Extraction Solvent Composition Research Articles

Exploring Varied (Green) Extraction Methods to Optimize Galia Melon Peel Antioxidant Potential

Cucumis melo L. (C. melo), commonly known as the melon, is a widely cultivated tropical fruit associated with nutritional benefits and bioactive properties. With global production reaching 40 million tons annually, the fruit processing industry generates significant waste, primarily peels, totaling 8 to 20 million tons yearly. These organic by-products are rich in bioactive compounds such as antioxidants, offering health benefits such as a reduced risk of cancer and cardiovascular diseases, as well as of diabetes and neurogenerative diseases, offering an opportunity for sustainable utilization. C. melo by-products have demonstrated various health benefits, including anti-inflammatory, analgesic, and antioxidant properties, attributed mainly to polyphenols. Recognizing the potential of melon waste, this study systematically explored different extraction methods, including stirring (ST), ultrasound (US), and pulsed electric field (PEF) methods, while considering factors such as extraction time, temperature, and solvent composition. The primary goal was to identify the most effective extraction procedures and optimal conditions for maximizing the yield of total polyphenols and antioxidant capacity (using the FRAP and DPPH methods) from C. melo peel by-products. According to the results, the optimum conditions include ST as the extraction method, an ethanolic solvent with a strength of 50%, a 150 min extraction duration, and an 80 °C extraction temperature. The maximum values of total polyphenols that can be observed are 3.75 mg gallic acid equivalents (GAE)/g of dry weight (dw) and 25.77 μmol ascorbic acid equivalents (AAE)/g dw and 34.44 μmol AAE/g dw from FRAP and DPPH antioxidant assays, respectively. The polyphenols identified were the following: gallic acid, neochlorogenic acid, catechin, chlorogenic acid, epicatechin, and kaempferol. By securing the maximum isolation of bioactive content and antioxidant activity, the research will contribute to sustainable waste management by reducing waste and developing value-added products.

Three-component deep eutectic solvent for revered-phase air-assisted liquid–liquid microextraction for the determination of furanic compounds in transformer oil by HPLC-UV

In this work, a revered-phase air-assisted liquid–liquid microextraction approach based on three-component deep eutectic solvent for pretreatment of petroleum oils was developed. The approach was utilized for the determination of furanic compounds in aged transformer oil by high-performance liquid chromatography with UV detection. The procedure assumed multiple aspiration of oil sample and deep eutectic solvent into a syringe and injection of the extraction mixture into an Eppendorf tube (11 instant extraction cycles). This process resulted in the formation of a cloudy solution, attributed to the dispersion of extraction solvent droplets into the oil sample. After centrifugation the obtained extract phase was introduced into a chromatographic system without additional purification and dilution. To establish the optimal microextraction procedure conditions, key parameters such as the extraction solvent composition, phase ratio and the number of extraction cycles were investigated. Cheap and available low viscosity deep eutectic solvent based on choline chloride, acetic acid and water provided the highest extraction recovery values (from 85 to 96 %). It was found, that acetic acid as precursor of extraction solvent acted key-role for maximum extraction recovery for all analytes. The phenomenon of the influence of hydroxyl groups in the structure of analytes on the extraction efficiency was revealed. Under optimal condition, the limits of detection were in the range from 3 to 6 μg L−1.

Optimization and Characterization of Phenolic Extraction Conditions and Antioxidant Activity Evaluation of Adenanthera pavonina L. Bark.

The presence of high levels of secondary metabolites in medicinal plants can significantly influence the progress of drug development. Here, we aimed to maximize phenolic extraction from Adenanthera pavonina L. stem bark using various solvents such as ethyl acetate, methanol, petroleum ether, and chloroform. A response surface method (RSM) with a central composite design (CCD) statistical technique was applied to optimize the extraction process, employing three important extracting parameters such as extraction time (h), temperature (°C), and solvent composition (% v/v of methanol/water) to obtain the highest phenolic content. Total phenolic content (TPC) and antioxidant activity (IC50 of extract's DPPH radical scavenging activity) were used as response variables to find the influence of these extracting parameters. Among the various solvents used, methanol extract showed the highest contents of phenolics and the maximum level of antioxidant activity with a lower IC50 value. The notable TPC and IC50 value of the extract's DPPH radical scavenging capacity were found to be 181.69 ± 0.20 mg GAE/g dry tissue and 60.13 ± 0.11 mg/mL, respectively, under the optimal conditions with a solvent composition of 71.61% (v/v) of methanol/water, extraction temperature of 42.52 °C, and extraction time of 24 h. The optimized extract of A. pavonina stem bark was further subjected to HPLC analysis, where six phenolic compounds, including coumarin, p-coumaric acid, chlorogenic acid, sinapic acid, gallic acid, and caffeic acid, were identified along with their respective quantities. Overall, the findings of this study uncover a low-cost analytical model for maximizing phenolic extraction from A. pavonina bark with enhanced antioxidant activity.

