Search Results (15)

Pod is the major solid waste from bean processing, and its accumulation is expected to increase in the coming years due to the increases in pulse consumption. This study aimed to investigate (a) the efficacy ultrasound (US)-assisted extraction of polyphenols from bean pod; (b) their solubilization rate constants and effective diffusivities (De), which are relevant parameters for scaling-up the process; and (c) the encapsulation efficiencies of the recovered phenolic compounds in hydrogel microbeads. Extracts were obtained either in water with US assistance (50–350 W·L⁻¹) at 30 °C; in water at 30, 45 and 60 °C; or in water/ethanol mixtures at room temperature. Extracts were analyzed using HPLC with diode array and fluorometric detectors. The extract from US-assisted extraction, selected as the most promising treatment among those evaluated, was then encapsulated in alginate or alginate/chitosan microbeads. Changes in the solubilization rate constants (from 0.097 to 0.480 min⁻¹) and De (from 3.4·10⁻¹¹ to 4.6·10⁻⁹ m²·s⁻¹) were observed upon the application of US. Increasing the acoustic energy density was more effective at accelerating solubilization than either increasing the temperature or using ethanol as a cosolvent. Polyphenols were better encapsulated in an alginate/chitosan matrix than in alginate alone, achieving 71% recovery of ferric reducing antioxidant power and 69% recovery of 2,2-diphenyl-1-picrylhydrazyl radical-scavenging activity. The cost-effective alginate/chitosan matrix entrapping of pod polyphenols is potentially useful in various food applications. Full article

Moringa oleifera leaves are a protein-rich source containing all essential amino acids and offering high nutritional value. Ultrasound-assisted extraction (UAE) has emerged as an efficient method to improve protein recovery while enhancing the structural and functional properties of plant proteins. This study aimed to improve protein extraction from M. oleifera leaves using UAE and to characterize the nutritional composition and gel-related properties of the resulting protein concentrate. Chosen conditions were a solubilization pH of 11.68, 20 min of ultrasound treatment, and precipitation at pH 4.5, resulting in an extraction yield of 79.90% and protein content of 53.97%. Moringa oleifera leaf flour (MOF) contained 29.38% protein, 37.98% dietary fiber, and high mineral levels (1751.85 mg/100 g of calcium; 512.55 mg/100 g of magnesium). Compared with MOF, the M. oleifera protein concentrate (MOPC) showed a 21.4% increase in essential amino acids, with leucine and lysine being the most abundant. Functionally, MOPC exhibited 24.26% solubility at pH 2, complete gelation at pH 8, 58.66% emulsifying capacity with 79.52% stability at pH 10, and 21.11% foaming capacity with 94.44% stability at pH 2. The gel-forming ability was the most promising characteristic, highlighting the potential of MOPC as a natural structuring agent in gel-based food systems and functional formulations. Full article

In the present study, ultrasound-assisted extraction using deep eutectic solvents was proposed for the preparation of uniced and iced gingerbread cookies prior to the determination of four macronutrients (potassium, sodium, magnesium, calcium), four micronutrients (manganese, zinc, iron, copper), the presence of toxic metal (cadmium), and antioxidant capacity. With the addition of 30% water in each green solvent, three acidic deep eutectic solvents, comprising xylitol with malic acid, choline chloride with malic acid, and choline chloride with lactic acid, were tested for their efficiencies in the simultaneous extraction of elements and antioxidants. The synthesized deep eutectic solvents were characterized by infrared spectroscopy, which provided evidence of generating new hydrogen bonds between two components of these solvents. Element profiles were analyzed by inductively coupled plasma–mass spectrometry after the extraction using green solvents and the microwave-assisted acid digestion of gingerbread samples. It was found that two deep eutectic solvents containing malic acid exhibited high abilities for solubilization of macronutrients and manganese from the samples studied, while the best extraction efficiencies for Zn, Fe and Cu micronutrients were achieved when the lactic acid-based deep eutectic solvent was used. However, the antioxidant capacity, evaluated by 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and cupric reducing antioxidant capacity (CUPRAC) methods, led to the selection of choline chloride–lactic acid as the most promising green solvent for extracting antioxidants from two types of gingerbread cookies. The deep eutectic solvent-based extraction conforms to the principles of green chemistry and is suitable for releasing elements and antioxidants from gingerbread cookies. Full article

