Conventional Solvent Extraction Method Research Articles

A Procedure for Solid-Phase Extractions Using Metal-Oxide-Coated Silica Column in Lipidomics.

Lipid enrichment is indispensable for enhancing the coverage of targeted molecules in mass spectrometry (MS)-based lipidomics studies. In this study, we developed a simple stepwise fractionation method using a titanium- and zirconium-dioxide-coated solid-phase extraction (SPE) silica column that separates neutral lipids, phospholipids, and other lipids, including fatty acids (FAs) and glycolipids. Chloroform was used to dissolve the lipids, and neutral lipids, including steryl esters, diacylglycerols, and triacylglycerols, were collected in the loading fraction. Second, methanol with formic acid (99:1, v/v) was used to retrieve FAs, ceramides, and glycolipids, including glycosylated ceramides and glycosylated diacylglycerols, by competing for affinity with the Lewis acid sites on the metal oxide surface. Finally, phospholipids strongly retained via chemoaffinity interactions were eluted using a solution containing 5% ammonia and high water content (45:50 v/v, 2-propanol:water), which canceled the electrostatic and chelating interactions with the SPE column. High average reproducibility of <10% and coverage of ∼100% compared to those of the non-SPE samples were demonstrated by untargeted lipidomics of human plasma and mouse brain, testis, and feces. The advantage of our procedure was showcased by characterizing minor lipid subclasses, including dihexosylceramides containing very long-chain polyunsaturated FA in the testis, monogalactosyl and digalactosyl monoacylglycerols in feces, and acetylated and glycolylated derivatives of gangliosides in the brain that were not detected using conventional solvent extraction methods. Likewise, the value of our method in biology is maximized during glycolipidome profiling in the absence of neutral lipids and phospholipids that cover more than 80% of the chromatographic peaks.

Simultaneous rare earth sulfate transformation and carbon dioxide mineralization

The wet metallurgical process route for recovering rare earth elements usually uses sulfuric acid. To obtain marketable individual rare earth products, converting rare earth sulfates to chlorides is essential. Conventional chemical precipitation and solvent extraction methods result in significant amounts of ammonia wastewater and greenhouse gas emissions. Therefore, we propose a novel process that integrates CO2 mineralization with rare earth sulfates transformation. By utilizing a base-catalyzed mechanism with trioctylamine (TOA), CO2 is effectively employed for selective precipitation of more than 95 % of rare earths from magnesium and calcium under optimized conditions. Subsequently, dissolution in hydrochloric acid allows for enrichment of the concentration of rare earths up to 188.3 g/L. The reaction mechanism is examined through Visual MINTEQ simulations and various analytical techniques. This process not only offers a sustainable approach to rare earth sulfates transformation but also contributes to carbon capture, utilization, and sequestration efforts.

Red beet betalains extraction process: A comprehensive review of methods, applications, and physicochemical properties.

Red beet extract is rich in bioactive compounds and possesses health-promoting properties. Moreover, the stability of red beet extract over a broad acidic pH range has given them great potential in developing new functional foods and drinks. The choice of extraction solvent and methodology significantly influences the efficiency of betalain extraction from plant vacuoles. Although the conventional solvent extraction method has been widely employed for betalain extraction, recent innovations have introduced alternative methods that offer advantages, such as reduced solvent consumption, energy efficiency, and minimized exposure to high temperatures. This paper aims to summarize the current knowledge about conventional and novel extraction methods, applications, biological activities, and purification of red beet betalains. Furthermore, the physicochemical properties of betalain-rich extract of red beet and associated safety considerations have been investigated.

Valorization of berry pomace for extraction of polyphenol compounds and its co-encapsulation with probiotic bacteria

