Pressurized Fluid Extraction Research Articles

Extraction of bioactive components from date palm waste, various extraction processes and their applications: A review

Dates are vital sources of nutrients and bioactive components which are widely consumed throughout the world. Agro-industrial waste, such as date palm waste, has been recognized as a potential candidate of bioactive chemicals and essential oils for utilization in food, medicine, and cosmetics. Date fruit and seed are well-known for their nutritional worth, which includes high sugar, vitamins, and mineral content that includes potassium and magnesium. Presence of phenolic compounds diverges the attention of researchers towards efficient extraction processes. Various traditional e.g., soxhlet, maceration, infusion, and digesting and advanced extraction techniques, i.e., pressurised fluid extraction (PFE), enzyme-assisted extraction (EAE), microwave-assisted extraction (MAE), ultrasound-assisted extraction (UAE), and supercritical CO2 extraction (SC-CO2) have been discussed briefly to extract bioactive components for instance flavonoids, tocopherols, tannins, carotenoids, tocotrienols and hydroxybenzoic acid from date palm fruit, seed, and leaves. The findings reveal that the higher total phenolic content in a shorter time can be obtained by combining ultrasonic with PLE or SFE extraction techniques. These bioactive components can be used in the food and pharmaceutical industries for pre-treatment of certain ailments. Moreover, the natural bioactive components with potential therapeutic benefits, such as non-starch polysaccharides and selenium. The purpose of this study is to highlight the advances achieved in understanding bioactive components e.g., phenolic compounds, flavonoids, tannins hydroxycinnamic, hydroxybenzoic and bio-oil of date palm fruits, including their synthesis, probable functions, and health advantages, to find prospective uses for date-derived materials in the cosmetics, pharmaceutical and food sector.

Validation of the Chemical and Biological Steps Required Implementing an Advanced Multi-Omics Approach for Assessing the Fate and Impact of Contaminants in Lagoon Sediments.

The increasing use of chemicals requires a better understanding of their presence and dynamics in the environment, as well as their impact on ecosystems. The aim of this study was to validate the first steps of an innovative multi-omics approach based on metabolomics and 16S metabarcoding data for analyses of the fate and impact of contaminants in Mediterranean lagoons. Semi-targeted analytical procedures for water and sediment matrices were implemented to assess chemical contamination of the lagoon: forty-six compounds were detected, 28 of which could be quantified in water (between 0.09 and 47.4 ng/L) and sediment (between 0.008 and 26.3 ng/g) samples using the UHPLC-MS/MS instrument. In addition, a non-targeted approach (UHPLC-HRMS) using four different sample preparation protocols based on solid/liquid extractions or an automated pressurized fluid extraction system (EDGE®) was carried out to determine the protocol with the best metabolome coverage, efficiency and reproducibility. Solid/liquid extraction using the solvent mixture acetonitrile/methanol (50/50) was evaluated as the best protocol. Microbial diversity in lagoon sediment was also measured after DNA extraction using five commercial extraction kits. Our study showed that the DNeasy PowerSoil Pro Qiagen kit (Promega, USA) was the most suitable for assessing microbial diversity in fresh sediment.

Enhanced recovery of R-phycoerythrin using recombination cell-assisted pressurized fluid extraction: yield, characterization, and antioxidant evaluation