Deep eutectic solvents (DESs) have been studied to obtain extracts from medicinal plants, aiming for a more environmentally friendly process. Aligned with this initiative, the use of predictive thermodynamic models for screening the best solvent represents a theoretical action to reduce experimental time and cost. Therefore, this study aimed to perform and validate a relative solubility screening of 5-methoxy-6,7-methylenedioxycoumarin and prenyletin-methyl-ether at 313 K in choline chloride, menthol, and betaine-based DES, using the COSMO-RS model in COSMOThermX software. The density of DES was also predicted with a maximum error of 7.31% for this property. Ultrasound-assisted extraction (UAE) with DES at 313 K, 30 min, and a solid/liquid ratio of 1:20 (w/w) was performed to confirm the theoretical solubility results experimentally, as the extracts were analyzed through ultrafast liquid chromatography (UFLC) for coumarin content. For the results, the coumarin molecules presented intense peaks in the nonpolar region of their σ-profile, and the relative solubility screening indicated the DES Men/Lau (2:1), known for its hydrophobic nature and low polarity, as the best DES to solubilize these coumarins. Nevertheless, the UFLC results, and the complementary solubility screening of pigments, showed an interaction preference of this DES with chlorophylls instead of coumarins. This result was corroborated by spectrophotometric analysis of the extracts in UV-Vis, demonstrating that experimental validation is still mandatory in extraction processes and that predictive methodologies such as COSMO-RS should be used as guiding tools and analyzed in a greater context, considering the complexity of plant matrices in the beginning of simulations. Full article

This comprehensive review explores the extraction and utilization of marine collagen, a sustainable alternative to traditional mammalian sources. The review covers conventional extraction methods like acid and pepsin solubilization, highlighting their limitations and contributing to the search for improved efficiency and sustainability. It also delves into innovative extraction technologies, such as ultrasound-assisted extraction, deep eutectic solvents, and supercritical carbon dioxide, showing their potential to revolutionize the field. The significance of collagen hydrolysis in generating bioactive peptides with diverse functionalities is also discussed, emphasizing their potential applications in various sectors. By providing an analysis of marine collagen extraction and its implications, this review presents a perspective for leveraging this valuable bioresource, promoting a circular economy, and satisfying the increasing demand for high-quality collagen in diverse industries. Full article

As a kind of bioactive component in the rhizome of natural plant Curcuma longa L. (turmeric), curcumin is almost insoluble in water at neutral and acidic pH, which limits its further utilization and development. At the same time, traditional extraction and separation processes typically require the use of a large number of organic solvents. Ionic liquids (ILs) are organic molten salts with melting points below 100 °C. When an ionic liquid exists in a liquid state at or near room temperature, it is referred to as a room-temperature ionic liquid (RTIL). They have a temperature range, good physical and chemical stability, and good structural designability. They have a strong solubilization enhancement effect for many organic compounds. This study first explored the molecular forms of curcumin in ionic liquid aqueous solutions and the intermolecular interactions between curcumin and ionic liquids using spectral analysis and computational chemistry methods; furthermore, using an ionic liquid aqueous solution as an extraction agent, curcumin-like substances (curcuminoids) were extracted from turmeric powders under ultrasound assisted conditions, revealing the relationship between the structure of the ionic liquid and the extraction efficiency. After that, a kinetic study was conducted for the extraction of curcuminoids from turmeric powders, using second-order kinetics fitting to obtain the rate constant and initial extraction rate during the extraction process. Finally, the comparison with a ComplexGAPI tool and antioxidant experiment was performed on the extraction by using ionic liquids and traditional solvent. The full results can provide reference for the design of IL extractants and their application for natural products. Full article

Hydroxycinnamic acids are an essential phenolic group in honey that are related with its diverse health effects. Furthermore, they can be considered as potential biomarkers for botanical and geographical origin. The extraction of hydroxycinnamic acids from honey requires complicated extraction techniques due to their low contents and matrix particularity. The goal of the present work was to develop a green sample preparation method for the solubilization of hydroxycinnamic acids in honey samples. Thus, a Box–Behnken design has been used to investigate the effect of four factors: (i) percentage of ethanol (60–90%, v/v), (ii) temperature (30–60 °C), (iii) solvent-honey ratio (10–30 mL g⁻¹), and (iv) sonication time (10–40 min) on the contents of caffeic, chlorogenic, and ferulic acids. Based on the desirability index, the ultrasound-assisted mixing of honey with 60.0% (v/v) ethanol at a solvent-honey ratio of 10 mL g⁻¹ for a period of 17.8 min at a temperature of 54.6 °C resulted in the maximum solubilization of hydroxycinnamates. Subsequently, the greenness of developed method was assessed and applied successfully on the analysis of honeys. The present study reports for first time the hydroxycinnamic acid fingerprint of multi-floral honey produced in Cyprus. Full article