Saskatoon berry pomace, an antioxidant rich byproduct, may be suitable for nutraceuticals and functional foods. The present study aimed to co-encapsulate polyphenol-rich berry extract with probiotics to utilize the polyphenolic compounds present in berry pomace. The major benefit of co-encapsulation is that polyphenolic compounds increase the survival characteristics of probiotic bacteria in gastrointestinal tract. To make the process cost-effective, a conventional solvent extraction method was used for extraction of polyphenolic compounds from berry pomace. Spray drying was used to co-encapsulate polyphenols and probiotics by using plant-based carrier materials (pea protein isolate with gum Arabic). Spray dried powder was evaluated for encapsulation efficiency, gastrointestinal stability, bio-accessibility index, along with functional, structural and thermal characteristics. Berry pomace was found to be a good source of TPC, DPPH and ABTS with 2.49 mg GAE/1 g, 4.48 mg QE/1 g and 2.96 mg QE/1 g, respectively. The encapsulation efficiency (retention of polyphenolics and bacteria in capsules) of polyphenolic compounds and probiotics was 72.6% and 94.4%, respectively. Probiotic cells encapsulated with polyphenolic compounds showed improved survival (9.08 log CFU/mL) during in vitro gastrointestinal digestion. The bio-accessibility of TPC was 63.6% after intestinal digestion. The spray dried powder was observed to possess good thermal stability but poor functional properties, thus limiting applications to products such as bakery goods, sports bars, cereals and other foods where dispersibility is not imperative. Therefore, co-encapsulation by spray drying method offers an efficient and cost-effective method for simultaneous delivery of bioactive compounds and probiotics to the gut, extending their benefits by this combination.

In-depth phytochemical profiling of Roscoea purpurea (Kakoli): Comparative UHPLC-MS/QToF and GC-MS/MS analysis of supercritical CO2 fluid - and conventional solvent - based extractive processes

The remarkable biodiversity of medicinal plants worldwide highlights their significance in traditional and alternative medicine. Astavarga, a group of eight medicinal herbs from the Himalayan region of India, including Roscoea purpurea (commonly known as Kakoli), is esteemed in Ayurveda for its health-promoting and rejuvenating properties. In this comprehensive study, we aimed to develop and optimise robust UHPLC-MS/QToF (Ultra-high-performance liquid chromatography-mass spectrometry coupled with quadrupole time of flight) and GC-MS/MS (Gas chromatography-tandem mass spectrometry) methods to identify the phytochemicals in R. purpurea root hydromethanolic extract and essential oil. We also conducted a comparative assessment of supercritical fluid extraction and conventional solvent extraction methods for the first time in R. purpurea root, highlighting their relevance to the medicinal field. Using the UHPLC/MS-QToF method, we identified a total of fifty-six phytometabolites, while sixteen volatile constituents were discerned within the essential oil of R. purpurea by GC-MS/MS method. Among the volatile constituents, β-eudesmol (40.84 %), guaiac acetate (10.55 %), and γ-eudesmol (10.31 %) were emerged as the principal components. Our findings were further compared with the volatile constituents extracted via supercritical fluid extraction and conventional solvent extraction methods. Notably, our research unveiled the presence of a carotenoid metabolite, 15-methyl retinol, for the first time. Furthermore, our fatty acid analysis of the supercritical fluid extract revealed elevated levels of unsaturated fatty acids, particularly oleic and linoleic acids. The methods were validated in terms of system specificity also. The discovery of these well-recognised therapeutically active components in R. purpurea significantly enhances its potential, highlighting its unique profile among medicinal plants in the Himalayan region and its suitability for traditional Ayurveda.

Antioxidant Activity and UHPLC-MS/MS Characterization of Polyphenol and Nicotine Content in Nicotiana Glauca Leaf Extracts: A Comparative Study of Conventional and Deep Eutectic Solvent Extraction Methods.

The leaves of Nicotiana glauca (N. glauca; Solanaceae) plant are a known, major human health concern. This study investigated the antioxidant activity and polyphenols composition of aerial parts of N. glauca collected from its wild habitat in Jordan, using Methanol-Conventional (MC) and deep eutectic solvents (DES) extraction methods in addition to nicotine content determination using UHPLC. Our results showed that the MC extract contains fewer total phenols and flavonoid content than the 90% DES extract, (0.1194 ± 0.009 and 0.311 ± 0.020 mg/mL equivalent to gallic acid) and (0.01084 ± 0.005 and 0.928 ± 0.09 mg/mL equivalent to rutin), respectively. Moreover, this study showed that the prepared MC extract contain 635.07 ppm nicotine, while the 90% DES extract contain 1194.91 ppm nicotine. Extracts prepared using the MC and the DES methods exhibited weak antioxidant activities; the highest was a 33% inhibition rate (equivalent to ascorbic acid), obtained by the 90% DES extract,. The performed UHPLC-MS/MS analysis in this study also revealed the presence of variations in the detected compounds between the two extraction methods. Furthermore, this study found that environmentally friendly DES extraction of N. glauca produced higher phenol and flavonoid content than the MC method; this highlights the superior efficiency and environmental benefits of sustainable chemistry methods for extracting valuable phytoconstituents.