The recovery of phycobiliproteins, with an emphasis on R-phycoerythrin (R-PE), from Solieria filiformis macroalgae was investigated in the current study. This is accomplished using an environmentally friendly method known as pressurized fluid extraction. Phycobiliprotein production was analyzed over time, considering four different parameters: i) solvents (ultrapure water and phosphate buffer), ii) macroalgae particle sizes, iii) stirring, and iv) pressure of 200 to 800 bar. Notably, the highest R-PE yield reached an impressive 22.53 mg/g dry biomass. The best extraction conditions were identified as a macerated structure, employing a combination of 500 bar pressure and agitation facilitated by a recombination cell. R-phycocyanin (R-PC) was also extracted with a 3.70 mg/g yield. Two distinct extracts, crude and precipitate, underwent comprehensive characterization. Extracted R-PE exhibited an α-helix structure (80.51–90.39 %), suggesting the existence of other proteins in both extracts. Three different subunits, α (15 kDa), β (21 kDa), and γ (29 kDa), were segregated under SDS-PAGE. Moreover, both extracts demonstrated antioxidant capacity, achieving a 99.55 % reduction in 2,2-diphenyl-1-picryl-hydrazil (DPPH) radicals and a 13.94 % chelation of ferrous ions. This study reports the extraction of biomolecules using the recombination cell for the first time in the literature, proving an appealing alternative for non-aggressive extraction with inherent biological activity. These findings underscore the potential applications of these extracted phycobiliproteins in various fields, including biotechnology and health.

Comparison of supercritical CO2 extraction and pressurized fluid extraction for isolation of alkaloids from Anacardium occidentale with the study of its anti-inflammatory activity

In recent years, there has been a growing interest in the therapeutic potential of natural compounds, particularly of plant origin, owing to their demonstrated anti-inflammatory properties. Among these, Anacardium occidentale, commonly known as cashew, has garnered significant attention due to its reputed health benefits. This study aim to establish a correlation between the bioactive compounds contained in the extracts of Anacardium occidentale and its anti-inflammatory activity. Dried Anacardium occidentale leaves powder was used as the extraction matrix. Extraction techniques are maceration, pressurized fluid extraction (PFE), and supercritical fluid extraction (SFE). The preliminary analysis of extracts was made by LC-MS/MS. The Response Surface Methodology (RSM), Principal Component Analysis (PCA), and heat maps were employed to model the influence of experimental conditions on extraction yield and peak area of specific compounds from the plant. To evaluate anti-inflammatory activity, RAW 264.7 cells were cultured, activated with LPS, and treated with varying concentrations of the plant extracts. Cell proliferation was assessed using the XTT assay. Indeed, Anacardium occidentale extracts contain anacardic acids, cardanols, and cardol, with distinct profiles yielded by SFE and ethanol-based methods. RSM shows that temperature and ethanol, as additives to CO2, significantly affect extraction efficiency in both PFE and SFE. Moreover, this composition with SFE demonstrate higher selectivity for specific group of compounds. The extracts exhibit anti-inflammatory properties without cytotoxicity in macrophages, reducing levels of pro-inflammatory proteins COX-2, COX-1, and TLR4 in activated cells. This suggests their potential as anti-inflammatory agents without adverse effects on cell viability or pro-inflammatory protein levels in non-activated cells. Overall, these findings underscore the promising therapeutic potential of Anacardium occidentale extracts in mitigating inflammation, while also providing crucial insights into optimizing the extraction process for targeted compound isolation. Thus, this makes a good prospect for the development of anti-inflammatory drugs from this plant.

Determining Polycyclic Aromatic Compounds in Bird Feathers Using Pressurized Fluid Extraction

Due to their ease of collecting and transporting from the field and their ability to accumulate pollutants, bird feathers are increasingly being used as a non-invasive biomonitoring tool for environmental monitoring programs. Polycyclic aromatic compounds (PACs) are a diverse class of environmental pollutants, and because of their deleterious impacts on biological species, monitoring these compounds in wildlife is of high importance. Current approaches to measuring PACs in bird feathers involve a time-consuming acid treatment with a concomitant solvent extraction step. Here, a validated method for measuring a suite of PACs in bird feathers using pressurized fluid extraction and identification and quantitation by gas chromatography-tandem mass spectrometry is presented. Chicken (Gallus domesticus) feathers were purposely fortified with a suite of 34 PACs separately at three fortification levels and placed inside a pressurized fluid extraction cell containing silica gel/deactivated alumina to provide in situ clean-up of the sample. Except for anthracene and naphthalene, the accuracy of our method ranged for PAHs from 70–120% (irrespective of fortification level), and our intra- and inter-day repeatability was smaller than 28%. For APAHs, our accuracies ranged from 38–158%, and the inter- and intra-day repeatability was less than 35%. Our limits of detection and quantitation for both groups of compounds ranged from 0.5–13 and 1.5–44.3 ng/g, respectively. Overall, the developed method represents an effective and efficient approach for the extraction and quantitation of PACs from bird feathers that negated the need for the time-consuming and potentially harmful acid treatment.

