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1.
Anthocyanins (Acys) are naturally occurring compounds that impart color to fruit, vegetables, and plants. The extraction of Acys from red raspberry (Rubus idaeus L. var. Heritage) by microwave-assisted process (MAP) was studied. A central composite rotate design (CCRD) was used to obtain the optimal conditions of microwave-assisted extraction (MAE), and the effects of operating conditions such as the ratio of solvents to materials, microwave power and extraction time on the extraction yield of Acys were studied through response surface methodology (RSM). The optimized conditions of MAE were ratio of solvents to materials 4:1 (ml/g), extraction time 12 min, and microwave power 366 W. Under these conditions 43.42 mg of Acys from 100 g of fresh fruits (T Acy, expressed as cyanidin-3-glucoside), approximately 98.33% of the total red pigments, could be obtained by MAE. The Acys compositions of extracts were identified by high-performance liquid chromatography – mass spectrometry (HPLC-MS), 12 kinds of Acys had been detected and 8 kinds of Acys were characterized. Result indicated that cyanidin-3-sophoroside, cyanidin-3-(2 G -glucosylrutinoside), cyanidin-3-sambubioside, cyanidin-3-rutinoside, cyanidin-3-xylosylrutinoside, cyanidin-3-(2 G -glucosylrutinoside), and cyanidin-3-rutinoside were main components in extracts. In addition, in comparison with the conventional solvent extraction, MAE is more efficient and rapid to extract Acys from red raspberry, due to the strong disruption of fruit tissue structure under microwave irradiation, which had been observed with the scanning electron microscopepy (SEM). However, the Acys compositions in extracts by both the methods were similar, which were investigated using HPLC profile.  相似文献   

2.
Growing interest in plant secondary metabolites has brought with it the need for economical, rapid and efficient extraction protocols. Microwave‐assisted extraction (MAE) was used to extract saponins from chickpea (Cicer arietinum). Several MAE conditions were tested, and the method proved to be superior to Soxhlet extraction with regard to amounts of solvents required, time and energy expended. The use of a butanol/H2O mixture showed selectivity towards saponin extraction. Using TLC, two distinct saponins were observed in the various chickpea extracts. The identification of the major saponin as a DDMP‐conjugated saponin was verified using 1H and 13C NMR, for the first time in chickpea. The MAE procedure most likely contributed to the conservation of the heat‐sensitive DDMP moiety. The pure chickpea saponin exhibited significant inhibitory activity against Penicillium digitatum and additional filamentous fungi. Two Fusarium strains tested were highly tolerant to the saponin. The potential for using MAE for the efficient extraction of natural products may assist in expediting the chemical analysis and characterization of the biological activities of such compounds. Copyright © 2004 Society of Chemical Industry  相似文献   

3.
An efficient microwave‐assisted extraction (MAE) technique was employed in the extraction of phenolic compounds from Agaricus blazei murrill, and phenolic compounds were quantified by High‐performance liquid chromatography (HPLC). The MAE procedure was optimised, validated and compared with other conventional extraction techniques. MAE gave the best result because of the highest extraction efficiency within the shortest extraction time. The optimal conditions of MAE were 60% ethanol, ratio of solid/liquid 1:30, temperature 110 °C, irradiation power 500 W and three extraction cycles, each 5 min. This is the first report on combining MAE with HPLC for the extraction and quantification of phenolic compounds in A. blazei murrill. The developed MAE method provided a good alternative for the extraction of phenolic compounds in A. blazei murrill as well as other materials.  相似文献   