Response Surface Optimization for the Enhancement of the Extraction of Bioactive Compounds from Citrus limon Peel.

Citrus limon is among the species of the genus Citrus that dominates the world market. It is highly nutritious for humans as it contains twice the amount of the suggested daily intake of ascorbic acid and is also a good source of phenolic compounds, carotenoids, and other bioactive compounds. This study aimed to identify the optimal extraction procedures and parameters to obtain the maximum quantity of bioactive components from lemon peel by-products. Various extraction techniques, including stirring, ultrasound, and pulsed electric field, were evaluated, along with factors such as extraction time, temperature, and solvent composition. The results revealed that simple stirring for 150 min at 20 °C proved to be the most effective and practical method. The ideal solvent mixture consisted of 75% ethanol and 25% water, highlighting the crucial role of solvent composition in maximizing extraction efficiency. Among the extracted compounds were phenolics, ascorbic acid, and carotenoids. Under optimum extraction conditions, the extract was found to contain high total phenolic content (TPC) (51.2 mg of gallic acid equivalents, GAE/g dry weight), total flavonoid content (TFC) (7.1 mg of rutin equivalents, RtE/g dry weight), amounts of ascorbic acid (3.7 mg/g dry weight), and total carotenoids content (TCC) (64.9 μg of β-carotene equivalents, CtE/g). Notably, the extracts demonstrated potent antioxidant properties (128.9 μmol of ascorbic acid equivalents, AAE/g; and 30.3 μmol of AAE/g as evidenced by FRAP and DPPH assays, respectively), making it a promising ingredient for functional foods and cosmetics. The study's implications lie in promoting sustainable practices by converting lemon peel into valuable resources and supporting human health and wellness through the consumption of natural antioxidants.

Ultrasound-Assisted Anthocyanins Extraction from Pigmented Corn: Optimization Using Response Surface Methodology.

This study aimed to determine the optimal UAE conditions for extracting anthocyanins from pigmented corn using the Box-Behnken design (BBD). Six anthocyanins were identified in the samples and were used as response variables to evaluate the effects of the following working variables: extraction solvent pH (2-7), temperature (10-70 °C), solvent composition (0-50% methanol in water), and ultrasound power (20-80%). The extraction time (5-25 min) was evaluated for complete recovery. Response surface methodology suggested optimal conditions, specifically 36% methanol in water with pH 7 at 70 °C using 73% ultrasound power for 10 min. The method was validated with a high level of accuracy (>90% of recovery) and high precision (CV < 5% for both repeatability and intermediate precision). Finally, the proposed analytical extraction method was successfully applied to determine anthocyanins that covered a wide concentration range (36.47-551.92 mg kg-1) in several pigmented corn samples revealing potential varieties providing more health benefits.

Rapid, efficient, and green analytical technique for determination of fluorotelomer alcohol in water by stir bar sorptive extraction