Subcritical and Supercritical Fluids to Valorize Industrial Fruit and Vegetable Waste.

The valorization of industrial fruit and vegetable waste has gained significant attention due to the environmental concerns and economic opportunities associated with its effective utilization. This review article comprehensively discusses the application of subcritical and supercritical fluid technologies in the valorization process, highlighting the potential benefits of these advanced extraction techniques for the recovery of bioactive compounds and unconventional oils from waste materials. Novel pressurized fluid extraction techniques offer significant advantages over conventional methods, enabling effective and sustainable processes that contribute to greener production in the global manufacturing sector. Recovered bio-extract compounds can be used to uplift the nutritional profile of other food products and determine their application in the food, pharmaceutical, and nutraceutical industries. Valorization processes also play an important role in coping with the increasing demand for bioactive compounds and natural substitutes. Moreover, the integration of spent material in biorefinery and biorefining processes is also explored in terms of energy generation, such as biofuels or electricity, thus showcasing the potential for a circular economy approach in the management of waste streams. An economic evaluation is presented, detailing the cost analysis and potential barriers in the implementation of these valorization strategies. The article emphasizes the importance of fostering collaboration between academia, industry, and policymakers to enable the widespread adoption of these promising technologies. This, in turn, will contribute to a more sustainable and circular economy, maximizing the potential of fruit and vegetable waste as a source of valuable products.

Research Progress on Separation and Detection Methods of Microplastics in Soil Environment

As a new type of environmental pollutant, microplastics (MPs) exists in the soil environment for a long time and pollutes the ecological environment of the surface system. Separation and detection of microplastics in soil environment is the basis of controlling microplastics pollution in soil environment. The research progress of separation and detection technology in microplastics was introduced, and the existing problems of separation and detection methods were put forward. The results show that the screening-filtration method and density separation method are simple, operable and effective, but the cross-contamination rate is high in the extraction process, and the recovery rate of high-density microplastics is not high. Pressurized fluid extraction technology is convenient and easy to operate, but it may affect the particle morphology of microplastics. Visual detection, Raman and infrared spectroscopy, chromatography and mass spectrometry combined pyrolysis analysis have some problems, such as high cost, long time and loss of samples. In the future, it is necessary to further explore the analytical method of microplastics, and develop the separation and detection method without loss of microplastics.

Management of de-oiled coffee beans biomass through pyrolysis process: Towards a circular bioeconomy

In this work, we proposed the pyrolysis process for the valorization of de-oiled defective coffee beans (DCB) residual biomass provided by the pressurized fluid extraction (PFE) process after the recovery of coffee oil. The proposal to subsequent thermoconversion of the de-oiled biomasses focuses in an integrated biorefinery concept to obtain value-added products, what fits into the circular bioeconomy strategy. DCB biomasses showed the highest coffee oil recovery yields (∼10%) from the PFE processes and presented yields of the pyrolysis condensate fraction (bio-oil + aqueous fraction) in the range between 53.7% and 59.4%. On the other hand, the yields of biochar and pyrolysis gas increased, with values from 23.6% to 27.3%, and from 17.0% to 19.5%, respectively, when compared to the yields from pyrolysis of the raw DCB. The biochars showed very similar compositions, with HHV between 24.7 and 25.3 MJ kg−1. Overall, the bio-oils showed same constituents with variation in the concentrations of some species detected by GC/MS. Among them, the main classes with such alterations were phenolic compounds and carboxylic acids, in which the relative contents ranged from 19.7% to 39.0% and 11.3–46.1%, respectively. The findings demonstrated the potential of using pyrolysis as a sequential step to add value to the de-oiled DCB biomass remaining after the extraction of coffee oil, which could contribute to a sustainable circular economy with zero waste generation.

