Jabuticaba (Plinia sp.) Peel as a Source of Pectin: Characterization and Effect of Different Extraction Methods.

The peel of jabuticaba, a small fruit native to Brazil, has been shown to be a potential source of antioxidants and soluble dietary fibers. In this study, flours prepared from these peels were evaluated as a source of pectin. Different extraction methods were employed: ultrasound (US) extraction followed by low temperature heating (40 °C); in a microwave (MW) without (method 1) or with cellulase (method 2) or hemicellulase (method 3); or in a water bath (method 4). Pectin yields ranged from approximately 18% for methods 1 and 4 up to 22% for enzyme-assisted extractions (methods 2 and 3). Methods that did not employ enzymes resulted in low amounts of methoxyl pectins, as opposed to high amounts of methoxyl pectins obtained after enzyme treatment. Cyanidin-3-O-glucoside (C3G) and ellagic acid were the main phenolic compounds found in jabuticaba peel pectins, with higher C3G levels obtained with enzyme-free extraction (methods 1 and 4). All pectins from jabuticaba peel presented a reddish tone, good emulsifying properties and high swelling capacity. The pectin extracted using US+MW+cellulase (method 2) presented better emulsifying performance (higher values of emulsifying activity and emulsion stability), more effective than commercially available citrus pectin.

Green Extraction by Ultrasound, Microencapsulation by Spray Drying and Antioxidant Activity of the Tucuma Coproduct (Astrocaryum vulgare Mart.) Almonds.

The industrial processing amazon fruits, like tucuma, generates a large amount of coproducts with large nutritional potential. Thus, this work obtained the oily extract of the tucuma almonds coproducts by green extraction using palm oil by the ultrasound method and then microencapsulated by atomization and verification of its antioxidant activity. Thermogravimetric techniques, infrared spectroscopy, scanning electron microscopy, moisture content, water activity were applied to characterize the microparticles. Total carotenoids were determined by UV spectroscopy and antioxidant activity was measured by 2,2'-azino-di-(3-ethylbenzthiazoline sulfonic acid and co-oxidation in the system ß-carotene/linoleic acid. The oily extract and microparticle had total carotenoid contents of 3.305 mg/100 g ± 0.01 and 2.559 mg/100 g ± 0.01, respectively. The antioxidant activity assessed through the 2,2'-azino-di-(3-ethylbenzthiazoline sulfonic acid value was 584.75 µM/trolox ± 0.01 (oily extract) and 537.12 µM/trolox ± 0.01 (microparticle) were determined. In the system ß-carotene/linoleic acid showed oxidation of 49.9% ± 1.8 lipophilic extract and 43.3% ± 2.3 microparticle. The results showed that the oily extract of the tucuma almond coproduct can be used as a carotenoid-rich source and microencapsuled with possible application for functional foods production.

Optimization of the ultrasoud-assisted extraction of saponins from quinoa (Chenopodium quinoa Wild) using response surface methodology.

BACKGROUND: Quinoa grain has a bitter tasting layer in the pericarp called saponin, a triterpenoid glycoside with industrial potential. Traditionally, quinoa saponins are extracted with a large amount of water, which is why ultrasound technology constitutes an emerging technological alternative which is considered efficient and profitable compared to traditional extraction methods. The objective of this research was to determine the amplitude, time, and concentration of ethanol that guarantee a higher content of saponin through extraction assisted by ultrasound. METHODS: To find the optimal extraction conditions, the response surface methodology was used using the Box Behnken design with 5 central points, taking as a response the content of saponins (expressed in oleanolic acid as it is the most abundant sapogenin). RESULTS: According to the results obtained, the R2 values were in agreement with the adjusted R2, showing that the data fit the model well. The results showed that ethanol concentration has a significant effect (p < 0.05) on the saponin content in the extract. Optimization showed that the optimal extraction conditions were 70% ethanol, 59% amplitude and an exposure time of 12 min. These values were obtained experimentally to compare theoretical values and found residual error percentages less than 3%. The emulsifying activity was evaluated, reporting a value of 52,495 units of emulsion activity per milliliter (UAE/mL), and the foaming stability indicated that 87.54% of the initial foam was maintained after 5 min, indicating high stability. CONCLUSIONS: The parameters of ethanol concentration, amplitude and time were optimized in the extraction of saponins, assisted by ultrasound. Furthermore, the extract obtained had good foaming and emulsifying characteristics, suggesting its suitability for use in industry.