Fluorotelomer alcohols (FTOHs) are one of the major classes of per- and polyfluoroalkyl substances (PFAS). Due to their potential toxicity, persistence, and ubiquitous presence in the environment, some common PFAS are voluntarily phased out; while FTOHs are used as alternatives to conventional PFAS. FTOHs are precursors of perfluorocarboxylic acids (PFCAs) and therefore they are commonly detected in water matrices, which eventually indicate PFAS contamination in drinking water supplies and thus a potential source of human exposure. Even though studies have been conducted nationwide to evaluate the degree of FTOHs in the water environment, robust monitoring is lacking because of the unavailability of simple and sustainable analytical extraction and detection methods. To fill the gap, we developed and validated a simple, rapid, minimal solvent use, no clean-up, and sensitive method for the determination of FTOHs in water by stir bar sorptive extraction (SBSE) coupled with thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS). Three commonly detected FTOHs (6:2 FTOH, 8:2 FTOH, and 10:2 FTOH) were selected as the model compounds. Factors such as extraction time, stirring speed, solvent composition, salt addition, and pH were investigated to achieve optimal extraction efficiency. This “green chemistry” based extraction provided good sensitivity and precision with low method limits of detection ranging from 2.16 ng/L to 16.7 ng/L and with an extraction recovery ranging 55%–111%. The developed method were tested on tap water, brackish water, and wastewater influent and effluent. 6:2 FTOH and 8:2 FTOH were detected in two wastewater samples at 78.0 and 34.8 ng/L, respectively. This optimized SBSE-TD-GC-MS method will be a valuable alternative to investigate FTOHs in water matrices.

Method optimization for the determinations of selected phytochemicals and antioxidant activities of wild Ethiopian Syzygium guineense fruit and seed under different drying conditions

This study aimed to optimize the ultrasound-assisted extraction (UAE) parameters using response surface methodology (RSM) for the determination of ascorbic acid (AA), antioxidant activities/the half maximal effective concentration (EC50), total phenolic contents (TPC), and total flavonoid content (TFC) of Ethiopian wild Syzygium guineense fruit and seed processed under different drying conditions. The optimizations of the UAE methods for the determination of AA, antioxidant activities (EC50 values), TPC, and TFC were evaluated using response surface methodology (RSM). The extraction time of 15 min, the temperature of 35 °C, extraction solvent composition (methanol:water) of 75 to 25%, and solid-to-solvent ratios of 1:15 w/v were the optimum independent parameters. The experimental and the predicted data of TPC, EC50, and AA were in good agreement with the overall error below 0.01%. It also indicated a hypothesized distribution of predicted data fitted with experimental data. The average TPC, EC50, and AA content in S. guineense fruits and the seed varied from 581.25 ± 37.13 to 1917.40 ± 26.15 mg GAE/100 g, 4.02 ± 0.42 to 155.73 ± 5.11 mg/100 g, and 1.96 ± 0.02 to 0.94 ± 0.00 mg/mL, respectively. This study indicated that this underutilized wild fruit and its seeds can be an alternative source of AA and antioxidant compounds.

Dispersive Liquid - Liquid Microextraction for the Determination of Sulfonamide Residues in Egg Samples

A dispersive liquid-liquid microextraction combined with high-performance liquid chromatography-diode array detection was developed for the extraction and determination of 15 sulfonamide residues in the egg matrix. The effects of various parameters such as the type, volume, and composition of extraction solvent for sample treatment procedure, the type and volume of disperser solvent, centrifugation time, salting-out effect and solution pH were studied, and optimum conditions were established. Linearity was found in the range of 5.4 – 1 000 μg kg-1 with regression coefficients ranging from 0.9918 - 0.9987. The limit of detection (LOD) and limit of quantification (LOQ) values of the proposed method were in the range of 4.3 - 8.0 μg kg-1 and 12.9 - 24.0 μg kg-1, respectively. Satisfactory intra-day and inter-day precision results in the range of 6.3 - 17.5% and 4.8 - 16.8%, respectively, were achieved. The accuracy of the method was acceptable with percentage recovery in the range of 73 - 108% and %RSD values in the range of 1.1 - 16.5%. The proposed method was applied in chicken egg samples obtained from supermarkets, and findings confirmed that the method is feasible to be used for extraction and determination sulfonamide residues in egg and related complex biological matrices.