Spent coffee ground oil as a valuable source of epoxides and epoxidation derivatives: Quantitation and characterization using low-field NMR

Coffee waste, commonly referred to as spent coffee grounds (SCG), is currently discarded and has a negative impact on the environment. However, SCG are rich in valuable ingredients including 15–20% oil, which has a profile comparable to the vegetable oils used in the production of epoxides, biobased polyols, and polymers. Our first objective was to evaluate the efficiency of three different methods, namely Soxhlet, pressurized fluid extraction, and supercritical CO2 (scCO2) on SCG oil extraction. Additionally, we aimed to test the potential of low-field (LF) NMR to analyze SCG oil and monitor the formation of epoxides and biobased polyols. Finally, we evaluated epoxidized SCG oil as a plasticizer for improving the properties of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) bioplastic. Overall, SCG showed a promising potential as a source of biopolymer precursors, while LF NMR can be an efficient and economic tool for oil evaluation and reaction monitoring.

Curcumin: Biological Activities and Modern Pharmaceutical Forms.

Curcumin (1,7-bis-(4-hydroxy-3-methoxyphenyl)-hepta-1,6-diene-3,5-dione) is a natural lipophilic polyphenol that exhibits significant pharmacological effects in vitro and in vivo through various mechanisms of action. Numerous studies have identified and characterised the pharmacokinetic, pharmacodynamic, and clinical properties of curcumin. Curcumin has an anti-inflammatory, antioxidative, antinociceptive, antiparasitic, antimalarial effect, and it is used as a wound-healing agent. However, poor curcumin absorption in the small intestine, fast metabolism, and fast systemic elimination cause poor bioavailability of curcumin in human beings. In order to overcome these problems, a number of curcumin formulations have been developed. The aim of this paper is to provide an overview of recent research in biological and pharmaceutical aspects of curcumin, methods of sample preparation for its isolation (Soxhlet extraction, ultrasound extraction, pressurised fluid extraction, microwave extraction, enzyme-assisted aided extraction), analytical methods (FTIR, NIR, FT-Raman, UV-VIS, NMR, XRD, DSC, TLC, HPLC, HPTLC, LC-MS, UPLC/Q-TOF-MS) for identification and quantification of curcumin in different matrices, and different techniques for developing formulations. The optimal sample preparation and use of an appropriate analytical method will significantly improve the evaluation of formulations and the biological activity of curcumin.

Procyanidins: From Agro-Industrial Waste to Food as Bioactive Molecules.

Procyanidins are an important group of bioactive molecules known for their benefits to human health. These compounds are promising in the treatment of chronic metabolic diseases such as cancer, diabetes, and cardiovascular disease, as they prevent cell damage related to oxidative stress. It is necessary to study effective extraction methods for the recovery of these components. In this review, advances in the recovery of procyanidins from agro-industrial wastes are presented, which are obtained through ultrasound-assisted extraction, microwave-assisted extraction, supercritical fluid extraction, pressurized fluid extraction and subcritical water extraction. Current trends focus on the extraction of procyanidins from seeds, peels, pomaces, leaves and bark in agro-industrial wastes, which are extracted by ultrasound. Some techniques have been coupled with environmentally friendly techniques. There are few studies focused on the extraction and evaluation of biological activities of procyanidins. The identification and quantification of these compounds are the result of the study of the polyphenolic profile of plant sources. Antioxidant, antibiotic, and anti-inflammatory activity are presented as the biological properties of greatest interest. Agro-industrial wastes can be an economical and easily accessible source for the extraction of procyanidins.

