Control and Optimization of Extractive Methodologies and Analysis of Natural Products

A special issue of Processes (ISSN 2227-9717). This special issue belongs to the section "Separation Processes".

Deadline for manuscript submissions: closed (31 December 2023) | Viewed by 50342

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Guest Editor
CERNAS-IPCB Research Centre, Polytechnic University of Castelo Branco, 6001-909 Castelo Branco, Portugal
Interests: vibrational spectroscopy; chemometrics; food science; new product development; sensory analysis
Special Issues, Collections and Topics in MDPI journals

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Guest Editor
1. Health Sciences Research Centre, University of Beira Interior (CICS-UBI), 6200-506 Covilhã, Portugal
2. Pharmaco-Toxicology Laboratory, UBIMedical, University of Beira Interior, 6200-284 Covilhã, Portugal
3. Centro Académico Clínico das Beiras (CACB)—Grupo de Problemas Relacionados com Toxicofilias, 6200-284 Covilhã, Portugal
Interests: toxicology; analytical method development; recreational drugs; natural psychoactive substances; therapeutic drug monitoring; sample preparation; alternative samples; miniaturized extraction procedures
Special Issues, Collections and Topics in MDPI journals

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1. CERNAS Research Centre, Polytechninc University of Viseu, 3504-510 Viseu, Portugal
2. Department of Food Industry, Polytechninc University of Viseu, 3504-510 Viseu, Portugal
Interests: food chemistry; food engineering; food science; nutrition; development of new foods; consumer studies
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

The interest in biobased compounds extracted from natural sources or recirculated materials has increased in recent decades due to the circular economy and their potential application as active ingredients in several industries (i.e., food and pharmaceutical, cosmetics and wellness).

The optimization and validation of extraction techniques are critical in the quality and quantity of the analytes obtained from a matrix, and represent an early and fundamental step in natural products’ isolation and application.

It is of great interest to isolate and study bioactive natural products from different parts of trees, shrubs, plants, foods, or industrial food wastes in order to identify potential bioactive properties—namely, antioxidant, anti-inflammatory, and anti-carcinogenic activities.

This Issue intends to provide an overview of innovative techniques for the extraction, isolation, and analysis of natural products that could have several applications. Presenting a vast scope, this Special Issue welcomes full papers, short communications, and review articles on , but not limited to, extract optimization and comparative studies of extraction techniques, and the analysis of qualitative and quantitative composition using chromatographic or spectroscopic techniques. Additionally, evaluations of the biological effects of natural compounds are encouraged, as are comparative studies investigating quality in terms of the variability of natural sources.

Furthermore, papers dealing with bioinformatic tools and mathematical models of extracts’ mechanisms of action are welcome.

This Issue should serve as a text for academia, or as a reference tool for researchers—particularly those working in the fields of phytochemistry, natural product chemistry, food, medicinal chemistry, toxicology, and health, as well as industry professionals.

Prof. Dr. Ofelia Anjos
Prof. Dr. Eugenia Gallardo
Prof. Dr. Raquel P. F. Guiné
Guest Editors

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Published Papers (15 papers)