4.
An efficient microwave-assisted extraction (MAE) technique was employed to extract total phenolics (TP) from sweetpotato [Ipomoea batatas (L.) Lam.] leaves (TPSL). The optimal conditions for microwave-assisted extraction of TPSL were determined by response surface methodology. A face-centered cubic design (FCD) was applied to evaluate the effects of three independent variables (microwave power, extraction time and ethanol proportion) on the recovery of TPSL. The correlation analysis of the mathematical-regression model indicated that quadratic polynomial model could be employed to optimize the microwave extraction of TPSL. From response surface plots, microwave power, extraction time and ethanol proportion exhibited independent and interactive effects on the extraction of TPSL. The optimal conditions to obtain the highest recovery of TPSL were as follows: microwave power, 302 W; extraction time, 123 s; ethanol proportion, 53% (v/v). Under these optimal conditions, the experimental values agreed with the predicted ones by analysis of variance. It indicated high fitness of the model used and the success of response surface methodology for optimizing TPSL extraction. After method development, the antioxidant activity of the MAE extract was preliminarily evaluated. MAE showed obvious advantages in terms of high extraction efficiency and antioxidant activity of extract with in shortest extraction time.Industrial Relevance: Sweet potato leaves have been neglected except for a partial use as livestock feed in China. This study describes the response surface optimization of microwave-assisted extraction (MAE) process for the enhanced recovery of total phenolics from sweetpotato leaves (TPSL). MAE showed obvious advantages in terms of high extraction efficiency and antioxidant activity of extract within shortest extraction time. TPSL obtained using MAE showed potential for use in health-care food and pharmaceutical industry.  相似文献   

5.
 A method based on microwave-assisted extraction (MAE) was developed to extract lipids from fish for the determination of the fatty acid composition. Microwave-assisted extraction was performed with an open-vessel extraction apparatus similar to the system of Soxhlet. The solvent was an equivolume mixture of ethyl acetate and cyclohexane. The solvent forms a ternary azeotrope with water, and water is separated after re-condensation in a water trap. With this technique, extraction can be performed without pre-drying of fish tissues. After lipid extraction, the esterification was performed with trimethylsulfonium hydroxide (TMSH) and the fatty acid methyl esters (FAMEs) were determined by GC/FID. The results were compared with those obtained after liquid-liquid extraction according to Bligh and Dyer. Fillets of mackerel (Scomber scombrus) and livers of cod (Gadus morhua) were used as the sample material. The water content (n=7) of the cod livers was 36.2±1.6% and that of mackerel fillets was 74.5±0.5%. The lipid contents (n=5) using the MAE method were 5.6±0.4% and 62.6±3.1% in mackerel and cod liver, respectively. Relative levels of 58 fatty acids (two co-eluted) were determined with GC/FID on two capillary columns with different polarity. These were 10 saturated, 24 unsaturated, and 24 unidentified peaks which are most likely unsaturated or branched-chain fatty acids. After MAE the composition of the 57 peaks was virtually the same as that obtained with the Bligh and Dyer method. The advantages are, however, that MAE is faster, requires less solvent, and avoids the use of chlorinated solvents and so is more environmentally friendly. Our results confirm that MAE is a well-suited alternative to the Bligh and Dyer method for the extraction of lipids followed by determination of the fatty acid profile. Received: 1 March 2000 / Revised version: 23 May 2000  相似文献   

6.
In recent years, there has been growing interest in the influence of sprouts on health. Fruit and vegetables are the main sources of organic acids for humans; however, little is yet known about organic acids in sprouts. In this study, the selection of the optimal parameters for extraction of organic acids from fresh, edible sprouts is reported. Two extraction techniques: microwave-assisted (MAE) and ultrasound-assisted were compared. The experimental conditions were optimized in terms of extraction time, temperature, and composition of extraction solution. To determine the influence of time and temperature of extraction or sample cooling, solvents used for extraction, on the analytical signal in isotachophoretic separation, the methods of experimental planning fractional factorial design: 3k?1 were used (three factor, three-level design). The optimal conditions for extraction of organic acids from radish sprouts were MAE, 90 °C; 18 min; and 0.01 M NaOH as a solvent.  相似文献   

