scholarly journals Microwave-assisted Extraction of Ochratoxin A from Roasted Coffee Beans: An Alternative Analytical Approach

2012 ◽  
Vol 1 (3) ◽  
pp. 121 ◽  
Author(s):  
Giulia Graziani ◽  
Antonello Santini ◽  
Rosalia Ferracane ◽  
Alberto Ritieni
Keyword(s):  
Ochratoxin A ◽  
High Performance ◽  
Microwave Assisted Extraction ◽  
Roasted Coffee ◽  
Microwave Assisted ◽  
Assisted Extraction ◽  
Coffee Beans ◽  
Conventional Extraction ◽  
Contamination Levels ◽  
Roasted Coffee Beans

<p>Microwave-assisted extraction (MAE) followed by high performance liquid chromatography (HPLC) with a fluorescent detector (DAD) was used and developed for the quantitative analysis of the mycotoxin ochratoxin A (OTA) in commercial roasted coffee beans. This alternative approach has been compared with the conventional extraction that uses hydrogen carbonate aqueous solution followed by OchraTest immunoaffinity analysis. The effect of two experimental tunable MAE parameters (temperature and pressure) on the extraction efficiency of OTA have been investigated using coffee samples forti?ed at different contamination levels. The optimum extraction conditions were obtained using a temperature of 50 °C and a 500 W microwave power. OTA quantity extracted using MAE was similar to that obtained by conventional extraction from samples fortified at 5, 10, and 100 ng g<sup>-1</sup> levels. At a 20 ng g<sup>-1</sup> level, MAE was more effective than the conventional method. The MAE setting parameters have been optimized showing both extraction time and solvent consumption have been considerably reduced, retaining high OTA recovery values.</p>

Microwave-Assisted Extraction of Chlorophyll from Filter Mud of Sugercane Mill and Component Analysis

2012 ◽  
Vol 518-523 ◽  
pp. 430-435 ◽  
Author(s):  
Hai Rong Guo ◽  
Shao Ying Ma ◽  
Xiao Fei Wang ◽  
Er Fang Ren ◽  
Yuan Yuan Li
Keyword(s):  
Irradiation Time ◽  
Extraction Time ◽  
Extraction Temperature ◽  
Microwave Assisted Extraction ◽  
Optimal Conditions ◽  
Microwave Assisted ◽  
Assisted Extraction ◽  
Conventional Extraction ◽  
Filter Mud ◽  
Strong Absorption Peak

Microwave-assisted extraction (MAE) was used to extract chlorophylls from filter mud. Ethanol was used as the solvent. The optimal conditions for the MAE of chlorophylls were concluded from the study as the irradiation time, 50 s, the ratio of liquid to solid, 8:1 (mL/g), the extraction temperature, 40 °C, and the extraction time, 60 min. Compared with conventional extraction, the MAE of chlorophylls from the filter mud was more effective. The extraction time for MAE was 60 min with 0.277 mg/g chlorophyll yield, while conventional extraction needed 240 min with only about 0.259 mg/g chlorophyll yield. The Ultraviolet Absorption Spectra of the extracted chlorophylls showed that there was a strong absorption peak at about 663 nm. C=N, Mg-N and C-N was not seen existed from the infrared spectroscopy probably because that the mixed extracts were not purified and the chlorophyll content was less.

scholarly journals Microwave-Assisted Extraction of Phlorotannins from Fucus vesiculosus

Marine Drugs ◽  
2020 ◽  
Vol 18 (11) ◽  
pp. 559
Author(s):  
Sónia J. Amarante ◽  
Marcelo D. Catarino ◽  
Catarina Marçal ◽  
Artur M. S. Silva ◽  
Rita Ferreira ◽  
...  
Keyword(s):  
Xanthine Oxidase ◽  
Conventional Method ◽  
Ethanol Concentration ◽  
Fucus Vesiculosus ◽  
Metabolic Enzyme ◽  
Microwave Assisted Extraction ◽  
Pharmaceutical Drug ◽  
Microwave Assisted ◽  
Assisted Extraction ◽  
Conventional Extraction

Microwave-assisted extraction (MAE) was carried out to maximize the extraction of phlorotannins from Fucus vesiculosus using a hydroethanolic mixture as a solvent, as an alternative to the conventional method with a hydroacetonic mixture. Optimal MAE conditions were set as ethanol concentration of 57% (v/v), temperature of 75 °C, and time of 5 min, which allowed a similar recovery of phlorotannins from the macroalgae compared to the conventional extraction. While the phlorotannins richness of the conventional extract was slightly superior to that of MAE (11.1 ± 1.3 vs. 9.8 ± 1.8 mg PGE/g DWextract), both extracts presented identical phlorotannins constituents, which included, among others, tetrafucol, pentafucol, hexafucol, and heptafucol structures. In addition, MAE showed a moderate capacity to scavenge ABTS•+ (IC50 of 96.0 ± 3.4 µg/mL) and to inhibit the activity of xanthine oxidase (IC50 of 23.1 ± 3.4 µg/mL) and a superior ability to control the activity of the key metabolic enzyme α-glucosidase compared to the pharmaceutical drug acarbose.

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