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Research

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13 pages, 2430 KiB  
Article
HPLC-UV Analysis of Chrysophanol in Senna occidentalis Extract Obtained by Using the RSM-Optimized Ultrasonic Extraction Process
by Gadah A. Al-Hamoud, Perwez Alam, Omer I. Fantoukh, Mohammed F. Hawwal and Ali Akhtar
Processes 2023, 11(5), 1410; https://doi.org/10.3390/pr11051410 - 6 May 2023
Viewed by 1526
Abstract
In this experiment, chrysophanol analysis in Senna occidentalis (aerial parts) extract obtained by optimizing ultrasound-assisted extraction (UAE) variables (temperature, time, and liquid-to-solid ratio) using response surface methodology (RSM) was performed by employing the HPLC-UV method. For UAE process optimization, a highly significant quadratic [...] Read more.
In this experiment, chrysophanol analysis in Senna occidentalis (aerial parts) extract obtained by optimizing ultrasound-assisted extraction (UAE) variables (temperature, time, and liquid-to-solid ratio) using response surface methodology (RSM) was performed by employing the HPLC-UV method. For UAE process optimization, a highly significant quadratic model (p < 0.001) was projected to attain maximum chrysophanol yield. The extraction temperature, time, and liquid-to-solid ratio for the best UAE method were determined to be 49.3 °C, 57.7 min, and 18.7 mL/g, respectively. The optimized extract was subjected to a chrysophanol analysis utilizing HPLC-UV (fitted with a Pinnacle C18 column), and a gradient mobile phase composed of 0.5% formic acid (solvent A), acetonitrile (solvent B), methanol (solvent C), at a flow rate of 1.0 mL/min, and an optimum wavelength of 279 nm, respectively. It furnished a compact and intense peak of chrysophanol at Rt = 23.809 min. The experimental value (20.47 mg/g) of chrysophanol obtained was close to the predicted value (19.32 mg/g), indicating that they agreed under the optimized extraction condition. UAE also displayed remarkable improvement in chrysophanol extraction compared with the conventional solvent extraction (CSE) method. Hence, our improved ultrasonic extraction process showed a potential use for effective chrysophanol extraction from commercial herbal supplements comprising the Senna species. Full article
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12 pages, 790 KiB  
Article
Essential Oils of Two Portuguese Endemic Species of Lavandula as a Source of Antifungal and Antibacterial Agents
by Joana Domingues, Manuela Goulão, Fernanda Delgado, José Carlos Gonçalves, Joana Gonçalves and Cristina Santos Pintado
Processes 2023, 11(4), 1165; https://doi.org/10.3390/pr11041165 - 10 Apr 2023
Cited by 2 | Viewed by 2274
Abstract
Chemical investigations of L. stoechas subsp. luisieri and L. pedunculata essential oils were analyzed by GC-MS, and the antimicrobial activity was performed against bacteria and fungi isolated from food sources. The cytotoxicity of the essential oil was performed in NHDF cells using the [...] Read more.
Chemical investigations of L. stoechas subsp. luisieri and L. pedunculata essential oils were analyzed by GC-MS, and the antimicrobial activity was performed against bacteria and fungi isolated from food sources. The cytotoxicity of the essential oil was performed in NHDF cells using the MTT method. According to the results, the main compounds of L. stoechas subsp. luisieri essential oil were trans-α-necrodyl acetate (40.2%), lavandulyl acetate (11%), and trans-α-necrodol (10.4%), while fenchone (50.5%) and camphor (30.0%) in L. pedunculata essential oil. The antifungal activity of essential oils was confirmed with MIC values ranging from 1.2 to 18.7 µL/mL; for bacteria, it ranged from 4.7 to 149.3 µL/mL. Both the Lavandula species tested showed low or equal MIC and MBC/MFC values for L. stoechas subsp. luisieri essential oil, revealing greater efficacy in antimicrobial activity. The L. stoechas subsp. luisieri essential oil revealed cytotoxic effects (30 ± 2% of cell viability) in NHDF cells at all concentrations tested. Full article
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20 pages, 2544 KiB  
Article
Application of Plant Surfactants as Cleaning Agents in Shampoo Formulations
by Káren G. O. Bezerra, Hugo M. Meira, Bruno O. Veras, Thayza C. M. Stamford, Emanuel L. Fernandes, Attilio Converti, Raquel D. Rufino and Leonie A. Sarubbo