Oil recovery from defective coffee beans using pressurized fluid extraction followed by pyrolysis of the residual biomass: Sustainable process with zero waste

In this study, oil was extracted from various types of defective coffee beans using pressurized fluids. After extraction using solvents, the residual biomass was used as a raw material in a pyrolysis process to obtain bio-oil. Palmitic and linoleic fatty acids were the predominant components of the obtained oils. When n-propane was used for pressurized extraction, the yield of coffee bean oil and the phytosterols and tocopherol content increased. The highest levels were found in oil extracted from green coffee. Increasing the solvent flow rates improved the yield of the extracted oil, while increasing the temperature had the opposite effect. Higher temperatures and pressure resulted in higher levels of phytosterols. Low extraction temperatures resulted in an oil with a higher tocopherol content. The main product of biomass pyrolysis was a bio-oil rich in caffeine and phenolic compounds. This is an effective strategy for the clean and sustainable production of bio-oil.

The effect of different pressurized fluids on the extraction of anthocyanins and total phenolics from cranberry pomace

Cranberry pomace, a byproduct of the juice manufacturing, is a rich source of phenolics, mainly anthocyanins. Anthocyanins and phenolics were removed from cranberry pomace with water, 30–100% ethanol, or 5% citric acid in a pressurized fluid reactor at 40–160 °C and 50 or 200 bar. Total anthocyanin (mg cyanidin 3-glucoside equivalent, Cy3GE), total phenolics (mg gallic acid equivalent, GAE), antioxidant activity (µmol trolox equivalent), and anthocyanin composition (HPLC-UV) of the extracts were determined. Pressurized ethanol (100%) recovered maximum anthocyanins (6.02–8.42 mg Cy3GE d.w.) with insignificant effect of temperature at 40–120 °C/50 bar. Irrespective of the treatment, major anthocyanins were cyanidin 3-galactoside, cyanidin 3-arabinoside, peonidin 3-galactoside, and peonidin 3-arabinoside. Maximum total phenolic content (84.96 ± 7.82 mg GAE d.w.) was obtained with pressurized 30% ethanol at 140 °C/50 bar. Pressurized ethanol showed better Pearson correlation value (P = 0.84) between total anthocyanins and antioxidant capacity compared to pressurized water. Results demonstrate potential of pressurized fluid extraction with ethanol to selectively remove anthocyanins and total phenolics from cranberry pomace.

Influence of photolysis on source characterization and health risk of polycyclic aromatic hydrocarbons (PAHs), and carbonyl-, nitro-, hydroxy- PAHs in urban road dust.

In this study, PAHs and their transformed PAH products (TPPs) in road dust were subjected to UV driven photolysis, and then extracted using simultaneous pressurized fluid extraction, and analysed using Shimadzu Triple Quadrupole GC/MS. The results of the analysis were used to investigate the robustness and reliability of 14 existing diagnostic ratios (DRs) and two newly proposed molecular DRs that are relevant for characterizing the sources of PAHs and TPPs. The influence of photolysis on the carcinogenic health risk posed to humans by these hazardous pollutants was then assessed. The findings indicated that the DRs segregated into stable, moderately stable and non-stable classes of source characteristics under the influence of photolysis. Only two of the existing DRs, namely, benzo(a)pyrene/benzo(ghi)perylene (BaP/BghiP) and total index exhibited consistent stability to photolysis, whilst fluoranthene/(fluoranthene+pyrene) (FRT/(FRT+PYR)) showed moderate stability. The two newly proposed DRs, naphthalene/1-nitronaphthalene (NAP/NNAP) and pyrene/(1-nitropyrene+1-hydroxypyrene) (PYR/(1NPY+HPY)) were found to be highly reliable in post-emission source characterization. The cross-plots of the most stable DRs showed that traffic emissions is the primary source of PAHs, whilst post-emission photolysis is the secondary source of nitro-PAH (NPAH) TPPs. The percent resonance energy thermodynamic stability of the PAH pollutants does not exert any direct influence on the source characteristics of the DRs. Adults are more vulnerable to potential carcinogenic risks as a result of PAH and TPPs photolysis whereas negligible risk exist for children. This study contributes to a more reliable diagnosis of PAH and TPP sources and thus, to the regulatory mitigation of these hazardous pollutants thereby, promoting enhanced protection of human health and the environment.

