Optimal Extraction Conditions Research Articles

Bioactive constituents of amphibious Rotala rotundifolia at different growth stages and response surface optimization for flavonoid extraction

Rotala rotundifolia is an amphibious aquatic plant that can live in submerged and emergent forms. It is superior in nitrogen and phosphorus removal and has been used as a traditional medicine in China for over a hundred years. In this study, the bioactive constituents from different tissues of submerged and emergent R. rotundifolia at different growth periods were investigated. The response surface method was used to optimize the flavonoids extraction condition. The amount of flavonoids and triterpenoids from different tissues of R. rotundifolia were much higher than tannins and alkaloids. The highest total flavonoids amount from the leaves of submerged R. rotundifolia was 270.92 ± 13.34 mg/g at day 30 (phyllomorphosis finished), 1.8 times that of the emergent form (150.45 ± 15.11 mg/g). The highest triterpenoids content from the submerged and emergent forms was 242.20 ± 11.51 and 163.09 ± 14.87 mg/g at days 90 and 150 (flowering stage), respectively. The optimal flavonoid extraction conditions were: extraction time 50 min, ultrasonic power 333 W, ethanol concentration 79.3%, and a solid–liquid ratio of 1:60. The LC-MS/MS analysis showed that the extracts from submerged and emergent R. rotundifolia contained 26 and 22 flavonoids, respectively. This study provides phytochemical evidence for the further utilization of R. rotundifolia.

Preparation of amyloid N-terminal nonapeptide imprinted monolithic column and evaluation of adsorption properties

A novel β-amyloid protein capillary microextraction column was designed and prepared using epitope molecular imprinting technology for specific recognition of trace β-amyloid proteins in complex biological matrices. Using N-terminal nonapeptide of β-amyloid protein as template molecule, choline chloride-MAA and N-hydroxymethyl acrylamide as functional monomers, ethylene glycol dimethacrylate as crosslinker, the imprinted capillary monolithic column was prepared by thermal polymerization in the acetonitrile-water system. The optimal preparation parameters were obtained with the ratio of template: functional monomer: crosslinker at 1:6:16 (mmol/mmol/mmol). The physical property evaluation through Scanning electron microscopy, Fourier transform infrared spectroscopy analysis, zeta potential analysis, particle size analysis, and Brunauer-emmett-teller showed that a porous imprinted monolithic column with a high specific surface area was successfully prepared. The static adsorption experiment showed that the theoretical maximum adsorption capacity was 0.060 μg/column and the optimal imprinting factor was 2.27. Under the optimal extraction conditions, the imprinted column exhibited good template selectivity and excellent robustness. Finally, the extraction efficiency of the capillary imprinted column in actual plasma was evaluated using ELISA method. For Aβ 40 and Aβ 42, the detection limits were 1.00 pg/mL and 0.67 pg/mL, the quantification limits were 3.00 pg/mL and 2.00 pg/mL, the detection ranges were 7.5–120.0 pg/mL and 5.0–80.0 pg/mL, respectively. After extraction of plasma samples, the measured concentrations of Aβ 40 and Aβ 42 by imprinted column were 157.31 pg/mL and 48.22 pg/mL, respectively, which were significantly higher than the measured concentrations by non-imprinted column of 89.60 pg/mL and 41.02 pg/mL. In summary, the epitope imprinted capillary monolithic column prepared in this study can effectively enrich and separate trace amounts of amyloid proteins in complex samples, and is expected to provide a new sample pretreatment method for clinical detection of amyloid proteins.

The polysaccharides from blackened jujube with ultrasonic assistance extraction: Optimization of extraction conditions, antioxidant activity and structural analysis

