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Highlights • Pectin was extracted from orange peel using surfactant and microwave assisted method. • Pectin yield, GA content, and DE were considered during Box–Behnken design. • Chemical properties of pectin extracted by different methods were compared. • S-MAE showed the best effect on the yield and characteristics of extracted pectin. Abstract Surfactant and microwave assisted extraction (S-MAE) was used for pectin extraction from orange peel. First, we optimized the conditions of microwave assisted extraction (MAE), e.g., irradiation time, liquid-to-solid ratio (LSR), and pH on pectin yield (PY), galacturonic acid (GA) content, and degree of esterification (DE) using a Box-Behnken design. Under optimal conditions (pH 1.2, 7.0 min, and 21.5 v/w LSR), we obtained a PY of 28.0 ± 0.5%, which was close to the predicted value (31.1%). Second, we analyzed the effect of surfactant on microwave extraction of pectin. Among the surfactants investigated, Tween-80 (8 g/L, w/v) increased PY by 17.0%. Compared with conventional solvent extraction, S-MAE is a novel and efficient method for pectin extraction, which generated a higher (p < 0.05) PY (32.8%), GA content (78.1%), DE (69.8%), and M w (286.3 kDa). [ABSTRACT FROM AUTHOR]

Due to the great interest in obtaining natural bioactive carbohydrates to be used as functional ingredients, a selective microwave assisted extraction (MAE) method was optimized to ensure the exhaustive extraction of inositols and α-galactooligosaccharides (α-GOS) from mung bean. Thereafter, a comprehensive characterization of these compounds was carried out by gas chromatography coupled to mass spectrometry (GC–MS). Apart from free inositols and α-GOS, several glycosyl-methyl- scyllo -inositols and glycosyl-inositols were detected for the first time in this legume. Under optimized MAE conditions (0.5 g dry sample, 2 cycles of 3 min, 50 °C, 10 mL 50:50 ethanol:water, v:v), bioactive carbohydrates yields were similar to those found using solid–liquid extraction (SLE), but with shorter analytical times. Concentrations of bioactive carbohydrates in MAE extracts from samples of different geographical origins ranged between 74.1 and 104.2 mg.g −1 dry sample. MAE was proved a good alternative to SLE to obtain extracts enriched in bioactive carbohydrates. [ABSTRACT FROM AUTHOR]

Optimization process is an important aspect in the natural product extractions. Herein, an alternative approach is proposed for the optimization in extraction, namely, the Generalized Likelihood Uncertainty Estimation (GLUE). The approach combines the Latin hypercube sampling, the feasible range of independent variables, the Monte Carlo simulation, and the threshold criteria of response variables. The GLUE method is tested in three different techniques including the ultrasound, the microwave, and the supercritical CO 2 assisted extractions utilizing the data from previously published reports. The study found that this method can: provide more information on the combined effects of the independent variables on the response variables in the dotty plots; deal with unlimited number of independent and response variables; consider combined multiple threshold criteria, which is subjective depending on the target of the investigation for response variables; and provide a range of values with their distribution for the optimization. [ABSTRACT FROM AUTHOR]

The edible oil processing industry involves large losses of organic solvent into the atmosphere and long extraction times. In this work, fast and environmentally friendly alternatives for the production of echium oil using green solvents are proposed. Advanced extraction techniques such as Pressurized Liquid Extraction (PLE), Microwave Assisted Extraction (MAE) and Ultrasound Assisted Extraction (UAE) were evaluated to efficiently extract omega-3 rich oil from Echium plantagineum seeds. Extractions were performed with ethyl acetate, ethanol, water and ethanol:water to develop a hexane-free processing method. Optimal PLE conditions with ethanol at 150 °C during 10 min produced a very similar oil yield (31.2%) to Soxhlet using hexane for 8 h (31.3%). UAE optimized method with ethanol at mild conditions (55 °C) produced a high oil yield (29.1%). Consequently, advanced extraction techniques showed good lipid yields and furthermore, the produced echium oil had the same omega-3 fatty acid composition than traditionally extracted oil. [ABSTRACT FROM AUTHOR]