Processes 2023, 11(3), 879; https://doi.org/10.3390/pr11030879 - 15 Mar 2023
Cited by 6 | Viewed by 4933
Abstract
With the increased demand for sustainable, hypoallergenic products, plant surfactants are a promising, eco-friendly option for cleaning products due to their low toxicity or even the absence of toxicity. In the present study, surfactant-rich extracts from Chenopodium quinoa, Glycine max, and [...] Read more.
With the increased demand for sustainable, hypoallergenic products, plant surfactants are a promising, eco-friendly option for cleaning products due to their low toxicity or even the absence of toxicity. In the present study, surfactant-rich extracts from Chenopodium quinoa, Glycine max, and Malpighia emarginata were assessed for their stability, antioxidant capacity, toxic potential, and cleaning potential in shampoo formulations. The surfactants in the extracts were isolated and characterized by NMR, UV-Vis, and FTIR spectroscopy. The results demonstrated that the extracts remained stable within the temperature and pH ranges tested. The antioxidant properties were also determined. In the analysis of irritation potential, G. max and C. quinoa exhibited low toxicity and no toxicity, respectively. The cleaning potential analysis confirmed that the extracts could be used as primary surfactants. Seven shampoo formulations were developed, which showed potential to reduce surface tension to the range of 27.1–31.7 mN/m and interfacial tension to the range of 5.4–7.3 mN/m. The wettability, percentage of solids, density, pH, and dirt dispersion of the formulas were within standard ranges, and the sebum removal capacity of the seven formulations was similar to or even better than that of a commercial shampoo. Full article
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12 pages, 2898 KiB  
Article
Production of Extracellular Lipase by Bacillus halotolerans from Oil-Contaminated Soil in a Pilot-Scale Submerged Bioreactor
by Mater H. Mahnashi, Veeranna S. Hombalimath, Ibrahim Ahmed Shaikh, Uday M. Muddapur, Shivalingsarj V. Desai, Sharanappa Achappa, Mohamed El-Sherbiny, Mohammed M. Ghoneim, Ohoud A. Jefri, Mohammed Merae Alshahrani, Muhanad Alhujaily, Amer Al Ali, Basheerahmed Abdulaziz Mannasaheb, Ahmed Abdullah Al Awadh and Aejaz Abdullatif Khan
Processes 2022, 10(8), 1548; https://doi.org/10.3390/pr10081548 - 7 Aug 2022
Cited by 4 | Viewed by 2749
Abstract
Microbial lipases are the biocatalyst of choice for the present and future because of their characteristics, including their ability to remain active as an enzyme throughout a broad pH, temperature, and substrate range. The goal of the current investigation was to find novel [...] Read more.
Microbial lipases are the biocatalyst of choice for the present and future because of their characteristics, including their ability to remain active as an enzyme throughout a broad pH, temperature, and substrate range. The goal of the current investigation was to find novel sources of substrates and isolates from soil contaminated by oil for the synthesis of lipase. On tributyrin media, 10 lipolytic bacterial strains that were isolated from oil-contaminated soil were grown. Using the zone of clearance, it was possible to identify the isolates with the highest activity. Following phylogenetic tree analysis, molecular characterization of the 16S rRNA sequence of the bacterial isolates revealed that it was Bacillus halotolerans (VSH 09). The enzyme was purified to near homogeneity. The enzyme activity was found to be optimum at a pH of 7.0 and a temperature of 35 °C. While Ni2+ and Cu2+ had no effect, the presence of Mg2+ and Ca2+ exhibited the highest levels of enzyme activity. At 1%, tributyrin as a substrate exhibited its highest level of activity. The molecular weight, as determined by SDS-PAGE, was found to be 38 kDa. The kinetics of the enzyme were found to be 41.66 and 9.37 mg/mL for Vmax and Km, respectively. The high yield of lipase produced by this method suggests that it holds potential for production on a large scale and could be used for various biotechnological applications. Full article
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19 pages, 1853 KiB  
Article
Overview of Different Modes and Applications of Liquid Phase-Based Microextraction Techniques
by José S. Câmara, Rosa Perestrelo, Basit Olayanju, Cristina V. Berenguer, Abuzar Kabir and Jorge A. M. Pereira