Clean Technologies for Obtaining Biocomposites of Brazilian Ginseng Pfaffia glomerata (Spreng.) Pedersen: A Review

The Brazilian ginseng Pfaffia glomerata (Spreng.) Pedersen belongs to the Amaranthaceae family and has as its main component β-ecdysone, a phytoecdysteroid, found in the roots, stem, flowers and leaves of the plant. In the last years sustainability and the environment concern were decisive for the emerging supercritical fluid extraction and pressurized fluid extraction technologies to obtain biocomposites from the plant. These extraction technologies use solvents (CO2, ethanol and water) and uses as controllable parameters pressure, flow, time and temperature. The combination of these factors generates atoxicity, no residue in the final extract and have a reduced energy cost and an excellent extraction yield. This work reviews the literature from 2007 to 2020 on the use of clean technology to obtain chemical biocomposites of interest in the areas of biology, agronomy, food and pharmaceutics. It is was concluded that the supercritical fluid extraction and pressurized liquid extraction extracts were very efficient in obtaining β-ecdysone, since both presents low energy consumption, uses environmentally correct solvents which reduces harmful effects on the environment. Finally, to choose the best technology for extraction of other biocomposites depends on the chemical compound of interest.

Optimized simultaneous pressurized fluid extraction and in-cell clean-up, and analysis of polycyclic aromatic hydrocarbons (PAHs), and nitro-, carbonyl-, hydroxy -PAHs in solid particles

The development, modification and optimization of analytical methods capable of simultaneous extraction and in-cell clean-up of extracts for subsequent determination of parent PAHs and their associated transformed nitro-PAHs (NPAH), carbonyl-PAHs (CPAH) and hydroxy-PAHs (HO-PAH) products (TPPs) is essential for reducing the time and cost of analysis. The aim of this study was to modify and optimize the pressurized fluid extraction (PFE) technique capable of simultaneous extraction and in-cell clean-up of PAHs and TPPs in urban dust standard reference material and road dust for GC-MS analyses. In this study, multivariate data analysis such as factor analysis (FA), and preference ranking organisation method for enrichment evaluation (PROMETHEE) and geometrical analysis for interactive aid (GAIA) were used to assess the performance of the methods. As the key outcome of the study, an optimized selective reaction monitoring (SRM) Triple Quadrupole (TQ) electron ionization (EI)-GC/MS for measuring PAHs and TPPs without derivatization of polar HO-PAHs was developed. The limits of detection (LOD) for parent PAHs, CPAHs, NPAHs and HO-PAHs using Shimadzu TQ were 1.0–5.0 pg, 1.0–5.0 pg, 1.0–50.0 pg, and 1.0–25.0 pg, respectively. The PROMETHEE-GAIA analysis of the results showed that a combination of 3% deactivated silica gel and activated alumina (2:1) as in-cell clean-up material, and sequential PFE extraction (200 °C ASE temperature, 9 min preheat time and 3 times extraction cycle) using 100% hexane followed by hexane/DCM (1:1) is the best condition for analytes extraction from road dust. An optimized, fast and reliable GC/MS method operated solely in electron ionization (EI) mode was developed for measuring all analytes. The outcomes of this study will contribute significantly to future research on PAHs and TPPs, thereby promoting a safe and sustainable environment.