Jujube is a widely grown agricultural product. In order to avoid the waste of resources and improve the added value of the blackened jujube, the blackened jujube was processed under certain temperature and humidity conditions. At present, there are relatively few researches on polysaccharides of blackened jujube. The selection of extraction method is very important for the study and utilization of plant polysaccharides. Ultrasonic assisted extraction technology has been widely used in polysaccharide extraction for its advantages of environmental protection, economy and high extraction rate. In order to fully tap the utilization potential of polysaccharides from blackened jujube, the ultrasonic assisted extraction technology of polysaccharides from blackened jujube was optimized. Based on the optimal conditions obtained by response surface analysis, the extraction rate of polysaccharide was as high as 12.75 ± 0.05%. The IC50 values of hydroxyl radical, DPPH radical and superoxide anion were 2.604 mg/mL, 0.754 mg/mL and 8.069 mg/mL, respectively. The blackened jujube polysaccharide (BJP) was mainly composed of rhamnose (Rha), arabinose (Ara), galactose (Gal) and galacturonic acid (Gal-UA), with a molecular weight of 1.42 × 106 Da, and the surface was a dense network structure with voids. The results showed that ultrasound-assisted extraction could extract polysaccharides more economically and efficiently. In this study, the polysaccharide extracted from blackened jujube has natural antioxidant effect, which may be related to the high content of galacturonic acid in polysaccharide and the molecular chain structure of polysaccharide can be destroyed by ultrasonic wave. As a kind of natural antioxidant, blackened jujube polysaccharide has important application value in functional products in food and medicine industries.

A comparison of extraction methods for preparation of glucosinolate-containing extracts from Brassica juncea antagonistic toward Ditylenchus dipsaci

Summary The stem and bulb nematode, a globally distributed pest, primarily affects onions and garlic, causing significant yield losses. Chemical treatments are a practical and effective method for controlling plant-parasitic nematodes to protect high-value crops. However, to minimise environmental damage, chemicals of natural origin need to be investigated. Brown mustard (Brassica juncea) plant is an annual plant in the Brassicaceae family, which is rich in bioactive compounds called glucosinolates. These bioactive compounds play a major role in the defence of Brassica plants against biotic stress factors in nature. Based on this point, efforts to develop plant protection products from the brown mustard plant are ongoing. In this study, the most suitable pre-extraction and extraction conditions were determined to ensure the maximum preservation of glucosinolate content and biological activity, to process brown mustard on an industrial scale. For this purpose, steam treatment was applied before extraction at 3 bar (=3 × 105 Pa) pressure for 1 and 3 min. Four different temperatures (room temperature, 40, 55 and 70°C) and two different methanol concentrations (70% and 80%) were tested to optimise glucosinolates extraction from brown mustard. It was found that sinigrin was the most abundant glucosinolate, with extraction yields 1184.4 ± 14.4 mg kg−1 at 55°C for 3 min, and 2624.2 ± 98.5 mg kg−1 at 70°C/70% MeOH for 1 min. However, nematode immobility was higher at 55°C/70% MeOH for 3 min. It was determined that the application of hot steam for 3 min at 3 bar pressure as a pre-extraction process provided optimal conditions for methanolic extraction. The results may contribute significantly to the development of potential plant protection products with further studies.

Optimization of Extraction Conditions of Phenolic Compounds and Antioxidant Activity from Myrtle (Myrtus communis L.) Fruit.

The extraction of polyphenols from myrtle (Myrtus communis L.) fruits using a conventional solid-liquid extraction was optimized using a single factor experiment approach. The influence of several parameters such as type of solvent (50% acetone, 50% methanol, 50% ethanol and water), solvent concentration (30-100%; v/v), solvent acidity (0-0,1 N), temperature (20-40°C) and time (30-360 min) on the yield extraction of total phenolic content (TPC), total flavonoid content (TFC), total proanthocyanidin content (TPAC), and on the antioxidant activity : DPPH-radical scavenging activity (DPPH-RSA), ABTS-radical scavenging activity (ABTS-RSA) and ferric reducing power (FRP) was studied. The results showed that 50% acetone, 40°C and 180 min were the best conditions for extracting TPC (87 mg GAE/g DW), TFC (12 mg QE/g DW), and TPAC (76 mg CE/g DW). Myrtle berries extracted with these conditions also exhibited the strongest antioxidant activity: DPPH-RSA (7166 mg TE/g DW), ABTS-RSA (164 mg TE/g DW), and FRP (69 mg AAE/g DW). Pearson correlation coefficients showed a good positive correlations between TPC, TFC and TPAC and antioxidant activities (DPPH-RSA, ABTS-RSA and FRP), mainly under the effect of solvent type (0.93 < r < 0.99) and solvent concentration (0.91 < r < 0.99).