[Display omitted] • Extraction of pectin from jackfruit rag was optimized by response surface methodology. • Optimal microwave-assisted extraction of pectin was at 66 °C for 10.56 min. • Microwave-extracted pectin had excellent antioxidant and antibacterial activities. • Microwave extraction was an efficient method to recover pectin from jackfruit rags. While fruit biowastes pose an environmental hazard, they can be utilized as a source of beneficial biopolymers such as pectin. However, conventional extraction techniques require long processing time with low, impure yields, and microwave assisted extraction (MAE) can suffer from these drawbacks. Here, MAE was applied to extract pectin from jackfruit rags and compared with conventional heating reflux extraction (HRE). Response surface methodology was adopted to optimize pectin yield, based on pH (1.0–2.0), solid–liquid ratio (1:20–1:30), time (5–90 min), and temperature (60–95 °C). Pectin extraction by MAE required lower temperatures (65.99 °C) and shorter reaction times (10.56 min). Pectin HRE resulted in a product with amorphous structures and rough surfaces, while pectin-MAE was high crystalline with smooth surfaces. Although both pectin samples showed shear-thinning behavior, pectin-MAE exhibited higher antioxidant and antibacterial activities. Therefore, microwave assisted extraction was an efficient method to extract pectin from jackfruit rags. [ABSTRACT FROM AUTHOR]

The development of a new method to determine the presence of the organoarsenic additives p -arsanilic acid (ASA), roxarsone (ROX) and nitarsone (NIT) in livestock feeds by high performance liquid chromatography coupled to ultraviolet oxidation hydride generation atomic fluorescence spectrometry (HPLC-UV/HG-AFS) after microwave assisted extraction (MAE) was proposed. Chromatographic separation was achieved on a C18 column with 2% acetic acid/methanol (96:4, v/v) as the mobile phase. The limits of detection (LODs) were 0.13, 0.09 and 0.08 mg L −1 , and the limits of quantification (LOQs) were 0.44, 0.30 and 0.28 mg L −1 . The relative standard deviations (RSDs) for ASA, ROX and NIT determined from five measurements of the mixed calibration standard were 3.3, 5.3, and 5.4%, respectively. MAE extraction of phenylated arsenic compounds using 1.5 M H 3 PO 4 at 120 °C for 45 min allowed for maximum recoveries (%) of total arsenic (As) and organoarsenic species, with no degradation of these compounds. The extraction of total As was approximately 97%, and the As species recoveries were between 95.2 and 97.0%. The results of the analysis were validated using mass balance by comparing the sum of extracted As with the total concentration of As in the corresponding samples. The method was successfully applied to determine the presence of these compounds in feed samples. ASA was the only As species detected in chicken feed samples, with a concentration between 0.72 and 12.91 mg kg −1 . [ABSTRACT FROM AUTHOR]

Berberis jaeschkeana fruits, source of nutraceutically important polyphenolics were investigated. A total of 32 experimental run were conducted under Plackett-Burman and central composite design. Microwave power, methanol and HCl concentration significantly (p < 0.05) affect extraction of polyphenols under linear, quadratic and interactive effect. The model showed good fitness with significant (p < 0.05) model F-value and a non-significant lack of fit. Under optimum microwave assisted extraction (MAE) condition the total phenolics, flavonoids, tannins and antioxidant activity were in closed context with predicted values. As compared to ultrasonic (UAE) and maceration extraction (ME), MAE showed significantly (p < 0.05) higher recovery of TP, TF and FRAP antioxidant activity. HPLC-DAD analysis detects a total of 10 polyphenolic compounds under MAE as compared to 9 under UAE and ME. Designing of MAE conditions showed promising results for polyphenolic antioxidants extraction as revealed by higher yield with lesser time and solvent consumption, which can contribute in green extraction technology and its application in nutraceutical industry. [ABSTRACT FROM AUTHOR]