Simultaneous extraction and purification of fucoxanthin from Tisochrysis lutea microalgae using compressed fluids

The marine microalga Tisochrysis lutea, a Haptophyta with a thin cell wall and currently used mainly in aquaculture is a potential source of several bioactive compounds of interest such as carotenoids. In the present study, the simultaneous extraction and purification of fucoxanthin, the main carotenoid from T. lutea, was optimized using pressurized fluid extraction followed by in-cell purification. An experimental design was employed to maximize carotenoids' extraction; the experimental factors chosen were: (i) percentage of ethanol/ethyl acetate (0-100 %), (ii) temperature (40-150°C), and (iii) number of static extraction cycles (1-3). The maximum carotenoids' recovery, mainly fucoxanthin, was obtained with pure ethyl acetate at 40°C using one extraction cycle, achieving values of 132.8mg of carotenoids per gram of extract. Once the optimum extraction conditions were confirmed, in-cell purification strategies using different adsorbents were developed to obtain fucoxanthin-enriched extracts. Activated charcoal showed potential retention of chlorophylls allowing an effective purification of fucoxanthin in the obtained extracts. Chemical characterization of extracts was carried out by reversed-phase high-performance liquid chromatography with diode array detection. Therefore, a selective fractionation of high value compounds was achieved using the proposed green downstream platform based on the use of compressed fluids.

Different Extraction Techniques on the Characteristic Properties of Valonea Tannin

Valonea extract is a natural tannage widely applied in leather industry which is produced via conventional hot water extraction method. On the otherhand more environmental friendly methods have started to be used in extraction technology recently. Present paper reports on the effect of different extraction methods on the properties of valonea extracts. For this purpose, conventional solvent extraction (CSE) (methanol/water mixture), supercritical CO2 (scCO2) extraction and pressurized fluid extraction (PFE) (water/CO2 binary system) techniques have been employed on valonea and the obtained extracts have been characterized. Molecular weight of the tannins was determined by gel permeation chromatography (GPC), particle size was examined by Malvern Zetasizer instrument, chemical structure by Fourier Transform Infrared Spectroscopy (FTIR). Tannin content was also examined and the results were compared with commercial valonea extract (CVT). The results showed that especially particle size of the tannins was affected by the applied extraction method and the smallest particle size was obtained by PFE method as 505.3 nm compared to commercial tannin as 983.0 nm of average particle size. PFE method was also provided more uniform extract according to the polydispersity index values. GPC and FTIR analyses showed slightly differences on the characteristics of tannins.

Distribution and Source of Sedimentary Polycyclic Aromatic Hydrocarbon (PAHs) in River Sediment of Jakarta

In this study, the distribution and source identification of sedimentary PAHs from 13 rivers running through Jakarta City were investigated. Freeze-dried sediment samples were extracted by pressurized fluid extraction and purified by two-step of column chromatography. PAHs were identified and quantified by gas chromatography-mass spectrometry (GC-MS). High concentrations of PAHs, ranging from 1992 to 17635 ng/g-dw, were observed at all sampling locations. Ratios of alkylated PAHs to parent PAHs exhibited both petrogenic and pyrogenic signatures with predominantly petrogenic inputs. High hopanne concentrations (4238-40375 ng/g dry sediment) supported the petrogenic input to Jakarta’s rivers. The high concentration of PAHs is indicator for organic micropollutant in the aquatic urban environment in Jakarta that may have the potential to cause adverse effect to the environment.

Techniques for Extraction of Brewer’s Spent Grain Polyphenols: a Review

Million tons of brewer’s spent grain (BSG) are annually produced worldwide as brewing industry by-products. BSG represents a valuable source of phenolic compounds, which have attracted much attention due to their diverse health benefits. Relevant strategies have been developed for their efficient extraction, in order to commercially exploit these resources. This review focuses on the current extraction methods used to obtain phenolic compounds from BSG, ranging from more traditional to advanced techniques. The commonly used methods are the conventional solid–liquid extractions, employing organic solvents, alkaline, and enzymatic reactions. However, the inherent difficulties in screening and obtaining these compounds have led to the development of advanced extraction techniques. Pressurized fluid extraction, supercritical extractions, and microwave-assisted and ultrasound-assisted extractions are some of the novel extraction techniques that have been recently explored. These techniques have been mostly applied for phenolic recovery from barley and malt, as well as other types of cereals. In this review, it is shown that these novel techniques may provide an innovative approach to extract phenolics from BSG or related products, following an in-depth discussion on the major strengths and weaknesses identified in each technique.