Optimization of Extraction Conditions of Polyphenols and Flavonoids from Olax subscorpioidea leaves, a Medicinal Plant Traditionally Used in Korhogo (Cote d’ivoire)

Secondary metabolites, including polyphenols and flavonoids, play a key role in the expression of the active principles of several medicinal plants from Côte d'Ivoire, such as Olax subscorpioidea Oliv. This study was initiated to help improve conditions for extracting polyphenols and flavonoids from Olax subscorpioidea Oliv leaves harvested in Korhogo. Experimental design methodology was used. The effect of four independent variables on polyphenol and flavonoid content was evaluated: extraction time (12h-24h), evaporation temperature (45°C - 55°C), plant material-solvent ratio (1/20 g/mL - 1/5 g/mL) and ethanol proportion (20% - 100%). The Central Composite Design (CCD) was used to optimize responses after factor screening using the Plackett and Burman design. Optimum extraction conditions were obtained with an ethanolic proportion of 88.29% and 17g of Olax subscorpioidea Oliv leaves dissolved in 100 mL ethanol. The experimental values (96.31 ± 5.29 mg Eq AG/g for polyphenols and 62.44 ± 4.58 mg Eq Q/g) were close to those expected (94.51 mg Eq AG/g for polyphenols and 58.22 mg Eq Q/g for flavonoids), confirming the relevance of the mathematical model used and the success of the response surface methodology in optimizing the extraction conditions of the system studied. These results show that by taking extraction conditions into account in this preliminary study, we can optimize the quantities of secondary metabolites of therapeutic interest.

Optimization of the iron content of Eremomastrax speciosa drink and evaluation of its antianemic potential

Iron deficiency anemia represents a significant public health challenge, leading many to seek herbal remedies from locally available plants. In Cameroon, E. speciosa leaves are commonly consumed to address this condition. This study aimed to optimize iron extraction from E. speciosa leaves and evaluate its effectiveness against iron deficiency anemia. The leaves were dried at 50 °C, ground, and sieved. An E. speciosa drink was produced by extracting the powdered leaves using a Central Composite Design, focusing on four factors: temperature, time, pH, and solid-to-liquid ratio (w/v). Various volumes (1, 2, or 4 mL/kg) of the extracted drink were administered to anemia-induced rats over a two-week period. The optimization results indicated that the ideal extraction conditions were: temperature of 20 °C, extraction time of 50 min, pH of 11, and a solid-to-liquid ratio of 15 g/L. Administration of 1 mL/kg of the E. speciosa drink successfully restored red blood cell counts and hemoglobin levels to normal after two weeks. In contrast, doses of 2 or 4 mL/kg alleviated anemia within just one week. Overall, the E. speciosa drink produced under these optimal extraction conditions is iron-rich and demonstrates significant potential as an effective treatment for iron deficiency anemia.

Extraction, purification, structural identification, and anti-senescent activity of novel pearl peptides on human dermal fibroblasts

The purpose of the present study was to prepare novel anti-senescent peptides from pearls, characterize their primary sequence and secondary structure, and investigate their protective effects and molecular mechanisms towards D-galactose (D-gal)-induced senescence on human dermal fibroblasts (HDFs). Novel pearl peptides with a purity of 96.58 % and maximum yield of 3.29 % were obtained using ultrasonic-assisted acetic acid extraction strategy under the optimal extraction conditions (ultrasonic power 200 W, ultrasonic time 70 min, and the ratio of pearl powder to acetic acid 1:20). It is sequenced mainly as five novel anti-senescent peptides with molecular weight < 2000 Da, and consisted of β-sheet (43.2 %), random coil (32.1 %), β-turn (21.2 %) and α-helix (3.5 %) analyzed by LC-MS/MS, FT-IR and CD spectroscopy. Further anti-senescent experiments showed that pearl peptides can increase cell viability, restore DNA damage, and suppress the accumulation of ROS as well as senescence-associated-β-galactosidase (SA-β-gal). The molecular mechanism may be that pearl peptides down-regulate the gene and protein expressions of senescence-associated proteins p53, p21, and p16. Therefore, novel pearl peptides could be developed as functional foods or nutritional supplements for the prevention of skin aging.