7.
Coffee silverskin (CSS), a potential source of soluble dietary fibre (8%–11%), is a major coffee by-product obtained during the coffee roasting process. Ultrasound-assisted extraction (UAE) and microwave-assisted extraction (MAE) have been considered as efficient and economic novel extraction techniques. In this study, UAE, MAE and simultaneous ultrasound–microwave-assisted extraction (UMAE) techniques were investigated for soluble dietary fibre (SDF) extraction from CSS and compared with conventional solvent extraction (CSE). The highest recovery rate of SDF was accomplished by UMAE (42.7 ± 0.4%), which was 1.5-fold, 1.9-fold and 1.2-fold of the recovery rates achieved by CSE, UAE and MAE, respectively. The extraction time of UMAE was 20 min, which was the same as UAE and MAE, and 4.5-fold less than CSE. It implied that the combination of UAE and MAE could enhance the extraction process by increasing the recovery rate as well as by reducing extraction time as compared with CSE or other individual novel extraction methods applied. Nutritional composition and physicochemical characteristics of the SDF extracts from CSS were also investigated in the study.  相似文献   

8.
The use of natural antioxidants in the food industry has increased in the last years and there is a growing interest in improving the extraction processes using GRAS (general recognize as safe) solvents. In this work the extraction of antioxidants from rosemary with ethanol and water as solvents has been studied using different extraction processes (conventional, microwave assisted - MAE - and ultrasound assisted - USAE -) and plant pretreatments (deoiled and milled, deoiled and fresh plant). Total phenolic compounds in the extracts were determined by the Folin-Ciocalteu assay and HPLC with UV detection was employed for the quantitation of the main antioxidant compounds: rosmarinic acid and carnosic acid. The antioxidant activity of the extract was determined by the DPPH scavenging assay. The double pretreatment, deoiling by solvent free microwave extraction (SFME) and milling, has shown to be essential to overcome inner mass transfer limitations. Extraction efficiency can be additionally enhanced by microwave and ultrasound assisted extraction process, being this latter more significant in aqueous extracts.  相似文献   

9.
Physicochemical and functional properties of arabinoxylans (AXs) can be significantly influenced by their isolation method. Finding balanced process conditions that allow optimal extraction yields while preserving AXs functionality is a challenge. The aim of this study was to determine the effect of different chemical solvents with neutral and alkaline pH on the intrinsic properties and extraction yield of AXs isolated from rye bran. Additionally, the application of xylanases and other cell wall degrading enzymes (Pentopan Mono BG, Deltazym XL‐VR, Viscoflow BG) to solubilize bound AXs was investigated. Results show that the use of Ca(OH)2 for isolation was superior to water and Na2CO3, as it selectively solubilized AXs and delivered isolates with a purity of up to 43.92% AX and a moderate ferulic acid (FA) content (209.35 ± 16.79 mg FA/100 g AX). Application of xylanases was further able to duplicate these achieved AX yields (7.50 to 9.85g AX/100 g bran). Additionally, isolates displayed highest ferulic acid contents (445.18 to 616.71 mg FA/100 g AX) and lowest impurities in comparison to chemical extracted AXs. Rheological characterization of the isolates showed a pronounced shear thinning behavior which fitted well to the power‐law model (R2 > 0.989). Differences in pseudoplasticity of the isolates suggested that structural and chemical properties might have been responsible for this behavior.  相似文献   

10.
Grape skin, seed and flesh, a potential source of bioactive compounds, were investigated to discriminate Kyoho skin, seed and flesh antioxidant activities by solvent extraction using chemometrics, including multivariate, discriminant analysis (DA) and hierarchical cluster analysis (HCA). Multivariate analysis (Wilk's Λ = 0.02 × 10-4, P < 0.01) explained the discrimination behaviour of phenolics and antioxidants by different solvents. Moreover, DA with three discrimination functions (DFs) and HCA with three well-defined clusters (clusters 1 to 3) further demonstrated the differences and/or similarities among the solvents. Solvent I (75% ethanol: water) exhibited the different extraction process over the solvents IV (water) and III (acetone: water). Quercetin (39.25 mg kg−1), epicatechin (53.08 mg kg−1) and gallocatechin gallate (1.28 mg kg−1) were the major phenolic compounds in Kyoho skin, seed and flesh extracts, respectively. These further confirmed the chemometric approach that could be used to discriminate solvents. Therefore, these findings suggested the application of chemometrics in extraction studies to understand the role of solvents and high recovery of grape bioactive compounds.  相似文献   