Supercritical fluids in analysis of cannabinoids in various Cannabis products

We developed a fast, selective, and sensitive method for the determination of various neutral and acidic phytocannabinoids with an emphasis on the separation of structurally related compounds. Optimized ultra-high performance supercritical fluid chromatography (UHPSFC) allowed the separation of 2 groups of structural isomers, including isomers of m/z 357: cannabidiolic and Δ9-tetrahydrocannabinolic acid, and isomers of m/z 315: cannabichromene, Δ9-tetrahydrocannabinol, Δ8-tetrahydrocannabinol, cannabicyclol, and cannabidiol only in mere 3.5 min followed by 1.5 min equlibration. The 2-ethylpyridine functionalized stationary phase and gradient elution using mobile phase comprising carbon dioxide and methanol: acetonitrile (25:75) + 5% water mixture were selected after the optimization. Tandem mass spectrometry (MS/MS) with electrospray ionization in positive and negative modes with methanol + 5% water as a make-up solvent provided adequate selectivity and sensitivity needed for analysis of phytocannabinoids in complex matrices. The limits of quantification were in the range 0.01–0.5 ng/mL for most of the monitored cannabinoids. The optimized UHPSFC-MS/MS method was then used for the determination of cannabinoids in various products, such as dietary supplements, nutraceuticals, and cosmetics. Solvent extraction methods were optimized for the cosmetic and nutraceutical products with the accuracy in the range 80.4–120.6% and precision 0.5–18.9%. To extract cannabinoids from the herbal infusion matrix, supercritical fluid extraction (SFE) and pressurized liquid extraction (PLE) methods were developed using environmentally friendly solvents water, ethanol, and carbon dioxide. The detailed optimization of extraction solvent composition, temperature, and pressure was carried out with the emphasis on avoiding the thermal degradation of cannabinoids. Optimized SFE and PLE methods were compared and applied to different herbal infusions to confirm declared cannabinoids content.

COMBINED MIXTURE DESIGN IN OPTIMIZATION OF EXTRACTION SOLVENT FOR ASSAY TEST OF ETHYL CELLULOSE COATED TRAMADOL TABLETS

The aim of the present study was to apply combined mixture design to optimize extraction solvent composition to enhance filtration volume and recovery of assay test sample with ethyl cellulose coated tablets. Solvent composition, centrifugation time and additional filtration step were evaluated as variables. Filtrate volume through Whatman™ No: 1 filter paper followed by 0.45 micron PVDF membrane filter were selected as responses. Results indicated that higher organic phase in solvent composition, extended centrifugation time and inclusion of additional filtration step enhanced filtrate volume and assay recovery. Conclusively, design of experiments as an effective tool for optimization of extraction solvent in assay method was established and validated. The proposed method has adequate reproducibility and proved to be accurate for estimation of tramadol HCl in ethyl cellulose coated extended release tablets.

Systematic HPLC/DAD/MSn study on the extraction efficiency of polyphenols from black goji: Citric and ascorbic acid as alternative acid components in the extraction mixture

BACKGROUND: The beneficial effects of the fruit of Lycium rhutenicum (black goji) have been linked to their polyphenolic profile. OBJECTIVE: Systematic examination of the extraction efficiency of polyphenols from cultivated black goji from Macedonia was carried out using 25 different solvent mixtures containing methanol, acetone or water combined with different acids (hydrochloric, acetic, citric and ascorbic acid). METHODS: An HPLC/DAD/MSn method was used for identification and quantification of phenolic acids, flavonoids, anthocyanins and also spermines and spermidines. RESULTS: The extraction solvent composition was found to have a significant effect on the yield of total as well as specific polyphenols. Pure methanol was found to be more efficient solvent for extraction of total phenolic compounds than pure water or acetone. Ascorbic acid in methanol (2%, m/v) was found to be the most efficient extraction solvent for total phenolic compounds. Aqueous solutions of citric and ascorbic acid gave the highest yield of phenolic acids, spermidines and flavonoids. The anthocyanin content in these extracts was somewhat lower in comparison with the one obtained with methanol/water/ascorbic acid (70 : 28 : 2). The qualitative analysis of the fruits cultivated in Macedonia showed similar polyphenolic pattern and anthocyanin content to the native plant growing in China. CONCLUSIONS: Citric and ascorbic acid can be used as alternative acid components in the extraction mixture.