Processes 2022, 10(7), 1347; https://doi.org/10.3390/pr10071347 - 11 Jul 2022
Cited by 11 | Viewed by 4404
Abstract
Liquid phase-based microextraction techniques (LPµETs) have attracted great attention from the scientific community since their invention and implementation mainly due to their high efficiency, low solvent and sample amount, enhanced selectivity and precision, and good reproducibility for a wide range of analytes. This [...] Read more.
Liquid phase-based microextraction techniques (LPµETs) have attracted great attention from the scientific community since their invention and implementation mainly due to their high efficiency, low solvent and sample amount, enhanced selectivity and precision, and good reproducibility for a wide range of analytes. This review explores the different possibilities and applications of LPμETs including dispersive liquid–liquid microextraction (DLLME) and single-drop microextraction (SDME), highlighting its two main approaches, direct immersion-SDME and headspace-SDME, hollow-fiber liquid-phase microextraction (HF-LPME) in its two- and three-phase device modes using the donor–acceptor interactions, and electro membrane extraction (EME). Currently, these LPμETs are used in very different areas of interest, from the environment to food and beverages, pharmaceutical, clinical, and forensic analysis. Several important potential applications of each technique will be reported, highlighting its advantages and drawbacks. Moreover, the use of alternative and efficient “green” extraction solvents including nanostructured supramolecular solvents (SUPRASs, deep eutectic solvents (DES), and ionic liquids (ILs)) will be discussed. Full article
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20 pages, 5726 KiB  
Article
Green Extraction of Date Palm Fruits via Ultrasonic-Assisted Approach: Optimizations and Antioxidant Enrichments
by Hisham Mohamed, Mohamed Al-Hajhoj, Mohamed Al-Saikhan, Nashi Alqahtani, Mohammad Zayed, Mahmoud Moawad, Waleed Alsenaien and Maged E. Mohamed
Processes 2022, 10(6), 1049; https://doi.org/10.3390/pr10061049 - 24 May 2022
Cited by 4 | Viewed by 2233
Abstract
Background: Green extraction involves using green solvents, such as water, to reduce energy consumption, avoid health and environmental hazards and induce the quality and quantity of the extract. Date palm fruits are a vital source of food and medicinal activities, as they contain [...] Read more.
Background: Green extraction involves using green solvents, such as water, to reduce energy consumption, avoid health and environmental hazards and induce the quality and quantity of the extract. Date palm fruits are a vital source of food and medicinal activities, as they contain a high diversity of phytochemicals, mainly phenolic and flavonoid compounds. The main aim of this study is to investigate the use of water as a green solvent, when assisted by different ultrasonic frequencies, in the extraction of four different cultivars of date palm fruits, by evaluating the phenolic and flavonoid composition as well as the antioxidant capacity of the extract. Methods: Four date palm fruits’ cultivars (Agwa, Anbarah, Khalas, and Reziz) were extracted using conventional methods (by water and ethanol) and by ultrasonic means, using two frequencies, 28 and 40 kHz, and applying temperatures (30, 45, and 60 °C), also measuring extraction times (20, 40, 60 min.). Response surface methodology was used for the statistical analysis, applying three factors (temperature, time, and ultrasonic frequency), four responses (total phenolic content, total flavonoid content, FRAP, and ABTS), and four cultivars (categories). Results: Conventional water extraction obtained minimal phenolic and flavonoid compounds (up to 52% of ethanol extraction). This percent improved to reach 60% when heat was utilized. The application of ultrasonic frequencies significantly enhanced the extraction of phenolics/flavonoids and the antioxidant ability of the extract to nearly 90% and 80%, respectively. The use of 40 kHz ultrasonic power managed to extract more phenolic and flavonoid components; however, the antioxidant capacities of the extract were less than when the 28 kHz power was utilized. Agwa and Khalas demonstrated themselves to be the best cultivars for ultrasonic-assisted extraction, depending on the results of the optimized responses. Conclusion: This study could be implemented in the industry to produce date palm fruits’ enriched extracts with phenolic and flavonoid components and/or antioxidants. Full article