11.
BACKGROUND: Hydrodistillation (HD) has been used since ancient times for the extraction of essential oils (EO). Despite the intrinsic limitations of this technique, it remains the most common method both in the laboratory and on an industrial scale. The main drawbacks are the long extraction time involved and the risk of thermal degradation. Over the last decade, microwave‐assisted extraction (MAE) and in situ microwave‐generated hydrodistillation (MGH) have been shown to be the most promising techniques in improving plant extraction and hydrodistillation. RESULTS: In this study we compare HD with MGH in the extraction of several mint species cultivated in Piedmont: Mentha spicata L. var. rubra, Mentha spicata L. var. viridis and Mentha piperita L. MGH requires either fresh plant or rehydrated material, it is extremely fast and allows a reduction in energy consumption and overall cost. All the EO have been analyzed by gas chromatography‐mass spectrometry. A mechanism of microwave‐generated essential oil extraction has been proposed to explain the differences in the composition of the oil obtained from this environmentally friendly technique. CONCLUSIONS: The yields and composition percentages of the EO obtained by HD and in situ MGH of fresh and dried mint leaves lie in a relatively narrow range, although MGH is faster. MW polarization effects and the water solubility of the components influence extract composition Copyright © 2012 Society of Chemical Industry  相似文献   

12.
The efficiencies of pressurised liquid extraction (PLE) and a traditional solid–liquid extraction (SLE) at extracting antioxidant polyphenols from Irish macroalgae Ascophyllum nodosum, Pelvetia canaliculata, Fucus spiralis and Ulva intestinalis were compared. PLE was more effective for extracting polyphenols with acetone/water (80:20); however, when food‐friendly solvents of ethanol/water (80:20) and water were employed, SLE resulted in higher phenolic content in brown macroalgal extracts. For example, the Fucus spiralis SLE water and ethanol/water extracts displayed total phenolic contents (TPCs) of 130.58 ± 2.78 and 142.81 ± 1.77 μg phloroglucinol equivalents (PGE) mg?1 sample, respectively, compared with TPCs of 90.79 ± 1.16 and 124 ± 6.54 μg PGE mg?1 sample for the corresponding PLE extracts. All SLE aqueous ethanolic macroalgal extracts possessed higher DPPH radical scavenging abilities (RSA) and ferric reducing antioxidant power (FRAP) than their PLE equivalents . This study indicates that the application of high extraction temperatures (50–200 °C) and pressures (500–3000 psi) used in PLE does not enhance the antioxidant activities of macroalgal extracts relative to SLE extraction. The ability to produce antioxidant food‐friendly macroalgal extracts using SLE could represent significant cost reductions on an industrial scale further enhancing the potential of macroalgal polyphenols to be used in functional food preparations.  相似文献   

13.
Ethanol and hexane mixture agent microwave‐assisted extraction (MAE) method was conducted to extract peony (Paeonia suffruticosa Andr.) seed oil (PSO). The aim of the study was to optimise the extraction for both yield and energy consumption in mixture agent MAE. The highest oil yield (34.49%) and lowest unit energy consumption (14 125.4 J g?1) were obtained under optimum extraction condition: solid‐liquid ratio 0.37 g mL?1, extraction time 3.72 min, extraction temperature 80.92 °C, ethanol ratio 20.00%. GC–MS results showed that unsaturated fatty acids (UFAs) accounted for 88.60% of total fatty acids in PSO. Moreover, linolenic acid content of 37.35% was the highest UFA and caused PSO to possess good nutrition. PSO in DPPH radical scavenging experiment showed that IC50 value of 28.80 ± 2.13 mg mL?1 exhibited strong antioxidant property. All experiments proved that mixed solvent MAE is an efficient and promising method to extract PSO. This method can effectively reduce the energy consumption and extraction time.  相似文献   