Relative comparisons of extraction methods and solvent composition for Australian blueberry anthocyanins

Anthocyanins accumulate in plant vacuoles and are highly unstable at ambient temperatures, making them difficult to extract without denaturing their properties. This research aimed to determine a suitable extraction method and solvent composition for anthocyanin compounds. Australian blueberries were extracted using 12 different solvent compositions, with ultra-assisted extraction, Geno grinder, and Dounce grinder methods. The blueberry anthocyanin composition was analyzed against six commercial standards and quantified by mass spectrometry. The method was evaluated for linearity, food matrix effect, instrumental detection, and quantification limits. The total anthocyanin content ranged from 55.8 ± 0.7 mg/100 g to 84.9 ± 1.2 mg/100 g. The major anthocyanin detected was malvidin-3-glucoside. Ultra-sonication using methanol/water (80/20 v/v) at pH 3.0 produced the most effective homogenization with maximal extraction yield of anthocyanins. This study showed that the solubility of anthocyanin compounds is influenced by the solvent composition and extraction methods.

A microwave-based technique to determine saccharides and polyols contents in Spirulina (Arthrospira platensis)

The growing demand for Spirulina (Arthrospira platensis) as a dietary supplement suggests that a rapid and reliable method to determine its saccharides and polyols content would be of great interest. Additionally, the impact of these microalga growing conditions may have on such content would be really useful for Spirulina producers. This manuscript presents the development and validation of a new analytical microwave-assisted extraction (MAE) method as the first step in determining saccharides and polyols in spirulina samples. A Box Behnken design has been employed to evaluate three extraction variables, viz., temperature (x1: 30, 55 and 80 °C), solvent composition (x2: 0, 25, and 50% ethanol in water), and solvent to sample ratio (x3: 10:1, 20:1, and 30:1 mL of solvent per g of sample). These extraction variables have been optimized by Response Surface Methodology (RSM). Under the optimal conditions that have been thereby established (i.e., 30 °C, 50% ethanol in water, and 30:1 solvent to sample ratio), a kinetic study has been performed with full recovery in 15 min. Subsequently, the developed MAE method was validated by determining the number of parameters, including linearity, LODs, LOQs, accuracy, and precision. Finally, the resulting MAE method was successfully applied to determine saccharides and polyols contents in a number of Spirulina samples that had been cultivated in varying salinity media. Five saccharides and polyols were identified in Spirulina, i.e., inositol, glycerol, sorbitol, glucose, and maltose. The total amount of the compounds of interest in the Spirulina that had been cultivated in a higher salinity media (17 and 25 g L−1 of sodium chloride in water) was six-folds higher than the one cultivated in low saline water (0 and 3 g L−1 of sodium chloride in water). This substantial content difference was mainly explained by the considerable increment in glycerol and glucose contents when grown in a more saline medium. Therefore, it has been demonstrated that the new method is suitable to determine saccharides and polyols contents in different Spirulina samples.

Extraction Solvents Composition Effect In Biodiesel Production From Microalgae Consortium Botryococcus Braunii And Dunaliella Sp.

Indonesia has entered an energy emergency phase, proven that Indonesia is no longer a surplus oil producer due to the productivity of the wells decrease over the years and the pattern of people's consumption of fossil fuels has been exceeding the production capacity. Therefore, we need the right solution to overcome this problem, which is developing biodiesel as renewable energy based on microalgae oil. The microalgae used in this research is the consortium of microalgae Botryococcus braunii and Dunaliella sp. Microalgae were cultivated and harvested through the dewatering process with 1 g naoh/1 L water concentration. Water contents of cultivated Botryococcus braunii are 60.2505% while Dunaliella sp. Is 64.5002%. The oil from microalgae is obtained by extracted dry microalgae through the soxhlet extraction (leaching) method with mixed solvent n-hexane and ethanol as the co-solvent using a variety of solvent ratio 2:1 and 3:1. Pure microalgae consortium oil separated from the solvent using the distillation process then analyzed with GC-FID. The analysis result is trans-linoleic acid is the most dominant fatty acid contained in this oil. Transesterification process with cao (1.5% of oil weight) as a catalyst. The results obtained from this study are the oil yield 72% extracted with a solvent mixture of n-hexane and ethanol 2:1 and 60.4% for 3:1. The biodiesel synthesis resulted in the amount of yield obtained from the solvent ratio 2:1 extraction is 94.3%, while with solvent ratio 3:1 is 79.2%. The quality of both biodiesels has met the requirements of SNI 7182:2015 and ASTM D7467, except the density of biodiesel with extraction solvent composition 3:1 which is below the standard. Therefore, the best biodiesel quality is obtained from microalgae consortium’s oil with the composition of extraction solvent 2:1.