Optimizing extraction methods by a comprehensive experimental approach and characterizing polyphenol compositions of Ecklonia radiata

Brown seaweed Ecklonia radiata harbors valuable polyphenols, notably phlorotannins, prized for their health benefits. This study optimized phlorotannin extraction via conventional solvent extraction and ultrasound-assisted extraction methods, utilizing variable concentrations of ethanol. Employing fractional factorial designs, key variables were identified. Steepest ascent/descent method and central composite rotatable designs refined optimal conditions, enhancing phlorotannin and polyphenol yields, and antioxidant capacities. Under optimized conditions, phlorotannin contents reached 2.366 ± 0.01 and 2.596 ± 0.04 PGE mg/g, total polyphenol contents peaked at 10.223 ± 0.03 and 10.836 ± 0.02 GAE mg/g. Robust antioxidant activity was observed: DPPH and OH radical scavenging capacities measured 27.891 ± 0.06 and 17.441 ± 0.08 TE mg/g, and 37.498 ± 1.12 and 49.391 ± 0.82 TE mg/g, respectively. Reducing power capacities surged to 9.016 ± 0.02 and 28.110 ± 0.10 TE mg/g. Liquid chromatography-mass spectrometry (LC-MS) and high-performance liquid chromatography (HPLC) analyses revealed enriched antioxidant compounds. Variations in polyphenol profiles were noted, potentially influencing antioxidant capacity nuances. This study illuminated the potential of E. radiata potential as a polyphenol source and offers optimized extraction methods poised to benefit various industries.

Assisted extraction using green technologies and conventional solvent extraction method: a comparison of the phenolic content and profile of sorghum and their antioxidant activity

Assisted extraction using green technologies and conventional solvent extraction method: a comparison of the phenolic content and profile of sorghum and their antioxidant activity

Optimisation of supercritical fluid extraction of orange (Citrus sinenis L.) peel essential oil and its physicochemical properties

In this study, the choice of supercritical fluid extraction as a renewable alternative for extracting orange peel essential oil (OPEO) was motivated by concerns about sustainability with conventional solvent extraction methods. The physical and chemical characteristics of OPEO were examined to assess its potential as a sustainable resource. The extraction process was optimised, and the ideal conditions determined were 317.51 min of extraction time at 74.85 °C with a solvent-to-sample ratio of 4. Analysis of the extracted OPEO revealed significant values for saponification (121.67 mg KOH/g), acid (4.13 mg KOH/g), ester (117.54 mg KOH/g), and free fatty acid (1.56 mg KOH/g) content, demonstrating its composition. Notably, key ingredients such as Limonene (43.96%), α-pinene (15.60%), β-myrcene (10.21%), γ-terpinene (5.00%), and α-terpineol (4.15%) were found in high proportions according to chemical composition analysis. Furthermore, OPEO exhibited excellent antioxidant properties with an IC50 value of 7.73 ± 2.00 mg/mL and displayed notable antimicrobial activity against various microorganisms, including P. aeruginosa (17.7 ± 0.6 mm), E. coli (11.0 ± 0.0 mm), K. pneumoniae (10.7 ± 0.6 mm), and S. aureus (10.3 ± 0.6 mm). These findings have significant implications for the flavor and fragrance sector, as well as for the food preservation industry.

HPLC-UV Analysis of Chrysophanol in Senna occidentalis Extract Obtained by Using the RSM-Optimized Ultrasonic Extraction Process

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 &lt; 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.

Effect of ultrasound-assisted cold plasma pretreatment on cell wall polysaccharides distribution and extraction of phenolic compounds from hyssop (Hyssopus officinalis L.)