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21 pages, 4692 KiB  
Article
A New LC-MS Method for Evaluating the Efficacy of Pesticide Residue Removal from Fruit Surfaces by Washing Agents
by Magdalena Zarębska, Zofia Hordyjewicz-Baran, Tomasz Wasilewski, Ewa Zajszły-Turko and Natalia Stanek
Processes 2022, 10(4), 793; https://doi.org/10.3390/pr10040793 - 18 Apr 2022
Cited by 10 | Viewed by 4048
Abstract
Modern agriculture uses pesticides to improve the quality and quantity of crops. However, pesticide residues can remain on agricultural products, posing very serious risks to human health and life. It is recommended to wash fruits and vegetables before consumption. To assess the removal [...] Read more.
Modern agriculture uses pesticides to improve the quality and quantity of crops. However, pesticide residues can remain on agricultural products, posing very serious risks to human health and life. It is recommended to wash fruits and vegetables before consumption. To assess the removal efficacy of pesticide residue, a sensitive and reliable method based on ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) was developed and optimized for the simultaneous determination of four pesticide residues (acetamiprid, boscalid, pyraclostrobin, and pendimethalin). Isotope-labeled standards were used to validate the method in terms of recovery, linearity, matrix effects, precision, and sensitivity. The mean recovery values for both low-quality control (LQC) and high-quality control (HQC) transitions were in the range of 89–105%, and the intra-day precision was less than 13.7%. The limits of detection (LOD) and quantification (LOQ) were 0.003 mg/kg and 0.01 mg/kg, respectively. The proposed method is suitable for evaluating the quality of detergents for removing pesticide residues from fruit surfaces. Full article
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10 pages, 2212 KiB  
Article
Extraction and Purification of (E)-Resveratrol from the Bark of Conifer Species
by Panduka S. Piyaratne, Regan LeBlanc, Angela D. Myracle, Barbara J. W. Cole and Raymond C. Fort, Jr.
Processes 2022, 10(4), 647; https://doi.org/10.3390/pr10040647 - 26 Mar 2022
Cited by 7 | Viewed by 4001
Abstract
(E)-Resveratrol is a naturally occurring polyphenolic compound in plants with a variety of widely studied health benefits. The bark of Northern American, Canadian, and Northern European conifer species, which is an underutilized by-product generated by forest industries, is a source of (E)-resveratrol, providing [...] Read more.
(E)-Resveratrol is a naturally occurring polyphenolic compound in plants with a variety of widely studied health benefits. The bark of Northern American, Canadian, and Northern European conifer species, which is an underutilized by-product generated by forest industries, is a source of (E)-resveratrol, providing a potential value-added product for these industries. Bark may serve as a good alternative to the invasive plant Japanese knotweed (Polygonum cuspidatum), which currently is the leading commercial source of (E)-resveratrol. This work describes a method to extract and purify (E)-resveratrol from conifer bark with high yield and high purity and investigates the relationship between the amount of (E)-resveratrol and the total phenolic contents in the bark of common conifer species. In this work, barks of four conifer species were extracted and the total phenolic contents were determined by Folin–Cicoalteu’s assay. The (E)-resveratrol content was determined by HPLC-MS. A purification method that utilizes solvent extraction and column chromatography was developed to isolate (E)-resveratrol in high yield from black spruce (Picea mariana) bark. The quantitative analysis of bark samples suggests the presence of (E)-resveratrol in black spruce (Picea mariana) and Norway spruce (Picea abies), in comparable amounts to Japanese knotweed. Based on HPLC-MS and HPLC-UV analyses, the purification method isolates the compound with a yield of 84% and purity of 99%. Hence, our method extracts and isolates (E)-resveratrol from conifer bark in high purity and high yield. The results do not support any correlation between the total phenolic content and the amount of (E)-resveratrol. Full article
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16 pages, 2945 KiB  