Achievement of antioxidants from Abelmoschus esculentus L. seeds using ultrasound-assisted extraction optimized by the help of experimental design approach

Developments of food supplements and nutraceuticals from different natural origins require the use of some extraction methods. The success of the procedure relies on theefficiency of the extraction methods. Therefore, extraction methods need to be optimized. This work aimed for the determination of optimal conditions of ultrasonic-assisted extraction (UAE) of antioxidant constituents from okra (Abelmoschus esculentus L.) seeds which contain high contents of polysaccharides, polyphenols and flavonoids using response-surface methodology based on Box-Behnken experimental design (BBD). The independent variables of UAE were extraction time (Et, 10-20 min), extraction solvent composition (EC, 50-100% methanol) and extraction solvent volume (EV, 10-20 mL). 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging activity, 2,2'-azinobis- (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical-scavenging activity and N,N-dimethyl-p-phenylenediamine dihydrochloride (DMPD) radical-scavenging activity were dependent variables. Optimal extraction conditions for UAE from okra seed were: 20 mL volume of 70% methanol at 10 min extraction time for DPPH inhibition; 20 mL volume of 50% methanol at 20 min for ABTS inhibition; 15 mL volume of 55% methanol at 12 min for DMPD inhibition. Under these optimum extraction conditions, the effectiveness of UAE of okra seed was successfully revealed. So, this practical extraction technique can be widely used for the achievement of dietary supplements and nutraceuticals.

Investigation of different antioxidant capacity measurements suitable for bioactive compounds applied to medicinal plants

The aim of this study was to investigate the adequate antioxidant capacity measurement of the major bioactive compounds of medicinal plants. Response surface methodology (RSM) modeling was used for predictive estimation of total polyphenols (TPC), flavonoid (TFC) and tannin (TTC) contents obtained from five folk medicinal plants. The RSM based on Central Composite Design was used to optimize microwave-assisted Soxhlet extraction (MASE) for extraction time, solvent composition and microwave power. Maximum contents of the three parameters were obtained under optimum extraction conditions and validated experimentally at level p ≤ 0.05. The antioxidant capacities were evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP) and cyclic voltammetry (CV) assays. Principal component analysis (PCA) was used to identify the interrelationships between bioactive compounds and antioxidant capacity measurements. PCA shows that the most suitable antioxidant measurement method for flavonoids is the FRAP (r = 0.9314) followed by the CV (r = 0.9313). The most suitable method for tannins (r = 0.9512) and polyphenols (r = 0.9200) is the DPPH.

Comparison of the Effect of Acids in Solvent Mixtures for Extraction of Phenolic Compounds From Aronia melanocarpa

Thirty-two different solvent mixtures containing methanol and acid (acetic, formic, and hydrochloric); methanol, water, and acid; and pure methanol were tested for their efficiency for extraction of phenolic compounds from aronia ( Aronia melanocarpa) belonging to the groups of anthocyanins, flavonols, and hydroxycinnamic acid derivatives. Thirteen compounds were detected and quantified in the extracts using HPLC/DAD/ESI-MS n. The yield of each compound and group was evaluated with regard to the extraction solvent composition. Extraction mixtures containing HCl were superior to the ones containing acetic or formic acid for the extraction yield of total phenolic compounds, which was especially pronounced for anthocyanins. The solvent mixture containing methanol/water/HCl (90:8:2, v/v/v) gave best results for the qualitative and quantitative assay of anthocyanins. However, this solvent mixture caused O-methylation of 3- and 5-caffeoylquinic acids transforming them to 3- and 5-feruloylquinic acids, respectively, during extraction. This peculiar finding must be taken into account during sample preparation for the analysis of polyphenols in any sample. It was observed that this O-methylation is specific for dihydroxycinnamic acid compounds containing neighboring hydroxyl groups. These results suggest the need for a detailed study of the behavior of various polyphenolic compounds during extraction with solvent mixtures containing methanol/HCl since it is very often used for the analysis of anthocyanins.