A simple and rapid method was developed using microwave-assisted extraction (MAE) combined with HPLC–DAD–ESI–MS/MS for the simultaneous extraction, identification, and quantification of phenolic compounds in Eclipta prostrata , a common herb and vegetable in China. The optimized parameters of MAE were: employing 50% ethanol as solvent, microwave power 400 W, temperature 70 °C, ratio of liquid/solid 30 mL/g and extraction time 2 min. Compared to conventional extraction methods, the optimized MAE can avoid the degradation of the phenolic compounds and simultaneously obtained the highest yields of all components faster with less consumption of solvent and energy. Six phenolic acids, six flavonoid glycosides and one coumarin were firstly identified. The phenolic compounds were quantified by HPLC–DAD with good linearity, precision, and accuracy. The extract obtained by MAE showed significant antioxidant activity. The proposed method provides a valuable and green analytical methodology for the investigation of phenolic components in natural plants. [ABSTRACT FROM AUTHOR]

A simple and sensitive procedure was developed for extraction and speciation of mercury in fish. Species separation was accomplished with reverse phase-high performance liquid chromatography (HPLC) hyphenated to inductively coupled plasma mass spectrometry (ICP-MS). Oxygen addition into plasma allowed use of organic-rich mobile phase, achieving species separation in 4 min. Mercury species extraction was achieved by microwave exposure for 2 min at mild conditions (60 °C, pH 2.0), avoiding necessity of neutralizing sample prior to injection in HPLC, and reducing number of sample preparation steps, analytical source of errors and inter conversion of species. Limit of detection for entire procedure was found to be 0.2 and 0.1 ng g −1 for mercuric ion and methylmercury, respectively. The method was applied to certified reference materials (TORT-2 and DORM-2) and commercialized fish samples ( Mullus barbatus , Sparus aurata , Trachurus mediterraneus , Mugil soiuy , Dicentrarchus labrax , and Pomatomus saltatrix ) from Black Sea. [ABSTRACT FROM AUTHOR]

A response surface methodology and a kinetic study were used to optimise the pulsed ultrasonic and microwave techniques in the extraction of curcuminoids. Microwave-assisted extraction had the same efficiency as pulsed ultrasonic-assisted extraction, and both methods were better than continuous ultrasonic extraction of curcuminoids. For the pulsed ultrasonic-assisted extraction, the optimal conditions were 60% amplitude (AMP), 83% ethanol (v/v), 3/1 (s/s) pulsed duration/interval time and 10min irradiation time. For the microwave-assisted extraction, the optimal conditions were 82% ethanol, 10% power level and 7min of extraction time. Both methods used a 1:200 mass to solvent ratio. [ABSTRACT FROM AUTHOR]

Abstract: An extraction method consisting of both microwave-assisted extraction (MAE) and solid phase extraction (SPE) was developed to extract pesticides of different polarities in infant milk formula. An experimental central face composite design was established to evaluate the effects of several MAE variables simultaneously such as temperature and pH of extractant. With Derringer desirability function, all pesticides were optimally extracted at 102°C within 20min with 4.56mL of extractant consisting of 0.1% of water in methanol at pH 12. Extraction efficiency was subsequently analysed with LC–MS/MS. The extraction recoveries ranging from 72% to 111% were obtained for all pesticides at fortification level of 5–100μgkg−1 with relative standard deviations (RSDs) of less than 8%. Compared with Soxhlet/SPE, the MAE/SPE method utilised less solvent and higher recoveries were achieved with a shorter extraction time. [Copyright &y& Elsevier]

