Isabel C.N. Debien

Fast analysis of β-ecdysone in Brazilian ginseng (Pfaffia glomerata) extracts by high-performance liquid chromatography using a fused-core column

The recent development of fused-core technology in HPLC columns is enabling faster and highly efficient separations. This technology was evaluated for the development of a fast analysis method for β-ecdysone in extracts of Pfaffia glomerata. A step-by-step strategy was used to optimize temperature (30–55 °C), flow rate (1.0–2.0 mL min−1), mobile phase composition (mixtures of water and methanol or acetonitrile) and equilibration time (1–5 min). A gradient method has been developed using two solvents: 0.1% acetic acid in water and 0.1% acetic acid in acetonitrile. Optimized conditions provided a method for the separation of β-ecdysone in approximately 2 min with a total analysis time (sample-to-sample) of 9 min, including the return to initial conditions and the re-equilibration of the column. Evaluation of chromatographic performance revealed excellent intraday and interday reproducibility (>99.5%), resolution (2.78), selectivity (1.13), and peak symmetry (1.09) while presenting low limits of detection (0.20 mg L−1) and quantitation (0.67 mg L−1). The robustness of the method has also been calculated according to the concentration/dilution of the sample. Several sample solvents were evaluated and the best chromatographic results were obtained using 80% methanol in water. Finally, the developed method was validated with different extracts of Pfaffia glomerata samples.

Pressurized Liquid Extraction as a Promising and Economically Feasible Technique for Obtaining Beta-Ecdysone-Rich Extracts from Brazilian Ginseng (Pfaffia glomerata) Roots

Pressurized liquid extraction was used to obtain beta-ecdysone-rich extracts from Brazilian ginseng (Pfaffia glomerata) roots. The effects of temperature, pressure, and solvent on extraction yield, beta-ecdysone content, and antioxidant activity were determined. Extraction yield increased with temperature up to 25% (dry basis) while the selectivity decreased. The use of Ethanol:Water (80:20 v/v) as solvent produced extracts with the highest antioxidant activity. Beta-ecdysone recovery was maximized using pure ethanol. In the first hour of extraction, approximately 70% of the total yield and 74% of the total beta-ecdysone mass is obtained. The cost of manufacturing significantly decrease as the extractor capacity increased.

Ultrafiltration performance of PVDF, PES, and cellulose membranes for the treatment of coconut water (Cocos nucifera L.)

Ultrafiltration (UF) inhibits the enzymatic activity which is responsible for color changes of coconut water without the need for heat treatment. In the present study, UF performance in terms of the permeate flux and enzymatic retention of the coconut water was evaluated at laboratory unit (LU) and pilot unit (PU). The membranes studied were polyethersulfone 150 kDa (UP150), polyvinylidene fluoride 150 kDa (UV150) and cellulose 30 kDa (UC030). The UP150 membrane showed the best permeate flux. The UC030 membrane showed the lowest flux, but it resulted in 100% enzymatic retention, while the other membranes showed enzymatic retentions between 71 and 85%. The application of the UC030 in the pilot unit (PU) resulted in a flux value higher than that obtained in the LU due to the tangential velocity effect. The UC030 membrane has proved adequate for industrial applications.

Chapter 6 – Conventional extraction

Traditional extraction technologies, such as solvent extraction and steam distillation, have been used for the recovery of natural extracts from plant and animal sources for a long time. These extracts have mainly been used as food additives and medicines. Later, other more efficient and environmentally friendly methods like enzyme-, ultrasound-, and microwave-assisted extraction, and supercritical fluid extraction were developed. Following the tendency of modern society to decrease pollution, recovery of bioactive compounds from food wastes is an alternative option that adds value to such residues and at the same time decreases their environmental footprint. In this chapter, the use of well-established extraction technologies to recover bioactive compounds from food industry wastes is presented.

Phenolic Compounds in Coffee Compared to Other Beverages

Abstract Coffee is the most important product obtained from roasted coffee beans and one of the most consumed beverages in the world. Although coffee is known for its stimulating properties attributed mainly to caffeine, it also contains other biologically active compounds, including phenolic compounds, with chlorogenic acids being the most abundant. The critical factor that affects these compounds in green coffee is the roasting time–temperature profile. Another beverage that contains a great amount of phenolic compounds is “tea” (Camellia sinensis L.), in which the flavonoids are the most abundant, particularly the catechins. Wine and fruit juices have also phenolic compounds, but in lower concentrations, such as phenolic acids, flavonoids, anthocyanins, stilbenes, and tannins, with different biological activities and intensities.

Thermodynamic Modeling of High-pressure Equilibrium Data for the Systems L-lactic Acid + (Propane + Ethanol) and L-lactic Acid + (Carbon Dioxide + Ethanol)

This short communication reports the thermodynamic modeling of high-pressure equilibrium data (cloud points) for the systems L-lactic acid + (propane + ethanol) and L-lactic acid + (carbon dioxide + ethanol) from 323.15 K to 353.15 K and at pressures up to 25 MPa.The experimental data were modeled using the Peng-Robinson equation of state with the classical van der Waals quadratic mixing rule (PR-vdW2) and with the Wong-Sandler mixing rule (PR- WS). It is shown that the PR-vdW2 and PR-WS models were both able to satisfactorily represent the phase behavior of the system L-lactic acid + (carbon dioxide + ethanol). However, for the system L-lactic acid + (propane + ethanol), the PR-vdW2 model was not able to appropriately describe its phase behavior.