Hyssopus officinalis L (Hyssop) is a good source of phenolic compounds. However, conventional methods for extraction of these compounds typically take a long time and have relatively low recovery rates. This study focused on cold atmospheric plasma (CAP) pretreatment and investigated its effects on the ultrasound-assisted extraction (UAE) of phenolic compounds from hyssop. Hyssop was treated at dielectric barrier discharge plasma with air and nitrogen gases for 5, 10, and 15 min. Optical emission spectroscopy was used to evaluate present active species in the plasma. The water contact angle changes, cell wall polysaccharides distribution, and structural variations of the treated samples were determined after treatment. Antioxidant activity and total phenolic contents (TPC) of the extracts were also evaluated. The results showed that CAP treatment reduced the contact angle making surface more hydrophilic. Compared with hyssop, overall no significant changes in the basic structure of all treated samples or the formation of new functional groups were recognized. In addition, CAP pretreatment before UAE increased the antioxidant activity of extracts according to the FRAP assay than the un-pretreated sample and conventional solvent extraction method. Also, TPC increased in samples treated with nitrogen plasma.

Optimization of solvent extraction conditions of Cambodian soybean oil using response surface methodology

The conventional solvent extraction (CSE) method is commonly used to extract oil from oilseeds. Even though the extraction of oil from soybean seeds using the CSE method has been studied extensively, the application of response surface methodology (RSM) has not yet been widely explored. In this paper, the CSE method was employed using three different types of solvents – ethanol (Eth), n-hexane (Hex), and a mixture of Hex:Eth in a ratio of 2:1 – and optimized using RSM to extract the oil from Cambodian soybean seeds. For each solvent, a central composite design (CCD) was applied to optimize the extraction conditions, such as the extraction times (15, 30, and 45 min) and solvent-to-solid ratios (5:1, 10:1, and 15:1 mL/g). This CCD generated 11 experimental runs for each type of solvent. The optimum oil yields when using ethanol, Hex:Eth, and n-hexane were 20.53%, 18.78%, and 17.39%, respectively. The optimum condition was obtained at 15 min extraction time and 15:1 (mL/g) solvent-to-solid ratio for all solvent types. The coefficients of determination of ethanol, Hex:Eth, and n-hexane were 0.9710, 0.9954, and 0.9263, respectively, which mathematically indicated a good model for the prediction. Therefore, the model was considered accurate and reliable for predicting oil yields in this study.

Assessment of the Phytochemical Analysis and Antimicrobial Potentials of Zingiber zerumbet

Antimicrobial resistance (AMR) has arisen as a global concern in recent decades. Plant extracts used in combination with antibiotics are promising against AMR, synergistically. The purpose of this study was to evaluate the component of the bitter ginger (Zingiber zerumbet) extract in different solvents using high-performance liquid chromatography (HPLC), in addition to evaluate the antibacterial activity of these extracts, in combination with their antibiotic potential against four multi-drug resistant (MDR) bacterial strains (Lactobacillus acidophilus, Streptococcus mutans, Enterococcus faecalis and Staphylococcus aureus). Ethanol and the aqueous extracts of bitter ginger were prepared using a conventional solvent extraction method and were evaluated for their phytochemistry using HPLC, qualitatively and quantitatively. Moreover, the antibiotic susceptibility of the pathogenic isolates was determined. A disc diffusion assay was used to obtain the antimicrobial potential of the extracts alone and with antibiotics. Eight components were identified from the separation of the bitter ginger extract by HPLC. For AMR bacteria, the combination of the antibiotic solution with the bitter ginger crude extracts could improve its susceptibility of these antibiotics. This study indicates that the combination of an antibiotic solution with the bitter ginger crude extract exhibits potent antibacterial activities against MDR bacterial strains. Therefore, they can be used for the treatment of various diseases against the microbial pathogen and can be incorporated into medication for antibacterial therapy.

High-Yield Recovery of Antioxidant Compounds from Bambusa chungii Culms Using Pressurized Hot Water Extraction.