Article
Simultaneous Optimization of Extraction Yield, Phenolic Compounds and Antioxidant Activity of Moroccan Propolis Extracts: Improvement of Ultrasound-Assisted Technique Using Response Surface Methodology
by Abderrazak Aboulghazi, Meryem Bakour, Mouhcine Fadil and Badiaa Lyoussi
Processes 2022, 10(2), 297; https://doi.org/10.3390/pr10020297 - 2 Feb 2022
Cited by 23 | Viewed by 4084
Abstract
Propolis has given rise to refreshing interest in recent years in the field of conventional medicine. Its extraction represents an important process that requires optimal conditions, which strongly affect the yield of extraction, total polyphenols, flavonoid content, and radical scavenging capacity markers. The [...] Read more.
Propolis has given rise to refreshing interest in recent years in the field of conventional medicine. Its extraction represents an important process that requires optimal conditions, which strongly affect the yield of extraction, total polyphenols, flavonoid content, and radical scavenging capacity markers. The objective of the present study was to optimize the ultrasound-assisted extraction conditions of Moroccan propolis. The studied responses were the extraction yield, total polyphenols, flavonoid contents (TPC, TFC), and antioxidant activity of the extract evaluated by DPPH-IC50 and FRAP-EC50 assays. The response surface methodology (RSM) and specifically the Box–Behnken design (BBD) were used, taking into account three variables: sonication time (min), solvent/propolis ratio (mL/g), and ethanol concentration (%). After the realization of experiments and data analysis, optimal response values were 15.39%, 192 mg GAE/g of propolis,45.15 mg QEq/g, 29.8 µg/mL, and 128.3 µmol Fe2+/g for extraction yield, TPC, TFC, DPPH-IC50, and FRAP-EC50, respectively. Besides, optimal ultrasound extraction conditions were 15 min for sonication time, 30 mL/g for solvent/propolis ratio, and 40% for ethanol concentration. All obtained experimental values were in good agreement with the predicted values, suggesting that using an experimental design in the ultrasound-assisted extraction process and optimization was prudently chosen. Full article
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15 pages, 1319 KiB  
Article
Property Determination, FA Composition and NMR Characterization of Palm Oil, Used Palm Oil and Their Methyl Esters
by Omojola Awogbemi, Daramy Vandi Von Kallon, Victor Sunday Aigbodion and Vuyisa Mzozoyana
Processes 2022, 10(1), 11; https://doi.org/10.3390/pr10010011 - 22 Dec 2021
Cited by 11 | Viewed by 3123
Abstract
The search for a cost-effective, environmentally friendly and sustainable feedstock for biodiesel production has attracted attention among researchers. After frying, palm oil may become thermally degraded and unsuitable for consumption. In the current effort, neat palm oil (NPO), waste palm oil earlier utilized [...] Read more.
The search for a cost-effective, environmentally friendly and sustainable feedstock for biodiesel production has attracted attention among researchers. After frying, palm oil may become thermally degraded and unsuitable for consumption. In the current effort, neat palm oil (NPO), waste palm oil earlier utilized for frying fish and chips (WPOFC) and waste palm oil previously utilized to fry sausage and chips (WPOSC) were transesterified into waste palm oil methyl ester, namely, WPOMEFC and WPOMESC, respectively. The PO, WPOs and their ester derivatives were subjected to physicochemical properties, fatty acid (FA) compositions and 1H and 13C nuclear magnetic resonance (NMR) analyses. The thermal degradation, transesterification process and the foods the palm oil was used to fry affected the density, kinematic viscosity, acid value, pH, iodine value and FA profile of the samples. The outcome of the characterization reveals that the 1H and 13C NMR spectra of NPO, WPOFC and WPOSC show clear similarity, but NPO exhibits different intensities from that of the WPO samples. The absence of the peaks between δ 4.6 ppm and 5.0 ppm in the 1H NMR spectrum signifies the complete transformation of triglycerides in the WPO samples into biodiesel. The 13C NMR spectrum indicates the presence of ester carbonyl carbon (C=O) in WPOMEFC and WPOMESC, peculiar to ester, at a chemical shift ranging from 174.8 ppm to 174.9 ppm. Full article
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Review