Abstract: In this paper, a method based on microwave assisted extraction (MAE) in combination with dispersive liquid–liquid microextraction (DLLME) has been proposed as a new approach for the sensitive determination of cork taint responsible compounds in cork stoppers and oak barrel sawdust. For this purpose, haloanisoles and halophenols were extracted from the solid samples using a MAE method. Subsequently, a DLLME-derivatisation procedure was applied on the MAE extracts and the analytes were determined by gas chromatography–electron capture detection (GC–ECD). Parameters affecting the DLLME-derivatisation method were exhaustively investigated by means of experimental design methodology. Once optimised, the proposed method showed satisfactory linearity (correlation coefficients over 0.991), repeatability (below 10.4%) and inter-day precision (below 11.2%). Detection limits obtained were similar or even lower than previously reported. The results obtained proved the suitability of the combination of MAE with DLLME as a sensitive sample preparation methodology for the analysis of haloanisoles and halophenols in solid enological matrices. [Copyright &y& Elsevier]

Abstract: Microwave-assisted extraction (MAE) has been considered as a potential alternative to conventional solvent extraction for the isolation of phenolic compounds from plants. Aqueous and alcoholic extracts of green coffee bean obtained by MAE were quantitatively analysed for total yield of extracts, chlorogenic acids, caffeine and total polyphenol content. The extracts were also evaluated for radical-scavenging activity, using 1,1-diphenyl-β-picrylhydrazyl radical. Under optimum conditions of time (5min), temperature (50°C) and wattage (800W), the maximum chlorogenic acids and caffeine could be extracted with water as solvent. The extracts contained chlorogenic acids and caffeine in the ranges of 31–62% and 22–40%, respectively. The yields of MAE under optimum conditions were higher than those from the conventional solvent extraction at 5min and 50°C and the extracts showed radical-scavenging activity of >75%, even at the concentration of 25ppm. The MAE process can thus be predicted and controlled for industrial application. [Copyright &y& Elsevier]

Abstract: A new method for the analysis of anthocyanins in grapes based on a systematic study of the extractability of eleven anthocyanins from grapes has been developed. Microwave assisted extraction was applied as a prior stage to the chromatographic determination of anthocyanins in the extracts. The stability of anthocyanins under the extraction conditions was checked using a standardised extract from grape skins. Temperatures from 50°C up to 150°C were evaluated. A fractional factorial experimental design was developed to analyse the influence on the extraction process of six different extraction variables: solvent (mixtures of methanol and water), stirring, extraction temperature, extraction time, microwave power and extraction volume. The extraction solvent was the most important variable for the recovery of most anthocyanins from grapes. Finally, the influence of the extraction time was also studied. With this new method, anthocyanins can be extracted from grapes in 5min, using 100°C as extraction temperature and 40% methanol in water as the extraction solvent. Repeatability and reproducibility were also checked, the resulting RSDs (n =9) were lower than 7% for glucosides, the main components, and lower than 9% for the acyl derivatives, the compounds found in the lowest concentrations. [Copyright &y& Elsevier]

Abstract: High pressure microwave assisted extraction (HPMAE) was applied to extract the ginsenosides from Panax ginseng root. The influences of extraction solvent, extraction pressure and extraction time were individually investigated. HPMAE has been compared with other extraction methods, including Soxhlet extraction, ultrasound-assisted extraction and heat reflux extraction. The determination of ginsenosides was performed by HPLC–ESI-MS. The results indicated that the HPMAE not only took a shorter time but also afforded higher extraction yields of ginsenosides, especially ginsenoside Rb1, Rc, Rb2 and Rd. Furthermore, the neutral ginsenosides and malonyl ginsenosides in Panax ginseng root extracts by HPMAE were investigated. The malonyl ginsenoside m-Rb1, m-Rc, m-Rb2 and m-Rd degraded in HPMAE at 400kPa (109–112°C) in 70%(v/v) ethanol–water and at 600kPa (112–115°C) in methanol, and transformed into corresponding neutral ginsenoside Rb1, Rc, Rb2 and Rd. Using water as extraction solution, the neutral ginsenosides degraded under HPMAE at 400kPa (135–140°C), and transformed into less polarity rare ginsenosides. [Copyright &y& Elsevier]