A large amount of waste from Bambusa chungii culms is generated from the bamboo pulping industry, causing disposal problems. Nevertheless, bamboo culms are a suitable source of functional ingredients, such as antioxidant compounds. However, because of the high compactness and tightness in their material structure, obtaining phytochemicals from bamboo culms using conventional organic solvent extraction methods can be inefficient. In this research, we developed a pressurized hot water extraction (PHWE) method to recover 19 target phenolic compounds from Bambusa chungii culms. The extracted compounds were determined by ultra-high performance liquid chromatography-quadrupole time-of-flight-mass spectrometry (UPLC-QTOF-MS). The antioxidant potential of the extracts was evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and ferric reducing antioxidant power (FRAP) assays. We investigated the effects of temperature, extraction time, and the material-to-liquid ratio on PHWE, and these parameters were optimized with a Box-Behnken design experiment and response surface tool. The optimal extraction condition was found at 170 °C, with a 1:30 g/mL material-to-liquid ratio and a 14 min extraction time. Following these optimal parameters, the total yield of target phenolic compounds (TYPC) reached 3.85 mg/g of raw material, and the half-maximal inhibitory concentrations (IC50) for the DPPH and ABTS tests were 94.7 mg/L and 21.88 mg/L, respectively. The FRAP value was 1.23 μmol FSE/mg of dried extract. A strong correlation between TYPC and the antioxidant activity of the extract was confirmed. The TYPC and antioxidant capacity of the optimal PHWE extract of the Bambusa chungii culms were both considerably higher than those of extracts obtained from conventional solvent extractions. These results indicated that PHWE is an excellent green technique for recovering phenolic compounds from bamboo culms, and the PHWE extracts of Bambusa chungii culms may be a good source of natural antioxidants.

Application of natural deep eutectic solvents in bulk liquid membrane system for removal of free glycerol from crude fatty acid methyl ester

Fatty Acid Methyl Ester (FAME) produced from biomass offers several advantages such as renewability and sustainability. The typical production process of FAME is accompanied by various impurities such as alcohol, soap, glycerol, and the spent catalyst. Therefore, the most challenging part of the FAME production is the purification process. In this work, a novel application of bulk liquid membrane (BLM) developed from conventional solvent extraction methods was investigated for the removal of glycerol from FAME. The extraction and stripping processes are combined into a single system, allowing for simultaneous solvent recovery whereby low-cost quaternary ammonium salt-glycerol-based deep eutectic solvent (DES) is used as the membrane phase. Moreover, for the first time, diethyl ether was introduced as a strip phase to strip the free glycerol in the BLM system. The effects of DES composition, DES:FAME ratio, stirring speed and operating time on the extraction and stripping efficiencies were investigated. A kinetic model was proposed for the transportation of free glycerol through the DES-based BLM, where the kinetic parameters (k1, k2, tmax, GMmax) for the extraction and stripping were calculated using the glycerol content in the feed and the strip phase. The performance of the lab-scale BLM system confirms the viability of the proposed system with a best DES molar composition of 1:2 (salt:glycerol), DES:FAME ratio of 1:1, mixing speed of 200 rpm and an extraction time of 4 hr. Glycerol content in the purified FAME meets the international standards such as EN 14214 and ASTM D6759. Under the optimal conditions, the suggested model curves of glycerol content in the feed, membrane, and strip phases showed a good fitting with the experimental results. Finally, the rate constants values of the kinetic model were 0.0037 min−1 for k1 and 0.0066 min−1 for k2.

Layered Double Hydroxide@Metal-Organic Framework Hybrids for Extraction of Indole-3-Carbinol From Cruciferous Vegetables.

Cruciferous vegetables are rich in glucosinolates, which can be metabolized to produce the antitumor compound indole-3-carbinol (I3C). The conventional solvent extraction method for I3C is inefficient. To improve the extraction efficiency of I3C from cruciferous vegetables, we prepared a metal-organic framework (MOF) material (Fe3O4@Zn-Al-LDH@B-D-MIL-100). First, Fe3O4 nanoparticles were introduced to layered double hydroxides by in situ polymerization. Then, the MOF material was grown on the surface of the layered double hydroxide by co-precipitation and the layer-by-layer self-assembly method. This gave Fe3O4@Zn-Al-LDH@B-D-MIL-100, which was characterized using a variety of techniques. The results showed that Fe3O4@Zn-Al-LDH@B-D-MIL-100 had a double-layer porous structure, excellent superparamagnetism (11.54955 emu/g), a large specific surface area (174.04 m2/g), and a pore volume (0.26 cm3/g). The extraction conditions for I3C were optimized. Non-linear fitting of the static adsorption model showed that the adsorption was mainly monolayer. Fe3O4@Zn-Al-LDH@B-D-MIL-100 had fast adsorption kinetics and could extract 95% of I3C in 45 min. It is superior to the traditional solvent extraction method because of its high enrichment efficiency in a short time and environmental friendliness. The successful preparation of the new nanomaterial will provide a new reference for the enrichment and extraction of the I3C industry.