14.
BACKGROUND: To evaluate the combined effects of high pressure extraction (HPE) and probiotic fermentation on the antimicrobial and antimutagenic activities, Berberis koreana was subjected to 500 MPa for 30 min and then fermented with Bifidobacterium longum B6 (HPE‐BLF) and Lactobacillus paracasei (HPE‐LPF) at 37 °C for 6 days. RESULTS: The phenol content was significantly increased to 228 mg GAE g?1 by the HPE compared to the conventional extraction (CE, 188 mg GAE g?1). The HPE‐BLF and HPE‐LPF showed the highest antimicrobial activity (MIC < 4 mg mL?1) against β‐lactam antibiotic sensitive and resistant Staphylococcus aureus. No significant mutagenic effect was observed for CE, HPE, HPE‐BLF, and HPE‐LPF extracts. The highest antimutagenic activities against frame‐shift mutant Salmonella typhimurium were observed at the HPE‐LPF (82%), followed by the HPE‐BLF (77%). CONCLUSION: The combined HPE and fermentation process could be used as an alternative extraction method for improving the extraction efficacy of medicinal plants. The results will provide pharmaceutically useful information and potential direction for finding new drug sources from medicinal plants. Copyright © 2010 Society of Chemical Industry  相似文献   

15.
Microwave-assisted extraction (MAE) of triterpene saponins from defatted residue of yellow horn (Xanthoceras sorbifolia Bunge.) kernel was optimized in this study. Compared with the conventional extraction methods ultrasonic-assisted extraction (UAE) and heat reflux extraction (HRE), MAE possessed higher efficiency for the extraction of triterpene saponins. The MAE conditions including extraction temperature, extraction duration, irradiation power, ethanol concentration, ratio of solvent to material and extraction cycles were studied and optimized. The optimum extraction parameters were as follows: 51 °C, 7 min, 900 W, 32 ml/g, 42% (v/v) ethanol and 3 cycles. Under the above conditions, the highest extraction yield of triterpene saponins reached 11.62 ± 0.37% of defatted kernel, which was much higher than those of conventional extraction methods. In addition, MAE extract of triterpene saponins exhibited substantial free radical-scavenging activity with an IC50 value of 0.782 mg/ml.

Industrial relevance

Large amounts of defatted kernels of yellow horn are discarded after oil extraction in biodiesel production. It is not only an environmental pollution but also a waste of bioresource. In fact, the residue still has potential for bioactive and medicinal use. Therefore, this study focused on the utilization of defatted kernels of yellow horn by optimizing MAE and evaluation of the antioxidant activity of the resulting extract. MAE provided a better way to deal with defatted kernels of yellow horn as a utilization of waste material of the bioactive resource in food and pharmaceutical industry.  相似文献   

16.
The exploitation of phenolic compounds in different fields has motivated researchers to explore eco-friendly and efficient extraction techniques. This study aimed to comparatively reveal that green extraction techniques (microwave- and ultrasound-assisted) are alternative to conventional extraction (maceration and magnetic stirring) with positive impact on the phenolic content, antioxidant activity, and bioactive profile of bee pollen extracts. The highest total phenolic and flavonoid content was reached using the microwave-assisted technique (MAE) with equivalent values of 28 and 8 mg g−1, with magnetic stirring and maceration showing a lower value. The composition profile of the extracts revealed the presence of twenty-six bioactive compounds, including thirteen phenolics and thirteen phenylamides. Although the extraction technique had little impact on the chemical diversity, the amount of bioactive compounds raised significantly with the use of the green extraction techniques, with gains between 40% and 60% for phenolics and up to 200% for phenylamides. The radical scavenging activity and the reducing power of the extracts confirmed that bee pollens are potent antioxidant source, with the most bioactive extracts corresponding to green extraction techniques. Consequently, all findings recommend the use of MAE as the technique most effective for the extraction of bioactive compounds from naturally encapsulated structures such as bee pollen.  相似文献   