The use of bioactive plant extracts in cosmetic products is a common practice. Most of these extracts are obtained by maceration in organic solvents, and depending on which solvents are used, the polarity and the structure of the target molecules will vary. Polyphenols are polar compounds that often display antioxidant and/or antibacterial activities. To extract them, ethanol/water mixtures are usually selected as green solvents. This solid–liquid extraction (assisted or not) requires the use of high volumes of solvents and many additional steps like mixing, agitation, filtration, and evaporation. Alternatively, supercritical carbon dioxide (SC-CO₂) offers many benefits for plant extraction: economical, non-toxic, and naturally concentrated extracts. However, its low polarity is not suitable to solubilize polar compounds. In this study, an experimental design was used to optimize supercritical fluid extraction (SFE) of caffeine and catechins from Camellia sinensis. Catechins are recognized for skin care use (antioxidant) and caffeine is also used for its skin care properties and to prevent excess storage of fat in cells. The temperature, modifier content, and water additive percentage were used as independent variables. The results showed that while the temperature was an insignificant parameter, a higher percentage of water (up to 20% in ethanol) and modifier favored the extraction of the polar target molecules. Additionally, the SFE results were compared with ultrasound-assisted extraction (UAE). Finally, a sequential selective extraction of caffeine from catechins is also presented. Full article

Collagen is the most abundant structural protein in animals. It is the major component of skin. It finds uses in cosmetics, medicine, yarn production and packaging. This paper reviews the extraction of collagen from hides of most consumed animals for meat with the focus on literature published since 2000. The different pretreatment and extraction techniques that have been investigated for producing collagen from animal skins are reviewed. Pretreatment by enzymatic, acid or alkaline methods have been used. Extraction by chemical hydrolysis, salt solubilization, enzymatic hydrolysis, ultrasound assisted extraction and other methods are described. Post-extraction purification methods are also explained. This compilation will be useful for anyone wishing to use collagen as a resource and wanting to further improve the extraction and purification methods. Full article

The current interest in using olive biophenols to promote functional ingredients and antioxidant additives is increasing. These compounds can be obtained from olive fruit and olive-derived biomasses using different technologies. However, other components can be co-extracted. Therefore, the main objective of this study was to evaluate the effect on protein solubilization of several extraction technologies, which were applied to obtain olive biophenols from olive-derived biomasses. For this purpose, conventional (Soxhlet and water bath) and non-conventional technologies (ultrasound and microwave) were evaluated. The total phenolic content was measured using the Folin and Ciocalteu method and the protein content was measured using the Dumas combustion method. The phenolic profile and the hydroxytyrosol content were also determined. Overall, the highest total phenolic content was obtained using the Soxhlet method, while the microwave-assisted extraction at 100 °C led to the highest protein solubilization (closer to 60%) using water. Full article

Isoflavones can be found in different chemical forms, but the health beneficial effects mainly appear in their free forms—aglycones. Their yield in red clover (Trifolium pratensis L.) extracts differs due to different extraction and hydrolysis methodologies. The main aim of this study was to obtain the highest yields of daidzein and genistein from red clover blossoms through the various extraction and hydrolysis methods and to increase their quantities using additional excipients. Extracts were obtained by ultrasound-assisted, heat-reflux and maceration methods combining them with acidic, alkaline, and thermal hydrolysis. Using ultrasound-assisted extraction with optimal conditions and heat-reflux method highest yields of isoflavones were obtained in UTE510 (393.23 ± 19.66 µg/g daidzein and 171.57 ± 8.58 µg/g genistein); UTE530 (415.07 ± 20.75 µg/g daidzein and 150.57 ± 7.53 µg/g genistein) and HNE5 (432.30 ± 21.61 µg/g daidzein and 154.50 ± 7.72 µg/g genistein) samples. These conditions were used with excipients: magnesium aluminometasilicate, croscarmellose sodium, sodium carboxymethyl starch and vinylpyrrolidone-vinyl acetate copolymer. This is the first study reporting the ability of the vinylpyrrolidone-vinyl acetate copolymer to promote solubilization and availability of active compounds from a herbal extract, resulting in enhanced isoflavones yield. The results of the present study showing increased solubility and availability provided by the vinylpyrrolidone-vinyl acetate copolymer suggest that this preparation could in principle also reduce variability due to limited water solubility of isoflavones. Full article

Trifolium pratense L. is receiving increasing attention due to the isoflavones it contains, which have been studied for their benefits to human health. A common problem with isoflavone aglycones is a rather low water solubility and limited pharmaceutical applications. The use of excipients, such as cyclodextrins in the production of isoflavone rich extracts, could become one of the new strategies for the extraction of target compounds. The aim of this study was to evaluate an eco-friendly method using the effects of α-, β- and γ-cyclodextrins for isoflavone solubilization in plant extracts in comparison to a standard extract without excipients. Extractions of red clover were prepared using ultrasound-assisted combined with thermal hydrolysis and heat reflux. It was determined that cyclodextrins significantly increased the isoflavones aglycone yields. By increasing cyclodextrins in the extraction media from 1 to 5%, the daidzin concentration increased on average by 1.06 (α-cyclodextrins), 1.4 (β-cyclodextrins) and 1.25 (γ-cyclodextrins) times. Genistein concentration increased using α- and γ-cyclodextrins (1.28 and 1.12 times, α- and γ-cyclodextrins, respectively), but decreased using β-cyclodextrins. The results showed that the cyclodextrin-assisted extraction enhanced the yields of isoflavones from red clover, which suggests using cyclodextrins as a green alternative and a cost-effective method to increase its pharmaceutical application. Full article