Effect of Extraction Method on the Bioactive Composition, Antimicrobial Activity and Phytotoxicity of Pomegranate By-Products

Pomegranate by-products can be an asset to the food industry due to the richness in bioactive and antimicrobial compounds. This work studied the influence of conventional solvent and sonication-assisted extraction methods on the bioactive profile, antimicrobial properties, and phytotoxicity effect of the peels and seeds extracts from Acco, Big Full, and Wonderful pomegranate cultivars. The bioactive composition of the extracts was evaluated for the content of total phenolics, total flavonoids, and antioxidant activity (expressed as the half-maximal inhibitory concentration—IC50) by spectrophotometric methods, while the tannins were determined by titration and the anthocyanins were estimated by the pH-differential method. For the evaluation of the antimicrobial activity, the disk diffusion method of Kirby-Bauer was adapted through inhibition halos against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus cereus, and Yarrowia lipolytica. The extracts’ phytotoxicity was evaluated in vitro on garden-cress seeds. Extracts from conventional extraction were richer in total phenolics, expressed as gallic acid equivalents (0.16–0.73 mg GAE/mg extract), while those from sonication-assisted extraction had higher contents of total flavonoids, expressed as catechin equivalents (0.019–0.068 mg CATE/mg extract); anthocyanins, expressed as cyanidin-3-glucoside (0.06–0.60 µg C3G/mg, dry basis); and antioxidant activity (IC50, 0.01–0.20 mg/mL). All extracts were more effective against Gram-positive bacteria and yeasts than Gram-negative bacteria. In general, the sonication-assisted extracts led to higher inhibition halos (8.7 to 11.4 mm). All extracts presented phytotoxicity against garden-cress seeds in the tested concentrations. Only the lowest concentration (0.003 mg/mL) enabled the germination of seeds and root growth, and the sonication-assisted extracts showed the highest Munoo-Liisa vitality index (51.3%). Overall, sonication-assisted extraction obtained extracts with greater bioactive and antimicrobial potential and less phytotoxicity.

Lipid markers in archaeological pottery vessels excavated at Jneneh Site, in North-Central Jordan

This study is part of a long-term project attempts to better understand the content and use of pottery vessels in the Bronze and Iron Ages in Jordan by examining organic residues preserved in their interior fabrics. The main purpose of this study is to analyse organic residues retained in a second collection of Iron Age II pottery sherds excavated at the site of Jneneh in North-Central Jordan, in order to determine the content and the potential use of the mother vessels based on integrating data obtained from this bimolecular study with those found in the archaeological record. The analysis was applied on these sherds and their associated soils. Residues were retrieved from the pottery fabrics and soils using the conventional solvent extraction method. One portion of each residue was analysed using gas chromatography-mass spectrometry (GC–MS) technique, and when needed, another portion was first saponified (alkaline hydrolysed) and then analysed. The analysis revealed the existence of: (1) Markers related to two materials preserved in a sherd that belongs to a coarse storage jar with collared decoration (Jn9; Class 1). The first material is beeswax, which may have intentionally been applied as a sealant on the inner side of the jar in order to store aqueous liquids like water or to store dry goods. Using the jar for storing honey, which probably was not completely filtered from beeswax, was also proposed. The second material is being of plant origin, possibly oil or mixture of oils, preserved as a result of using the same jar for storing, either before or unlikely after sealing the jar with beeswax. Using both materials as a mixture inside the jar was also suggested. These two materials reoccurred for the second time in vessels from the same site. (2) Markers related to animal fat (possibly ruminant-based milk lipid, which requires confirmation) preserved in a sherd that belongs to a fine miniature jug (Jn4; Class 2), which was probably used for holding the milk products for daily based use. (3) Markers with very low concentrations related to a plant wax originated from unknown source were also observed in seven pottery sherds (Class 3), some of these sherds have contamination signals from handling and modern materials. (4) Few number of undiagnostic markers with very low concentrations were also detected in other five sherds (Class 4), therefore, their origin could not be determined. The organic contents of the latter two classes, and particularly Class 4, may have been subjected to a high level of degradation and depletion, therefore, residue analysis of this study could not provide data on the use of Classes 3 and 4 mother vessels but archaeologically their potential uses were discussed in this paper. Analysis of the markers present in the soils adhering onto the surfaces of pottery sherds provided evidences on the occurrence of lipid-based natural materials inside Jn9 and Jn4 vessels and on degradation and depletion of organic contents, as well as contamination from soil lipids in case of the other vessels. Hence, this study presents further evidence on, possibly, the common use of bees and plant products in the IA II settlement at Jneneh.

