Extraction Method

The coherent vorticity extraction method (CVE) is based on the nonlinear filtering of the vorticity field pro- jected onto an orthonormal wavelet basis made of compactly supported functions. CVE decomposes each tur- bulent flow realization into two orthogonal components: a coherent and an incoherent random flow. They both contribute to all scales in the inertial range, but exhibit different statistical

The Agave americana plant has been largely used in traditional medicine. The setting up of efficient methods for phenolics extraction from A. americana leaves is one of great interest. With the aim of optimizing phenolics extraction from this material, the effects of temperature (from 25 to 150 • C) and extraction time (from 15 to 240 min) were investigated using a high-temperature, high-pressure (PARR) reactor, under either air or nitrogen atmosphere. Total polyphenols and flavonoids were determined, and their antioxidant activity was measured by the DPPH radical method. The use of PARR reactor for phenolics extraction proved to be more efficient compared to the conventional solid-liquid extraction at room temperature. The results of this work demonstrated that an increase in both temperature and extraction time led to a corresponding increase in the amount of phenolic compounds extracted and suggested that, after process optimization, this material could be used as an interesting alternative source of polyphenols.

A rapid and sensitive LC-UV method was developed and validated for the determination of meropenem, in human plasma and urine. Meropenem retention time was 4.8 min. Method development was based on comparative analysis of different extraction methods published as well as careful study of meropenem stability in biological samples under different conditions. Best results in plasma sample preparation were obtained from protein precipitation with methanol. LOQ was 0.1 lg mL -1 for plasma and 1 lg mL -1 for urine samples. Meropenem in plasma has low stability at room temperature (<20% of original content after 12 h), but had acceptable stability when the whole analysis procedure was designed to minimize the exposure of meropenem-containing samples and solutions to temperatures higher than 4°C. The developed method was applied to a human pharmacokinetic study in patients with acute peritonitis.

Distribution of sinigrin (2-propenylglucosinolate) and glucoraphanin (4-methylsulphinylbutylglucosinolate) concentration was determined in seeds and seedlings of Brassica species: B. oleracea, B. nigra, B. juncea, B. rapa and B. napus using a simple and reliable extraction method. Glucosinolates were extracted from seeds and seedlings using boiling water and were analysed by reverse phase ion-pair chromatography with UV detection. High concentrations of sinigrin were found in B. nigra, B. juncea var. rugosa (mustard greens) and B. oleracea (Brussels sprouts, cabbage, cauliflower, and Chinese broccoli). Sinigrin was absent from B. rapa and B. napus and was present in negligible concentrations in B. oleracea var. italica (broccoli). The concentration of sinigrin in the seed was similar to that in the cotyledon and hypocotyl tissues (7-day-old seedling) in most Brassica species tested. Glucoraphanin was found at high concentrations in B. oleracea var. italica and moderate concentrations in B. oleracea var. capitata (cabbage), whilst was absent in B. nigra, B. juncea, B. rapa and B. napus. Glucoraphanin concentration was between 44.2 and 274.1 mmol g À1 DW among broccoli genotypes. Kalibrini 1 , a new hybrid line between broccoli and Chinese broccoli (kailan) contained a moderate concentration of glucoraphanin (145.3 mmol g À1 DW) compared to its parent lines (274.1 mmol g À1 DW in broccoli but only 1.2 mmol g À1 DW in kailan). Glucoraphanin concentration in seedlings was significantly lower than that in the seed of broccoli while there was no significant difference in sinigrin concentration in seedlings of most Brassica species tested. The study has shown the extensive variability in sinigrin and glucoraphanin concentrations among Brassica Scientia Horticulturae 96 (: S 0 3 0 4 -4 2 3 8 ( 0 2 ) 0 0 1 1 9 -X species and genotypes that is available for selection and breeding. New elite lines can be produced for use as commercial crops in the health food or nutraceutical industries. #

A solid-liquid extraction procedure followed by reversed-phase high-performance liquid chromatography (RP-HPLC) coupled with a photodiode array detector (DAD) for the determination of polyphenols in freeze-dried apple peel and pulp is reported. The extraction step consists in sonicating 0.5 g of freeze-dried apple tissue with 30 mL of methanol-water-acetic acid (30:69:1, v/v/v) containing 2 g of ascorbic acid/L, for 10 min in an ultrasonic bath. The whole method was validated, concluding that it is a robust method that presents high extraction efficiencies (peel: >91%, pulp: >95%) and appropriate precisions (within day: R.S.D. (n = 5) <5%, and between days: R.S.D. (n = 5) <7%) at the different concentration levels of polyphenols that can be found in apple samples. The method was compared with one previously published, consisting in a pressurized liquid extraction (PLE) followed by RP-HPLC-DAD determination. The advantages and disadvantages of both methods are discussed.