Olive-derived biomass is not only a renewable bioenergy resource but also it can be a source of bioproducts, including antioxidants. In this study, the antioxidant composition of extracted olive pomace (EOP) and a new byproduct, the residual fraction from olive pit cleaning (RFOPC or residual pulp) was characterized and compared to olive leafy biomass, which have been extensively studied as a source of antioxidants and other bioactive compounds with pharmacological properties. The chemical characterization showed that these byproducts contain a high amount of extractives; in the case of EOP, it was even higher (52.9%) than in olive leaves (OL) and olive mill leaves (OML) (35.8–45.1%). Then, ultrasound-assisted extraction (UAE) was applied to recover antioxidants from the extractive fraction of these biomasses. The solubilization of antioxidants was much higher for EOP, correlating well with the extractives content and the total extraction yield. Accordingly, this also affected the phenolic richness of the extracts and the differences between all biomasses were diminished. In any case, the phenolic profile and the hydroxytyrosol cluster were different. While OL, OML, and EOP contained mainly hydroxytyrosol derivatives and flavones, RFOPC presented novel trilignols. Other compounds were also characterized, including secoiridoids, hydroxylated fatty acids, triterpenoids, among others, depending on the bioresource. Moreover, after the UAE extraction step, alkaline extraction was applied recovering a liquid and a solid fraction. While the solid fraction could of interest for further valorization as a biofuel, the liquid fraction contained proteins, sugars, and soluble lignin, which conferred antioxidant properties to these extracts, and whose content depended on the biomass and conditions applied. Full article

Fermentation in solid state culture (SSC) has been the focus of increasing interest because of its potential for industrial applications. In previous studies SSC of pomegranate wastes by Aspergillus niger has been extensively developed and optimized for the recovery of ellagic acid (EA), a high value bioactive. In this study we comparatively investigated the SSC of powdered pomegranate husks by A. niger and Saccharomyces cerevisiae and evaluated the recovery yields of EA by an ultrasound and microwave-assisted 7:3 water/ethanol extraction. Surprisingly enough, the yields obtained by S. cerevisiae fermentation (4% w/w) were found 5-fold higher than those of the A. niger fermented material, with a 10-fold increase with respect to the unfermented material. The EA origin was traced by HPLC analysis that showed a significant decrease in the levels of punicalagin isomers and granatin B and formation of punicalin following fermentation. Other extraction conditions that could warrant a complete solubilization of EA were evaluated. Using a 1:100 solid to solvent ratio and DMSO as the solvent, EA was obtained in 4% yields from S. cerevisiae fermented husks at a high purity degree. Hydrolytic treatment of S. cerevisiae fermented pomegranate husks afforded a material freed of the polysaccharides components that gave recovery yields of EA up to 12% w/w. Full article

Recent advances in the electronics sector and the short life-span of electronic products have triggered an exponential increase in the generation of electronic waste (E-waste). Effective recycling of E-waste has thus become a serious solid waste management challenge. E-waste management technologies include pyrometallurgy, hydrometallurgy, and bioleaching. Determining the metal content of an E-waste sample is critical in evaluating the efficiency of a metal recovery method in E-waste recycling. However, E-waste is complex and of diverse origins. The lack of a standard digestion method for E-waste has resulted in difficulty in comparing the efficiencies of different metal recovery processes. In this study, several solid digestion protocols including American Society for Testing and Materials (ASTM)-D6357-11, United States Environment Protection Agency Solid Waste (US EPA SW) 846 Method 3050b, ultrasound-assisted, and microwave digestion methods were compared to determine the metal content (Ag, Al, Au, Cu, Fe, Ni, Pb, Pd, Sn, and Zn) of electronic scrap materials (ESM) obtained from two different sources. The highest metal recovery (mg/g of ESM) was obtained using ASTM D6357-11 for most of the metals, which remained mainly bound to silicate fractions, while a microwave-assisted digestion protocol (MWD-2) was more effective in solubilizing Al, Pb, and Sn. The study highlights the need for a judicious selection of digestion protocol, and proposes steps for selecting an effective acid digestion method for ESM. Full article