SENSORY PREFERENCE DETERMINATION OF GREEN TEA EXTRACTS FROM UNCONTROLLED AND RELAY-CONTROLLED BREWING PROCESSES USING RANK ORDER CENTROID AND SIMPLE ADDITIVE WEIGHTING

Green tea extract is a popular beverage known for its health benefits. To increase its market appeal, understanding the sensory profiles—taste, aroma, and color—of green tea extract is essential to ensure customer satisfaction. In this study, experiments were conducted to determine the optimal extraction conditions by varying extraction times (3 or 6 minutes) and temperatures (60°C, 80°C, or 100°C) in two brewing methods: (1) a relay-controlled brewing system utilizing Arduino, and (2) a standard brewing process without automated control. Sensory evaluations were conducted by 30 untrained panelists using a 9-point hedonic scale.. Decision-making methods, Rank Order Centroid (ROC) and Simple Additive Weighting (SAW), were then applied to identify the most preferred product. Results indicated that the highest taste score was achieved by the 80°C-6 min sample, while the best aroma and color scores were observed in the 100°C-3 min sample. Overall, the decision-making process using the combination of ROC and SAW methods concluded that the green tea extract from the 100°C-3 min sample was the most preferred by the panelists.

Ultrasound-assisted extraction and antioxidant activity of polysaccharides from Tenebrio molitor

Tenebrio molitor, which is rich in various nutrients, and its polysaccharides, as significant bioactive substances, exhibit strong antioxidant effects. This study utilized defatted T. molitor as raw material and employed an ultrasound-assisted extraction method. The factors considered include extraction temperature, time, ultrasound power, and liquid-to-feed ratio, with the yield of T. molitor polysaccharides as the response value. Based on single-factor experiments and response surface methodology, the optimal extraction parameters for T. molitor polysaccharides were determined. Following purification, protein removal, and dialysis to eliminate impurities, the structure of the extracted polysaccharides was preliminarily investigated using infrared spectroscopy. Their antioxidant activities were explored by measuring their DPPH·, OH·, and ABTS+· radical scavenging abilities and Fe3+ reducing power. The results indicated that the optimal conditions for ultrasound-assisted extraction were an extraction temperature of 75 °C, an extraction time of 150 min, an ultrasound power of 270 W, and a liquid-to-feed ratio of 15:1 mL/g, yielding a polysaccharide extraction rate of 9.513%. Infrared spectroscopy analysis revealed the presence of pyranose sugars with main functional groups including C-O, C=O, and O-H. Antioxidant activity tests showed that within a certain concentration range, the higher the polysaccharide concentration, the stronger its radical scavenging abilities. Compared with Vitamin C(Vc), the polysaccharides had stronger scavenging abilities for DPPH· and OH·, some scavenging ability for ABTS+·, and Fe3+ reduction ability, and corresponding to IC50 values of 0.9625, 9.1909, and 235.69 mg/mL respectively. The Fe3+ reducing power reached a maximum absorbance of 0.38899 at a concentration of 1.6 mg/mL. T. molitor polysaccharides demonstrate promising antioxidant activity and potential as functional ingredients in food, health products, and pharmaceuticals, providing new technical references for the development and utilization of T. molitor resources.

Ultrasound-Assisted Extraction of Alginate from Fucus vesiculosus Seaweed By-Product Post-Fucoidan Extraction.

The solid phase byproduct obtained after conventional fucoidan extraction from the brown seaweed Fucus vesiculosus can be used as a source containing alginate. This study involves ultrasound-assisted extraction (UAE) of alginate from the byproduct using sodium bicarbonate. Response surface methodology (RSM) was applied to obtain the optimum conditions for alginate extraction. The ultrasound (US) treatments included 20 kHz of frequency, 20-91% of amplitude, and an extraction time of 6-34 min. The studied investigated the crude alginate yield (%), molecular weight, and alginate content (%) of the extracts. The optimum conditions for obtaining alginate with low molecular weight were found to be 69% US amplitude and sonication time of 30 min. The alginate extracts obtained were characterized using Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). Ultrasound-assisted extraction involving a short treatment lasting 6-34 min was found to be effective in extracting alginate from the byproduct compared to the conventional extraction of alginate using stirring at 415 rpm and 60 °C for 24 h. The US treatments did not adversely impact the alginate obtained, and the extracted alginates were found to have similar characteristics to the alginate obtained from conventional extraction and commercial sodium alginate.