Ultrasound-assisted extraction of rare-earth elements from carbonatite rocks.

In view of the increasing demand for rare-earth elements (REE) in many areas of high technology, alternative methods for the extraction of these elements have been developed. In this work, a process based on the use of ultrasound for the extraction of REE from carbonatite (an igneous rock) is proposed to avoid the use of concentrated reagents, high temperature and excessive extraction time. In this pioneer work for REE extraction from carbonatite rocks in a preliminary investigation, ultrasonic baths, cup horn systems or ultrasound probes operating at different frequencies and power were evaluated. In addition, the power released to the extraction medium and the ultrasound amplitude were also investigated and the temperature and carbonatite mass/volume of extraction solution ratio were optimized to 70°C and 20mg/mL, respectively. Better extraction efficiencies (82%) were obtained employing an ultrasound probe operating at 20kHz for 15min, ultrasound amplitude of 40% (692Wdm-3) and using a diluted extraction solution (3% v/v HNO3+2% v/v HCl). It is important to mention that high extraction efficiency was obtained even using a diluted acid mixture and relatively low temperature in comparison to conventional extraction methods for REE. A comparison of results with those obtained by mechanical stirring (500rpm) using the same conditions (time, temperature and extraction solution) was carried out, showing that the use of ultrasound increased the extraction efficiency up to 35%. Therefore, the proposed ultrasound-assisted procedure can be considered as a suitable alternative for high efficiency extraction of REE from carbonatite rocks.

Application of Focused Ultrasound-Assisted Extraction for the Quantification of Persistent Organic Pollutions in Liver Tissue of Giant Toad (Rhinella marina).

A simple and rapid focused ultrasound extraction method was developed for the determination of Persistent Organic Pollutants (POPs) in liver tissue obtained of giant toad (Rhinella marina) using a gas chromatography coupled to a mass detector with electron impact ionization. The performed method for POPs, was validated in fortified matrix, showing linearity from the LOQ up to 100 ng/mL; LODs and LOQs for each compound were between 1.7 and 4.8 and 3.5-7.5 ng/mL, respectively. Recovery rates were among 79%-116% for POPs determined. Finally, the method was applied in liver samples of giant toads found in a malarial area in Mexico. The sensitivity of the proposed method was good enough to ensure reliable determination of target analytes at concentration levels commonly found in this kind of samples.

Validation of analytical conditions for determination of polycyclic aromatic hydrocarbons in roasted coffee by gas chromatography-mass spectrometry.

Polycyclic aromatic hydrocarbons (PAHs) are of significant interest due to their genotoxicity in humans. PAHs quantification in coffee is complex since some of its compounds interfere in the chromatographic analysis, which hinders the reliable determination of the PAHs. Analytical conditions for the ultrasound extraction, purification and quantification of 16 PAHs in roasted coffee were studied. The better extraction efficiency of benzo[a]pyrene (68%) from ground-roasted coffee was achieved with a solvent ratio of Hex:MC (9:1 v/v) and three extraction periods of 20 min, followed by alkaline saponification and purification of the extracts. The detection limits were 0.85-39.32 ng mL(-1), and the quantification limits from 2.84 to 131.05 ng mL(-1), obtained for fluoranthene and chrysene, respectively. The extraction was effective for most of the analytes, with recoveries of 39.8% dibenzo[ah]anthracene and 69.0% benzo[b]fluoranthene. For coffee roasted in a spouted bed reactor, the summation of the 16 PAHs ranged from 3.5 to 16.4 µg kg(-1).