Abstract: Cranberry press cake, an under utilized by-product of the cranberry processing industry is a potential source of food antioxidants. The objective of this research were (1) to prepare extracts from cranberry press cake using solvent extraction (SE) and microwave assisted solvent extraction (MASE), and (2) to test the ability of these extracts to inhibit lipid oxidation in mechanically separated turkey (MST). Water, ethanol and acetone were used as extraction solvents. Heating press cake prior to extraction with 70% ethanol increased antioxidant efficacy compared to extracting unheated press cake. Water extracts were least effective in inhibiting lipid oxidation. The most effective extracts were obtained by SE with 100% acetone or MASE with 100% ethanol. A poor correlation of 0.69 was obtained between the total phenols in the extracts and their ability to inhibit thiobarbituric acid reactive substances (TBARS) formation in MST. The correlation coefficient between the amount of quercetin in the extracts and the number of days of TBARS inhibition in MST was 0.87. This indicates that although quercetin may be good inhibitor of lipid oxidation, polyphenols other than quercetin are likely have a role in the inhibition of TBARS in MST. For a similar yield of the extracts, MASE extract using 100% ethanol was a better inhibitor than 100% ethanol SE extract of lipid oxidation in MST. In terms of choice of solvent, based on their flammability and toxicity, MASE with 100% ethanol would be a more likely a choice over SE with 100% acetone, for inhibiting oxidation in MST. [Copyright &y& Elsevier]

• Green method was developed for curcumin and antioxidants extraction from turmeric. • Natural deep eutectic solvents (NADES) from sugar, lactic acid and choline were used. • Microwave-assisted extraction (MAE) was modelled and optimized for each NADES. • NADES constituents did not interfere with CUPRAC antioxidant capacity measurement. • Most NADES gave higher extraction than 80% CH 3 OH-H 2 O for curcumin and TAC. Natural deep eutectic solvents (NADES) have recently come to the fore as new green solvents for foods, cosmetics and pharmaceuticals due to their unique solvation power and low toxicity. Turmeric extracts were prepared using the microwave assisted extraction method (MAE) using five NADES containing binary combinations of choline chloride, lactic acid, fructose, and sucrose. The MAE method was optimized and modeled by using response surface methodology to obtain maximum total antioxidant capacity (TAC) and curcumin contents (CC) in extracts for each NADES. All NADES extracts, except NADES-1 containing fructose and cholin chloride, exhibited higher TAC and CC than those in 80% methanol:water which was the preferred solvent in literature. NADES solvents did not interfere with subsequent antioxidant capacity measurements using the CUPRAC method. The proposed MAE is a potentially efficient and sustainable procedure in pharmaceutical and food industries for the extraction of antioxidants and curcumin from turmeric. [ABSTRACT FROM AUTHOR]

• A "green" methodology was optimized for the extraction of bioactive compounds. • Temperature, time, ethanol concentration and solvent-sample ratio were optimized. • 53 compounds were identified under the optimal microwave assisted extraction conditions. • Procyanidin and catechin were the most abundant phenolic compounds. • The extracts showed high matrix metalloproteinases inhibitory and antioxidant capacities. Avocado peel is a by-product obtained in high amounts in the food industry with no further applications despite its richness in bioactive compounds. In this context, an efficient "green" microwave assisted extraction (MAE) was optimized to maximize the extraction of bioactive polyphenols. Moreover, the phenolic composition of the developed green avocado extract was characterized by HPLC coupled to MS analysers and the potential applications for the food industry were studied assaying different bioactivities. Thus, the matrix metalloproteinases inhibition, the antioxidant capacity and the antimicrobial activity against gram-positive and gram-negative bacteria, yeast and mold were tested. The results pointed out both, high matrix metalloproteinases inhibitory capacity and antioxidant activity of avocado peel MAE extract. These findings suggest the potential food industry applications of this extract as natural food preservative, functional food ingredient or nutraceuticals with antioxidant and anti-aging activities. [ABSTRACT FROM AUTHOR]