Optimization of Ultrasonication Probe-Assisted Extraction Parameters for Bioactive Compounds from Opuntia macrorhiza Using Taguchi Design and Assessment of Antioxidant Properties

Opuntia macrorhiza, commonly referred to as red prickly pear, is a type of cactus fruit. The Opuntia macrorhiza (OM) fruit is rich in polyphenols and contains a high amount of ascorbic acid and betalains. The fruit peels have demonstrated many biological abilities, including antioxidant, antifungal, and antibacterial activities. Ultrasound probe-assisted extraction (UPAE) is a highly promising method for efficiently extracting valuable molecules from natural sources. The objective of this study is to optimize the parameters of UPAE, including the appropriate solvent, liquid-to-solid ratio, extraction duration, and pulsation level. The aim is to maximize the yield of bioactive compounds (polyphenols, betalains, and ascorbic acid) from OM fruits (pulps and peels) and assess their antioxidant activities using Taguchi design. The optimal extraction conditions through the partial least squares method for OM pulp were determined to be aqueous extraction for 12 min with a liquid-to-solid ratio of 60 mL/g and 48 pulses/min, while for OM peels they were determined to be aqueous extraction for 20 min with a liquid-to-solid ratio of 60 mL/g and a pulsation of 48 pulses/min. The optimum UPAE conditions were compared with the values obtained from the optimum extraction under stirring extraction (STE). Overall, UPAE exhibited higher yields than STE. The obtained total polyphenol content ranged from 10.27 to 13.07 mg gallic acid equivalents/g dry weight, while the betalain content ranged from 974 to 1099 μg/g dry weight. Overall, these fruits demonstrated potential as new components for food and medicinal uses due to their good health effects and lack of toxicity.

Microencapsulation of Caucasian blueberries (Vaccinium arctostaphylos L.) anthocyanins: Colour stability in varying storage conditions

AbstractThe aim of this study was to investigate the extraction of anthocyanins from the fruits of Caucasian blueberry (Vaccinium arctostaphylos L.) and examine the colour stability of anthocyanins encapsulated through spray drying in model systems. The trials were conducted to determine the optimal conditions for anthocyanin extraction using an ultrasonic water bath at temperatures of 25, 50 and 75°C. The ideal anthocyanin extraction occurred at 25°C using 100% acetone in an ultrasonic bath for 15 min at 35 kHz. Anthocyanin concentrations were evaluated using the pH differential method. The extracted anthocyanins were encapsulated through spray drying with maltodextrin as the encapsulating material. The encapsulation efficiency was 80.4 ± 0.20%, and the anthocyanin retention rate was 83.0 ± 0.76%. The coloured capsules were added to model systems with pH values of 4.50, 5.00, 5.50 and 6.00. The colour values (L* 50.16 ± 0.05, a* 4.08 ± 0.04, b* −9.35 ± 0.01, H° 293.57 ± 0.15, C* 10.20 ± 0.03) were measured during varying storage conditions. The results showed, that colour loss began on the fifth day and this was accelerated with higher temperatures and pH values. It was found that encapsulation significantly preserved the stability of the blue colour and the loss of the blue colour followed first‐order reaction kinetics. The study showed that the blue colour of microcapsules was best preserved at pH 5.00 at 25°C. In this case, the measured total colour change (∆E) was 5.86, the activation energy (Ea) was 37.64 kJ/mol, and the half‐life (t1/2) was determined to be 19.08 days.

Extraction and Counter-Current Separation of Phenylpropanoid Glycosides from Pedicularis oederi Vahl by Deep Eutectic Solvent

Deep eutectic solvents (DESs) are mixtures of organic compounds displaying excellent solvent properties while keeping an ecofriendly character. In this study, DESs have been applied to the extraction of phenylpropanoid glycosides from Pedicularis oederi Vahl, successively separated by means of counter-current chromatography. Firstly, the ultrasonic-assisted extraction conditions were optimized by response surface methodology, and the results showed phenylpropanoid glycosides could be well extracted under the optimized extraction conditions with deep eutectic solvents. Then, the sample was separated by counter-current chromatography using ethyl acetate/aqueous solution of choline chloride and glycerol (6:6, v/v) as the solvent system. In about 360 min, four phenylpropanoid glycosides, including 31.6 mg of echinacoside, 65.3 mg of Jionoside A1, 28.9 mg of Forsythoside B, 74.1 mg of verbascoside, and 21.2 mg of kaempferol-3-O-rutinoside were obtained from about 900 mg of the sample. It revealed deep eutectic solvents could be well employed as a green solvent for the extraction and counter-current separation of natural products.