17.
Cordyceps sinensis is a well‐known tonic food with broad medicinal properties. The aim of the present study was to investigate the optimization of microwave‐assisted extraction (MAE) and characterize chemical structures and chain conformation of polysaccharides from a novel C. sinensis fungus UM01. Ion‐exchange and gel filtration chromatography were used to purify the polysaccharides. The chemical structure of purified polysaccharide was determined through gas chromatography‐mass spectrometry. Moreover, high performance size exclusion chromatography combined with refractive index detector and multiangle laser light scattering were conducted to analyze the molecular weight (Mw) and chain conformation of purified polysaccharide. Based on the orthogonal design L9, optimal MAE conditions could be obtained through 1300 W of microwave power, with a 5‐min irradiation time at a solid to water ratio of 1:60, generating the highest extraction yield of 6.20%. Subsequently, the polysaccharide UM01‐S1 was purified. The UM01‐S1 is a glucan‐type polysaccharide with a (1→4)‐β‐d ‐glucosyl backbone and branching points located at O‐3 of Glcp with a terminal‐d ‐Glcp. The Mw, radius of gyration (Rg) and hydrodynamic radius (Rh) of UM01‐S1 were determined as 5.442 × 106 Da, 21.8 and 20.2 nm, respectively. Using the polymer solution theory, the exponent (ν) value of the power law function was calculated as 0.38, and the shape factor (ρ = Rg/Rh) was 1.079, indicating that UM01‐S1 has a sphere‐like conformation with a branched structure in an aqueous solution. These results provide fundamental information for the future application of polysaccharides from cultured C. sinensis in health and functional food area.  相似文献   

18.
A novel method for protein extraction from sweet almonds with aqueous polyethylene glycol (PEG) as solvent and recovery from the extraction solution was developed. The extraction yields of different solvents, such as sodium hydroxide, sodium chloride, PEG 200, PEG 400, and PEG 600 aqueous solutions, were investigated and PEG 200 showed the highest extraction efficiency. The PEG-based microwave-assisted extraction (MAE) parameters were then optimized using response surface methodology. Under optimum condition, PEG 200 concentration of 25 % (w/w), liquid to solid ratio of 22 mL g?1, microwave power of 120 W, extraction temperature of 45 °C, and extraction time of 4 min, the average extraction yield was 93.75?±?3.15 %. Subsequently, the almond protein was recovered from the extraction solution containing PEG with an isoelectric point-ethanol synergy precipitation protocol. The combined technique integrated the speed of isoelectric point precipitation with the completeness of alcohol precipitation. The recovery of almond protein was 98.81 % with a time of 3–5 min. The proposed PEG-based MAE and synergy precipitation protocol provide a rapid and effective method for almond protein extraction and recovery and have the potential to be used for other plant proteins.  相似文献   

19.
Carminic acid is a natural colourant that can be obtained from the dried bodies of females of the Dactylopius coccus Costa insect species (cochineal). Carminic acid is the main pigment that can be extracted from the cochineal insect. Its main use is with cosmetics, foods and pharmaceutical applications and it can also have textile and plastic applications. The traditional extraction methods employed to obtain this dye involve several drawbacks, e.g. high extraction time, low selectivity and low extraction efficiency. Moreover, these conventional techniques need toxic solvents. In this work, new extraction methods have been studied in order to avoid the disadvantages mentioned above. Pressurised liquid extraction (PLE) and supercritical fluid extraction (SFE) techniques provide high selectivity and short extraction times.  相似文献   

20.
微波辅助提取苍耳子油的研究   总被引:1,自引:0,他引:1  
赵文英  朱庆书  金青 《食品科技》2008,33(2):203-205
利用微波辅助技术提取苍耳子中的苍耳子油.通过时不同溶剂、微波功率、微波作用时间以及料液比对微波辅助提取苍耳子油的影响进行单因素考察,以确定最佳提取工艺.试验结果表明:较佳的工艺条件为用无水乙醇提取,在微波功率为 595 W 条件下处理 12 min,料液比为 1:10.与传统提取方法相比.该法提取时间短、提取效率高、并且提取的苍耳子油与传统方法提取的苍耳子油的成分无明显差异.  相似文献   

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