Impact of ultrasound-assisted extraction and solvent composition on bioactive compounds and in vitro biological activities of thyme and rosemary

Mediterranean herbs, specially thyme and rosemary, are important ingredients in food preparation and more recently have been studied as natural sources of bioactive compounds. This study aimed to study the effect of matrix (thyme vs. rosemary), and extraction protocol (conventional extraction vs. ultrasound assisted extraction) solvent composition (water vs. 50:50 ethanol:water solution) on the extraction of high value compounds (phenolic compounds, flavonoids and carotenoids) and also explore the antioxidant, antimicrobial (Listeria innocua, Staphylococcus aureus, and Salmonella enterica), probiotic (Lactobacillus casei and Bifidobacterium lactis), and anti-inflammatory activities. The phenolic, flavonoid and carotenoid content of extracts was greatly influenced by extraction conditions wherein the ultrasound pre-treatment improved the extraction of carotenoids but induced the opposite effect for polyphenols and flavonoids in both herbs. Only the aqueous extract of thyme obtained from ultrasound pre-treatment was the only extract that inhibited the growth of potentially pathogenic bacteria, stimulated the probiotic bacteria and achieved high anti-inflammatory and antioxidant activity. Moreover, this extract also was rich on phenolic compounds (such as p-coumaric acid 4-O-glucoside, kaempferol 3-O-rutinoside, feruloyl glucose, and 4-vinylguaiacol) and carotenoids. Therefore, ultrasound extraction of bioactive compounds with water as solvent could be explored in food and pharmaceutical applications.

Rapid in situ quantitation of photoinitiators in packaging by two-points kinetic calibration of liquid microjunction surface sampling-mass spectrometry

Absolute quantitation is always a challenge for in situ analysis of solid samples with ambient liquid extraction mass spectrometry due to unknown sampling efficiencies of analytes from complex solid matrices such as commercial packaging materials. Standards were usually dropped onto the sample surface for signal calibration, but the mass transfer of standards would not be the same as analytes distributed in samples. In this work, an in situ quantitation method via liquid microjunction sampling (LMJSS) coupled with mass spectrometry (MS) for photoinitiators (PIs) in packaging was developed without standard spiking. For direct in situ quantitation, mass transfer kinetic model for LMJSS of solid surface was proposed and validated. Results showed that the detection data well fitted the mass transfer model with adjusted R2 mostly in the range of 0.8–0.9 for 12 PIs in both lab-made mimetic positive samples and commercial packaging samples. According to the mass transfer kinetic model, two-point kinetic calibration method was proposed for calculation of the absolute concentration of PIs in solid samples by LMJSS of the same sample area for two times. The conditions of LMJSS including extraction solvent composition and solvent flowrate were optimized. With the optimized LMJSS-MS method and new calibration method, in situ analysis was done within only 2 min, and detection limits and quantitation limits of 15 PIs in mimetic samples were in the range of 0.06–1.5 mg/m2 and 0.34–6 mg/m2 respectively with relative standard deviation (RSDs) in the range of 2%–26%. The quantitation accuracy by the new calibration method for 13 PIs was in the range of 61%–162%. The method was applied to the quantitation of PIs in commercial packaging samples. 6 PIs were detected and identified in four commercial packaging materials, and the quantitation results were comparable with that by traditional solvent extraction-LC-MS method (relative recovery, 63%–127%).

Effect of Solvent Composition on the Extraction of Phenolic Compounds and Antioxidant Capacity of Bacaba Juice (Oenocarpus bacaba Mart.)

Studying the phytochemical composition and bioactive potential of underexploited species is of great importance for promoting their valorization and for broadening the range of sources of bioactive compounds in the human diet. In this study, we used a simplex centroid mixture design to determine an optimal extraction solvent composition (using mixtures of water, acetone, and ethanol) for maximizing the extraction of phenolic compounds and the antioxidant capacity of bacaba juice (Oenocarpus bacaba). The compounds were identified and quantified by high-performance liquid chromatography coupled with mass spectrometry. Taxifolin, orientin, and isoorientin were identified and quantified in bacaba juice for the first time. It was possible to evidence the high potentiality of the bacaba regarding the contents of syringic, vanillic, ferulic, 3,4-dihydroxybenzoic acids, and orientin, which have significantly contributed to the antioxidant capacity of the extracts. Thus, this study indicates that bacaba juice can provide antioxidant compounds. Moreover, the determined extraction conditions can be applied for obtaining extracts rich in potential bioactive properties for food and pharmaceutical applications.