Jump to: Research

32 pages, 1727 KiB  
Review
Miniaturized Solid Phase Extraction Techniques Applied to Natural Products
by Luana M. Rosendo, Ana Teresa Brinca, Bruno Pires, Gonçalo Catarro, Tiago Rosado, Raquel P. F. Guiné, André R. T. S. Araújo, Ofélia Anjos and Eugenia Gallardo
Processes 2023, 11(1), 243; https://doi.org/10.3390/pr11010243 - 11 Jan 2023
Cited by 4 | Viewed by 3339
Abstract
Natural products are increasingly becoming part of our daily lives through their use in industry, food, as therapeutic agents, etc. To evaluate their possible applications, it is essential to characterize them chemically to explore their potential. Different techniques may be used to characterize [...] Read more.
Natural products are increasingly becoming part of our daily lives through their use in industry, food, as therapeutic agents, etc. To evaluate their possible applications, it is essential to characterize them chemically to explore their potential. Different techniques may be used to characterize natural products, including microextraction techniques. These techniques have been gaining popularity due to the advantages associated with their low use of organic solvents and the small amount of sample used relative to more classical sample preparation techniques. Their application in the extraction of compounds from natural products is still scarce. This manuscript intends to review the most used solid-based miniaturized sample preparation techniques applied to determining compounds in natural products. The main applications of these methodologies will be discussed, with a particular focus on natural product analysis, as well as their advantages and disadvantages over traditionally used sample preparation techniques. Full article
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40 pages, 3464 KiB  
Review
Extraction, Isolation, and Purification of Value-Added Chemicals from Lignocellulosic Biomass
by Tanmay Chaturvedi, Laura Sini Sofia Hulkko, Malthe Fredsgaard and Mette Hedegaard Thomsen
Processes 2022, 10(9), 1752; https://doi.org/10.3390/pr10091752 - 2 Sep 2022
Cited by 14 | Viewed by 4210
Abstract
This review covers the operating conditions for extracting top value-added chemicals, such as levulinic acid, lactic acid, succinic acid, vanillic acid, 3-hydroxypropionic acid, xylitol, 2,5-furandicarboxylic acid, 5-hydroxymethyl furfural, chitosan, 2,3-butanediol, and xylo-oligosaccharides, from common lignocellulosic biomass. Operating principles of novel extraction methods, beyond [...] Read more.
This review covers the operating conditions for extracting top value-added chemicals, such as levulinic acid, lactic acid, succinic acid, vanillic acid, 3-hydroxypropionic acid, xylitol, 2,5-furandicarboxylic acid, 5-hydroxymethyl furfural, chitosan, 2,3-butanediol, and xylo-oligosaccharides, from common lignocellulosic biomass. Operating principles of novel extraction methods, beyond pretreatments, such as Soxhlet extraction, ultrasound-assisted extraction, and enzymatic extraction, are also presented and reviewed. Post extraction, high-value biochemicals need to be isolated, which is achieved through a combination of one or more isolation and purification steps. The operating principles, as well as a review of isolation methods, such as membrane filtration and liquid–liquid extraction and purification using preparative chromatography, are also discussed. Full article
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25 pages, 906 KiB  
Review
A Systematic Review on Waste as Sustainable Feedstock for Bioactive Molecules—Extraction as Isolation Technology
by Adrian Drescher and Marlene Kienberger
Processes 2022, 10(8), 1668; https://doi.org/10.3390/pr10081668 - 22 Aug 2022
Cited by 5 | Viewed by 2913
Abstract
In today’s linear economy, waste streams, environmental pollution, and social–economic differences are increasing with population growth. The need to develop towards a circular economy is obvious, especially since waste streams are composed of valuable compounds. Waste is a heterogeneous and complex matrix, the [...] Read more.
