In addition, ChCl-Xyl and ChCl-Gly extracts showed higher antioxidant activities against 2,2-diphenyl-1-picrylhydrazyl (DPPH•), 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid (ABTS+•), ferric reducing antioxidant power (FRAP), reducing power (RP), and cupric ion reducing antioxidant capacity (CUPRAC) than extracts extracted by other solvents. A strong α-glucosidase-inhibiting activity (IC50, 156.25-291.11 μg/ml) was found in three DESs extracts. Furthermore, in silico analysis of the major phenolics in the CIOPs extracts was carried out to explore their interactions with α-glucosidase. Multivariate analysis was carried out to determine the key factors affecting the antioxidant activity and α-glucosidase-inhibiting activity. In short, DES can be taken as a promising solvent for valorization and recovery of bioactive compounds from agro-industrial by-products. The results verified that CIOPs can be used as a prospective source rich in bio-active compounds applied in the food and pharmacy industries.

Antioxidant capacity, total phenolic content and phenolic compounds of pulp and bagasse of four Peruvian berries

Revaluing agri-food waste to offer consumers bioactive compounds for a healthy diet is an important issue. In the present work, the antioxidant capacity (AC), total phenolic content (TPC) and phenolic compounds of pulp and bagasse of four Peruvian berries with UHPLC-DAD was determined. Elderberry (Sambucus peruviana Kunth) bagasse had a greater amount of TPC (4.87 ± 0.02 mg GAE/100 gfw) and AC (7.66 ± 0.04 and 7.51 ± 0.24 μmol TE/gfw in DPPH and ABTS, respectively) than the bagasse of the other berries, with a strong positive correlation between TPC and AC. Blueberry (Vaccinium floribundum Kunth) bagasse contains the highest amount of gallic acid (103.26 ± 1.59 μg/gfw), chlorogenic acid (1276.55 ± 1.86 μg/gfw), caffeic acid (144.46 ± 1.78 μg/gfw), epicatechin (1113.88 ± 1.82 μg/gfw) and p-coumaric acid (77.82 ± 1.92 μg/gfw). Elderberry (Sambucus peruviana Kunth) bagasse contains the highest amount of catechin (153.32 ± 0.79 μg/gfw). No significant differences were found in the content of chlorogenic acid and epicatechin of blackberry (Rubus roseus Poir). It was shown that the wastes of the four Amazonian berries have higher values of bioactive properties than their pulp, being the elderberry bagasse the one with the best properties.

Deep eutectic solvent-homogenate based microwave-assisted hydrodistillation of essential oil from Litsea cubeba (Lour.) Pers. fruits and its chemical composition and biological activity

As an important natural product, the sufficient separation of plant essential oil (EO) is helpful to improve its utilization value. In this work, deep eutectic solvent-homogenate based microwave-assisted hydrodistillation (DES-HMAHD) was developed and applied to isolate EO from the fruits of Litsea cubeba (Lour.) Pers. Different types of DES were investigated in terms of the EO kinetics and composition, among which oxalic acid/choline chloride (OA/ChCl) had obvious advantages. Following, molar ratio of OA and ChCl (1:1), water content (50%), liquid-solid ratio (12.5:1 mL/g), homogenate time (2 min), and microwave power (700 W) were found to be the optimum conditions. Gas chromatography-mass spectrometer (GC-MS) analysis showed that the EO isolated from DES-HMAHD contained a large proportion of m-cymene and trans-linalool oxide, which were quite different from the conventionally reported L. cubeba EO. In addition, the proposed DES-HMAHD resulted in higher separation efficiency and economic value, as well as lower environmental impact, as compared with other techniques. Afterwards, the EO isolated by different methods was evaluated from the perspective of biological activity. The EO obtained by DES-HMAHD showed higher antioxidant activity (DPPH and ABTS) but lower antifungal activity, which was related to its chemical composition. In general, DES-HMAHD produced a kind of L. cubeba EO with different components, which provided a scientific foundation for the sufficient isolation of plant EO and its application in the natural products.

Innovative Extraction Techniques Using Deep Eutectic Solvents and Analytical Methods for the Isolation and Characterization of Natural Bioactive Compounds from Plant Material

The growing interest of the food, pharmaceutical and cosmetics industries in naturally occurring bioactive compounds or secondary plant metabolites also leads to a growing demand for the development of new and more effective analysis and isolation techniques. The extraction of bioactive compounds from plant material has always been a challenge, accompanied by increasingly strict control requirements for the final products and a growing interest in environmental protection. However, great efforts have been made in this direction and today a considerable number of innovative extraction techniques have been developed using green, environmentally friendly solvents. These solvents include the deep eutectic solvents (DES) and their natural equivalents, the natural deep eutectic solvents (NADES). Due to their adjustable physical-chemical properties and their green character, it is expected that DES/NADES could be the most widely used solvents in the future, not only in extraction processes but also in other research areas such as catalysis, electrochemistry or organic synthesis. Consequently, this review provided an up-to-date systematic overview of the use of DES/NADES in combination with innovative extraction techniques for the isolation of bioactive compounds from various plant materials. The topicality of the field was confirmed by a detailed search on the platform WoS (Web of Science), which resulted in more than 100 original research papers on DES/NADES for bioactive compounds in the last three years. Besides the isolation of bioactive compounds from plants, different analytical methods are presented and discussed.

Optimization Ultrasound-Assisted Deep Eutectic Solvent Extraction of Anthocyanins from Raspberry Using Response Surface Methodology Coupled with Genetic Algorithm

Raspberries have been reported to contain abundant anthocyanins and other active compounds. To extract anthocyanins from raspberries more efficiently, a novel procedure of ultrasound-assisted deep eutectic solvent extraction (UADESE) was proposed in this paper. The extraction process was optimized by response surface methodology coupled with a genetic algorithm. The optimum extraction parameters to achieve the highest yield of anthocyanins 1.378 ± 0.009 mg/g from raspberry powder via UADESE were obtained at a water content of 29%, ultrasonic power of 210 W, extraction temperature of 51 °C and extraction time of 32 min. The AB-8 macroporous resin combined with the high-speed counter current chromatography (HSCCC) method were further used to isolate and purify the anthocyanins extracts obtained under optimum extraction conditions, and the structure of purified anthocyanins components were identified by UV-Visible spectrophotometer (UV-Vis), high-performance liquid chromatography (HPLC), high-performance liquid chromatography-electrospray ionization-mass spectrometry (HPLC-ESI-MS/MS), ¹H nuclear magnetic resonance (NMR) and ¹³C-NMR spectra. The two anthocyanins (cyanidin-3-glucoside with a purity of 92.25% and cyanidin-3-rutinoside with a purity of 93.07%) identified were consistent with those present in raspberries. These findings provided an effective and feasible method for extraction, isolation and purification of anthocyanins from natural plant resources.