From waste to resource: Hydrogen generation and antimicrobial activity of Ag-based photocatalysts recovered from biomedical waste

Electrocardiogram (ECG) disposable electrodes contain a substantial amount of silver (Ag), which can be extracted and recycled. Most current methods for recovering Ag from waste are expensive and environmentally harmful. This study investigated a sustainable chemical process for extracting Ag from discarded medical electrodes using a simple Cu(II) solution under moderately acidic conditions. Using response surface methodology (RSM) based on a three-level, full-factorial design, the optimized extraction conditions were determined as pH = 4.78, T = 80°C, [Cu(II)]₀ = 8.0 × 10⁻³ M, and [NaCl]₀ = 3.72 M. Under these conditions, a process efficiency approaching 100 % was achieved. Moreover, the recovery of metallic silver exceeded 85 %, even when using real matrices. (i.e., discarded ECG electrodes). As a result, the Ag-containing leachate solutions were utilized to synthesize silver-based materials with varying Ag content. These materials demonstrated (i) excellent photocatalytic activity for hydrogen production in aqueous solutions containing organic compounds and (ii) significant antipathogenic properties. In summary, effective Ag/TiO₂ photocatalytic materials with high efficiency for hydrogen production and antimicrobial activity were successfully prepared through a novel, sustainable, and cost-effective chemical recovery process of silver from discarded ECG electrodes.

Efficient separation of methyl ethyl ketone and water azeotrope using hydrophobic amino acid ester ionic liquids

BackgroundMethyl ethyl ketone (MEK), an essential organic solvent, is commonly produced via the n-butene method, where water emerges as the principal impurity. The conventional distillation processes, which are necessitated by the azeotropic behavior between MEK and water, result in a substantial expenditure of energy. As a result, liquid-liquid extraction represents a promising alternative for energy-efficient separation. MethodsIn this work, three hydrophobic amino acid ester ionic liquids L-phenylalanine ethyl ester bis(trifluoromethylsulfonyl) imide ([Phe][NTf2]), L-leucine ethyl ester bis(trifluoromethylsulfonyl) imide ([Leu][NTf2]) and L-valine ethyl ester bis(trifluoromethylsulfonyl) imide ([Val][NTf2]) were utilized as extractants for separation of the binary azeotrope methyl ethyl ketone and water. The effects of extraction time, extraction temperature, mass ratio of MEK-water mixture to ionic liquid and initial concentration of MEK on extraction efficiency were investigated. Significant findingsThe results demonstrate that the ionic liquid [Phe][NTf2] exhibits superior extraction ability for the separation of the azeotrope methyl ethyl ketone and water. The maximum extraction yield of 99.86 % was achieved with the optimum extraction conditions of extraction time, 10 min, extraction temperature, 293.15 K, mass ratio of mixture to ionic liquid, 1:1 and initial concentration of MEK, 20 %. In addition, the relationship between the structure of ionic liquids and their extraction performance was revealed by quantum chemical calculations of ionic liquids with MEK and water. These ionic liquids were positioned as promising environmentally friendly alternatives to traditional organic solvents for the recovery of MEK from aqueous solutions, providing valuable insights for industrial applications.

Bioactivity, chemical profiling, and validation of Moringa oleifera cultivated in Suncheon (KR)

Moringa oleifera is a vegetable rich in vitamins, minerals, and other nutrients that can be used medicinally to enhance human health. This study described how the antioxidative properties of several organs of M. oleifera were used to optimise extraction conditions through their antioxidative capacity. In addition, an analytical approach applying seven marker chemicals was developed and used to construct the chemical profile while simultaneously ascertaining the primary components and their contents in the leaf extract. Of those, the content of quercetin 3-O-malonylglucoside (5) was the greatest, at 12.50 mg/g, followed by neochlorogenic acid (1) at 5.67 mg/g. In a study using molecular docking to target antioxidation, the main constituents of the leaf extract provided some evidence. This was the first study to analyse M. oleifera grown in Suncheon and provide an effective analytical tool to control and verify the quality of this plant species by using standards.

An efficient extraction device for microplastics in marine sediments and its applications.