In today’s linear economy, waste streams, environmental pollution, and social–economic differences are increasing with population growth. The need to develop towards a circular economy is obvious, especially since waste streams are composed of valuable compounds. Waste is a heterogeneous and complex matrix, the selective isolation of, for example, polyphenolic compounds, is challenging due to its energy efficiency and at least partially its selectivity. Extraction is handled as an emerging technology in biorefinery approaches. Conventional solid liquid extraction with organic solvents is hazardous and environmentally unfriendly. New extraction methods and green solvents open a wider scope of applications. This research focuses on the question of whether these methods and solvents are suitable to replace their organic counterparts and on the definition of parameters to optimize the processes. This review deals with the process development of agro-food industrial waste streams for biorefineries. It gives a short overview of the classification of waste streams and focuses on the extraction methods and important process parameters for the isolation of secondary metabolites. Full article
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17 pages, 4429 KiB  
Review
Potential Applications of the Cytisus Shrub Species: Cytisus multiflorus, Cytisus scoparius, and Cytisus striatus
by Débora Caramelo, Celina Barroca, Raquel Guiné, Eugenia Gallardo, Ofélia Anjos and Jorge Gominho
Processes 2022, 10(7), 1287; https://doi.org/10.3390/pr10071287 - 30 Jun 2022
Cited by 4 | Viewed by 2529
Abstract
Cytisus spp. is present throughout the Portuguese territory. Although most of these species are considered native in Portugal, at least one species has already been reported as invasive in other parts of the world. Different measures of control have been investigated, and the [...] Read more.
Cytisus spp. is present throughout the Portuguese territory. Although most of these species are considered native in Portugal, at least one species has already been reported as invasive in other parts of the world. Different measures of control have been investigated, and the application of herbicides is the most commonly used. This review gathers information about the biochemical profile and analytical methods used for the evaluation of the potential bioactivities of three species of the genus Cytisus, better known as brooms, which were used in traditional medicine through the production of infusions and decoctions for the treatment of several health problems, mainly due to their high value of phenolic compounds. However, little research has been conducted on its biological activities as a potential antioxidant, anti-inflammatory, and antimicrobial agent. Furthermore, one species (Cytisus striatus) has not been subjected to extensive research in identifying chemical compounds and evaluating their potential bioactivities. This species (known as the Portuguese broom) has a great expression in one of the forest typologies with a considerable percentage in Portugal. This research work is essential to encourage a scientific and sustainable valorisation of Cytisus spp. (namely C. striatus), which will consequently contribute to forest cleaning and management to reduce the risk of wildfires. Full article
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15 pages, 1203 KiB  
Review
Isolation and Analysis of Carotenoids in Hungary from Zechmeister until Today
by Attila Agócs, Erika Turcsi, Veronika Nagy and József Deli
Processes 2022, 10(4), 707; https://doi.org/10.3390/pr10040707 - 5 Apr 2022
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Abstract
László Zechmeister, one of the most important pioneers of carotenoid chemistry, died 50 years ago. He founded a carotenoid research group in Pécs (Hungary), which is the only place in the world where carotenoid research has been conducted continuously over the past 95 [...] Read more.
László Zechmeister, one of the most important pioneers of carotenoid chemistry, died 50 years ago. He founded a carotenoid research group in Pécs (Hungary), which is the only place in the world where carotenoid research has been conducted continuously over the past 95 years. This review presents the life of Zechmeister and gives a summary about the evolution of the methods of analysis, isolation, and structure elucidation of carotenoids from the 1930s until today, based on the results of the research group founded by Zechmeister. Full article
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