Ultrasound-Assisted and Microwave-Assisted Extraction, GC-MS Characterization and Antimicrobial Potential of Freeze-dried L. camara Flower

Lantana camara is known to have anti-bacterial properties which can be exploited to develop a natural food preservative. There is huge demand for natural preservatives in food industry due to the increased health risks associated with synthetic preservatives, development of effecient extraction methods are essential to retain heat sensitive bioactive compounds. This aim of this study was to compare the performance of microwave-assisted extraction (MAE), ultrasound-assisted extraction (UAE), and conventional solvent extraction (CSE) methods for extraction of freeze-dried lantana flower. The phytochemicals in freeze-dried flowers were characterized by GC-MS analysis and antibacterial properties were tested at different concentrations (50, 100, and 150 µl) against E.coli, Salmonella, and S. aureus. It was evident that the UAE offered the highest yield (64%), followed by MAE (53%) and CSE (49%) with distilled water as solvent. The freeze-dried extract possessed a high amount of tannins (417 µg/g), followed by flavonoids such as catechol (88 µg/g) and quercetin (9.2 µg/g). The antibacterial potential results revealed that only distilled water-based extraction techniques offered positive inhibition zones of 2.0-2.67 mm (MAE), 1.67-2.67 mm (UAE), and 1.67-2.17 mm (CSE) against all three organisms, while the chloroform based extracts had no inhibition effect. The microwave-assisted extract at 150 µl concentration offered a significant inhibitory effect against all three pathogens. The GC-MS profiling of bioactive compounds in flower extract revealed the presence of hexadecanoic acid as the major phytochemical compound in all three extraction techniques. The study revealed that the chloroform extract failed to exhibit an antibacterial effect due to the absence of alkaloids, saponins, and anthraquinones as a result of its neutralizing effect.

Enhancing extraction of proanthocyanidins from Chinese quince fruit by ball-milling and enzyme hydrolysis: yield, structure, and bioactivities

Chinese quince fruits are rich in proanthocyanidins (PAs), which have antioxidant properties. This work describes a method to isolate PAs from Chinese quince fruits by a combination of ball-milling and enzyme hydrolysis pretreatments. The yield, total PA and total phenolic contents, structural characteristics, antioxidant activity, and α-amylase inhibitory activity of different pretreated PA samples were determined and analyzed. Among them, the ball-milling combined with multi-enzyme (cellulase, xylanase, and pectinase) hydrolysis pretreated sample (BEP-4) was the most outstanding. The yield of BEP-4 could be improved up to 7.72%, which was 2.51 times higher than that of the conventional organic solvent extraction method (3.02%). It had the highest total phenols and PAs content of 750.98 ± 6.95 and 948.72 ± 3.50 mg/g extract, respectively. The thermal stability and molecular weight (9610 Da) of BEP-4 were lower than other fractions. BEP-4 contained a high proportion of PC structure (98.35%) and flavan-3-ol content (87.88%). It also had the highest antioxidant capacity with IC50 values of 131.45 ± 0.97, 22.66 ± 0.32, 134.05 ± 0.71, and 182.07 ± 0.28 μg/mL for DPPH, ABTS, hydroxyl radical scavenging capacity, and α-amylase inhibiting capacity, respectively. These investigations provide a new, efficient way to isolate PAs from Chinese quince fruits, and reveal that Chinese quince fruits may be a good source of antioxidants, worthy of further development.