Microplastics, defined as small pieces of plastic with a size less than 5 millimeters, constitute a significant sink for microplastics in marine sediments. Given the potential harm to nature and human beings, accurate detection of microplastics in marine sediments is of the utmost importance. The separation of microplastics from marine sediments represents a pivotal step in the quantitative detection of microplastics. This paper presents a high-efficiency extraction device for microplastics in marine sediments, with the objective of enhancing the effectiveness and efficiency of microplastics extraction. The device employs an air pump to thoroughly mix the samples and incorporates metal perforated plate fillers to achieve efficient sedimentation, thus facilitating the separation of microplastics from the surrounding marine sediments. Subsequently, the separated microplastics are passed through a series of pore sizes of stainless steel screens and glass fibre filters via suction filtration, allowing for the collection of microplastics of varying particle sizes for subsequent identification. Following a series of method trials, the optimal extraction conditions for this device were identified. The results demonstrated its excellent extraction effectiveness and high efficiency. To verify the feasibility of this device, it was used to investigate the microplastics in the sediments of Dongzhai Harbor, Hainan. The abundance, particle size distribution, shape, and composition of microplastics in the sediments of this area were obtained, which not only validated the practicality of this microplastic extraction device but also provided significant insights for ecological and environmental protection in the region.

Antioxidant peptides from silver carp steak by alkaline protease and flavor enzyme hydrolysis: Characterization of their structure and cytoprotective effects against H2O2-induced oxidative stress.

Silver carp steak is a rarely utilized silver carp processing byproduct. This study aimed to optimize a dual enzymatic method to extract antioxidant peptide components from silver carp steak and characterize their structure and in vitro antioxidant activity through ultrafiltration purification, response surface methodology, molecular docking, and radical scavenging activity analysis. The optimal extraction conditions for silver carp steak antioxidant peptides (SCSAP) were determined as 1:6 solid-liquid ratio, 1500 U/g alkaline protease addition, 4 h alkaline protease hydrolysis time, 1946 U/g flavor enzyme addition, and 2.5 h flavor enzyme hydrolysis time. The <3 kDa SCSAP component (SCSAP-3kDa) showed the strongest antioxidant activity, with its 1,1-diphenyl-2-trinitrophenyl hydrazine (DPPH) radical scavenging rate, ABTS radical scavenging rate, hydroxyl radical scavenging rate, metal ion chelating rate, and reducing capacity reaching 88.75%, 91.21%, 67.02%, 69.07%, and 0.985, respectively. Moreover, the three peptides (PF-7, GP-8, and YF-10) of 100 µg/mL could protect HepG2 cells from oxidative stress damage by reducing the oxidative damage level and activating Keap1-Nrf2-ARE pathways, enabling an increase of superoxide dismutases (SOD) activity, and a decrease of malondialdehyde (MDA) content and reactive oxygen species (ROS) level. The integrated results indicate the enormous potential of SCSAP-3kDa as a functional food ingredient in the food industry. PRACTICAL APPLICATION: This study selected the antioxidant capacity of silver carp steak peptides as the index and developed a facile dual enzymatic hydrolysis method to obtain three antioxidant peptides (PF-7, GP-8, and YF-10) with biological activity, providing a theoretical basis for bioavailability of antioxidant peptides from silver carp steak and contributing to their application in new functional foods.

Efficient Simultaneous Isolation of Pinostrobin and Panduratin A from Boesenbergia rotunda Using Centrifugal Partition Chromatography.

The bioactive flavonoids pinostrobin (PN) and panduratin A (PA) from Boesenbergia rotunda are essential for research and therapeutic applications. This study introduces an innovative method utilizing ultrasound-assisted extraction with n-hexane pre-treatment, followed by one-step centrifugal partition chromatography (CPC) purification. Extraction efficiency was evaluated using ultra high-performance liquid chromatography (UHPLC), and the isolated compounds were characterized through 1H-NMR and liquid chromatography electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS), adhering to AOAC validation guidelines. Optimal extraction conditions comprised a particle size of 125 μm, a solid-to-liquid ratio of 1:30 g/mL, and a 10 min extraction time, yielding a crude extract of 6.96 ± 0.07%. Using an n-hexane/MeOH/water (5/3.4/1.6, v/v) solvent system in ascending mode, PN (2.16 mg, 98.78% purity) and PA (0.4 mg, 99.69% purity) were isolated from 67 mg of crude extract within 30 min. This streamlined approach enhances purification efficiency, allowing for faster extraction and higher purity, making it a suitable method for commercial applications.